Overview of root system architecture.The plant root system is a highly dynamic and multifunctional organ system composed of primary roots,lateral roots,adventitious roots,and root hairs.Based on topological morphology...Overview of root system architecture.The plant root system is a highly dynamic and multifunctional organ system composed of primary roots,lateral roots,adventitious roots,and root hairs.Based on topological morphology,root systems can be classified as taproot systems or fibrous root systems.Root system architecture(RSA)refers to the spatial distribution and extension patterns of roots within soil,encompassing characteristics such as root length,branching angle,density,and spatial arrangement.RSA not only determines the plant’s capacity to acquire water and nutrients but also influences other root functions,playing a decisive role in overall plant health.展开更多
What the researchers go in for is to establish models between root architecture （RA） changes and nutrition, mold ideal root architecture of apple trees, improve the nutrient uptake efficiency, and further explore th...What the researchers go in for is to establish models between root architecture （RA） changes and nutrition, mold ideal root architecture of apple trees, improve the nutrient uptake efficiency, and further explore the functional mechanism of nutrient elements during the course of RA construction. The cultivation system of filter paper is utilized to research the effect of nutrient deficiency on the RA of Malus hupehensis （Pamp.） Rehd. There may be eight types of RA. In complete Hogland solution, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂. With the lack of P, K or Ca, the main type of RA is ＂lateral roots clustering in the upper region primary root＂, and the ＂lateral roots clustering in the upper and middle regions of primary root＂ types of RA decrease. But with shortage of P, the type of lateral roots clustering in the upper and lower regions of primary root increases, and the type of lateral roots clustering in the middle region of primary root decreases, with the types of RA diversified. Under the condition of K deficiency, the type of no lateral root increases and types of lateral roots clustering in the middle region of primary root decrease, and the percentage of such types as ＂no lateral root＂, ＂lateral roots clustering in the upper region of primary root＂, and ＂lateral roots clustering in the upper and middle regions of primary root＂ accounts for 97.9% in all, with the types of RA simplified. With lack of Fe, Mg or Zn, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂, but the type of lateral roots evenly-distributed on primary root increases. The main type of RA is ＂lateral roots evenlydistributed on primary root＂, under the condition of N deficiency, and the types of RA turn out to be diversified. There exists a close relation between nutrient deficiency and RA changes. Owing to various forms of nutrient deficiency, correspondingly different types of RA have been produced.展开更多
In the experimental garden of the Department of Soil Bioengineering and Landscape Construction, University of Applied Life Sciences in Vienna, Austria, coarse root systems of three different brush species were complet...In the experimental garden of the Department of Soil Bioengineering and Landscape Construction, University of Applied Life Sciences in Vienna, Austria, coarse root systems of three different brush species were completely excavated and semiutomatically digitized. The species were Lonicera xylosteum, Ligustrum vulgare and Euonymus europaeus. The 3-D root architectures reveal different growth strategies between species, which are related to ecological characteristics and physical soil properties. The root architecture of Lonicera xylosteum and Ligustrum vulgare, planted in the under layer of the live slope grading, where the soil is very tight and the soil water content and fertility are relatively low, is shallow. However, the root distribution of E. europaeus, planted in the middle layer, where environmental conditions are better, is deeper. Most of the root biomass of the three species is concentrated in the 0-30 cm soil layer. A quarter of the root biomass ofLigustrum vulgare is distributed in the upper layer of the plant inlay. E. europaeus has a relatively even distribution in the 30-0 cm and 60-90 cm soil layer.展开更多
Sorghum’s natural adaptation to a wide range of abiotic stresses provides diverse genetic reserves for potential improvement in crop stress tolerance. Growing interest in sorghum research has led to the expansion of ...Sorghum’s natural adaptation to a wide range of abiotic stresses provides diverse genetic reserves for potential improvement in crop stress tolerance. Growing interest in sorghum research has led to the expansion of genetic resources though establishment of the sorghum association panel (SAP), generation of mutagenized populations, and recombinant inbred line (RIL) populations</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> etc. Despite rapid improvement in biotechnological tools, lack of efficient phenotyping platforms remains one of the major obstacles in utilizing these genetic resources. Scarcity of efforts in root system phenotyping hinders identification and integration of the superior root traits advantageous to stress tolerance. Here, we explored multiple approaches in root phenotyping of an ethyl methanesulfonate (EMS)-mutagenized sorghum population. Paper-based growth pouches (PGP) and hydroponics were employed to analyze root system architecture (RSA) variations induced by mutations and to test root development flexibility in response to phosphorus deficiency in early growing stages. PGP method had improved capabilities compared to hydroponics providing inexpensive, space-saving, and high-throughput phenotyping of sorghum roots. Preliminary observation revealed distinct phenotypic variations which were qualitatively and quantitatively systemized for association analysis. Phenotypes/ideotypes with root architecture variations potentially correlated with Pi acquisition were selected to evaluate their contribution to P-efficiency (PE). Sand mixed with P-loaded activated alumina substrate (SAS) provided closely to natural but still controlled single-variable conditions with regulated Pi availability. Due to higher labor and cost input we propose SAS to be used for evaluating selected sorghum candidates for PE. The ability of rapidly screening root phenotypes holds great potential for discovering genes responsible for relevant root traits and utilizing mutations to improve nutrient efficiency and crop productivity.展开更多
Drought is a natural disaster that profoundly impacts on global agricultural production,significantly reduces crop yields,and thereby poses a severe threat to worldwide food security.Addressing the challenge of effect...Drought is a natural disaster that profoundly impacts on global agricultural production,significantly reduces crop yields,and thereby poses a severe threat to worldwide food security.Addressing the challenge of effectively improving crop drought resistance(DR)to mitigate yield loss under drought conditions is a global issue.An optimal root system architecture(RSA)plays a pivotal role in enhancing the capacity of crops to efficiently uptake water and nutrients,which consequently strengthens their resilience against environmental stresses.In this review,we discuss the compositions and roles of crop RSA and summarize the most recent developments in augmenting drought tolerance in crops by manipulating RSA-related genes.Based on the current research,we propose the potential optimal RSA configuration that could be helpful in enhancing crop DR.Lastly,we discuss the existing challenges and future directions for breeding crops with enhanced DR capabilities through genetic improvements targeting RSA.展开更多
Root system architecture has often been overlooked in plant research despite its critical role in plant adaptation to environmental conditions.This study focused on the root system architecture of the desert shrub Rea...Root system architecture has often been overlooked in plant research despite its critical role in plant adaptation to environmental conditions.This study focused on the root system architecture of the desert shrub Reaumuria soongorica in the Alxa steppe desert,Northwest China.Plant samples were collected during May-September 2019.Using excavation methods,in situ measurements,and root scanning techniques,we analyzed the root distribution,topology,and branching patterns of R.soongorica across an age sequence of 7-51 a.Additionally,we investigated the allometric relationships of root collar diameter with total coarse root length,biomass,and topological parameters.The results showed that the roots of R.soongorica were predominantly concentrated in shallow soil layers(10-50 cm),with lateral root branching and biomass allocation increasing with shrub age.The root topology exhibited a herringbone-like structure,with average topological and modified topological indices of 0.89 and 0.96,respectively,both of which adjusted with shrub age.The root system displayed a self-similar branching pattern,maintaining a constant cross-sectional area ratio of 1.13 before and after branching,deviating from the area-preserving rule.These adaptive traits allow R.soongorica to efficiently expand its nutrient acquisition zone,minimize internal competition,and optimize resource uptake from the upper soil layers.Furthermore,significant linear relationships were observed between log10-transformed root collar diameter and log10-transformed total coarse root length,biomass,and topological parameters.These findings advance non-destructive approaches for studying root characteristics and contribute to the development of root-related models.Besides,this study provides new insights into the adaptive strategies of R.soongorica under extreme drought conditions,offering valuable guidance for species selection and cultivation in desert restoration efforts.展开更多
The D14 protein,an alpha/beta hydrolase,is a key receptor in the strigolactone(SL)signaling pathway.However,the response of VvD14 to SL signals and its role in grapevine root architecture formation remain unclear.This...The D14 protein,an alpha/beta hydrolase,is a key receptor in the strigolactone(SL)signaling pathway.However,the response of VvD14 to SL signals and its role in grapevine root architecture formation remain unclear.This study demonstrated that VvD14c was highly expressed in grapevine tissues and fruit stages than other VvD14 isoforms.Application of GR24,an SL analog,enhanced the elongation and diameter of adventitious roots but inhibited the elongation and density of lateral roots(LRs)and increased VvD14c expression.Additionally,GR24 is nested within the VvD14c pocket and strongly bound to the VvD14c protein,with an affinity of 5.65×10^(-9) M.Furthermore,VvD14c interacted with grapevine MORE AXILLARY GROWTH 2(VvMAX2)in a GR24-dependent manner.Overexpression of VvD14c in the d14 mutant and VvMAX2 in the max2 Arabidopsis mutant reversed the increased LR number and density,as well as primary root elongation.Conversely,homologous overexpression of VvD14c and VvMAX2 resulted in reduced LR number and density in grapevines.VvMAX2 directly interacted with LATERAL ORGAN BOUNDARY(VvLOB)and VvLBD19,thereby positively regulating LR density.These findings highlight the role of SLs in regulating grapevine root architecture,potentially via the VvD14c-VvMAX2-VvLOB/VvLBD19 module,providing new insights into the regulation of root growth and development in grapevines.展开更多
Characterizing the architecture of tree root systems is essential to advance the development of root-inspired anchorage in engineered systems.This study explores the structural root architectures of orchard trees to u...Characterizing the architecture of tree root systems is essential to advance the development of root-inspired anchorage in engineered systems.This study explores the structural root architectures of orchard trees to understand the interplays between the mechanical behavior of roots and the root architecture.Full three-dimensional(3D)models of natural tree root systems,Lovell,Marianna,and Myrobalan,that were extracted from the ground by vertical pullout are reconstructed through photogrammetry and later skeletonized as nodes and root branch segments.Combined analyses of the full 3D models and skeletonized models enable a detailed examination of basic bulk properties and quantification of architectural parameters.While the root segments are divided into three categories,trunk root,main lateral root,and remaining roots,the patterns in branching and diameter distributions show significant differences between the trunk and main laterals versus the remaining lateral roots.In general,the branching angle decreases over the sequence of bifurcations.The main lateral roots near the trunk show significant spreading while the lateral roots near the ends grow roughly parallel to the parent root.For branch length,the roots bifurcate more frequently near the trunk and later they grow longer.Local thickness analysis confirms that the root diameter decays at a higher rate near the trunk than in the remaining lateral roots,while the total cross-sectional area across a bifurcation node remains mostly conserved.The histograms of branching angle,and branch length and thickness gradient can be described using lognormal and exponential distributions,respectively.This unique study presents data to characterize mechanically important structural roots,which may help link root architecture to the mechanical behaviors of root structures.展开更多
Plant root systems,a crucial component of biogeotechnics,have been recognized as a promising and sustainable strategy to address novel challenges in geotechnical engineering,i.e.,climate change(Ng et al.,2022).Root-so...Plant root systems,a crucial component of biogeotechnics,have been recognized as a promising and sustainable strategy to address novel challenges in geotechnical engineering,i.e.,climate change(Ng et al.,2022).Root-soil composite and root-reinforced slopes have re-ceived widespread attention in recent decades,due to the ability of root to regulate soil properties through mechanical reinforcement and hy-draulic transpiration(Li&Duan,2023;Ni et al.,2024).Fig.1 provides a co-occurrence network plot of plant root-based soil reinforcement strategies published over the last decade,where three clusters are identified with different colors.On the left of the network map,clusters in red and blue are primarily driven by geotechnical investigations of vegetated slopes(i.e.,plant root reinforced slopes)and root-soil com-posite/root-permeated soils,as denoted by the terms like"model","test","slope","strength"and"vegetation",while the green cluster on the right side demonstrates botany-related domains,for instance,"plant growth",Indeed,the reinforcement of vegetated soil strength is com-plex and varies significantly with an abundance of factors,both me-chanically and hydraulically.Particularly,the impact of root mor-phology and architecture cannot be negligible,including keywords"root area ratio"root distribution""root morphology"root diame-ter"root density"in Fig.1 with the root size and root depth ranking foremost.展开更多
The formation of root system architecture(RSA)plays a crucial role in plant growth.OsDRO1 is known to have a function in controlling RSA in rice,however,the role of potato StDRO2,a homolog of rice OsDRO1,in root growt...The formation of root system architecture(RSA)plays a crucial role in plant growth.OsDRO1 is known to have a function in controlling RSA in rice,however,the role of potato StDRO2,a homolog of rice OsDRO1,in root growth remains unclear.In this study,we obtained potato dro2 mutant lines by Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-Associated 9(CRISPR/Cas9)-mediated genome editing system.The mutant lines were generated from a splicing defect of the StDRO2 intron 1,which causes a nonsense mutation in StDRO2.Furthermore,the secondary structure of StDRO2 mRNA analyzed with RNAfold Web Server was altered in the dro2 mutant.Mutation of StDRO2 conveys potato adaptation through changing the RSA via alteration of auxin transport under drought stress.The potato dro2 lines showed higher plant height,longer root length,smaller root growth angle and increased tuber weight than the wild-type.The alteration of RSA was associated with a disturbance of IAA distribution in the dro2 mutant,and the levels of StPIN7 and StPIN10 detected by using real-time PCR were up-regulated in the roots of potato dro2 lines grown under drought stress.Moreover,the microRNAs(miRNAs)PmiREN024536 and PmiREN024486 targeted the StDRO2 gene,and auxin positively and negatively regulated the expression of StDRO2 and the miRNAs PmiREN024536 and PmiREN024486,respectively,in the potato roots.Our data shows that a regulatory network involving auxin,StDRO2,PmiREN024536 and PmiREN024486 can control RSA to convey potato fitness under drought stress.展开更多
The use of nitrogen(N) fertilizers has contributed to the production of a food supply sufficient for both animals and humans despite some negative environmental impact.Sustaining food production by increasing N use ef...The use of nitrogen(N) fertilizers has contributed to the production of a food supply sufficient for both animals and humans despite some negative environmental impact.Sustaining food production by increasing N use efficiency in intensive cropping systems has become a major concern for scientists,environmental groups,and agricultural policymakers worldwide.In high-yielding maize systems the major method of N loss is nitrate leaching.In this review paper,the characteristic of nitrate movement in the soil,N uptake by maize as well as the regulation of root growth by soil N availability are discussed.We suggest that an ideotype root architecture for efficient N acquisition in maize should include(i) deeper roots with high activity that are able to uptake nitrate before it moves downward into deep soil;(ii) vigorous lateral root growth under high N input conditions so as to increase spatial N availability in the soil;and(iii) strong response of lateral root growth to localized nitrogen supply so as to utilize unevenly distributed nitrate especially under limited N conditions.展开更多
The remodeling of root architecture is a major developmental response of plants to phosphate （Pi） deficiency and is thought to enhance a plant＇s ability to forage for the available Pi in topsoil. The underlying mec...The remodeling of root architecture is a major developmental response of plants to phosphate （Pi） deficiency and is thought to enhance a plant＇s ability to forage for the available Pi in topsoil. The underlying mechanism controlling this response, however, is poorly understood. In this study, we identified an Arabidopsis mutant, hps 10 （hypersensitive to Pi starvation 10）, which is morphologically normal under Pi sufficient condition but shows increased inhibition of primary root growth and enhanced production of lateral roots under Pi defi- ciency, hpslO is a previously identified allele （als3-3） of the ALUMINUM SENSITIVE3 （ALS3） gene, which is involved in plant tolerance to aluminum toxicity. Our results show that ALS3 and its interacting protein AtSTAR1 form an ABC transporter complex in the tonoplast. This protein complex mediates a highly electro- genic transport in Xenopus oocytes. Under Pi deficiency, als3 accumulates higher levels of Fe3＋ in its roots than the wild type does. In Arabidopsis, LPR1 （LOW PHOSPHATE ROOT1） and LPR2 encode ferroxidases, which when mutated, reduce Fe3＋ accumulation in roots and cause root growth to be insensitive to Pi defi- ciency. Here, we provide compelling evidence showing that ALS3 cooperates with LPR1/2 to regulate Pi deficiency-induced remodeling of root architecture by modulating Fe homeostasis in roots.展开更多
Abstract: Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition. Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under condi...Abstract: Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition. Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under conditions of low phosphorus availability, the length of cells in the meristem zone of the lateral roots was longer, but the length of cells in the elongation and mature zones of the lateral roots was shorter, compared with seedlings grown under conditions of high phosphorus availability. The elongation rates of primary roots increased as phosphorus availability increased, but the elongation rates of the branched zones of the primary roots decreased. The number of lateral root primordia and the length of the lateral roots decreased as phosphorus availability increased. The topological index (altitude slope) decreased as phosphorus availability increased, suggesting that root architecture tended to be herringbone-like when seedlings were grown under conditions of low phosphate availability. Herringbone-like root systems exploit nutrients more efficiently, but they have higher construction costs than root systems with a branching pattern.展开更多
Improving crop nutrient ef ficiency becomes an essential consideration for environmentally friendly and sustainable agriculture. Plant growth and development is dependent on 17 essential nutrient elements,among them,n...Improving crop nutrient ef ficiency becomes an essential consideration for environmentally friendly and sustainable agriculture. Plant growth and development is dependent on 17 essential nutrient elements,among them,nitrogen（N） and phosphorus（P） are the two most important mineral nutrients. Hence it is not surprising that low N and/or low P availability in soils severely constrains crop growth and productivity,and thereby have become high priority targets for improving nutrient ef ficiency in crops. Root exploration largely determines the ability of plants to acquire mineral nutrients from soils. Therefore,root architecture,the 3-dimensional con figuration of the plant＇s root system in the soil,is of great importance for improving crop nutrient ef ficiency. Furthermore,the symbiotic associations between host plants and arbuscular mycorrhiza fungi/rhizobial bacteria,are additional important strategies to enhance nutrient acquisition. In this review,we summarize the recent advances in the current understanding of crop species control of root architecture alterations in response to nutrient availability and root/microbe symbioses,through gene or QTL regulation,which results in enhanced nutrient acquisition.展开更多
Studies on natural variation are an important tool to unravel the genetic basis of quantitative traits in plants. Despite the significant roles of phytohormones in plant development, including root architecture, hardl...Studies on natural variation are an important tool to unravel the genetic basis of quantitative traits in plants. Despite the significant roles of phytohormones in plant development, including root architecture, hardly any studies have been done to investigate natural variation in endogenous hormone levels in plants. Therefore, in the present study a range of hormones were quantified in root extracts of thirteen Arabidopsis thaliana accessions using a ultra performance liquid chromatography triple quadrupole mass spectrometer. Root system architecture of the set of accessions was quantified, using a new parameter （mature root unit） for complex root systems, and correlated with the phytohormone data. Significant variations in phytohormone levels among the accessions were detected, but were remarkably small, namely less than three-fold difference between extremes. For cytokinins, relatively larger variations were found for ribosides and glucosides, as compared to the free bases. For root phenotyping, length-related traits--lateral root length and total root length--showed larger variations than lateral root number-related ones. For root architecture, antagonistic interactions between hormones, for example, indole-3-acetic acid to trans-zeatin were detected in correlation analysis. These findings provide conclusive evidence for the presence of natural variation in phytohormone levels in Arabidopsis roots, suggesting that quantitative genetic analyses are feasible.展开更多
The architectural parameters of Reaumuria soongorica root system in different habitats of Gansu Province, China were analyzed to examine its ecological adaptability to arid environments. Results show that： （1） Topo...The architectural parameters of Reaumuria soongorica root system in different habitats of Gansu Province, China were analyzed to examine its ecological adaptability to arid environments. Results show that： （1） Topological indices of R. Soongorica root sys- tem are small in all habitats, and root branching pattem tends to be dichotomous. Also, the indices gradually increase in the Min- qin windblown sand region and the Zhangye Gobi region in Hexi Corridor, which indicates that drought tends to produce her- ringbone-like root branching pattems. （2） Fractal dimension values ofR. Soongorica root system are small and not obvious in the Minqin windblown sand region and the Zhangye Gobi region in Hexi Corridor, with values of 1.1778 and 1.1169, respectively. Fractal dimension values are relatively large in Jiuzhoutai semi-arid hilly and gully region of the Loess Plateau, which indicates that the R. Soongorica root system has better fractal characteristics in this region than in the other regions. （3） Total branching ra- tios of the R. Soongorica root system in arid regions of Hexi Corridor are smaller than that in the Jiuzhoutai semi-arid hilly and gully region of the Loess Plateau. This shows that root branching ability in the semi-arid region is stronger, and it decreases to some degree with increased drought. （4） The root connection lengths of R. soongorica root system are long in all habitats, but there are significant length differences between the different habitats. The root connection length at the Minqin windblown sand region is the longest. It is concluded that R. soongoriea adapts to arid environments by decreasing root branching, decreasing root overlap and increasing root connection length, which makes its root branching pattern tend to be herringbone-like to reduce com- petition in root internal environment for nutrients and to enhance root absorption rate of nutrients, and ensure effective nutrition space. Thus the roots can absorb enough water and nutrients in resource-poor settings to ensure normal physiological requirements.展开更多
Either arbuscular mycorrhizal fungi （AMF） or polyamines （PAs） may change root system architecture （RSA） of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied ...Either arbuscular mycorrhizal fungi （AMF） or polyamines （PAs） may change root system architecture （RSA） of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied the interaction between AMF （Paraglomus occultum） and exogenous PAs, including putrescine （Put）, spermidine （Spd） and spermine （Spin） on mycorrhizal development of different parts of root system, plant growth, RSA and carbohydrate concentrations of 6-m-old citrus （Citrus tangerine Hort. ex Tanaka） seedlings. After 14 wk of PAs application, PA-treated mycorrhizal seedlings exhibited better mycorrhizal colonization and numbers of vesicles, arbuscules, and entry points, and the best mycorrhizal status of taproot, first-, second-, and third-order lateral roots was respectively found in mycorrhizal seedlings supplied with Put, Spd and Spm, suggesting that PAs might act as a regulated factor of mycorrhizal development through transformation of root sucrose more into glucose for sustaining mycorrhizal development. AMF usually notably increases RSA traits （taproot length, total length, average diameter, projected area, surface area, volume, and number of first-, second-, and third-order lateral roots） of only PA-treated seedlings. Among the three PA species, greater positive effects on RSA change and plant biomass increment of the seedlings generally rank as Spd〉Spm〉Put, irrespective of whether or not AMF colonization. PAs significantly changed the RSA traits in mycorrhizal but not in non-mycorrhizal seedlings. It suggests that the application of PAs （especially Spd） to AMF plants would optimize RSA of citrus seedlings, thus increasing plant growth （shoot and root dry weight）.展开更多
The root system architecture(RSA) of a crop has a profound effect on the uptake of nutrients and consequently the potential yield. However, little is known about the genetic basis of RSA and resource adaptive response...The root system architecture(RSA) of a crop has a profound effect on the uptake of nutrients and consequently the potential yield. However, little is known about the genetic basis of RSA and resource adaptive responses in wheat(Triticum aestivum L.). Here, a high-throughput germination paper-based plant phenotyping system was used to identify seedling traits in a wheat doubled haploid mapping population, Savannah×Rialto. Significant genotypic and nitrate-N treatment variation was found across the population for seedling traits with distinct trait grouping for root size-related traits and root distribution-related traits. Quantitative trait locus(QTL) analysis identified a total of 59 seedling trait QTLs. Across two nitrate treatments, 27 root QTLs were specific to the nitrate treatment. Transcriptomic analyses for one of the QTLs on chromosome 2 D, which was found under low nitrate conditions, revealed gene enrichment in N-related biological processes and 28 differentially expressed genes with possible involvement in a root angle response. Together, these findings provide genetic insight into root system architecture and plant adaptive responses to nitrate, as well as targets that could help improve N capture in wheat.展开更多
Drought is an important abiotic stress factor in cotton production.The root system architecture(RSA)of cotton shows high plasticity which can alleviate drought-related stress under drought stress(DS)conditions;however...Drought is an important abiotic stress factor in cotton production.The root system architecture(RSA)of cotton shows high plasticity which can alleviate drought-related stress under drought stress(DS)conditions;however,this alleviation is cultivar dependent.Therefore,this study estimated the genetic variability of RSA in cotton under DS.Using the paper-based growth system,we assessed the RSA variability in 80 cotton cultivars at the seedling stage,with 0 and10%polyethylene glycol 6000(PEG6000)as the control(CK)and DS treatment,respectively.An analysis of 23 aboveground and root traits in the 80 cotton cultivars revealed different responses to DS.On the 10th day after DS treatment,the degree of variation in the RSA traits under DS(5–55%)was greater than that of CK(5–49%).The 80 cultivars were divided into drought-tolerant cultivars(group 1),intermediate drought-tolerant cultivars(group 2),and drought-sensitive cultivars(group 3)based on their comprehensive evaluation values of drought resistance.Under DS,the root lengthlower,root area-lower,root volume-lower,and root length density-lower were significantly reduced by 63,71,76,and 4%in the drought-sensitive cultivars compared to CK.Notably,the drought-tolerant cultivars maintained their root lengthlower,root area-lower,root volume-lower,and root length density–lower attributes.Compared to CK,the root diameter(0–2 mm)-lower increased by 21%in group 1 but decreased by 3 and 64%in groups 2 and 3,respectively,under DS.Additionally,the drought-tolerant cultivars displayed a plastic response under DS that was characterized by an increase in the root-lower characteristics.Drought resistance was positively correlated with the root area-lower and root length density-lower.Overall,the RSA of the different cotton cultivars varied greatly under DS.Therefore,important root traits,such as the root-lower traits,provide great insights for exploring whether drought-tolerant cotton cultivars can effectively withstand adverse environments.展开更多
Fractal geometry is a potential new approach to analyze the root architecture, which may offer improved ways to quantify and summarize root system complexity as well as yield ecological and physiological insights into...Fractal geometry is a potential new approach to analyze the root architecture, which may offer improved ways to quantify and summarize root system complexity as well as yield ecological and physiological insights into the functional relevance of specific architectural patterns. Fractal analysis is a sensitive measure of root branching intensity and fractal dimension expresses the ＂space filling＂ properties of a structure. The objective of this study was to find out the fractal characteristics of root systems in a remote area of the Taklimakan desert in China. The entire root system of two naturally occurring species were excavated and exposed with shov- els in 2007. The species were Tamarix taklamakanensis and Calligonum roborovskii. A one-factorial ANOVA with species as factor showed statistically a highly significant difference in fractal dimensions, indicating differences in their pattern of root branching. There was no relationship between root diameter and two parameters of fractal root models a and q, representing general characteris- tics of root systems, for either species （a： the ratio of the sum of root cross-sectional areas after a branching to the cross-sectional area before root division; q： the distribution of the cross-sectional areas after branching）. We have found significant linear relation- ships between the diameter after branching and root length and biomass respectively, because of the self-similarity of root branching. Branching rules are the same for roots of all sizes and lengths. Root biomass for the root systems of entire trees can be estimated by measuring the diameter of each root at the base of the trunk or the diameter after branching. We have shown that the diameter of each root at the base of the trunk and the diameter after branching are effective indices that can be measured easily in order to estimate the root lengths, biomass and other parameters of root architecture.展开更多
文摘Overview of root system architecture.The plant root system is a highly dynamic and multifunctional organ system composed of primary roots,lateral roots,adventitious roots,and root hairs.Based on topological morphology,root systems can be classified as taproot systems or fibrous root systems.Root system architecture(RSA)refers to the spatial distribution and extension patterns of roots within soil,encompassing characteristics such as root length,branching angle,density,and spatial arrangement.RSA not only determines the plant’s capacity to acquire water and nutrients but also influences other root functions,playing a decisive role in overall plant health.
文摘What the researchers go in for is to establish models between root architecture （RA） changes and nutrition, mold ideal root architecture of apple trees, improve the nutrient uptake efficiency, and further explore the functional mechanism of nutrient elements during the course of RA construction. The cultivation system of filter paper is utilized to research the effect of nutrient deficiency on the RA of Malus hupehensis （Pamp.） Rehd. There may be eight types of RA. In complete Hogland solution, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂. With the lack of P, K or Ca, the main type of RA is ＂lateral roots clustering in the upper region primary root＂, and the ＂lateral roots clustering in the upper and middle regions of primary root＂ types of RA decrease. But with shortage of P, the type of lateral roots clustering in the upper and lower regions of primary root increases, and the type of lateral roots clustering in the middle region of primary root decreases, with the types of RA diversified. Under the condition of K deficiency, the type of no lateral root increases and types of lateral roots clustering in the middle region of primary root decrease, and the percentage of such types as ＂no lateral root＂, ＂lateral roots clustering in the upper region of primary root＂, and ＂lateral roots clustering in the upper and middle regions of primary root＂ accounts for 97.9% in all, with the types of RA simplified. With lack of Fe, Mg or Zn, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂, but the type of lateral roots evenly-distributed on primary root increases. The main type of RA is ＂lateral roots evenlydistributed on primary root＂, under the condition of N deficiency, and the types of RA turn out to be diversified. There exists a close relation between nutrient deficiency and RA changes. Owing to various forms of nutrient deficiency, correspondingly different types of RA have been produced.
文摘In the experimental garden of the Department of Soil Bioengineering and Landscape Construction, University of Applied Life Sciences in Vienna, Austria, coarse root systems of three different brush species were completely excavated and semiutomatically digitized. The species were Lonicera xylosteum, Ligustrum vulgare and Euonymus europaeus. The 3-D root architectures reveal different growth strategies between species, which are related to ecological characteristics and physical soil properties. The root architecture of Lonicera xylosteum and Ligustrum vulgare, planted in the under layer of the live slope grading, where the soil is very tight and the soil water content and fertility are relatively low, is shallow. However, the root distribution of E. europaeus, planted in the middle layer, where environmental conditions are better, is deeper. Most of the root biomass of the three species is concentrated in the 0-30 cm soil layer. A quarter of the root biomass ofLigustrum vulgare is distributed in the upper layer of the plant inlay. E. europaeus has a relatively even distribution in the 30-0 cm and 60-90 cm soil layer.
文摘Sorghum’s natural adaptation to a wide range of abiotic stresses provides diverse genetic reserves for potential improvement in crop stress tolerance. Growing interest in sorghum research has led to the expansion of genetic resources though establishment of the sorghum association panel (SAP), generation of mutagenized populations, and recombinant inbred line (RIL) populations</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> etc. Despite rapid improvement in biotechnological tools, lack of efficient phenotyping platforms remains one of the major obstacles in utilizing these genetic resources. Scarcity of efforts in root system phenotyping hinders identification and integration of the superior root traits advantageous to stress tolerance. Here, we explored multiple approaches in root phenotyping of an ethyl methanesulfonate (EMS)-mutagenized sorghum population. Paper-based growth pouches (PGP) and hydroponics were employed to analyze root system architecture (RSA) variations induced by mutations and to test root development flexibility in response to phosphorus deficiency in early growing stages. PGP method had improved capabilities compared to hydroponics providing inexpensive, space-saving, and high-throughput phenotyping of sorghum roots. Preliminary observation revealed distinct phenotypic variations which were qualitatively and quantitatively systemized for association analysis. Phenotypes/ideotypes with root architecture variations potentially correlated with Pi acquisition were selected to evaluate their contribution to P-efficiency (PE). Sand mixed with P-loaded activated alumina substrate (SAS) provided closely to natural but still controlled single-variable conditions with regulated Pi availability. Due to higher labor and cost input we propose SAS to be used for evaluating selected sorghum candidates for PE. The ability of rapidly screening root phenotypes holds great potential for discovering genes responsible for relevant root traits and utilizing mutations to improve nutrient efficiency and crop productivity.
基金supported by the Key Technologies Research and Development Program,China(2022YFE0100500)the National Natural Science Foundation of China(31971954,31960405,32061143031)+2 种基金Hainan Yazhou Bay Seed Lab and China National Seed Group(B23YQ1510)Gansu Province Industrial Support Plan(2022CYZC-46)Postdoctoral Fellowship Program of CPSF(GZC20230909).
文摘Drought is a natural disaster that profoundly impacts on global agricultural production,significantly reduces crop yields,and thereby poses a severe threat to worldwide food security.Addressing the challenge of effectively improving crop drought resistance(DR)to mitigate yield loss under drought conditions is a global issue.An optimal root system architecture(RSA)plays a pivotal role in enhancing the capacity of crops to efficiently uptake water and nutrients,which consequently strengthens their resilience against environmental stresses.In this review,we discuss the compositions and roles of crop RSA and summarize the most recent developments in augmenting drought tolerance in crops by manipulating RSA-related genes.Based on the current research,we propose the potential optimal RSA configuration that could be helpful in enhancing crop DR.Lastly,we discuss the existing challenges and future directions for breeding crops with enhanced DR capabilities through genetic improvements targeting RSA.
基金funded by the Guangxi Science and Technology Plan Project(Guike AD22080050)the Basic Research Ability Improvement Project of Young and Middle-aged Teachers of Universities in Guangxi(2022KY0386)+1 种基金the Opening Foundation of Key Laboratory of Environment Change and Resources Use in Beibu Gulf,Ministry of Education,Nanning Normal University(NNNU-KLOP-K2202)the National Natural Science Foundation of China(42471055).
文摘Root system architecture has often been overlooked in plant research despite its critical role in plant adaptation to environmental conditions.This study focused on the root system architecture of the desert shrub Reaumuria soongorica in the Alxa steppe desert,Northwest China.Plant samples were collected during May-September 2019.Using excavation methods,in situ measurements,and root scanning techniques,we analyzed the root distribution,topology,and branching patterns of R.soongorica across an age sequence of 7-51 a.Additionally,we investigated the allometric relationships of root collar diameter with total coarse root length,biomass,and topological parameters.The results showed that the roots of R.soongorica were predominantly concentrated in shallow soil layers(10-50 cm),with lateral root branching and biomass allocation increasing with shrub age.The root topology exhibited a herringbone-like structure,with average topological and modified topological indices of 0.89 and 0.96,respectively,both of which adjusted with shrub age.The root system displayed a self-similar branching pattern,maintaining a constant cross-sectional area ratio of 1.13 before and after branching,deviating from the area-preserving rule.These adaptive traits allow R.soongorica to efficiently expand its nutrient acquisition zone,minimize internal competition,and optimize resource uptake from the upper soil layers.Furthermore,significant linear relationships were observed between log10-transformed root collar diameter and log10-transformed total coarse root length,biomass,and topological parameters.These findings advance non-destructive approaches for studying root characteristics and contribute to the development of root-related models.Besides,this study provides new insights into the adaptive strategies of R.soongorica under extreme drought conditions,offering valuable guidance for species selection and cultivation in desert restoration efforts.
基金funded by the National Natural Science Foundation of China(32102346)Shanghai Sailing Program(21YF1422100)+1 种基金National Postdoctoral Program for Innovative Talents(BX20180199)Startup Fund for Young Faculty at SJTU(21×010500643).
文摘The D14 protein,an alpha/beta hydrolase,is a key receptor in the strigolactone(SL)signaling pathway.However,the response of VvD14 to SL signals and its role in grapevine root architecture formation remain unclear.This study demonstrated that VvD14c was highly expressed in grapevine tissues and fruit stages than other VvD14 isoforms.Application of GR24,an SL analog,enhanced the elongation and diameter of adventitious roots but inhibited the elongation and density of lateral roots(LRs)and increased VvD14c expression.Additionally,GR24 is nested within the VvD14c pocket and strongly bound to the VvD14c protein,with an affinity of 5.65×10^(-9) M.Furthermore,VvD14c interacted with grapevine MORE AXILLARY GROWTH 2(VvMAX2)in a GR24-dependent manner.Overexpression of VvD14c in the d14 mutant and VvMAX2 in the max2 Arabidopsis mutant reversed the increased LR number and density,as well as primary root elongation.Conversely,homologous overexpression of VvD14c and VvMAX2 resulted in reduced LR number and density in grapevines.VvMAX2 directly interacted with LATERAL ORGAN BOUNDARY(VvLOB)and VvLBD19,thereby positively regulating LR density.These findings highlight the role of SLs in regulating grapevine root architecture,potentially via the VvD14c-VvMAX2-VvLOB/VvLBD19 module,providing new insights into the regulation of root growth and development in grapevines.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2024-00340851)the Engineering Research Center Program of the National Science Foundation(NSF)under NSF Cooperative Agreement EEC-1449501.
文摘Characterizing the architecture of tree root systems is essential to advance the development of root-inspired anchorage in engineered systems.This study explores the structural root architectures of orchard trees to understand the interplays between the mechanical behavior of roots and the root architecture.Full three-dimensional(3D)models of natural tree root systems,Lovell,Marianna,and Myrobalan,that were extracted from the ground by vertical pullout are reconstructed through photogrammetry and later skeletonized as nodes and root branch segments.Combined analyses of the full 3D models and skeletonized models enable a detailed examination of basic bulk properties and quantification of architectural parameters.While the root segments are divided into three categories,trunk root,main lateral root,and remaining roots,the patterns in branching and diameter distributions show significant differences between the trunk and main laterals versus the remaining lateral roots.In general,the branching angle decreases over the sequence of bifurcations.The main lateral roots near the trunk show significant spreading while the lateral roots near the ends grow roughly parallel to the parent root.For branch length,the roots bifurcate more frequently near the trunk and later they grow longer.Local thickness analysis confirms that the root diameter decays at a higher rate near the trunk than in the remaining lateral roots,while the total cross-sectional area across a bifurcation node remains mostly conserved.The histograms of branching angle,and branch length and thickness gradient can be described using lognormal and exponential distributions,respectively.This unique study presents data to characterize mechanically important structural roots,which may help link root architecture to the mechanical behaviors of root structures.
基金supported by Natural Science Foundation of Chongqing(No.CSTB2022NSCQ-LZX0001)High-end Foreign Expert Introduction program(No.G2022165004L)+1 种基金High-end Foreign Expert Introduction program(No.DL2021165001L)The fi-nancial supports are gratefully acknowledged.
文摘Plant root systems,a crucial component of biogeotechnics,have been recognized as a promising and sustainable strategy to address novel challenges in geotechnical engineering,i.e.,climate change(Ng et al.,2022).Root-soil composite and root-reinforced slopes have re-ceived widespread attention in recent decades,due to the ability of root to regulate soil properties through mechanical reinforcement and hy-draulic transpiration(Li&Duan,2023;Ni et al.,2024).Fig.1 provides a co-occurrence network plot of plant root-based soil reinforcement strategies published over the last decade,where three clusters are identified with different colors.On the left of the network map,clusters in red and blue are primarily driven by geotechnical investigations of vegetated slopes(i.e.,plant root reinforced slopes)and root-soil com-posite/root-permeated soils,as denoted by the terms like"model","test","slope","strength"and"vegetation",while the green cluster on the right side demonstrates botany-related domains,for instance,"plant growth",Indeed,the reinforcement of vegetated soil strength is com-plex and varies significantly with an abundance of factors,both me-chanically and hydraulically.Particularly,the impact of root mor-phology and architecture cannot be negligible,including keywords"root area ratio"root distribution""root morphology"root diame-ter"root density"in Fig.1 with the root size and root depth ranking foremost.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.32260085,31860064,31660501,31970609,32260718 and 31901870)the Key Projects of the Applied Basic Research Plan of Yunnan Province(Grant No.202301AS070082)+3 种基金the Start-up fund from Xishuangbanna Tropical Botanical Garden,the‘Top Talents Program in Science and Technology’from Yunnan Province,the Major Science and Technology Project in Yunnan Province(Grant Nos.202102AE090042 and 202202AE090036)the Young and Middle-Aged Academic and Technical Leaders Reserve Talent Program in Yunnan Province(Grant No.202205AC160076)China Postdoctoral Science Foundation(Grant No.2019M653849XB)the High-level Talents Introduction Plan of Yunnan Province-Young Talents Special Project。
文摘The formation of root system architecture(RSA)plays a crucial role in plant growth.OsDRO1 is known to have a function in controlling RSA in rice,however,the role of potato StDRO2,a homolog of rice OsDRO1,in root growth remains unclear.In this study,we obtained potato dro2 mutant lines by Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-Associated 9(CRISPR/Cas9)-mediated genome editing system.The mutant lines were generated from a splicing defect of the StDRO2 intron 1,which causes a nonsense mutation in StDRO2.Furthermore,the secondary structure of StDRO2 mRNA analyzed with RNAfold Web Server was altered in the dro2 mutant.Mutation of StDRO2 conveys potato adaptation through changing the RSA via alteration of auxin transport under drought stress.The potato dro2 lines showed higher plant height,longer root length,smaller root growth angle and increased tuber weight than the wild-type.The alteration of RSA was associated with a disturbance of IAA distribution in the dro2 mutant,and the levels of StPIN7 and StPIN10 detected by using real-time PCR were up-regulated in the roots of potato dro2 lines grown under drought stress.Moreover,the microRNAs(miRNAs)PmiREN024536 and PmiREN024486 targeted the StDRO2 gene,and auxin positively and negatively regulated the expression of StDRO2 and the miRNAs PmiREN024536 and PmiREN024486,respectively,in the potato roots.Our data shows that a regulatory network involving auxin,StDRO2,PmiREN024536 and PmiREN024486 can control RSA to convey potato fitness under drought stress.
基金supported by the National Basic Research Program of China (Grant No. 2009CB11860)the National Natural Science Foundation of China (Grant Nos. 31071852,30771289,and 30821003)the Special Fund for Agriculture Profession (Grant No. 200803030)
文摘The use of nitrogen(N) fertilizers has contributed to the production of a food supply sufficient for both animals and humans despite some negative environmental impact.Sustaining food production by increasing N use efficiency in intensive cropping systems has become a major concern for scientists,environmental groups,and agricultural policymakers worldwide.In high-yielding maize systems the major method of N loss is nitrate leaching.In this review paper,the characteristic of nitrate movement in the soil,N uptake by maize as well as the regulation of root growth by soil N availability are discussed.We suggest that an ideotype root architecture for efficient N acquisition in maize should include(i) deeper roots with high activity that are able to uptake nitrate before it moves downward into deep soil;(ii) vigorous lateral root growth under high N input conditions so as to increase spatial N availability in the soil;and(iii) strong response of lateral root growth to localized nitrogen supply so as to utilize unevenly distributed nitrate especially under limited N conditions.
文摘The remodeling of root architecture is a major developmental response of plants to phosphate （Pi） deficiency and is thought to enhance a plant＇s ability to forage for the available Pi in topsoil. The underlying mechanism controlling this response, however, is poorly understood. In this study, we identified an Arabidopsis mutant, hps 10 （hypersensitive to Pi starvation 10）, which is morphologically normal under Pi sufficient condition but shows increased inhibition of primary root growth and enhanced production of lateral roots under Pi defi- ciency, hpslO is a previously identified allele （als3-3） of the ALUMINUM SENSITIVE3 （ALS3） gene, which is involved in plant tolerance to aluminum toxicity. Our results show that ALS3 and its interacting protein AtSTAR1 form an ABC transporter complex in the tonoplast. This protein complex mediates a highly electro- genic transport in Xenopus oocytes. Under Pi deficiency, als3 accumulates higher levels of Fe3＋ in its roots than the wild type does. In Arabidopsis, LPR1 （LOW PHOSPHATE ROOT1） and LPR2 encode ferroxidases, which when mutated, reduce Fe3＋ accumulation in roots and cause root growth to be insensitive to Pi defi- ciency. Here, we provide compelling evidence showing that ALS3 cooperates with LPR1/2 to regulate Pi deficiency-induced remodeling of root architecture by modulating Fe homeostasis in roots.
文摘Abstract: Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition. Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under conditions of low phosphorus availability, the length of cells in the meristem zone of the lateral roots was longer, but the length of cells in the elongation and mature zones of the lateral roots was shorter, compared with seedlings grown under conditions of high phosphorus availability. The elongation rates of primary roots increased as phosphorus availability increased, but the elongation rates of the branched zones of the primary roots decreased. The number of lateral root primordia and the length of the lateral roots decreased as phosphorus availability increased. The topological index (altitude slope) decreased as phosphorus availability increased, suggesting that root architecture tended to be herringbone-like when seedlings were grown under conditions of low phosphate availability. Herringbone-like root systems exploit nutrients more efficiently, but they have higher construction costs than root systems with a branching pattern.
基金the National Natural Science Foundation of China (U1301212)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB15030202)
文摘Improving crop nutrient ef ficiency becomes an essential consideration for environmentally friendly and sustainable agriculture. Plant growth and development is dependent on 17 essential nutrient elements,among them,nitrogen（N） and phosphorus（P） are the two most important mineral nutrients. Hence it is not surprising that low N and/or low P availability in soils severely constrains crop growth and productivity,and thereby have become high priority targets for improving nutrient ef ficiency in crops. Root exploration largely determines the ability of plants to acquire mineral nutrients from soils. Therefore,root architecture,the 3-dimensional con figuration of the plant＇s root system in the soil,is of great importance for improving crop nutrient ef ficiency. Furthermore,the symbiotic associations between host plants and arbuscular mycorrhiza fungi/rhizobial bacteria,are additional important strategies to enhance nutrient acquisition. In this review,we summarize the recent advances in the current understanding of crop species control of root architecture alterations in response to nutrient availability and root/microbe symbioses,through gene or QTL regulation,which results in enhanced nutrient acquisition.
文摘Studies on natural variation are an important tool to unravel the genetic basis of quantitative traits in plants. Despite the significant roles of phytohormones in plant development, including root architecture, hardly any studies have been done to investigate natural variation in endogenous hormone levels in plants. Therefore, in the present study a range of hormones were quantified in root extracts of thirteen Arabidopsis thaliana accessions using a ultra performance liquid chromatography triple quadrupole mass spectrometer. Root system architecture of the set of accessions was quantified, using a new parameter （mature root unit） for complex root systems, and correlated with the phytohormone data. Significant variations in phytohormone levels among the accessions were detected, but were remarkably small, namely less than three-fold difference between extremes. For cytokinins, relatively larger variations were found for ribosides and glucosides, as compared to the free bases. For root phenotyping, length-related traits--lateral root length and total root length--showed larger variations than lateral root number-related ones. For root architecture, antagonistic interactions between hormones, for example, indole-3-acetic acid to trans-zeatin were detected in correlation analysis. These findings provide conclusive evidence for the presence of natural variation in phytohormone levels in Arabidopsis roots, suggesting that quantitative genetic analyses are feasible.
基金funded by the National Natural Science Foundation of China(4136110031360205)+1 种基金International Science and Technology Cooperation Program of China(2012DFR30830)the Gansu Science and Technology Support Program(1204NKCA084)
文摘The architectural parameters of Reaumuria soongorica root system in different habitats of Gansu Province, China were analyzed to examine its ecological adaptability to arid environments. Results show that： （1） Topological indices of R. Soongorica root sys- tem are small in all habitats, and root branching pattem tends to be dichotomous. Also, the indices gradually increase in the Min- qin windblown sand region and the Zhangye Gobi region in Hexi Corridor, which indicates that drought tends to produce her- ringbone-like root branching pattems. （2） Fractal dimension values ofR. Soongorica root system are small and not obvious in the Minqin windblown sand region and the Zhangye Gobi region in Hexi Corridor, with values of 1.1778 and 1.1169, respectively. Fractal dimension values are relatively large in Jiuzhoutai semi-arid hilly and gully region of the Loess Plateau, which indicates that the R. Soongorica root system has better fractal characteristics in this region than in the other regions. （3） Total branching ra- tios of the R. Soongorica root system in arid regions of Hexi Corridor are smaller than that in the Jiuzhoutai semi-arid hilly and gully region of the Loess Plateau. This shows that root branching ability in the semi-arid region is stronger, and it decreases to some degree with increased drought. （4） The root connection lengths of R. soongorica root system are long in all habitats, but there are significant length differences between the different habitats. The root connection length at the Minqin windblown sand region is the longest. It is concluded that R. soongoriea adapts to arid environments by decreasing root branching, decreasing root overlap and increasing root connection length, which makes its root branching pattern tend to be herringbone-like to reduce com- petition in root internal environment for nutrients and to enhance root absorption rate of nutrients, and ensure effective nutrition space. Thus the roots can absorb enough water and nutrients in resource-poor settings to ensure normal physiological requirements.
基金supported by the National Natural Science Foundation of China (30800747)the Key Project of Ministry of Education of China (211107)the Science-Technology Research Project of Hubei Provincial Department of Education, China (Q20111301)
文摘Either arbuscular mycorrhizal fungi （AMF） or polyamines （PAs） may change root system architecture （RSA） of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied the interaction between AMF （Paraglomus occultum） and exogenous PAs, including putrescine （Put）, spermidine （Spd） and spermine （Spin） on mycorrhizal development of different parts of root system, plant growth, RSA and carbohydrate concentrations of 6-m-old citrus （Citrus tangerine Hort. ex Tanaka） seedlings. After 14 wk of PAs application, PA-treated mycorrhizal seedlings exhibited better mycorrhizal colonization and numbers of vesicles, arbuscules, and entry points, and the best mycorrhizal status of taproot, first-, second-, and third-order lateral roots was respectively found in mycorrhizal seedlings supplied with Put, Spd and Spm, suggesting that PAs might act as a regulated factor of mycorrhizal development through transformation of root sucrose more into glucose for sustaining mycorrhizal development. AMF usually notably increases RSA traits （taproot length, total length, average diameter, projected area, surface area, volume, and number of first-, second-, and third-order lateral roots） of only PA-treated seedlings. Among the three PA species, greater positive effects on RSA change and plant biomass increment of the seedlings generally rank as Spd〉Spm〉Put, irrespective of whether or not AMF colonization. PAs significantly changed the RSA traits in mycorrhizal but not in non-mycorrhizal seedlings. It suggests that the application of PAs （especially Spd） to AMF plants would optimize RSA of citrus seedlings, thus increasing plant growth （shoot and root dry weight）.
基金supported by the Biotechnology and Biological Sciences Research Council,UK(BB/M001806/1,BB/L026848/1,BB/P026834/1,and BB/M019837/1)(MJB,DMW,and MPP)the Leverhulme Trust,UK(RPG-2016–409)(MJB and DMW)+1 种基金the European Research Council FUTUREROOTS Advanced Investigator Grant,UK(294729)to MG,JAA,DMW,and MJBthe University of Nottingham Future Food Beacon of Excellence,UK。
文摘The root system architecture(RSA) of a crop has a profound effect on the uptake of nutrients and consequently the potential yield. However, little is known about the genetic basis of RSA and resource adaptive responses in wheat(Triticum aestivum L.). Here, a high-throughput germination paper-based plant phenotyping system was used to identify seedling traits in a wheat doubled haploid mapping population, Savannah×Rialto. Significant genotypic and nitrate-N treatment variation was found across the population for seedling traits with distinct trait grouping for root size-related traits and root distribution-related traits. Quantitative trait locus(QTL) analysis identified a total of 59 seedling trait QTLs. Across two nitrate treatments, 27 root QTLs were specific to the nitrate treatment. Transcriptomic analyses for one of the QTLs on chromosome 2 D, which was found under low nitrate conditions, revealed gene enrichment in N-related biological processes and 28 differentially expressed genes with possible involvement in a root angle response. Together, these findings provide genetic insight into root system architecture and plant adaptive responses to nitrate, as well as targets that could help improve N capture in wheat.
基金the National Natural Science Foundation of China(31871569 and 32172120)the Natural Science Foundation of Hebei Province,China(C2020204066)。
文摘Drought is an important abiotic stress factor in cotton production.The root system architecture(RSA)of cotton shows high plasticity which can alleviate drought-related stress under drought stress(DS)conditions;however,this alleviation is cultivar dependent.Therefore,this study estimated the genetic variability of RSA in cotton under DS.Using the paper-based growth system,we assessed the RSA variability in 80 cotton cultivars at the seedling stage,with 0 and10%polyethylene glycol 6000(PEG6000)as the control(CK)and DS treatment,respectively.An analysis of 23 aboveground and root traits in the 80 cotton cultivars revealed different responses to DS.On the 10th day after DS treatment,the degree of variation in the RSA traits under DS(5–55%)was greater than that of CK(5–49%).The 80 cultivars were divided into drought-tolerant cultivars(group 1),intermediate drought-tolerant cultivars(group 2),and drought-sensitive cultivars(group 3)based on their comprehensive evaluation values of drought resistance.Under DS,the root lengthlower,root area-lower,root volume-lower,and root length density-lower were significantly reduced by 63,71,76,and 4%in the drought-sensitive cultivars compared to CK.Notably,the drought-tolerant cultivars maintained their root lengthlower,root area-lower,root volume-lower,and root length density–lower attributes.Compared to CK,the root diameter(0–2 mm)-lower increased by 21%in group 1 but decreased by 3 and 64%in groups 2 and 3,respectively,under DS.Additionally,the drought-tolerant cultivars displayed a plastic response under DS that was characterized by an increase in the root-lower characteristics.Drought resistance was positively correlated with the root area-lower and root length density-lower.Overall,the RSA of the different cotton cultivars varied greatly under DS.Therefore,important root traits,such as the root-lower traits,provide great insights for exploring whether drought-tolerant cotton cultivars can effectively withstand adverse environments.
文摘Fractal geometry is a potential new approach to analyze the root architecture, which may offer improved ways to quantify and summarize root system complexity as well as yield ecological and physiological insights into the functional relevance of specific architectural patterns. Fractal analysis is a sensitive measure of root branching intensity and fractal dimension expresses the ＂space filling＂ properties of a structure. The objective of this study was to find out the fractal characteristics of root systems in a remote area of the Taklimakan desert in China. The entire root system of two naturally occurring species were excavated and exposed with shov- els in 2007. The species were Tamarix taklamakanensis and Calligonum roborovskii. A one-factorial ANOVA with species as factor showed statistically a highly significant difference in fractal dimensions, indicating differences in their pattern of root branching. There was no relationship between root diameter and two parameters of fractal root models a and q, representing general characteris- tics of root systems, for either species （a： the ratio of the sum of root cross-sectional areas after a branching to the cross-sectional area before root division; q： the distribution of the cross-sectional areas after branching）. We have found significant linear relation- ships between the diameter after branching and root length and biomass respectively, because of the self-similarity of root branching. Branching rules are the same for roots of all sizes and lengths. Root biomass for the root systems of entire trees can be estimated by measuring the diameter of each root at the base of the trunk or the diameter after branching. We have shown that the diameter of each root at the base of the trunk and the diameter after branching are effective indices that can be measured easily in order to estimate the root lengths, biomass and other parameters of root architecture.
