In order to determine whether hydrogen peroxide （H2O2） generated by polyamlne oxidative degradation Is Involved In the development of lateral roots In soybean, the length and the number of lateral roots, the actlvlt...In order to determine whether hydrogen peroxide （H2O2） generated by polyamlne oxidative degradation Is Involved In the development of lateral roots In soybean, the length and the number of lateral roots, the actlvltlea of polyamlne oxldases and dlamlne oxldases, and the endogenous free polyamlne and H2O2 content were analyzed In soybean （Giycine max （Linn.） Merr.） main roots of 2-d-old seedlings after treatments for 2 d with exogenous β-hydroxyethylhydrazine （an Inhibitor of polyamlne oxldases）, H202, putresclne, cyclohexylamlne （an Inhibitor of spermidine synthase） or N,N＇-dimethylthlourea （a scavenger of hydrogen peroxide）.β-hydroxyethylhydrazlne treatment strongly Inhibited the development of lateral roots In soybean seedlings, reduced the activities of polyamine oxldases and dlamlne oxidases, decreased H2O2 levels, and led to the accumulation of endogenous polyamlnes In the main roots. The inhibitory effect of β-hydroxyethylhydrazlne on root development could be alleviated by exogenously applied 10 μmol/L H2O2 （a major product of polyamlne oxidation）. Treatment with cyclohexylamlne and putresclne promoted root growth slightly, but treatment with cyclohexylamlne plus N,N＇dlmethylthlourea or putresclne plus N,N＇-dlmethylthlourea prevented the development of soybean lateral roots. The effects of these treatments on the development of soybean lateral roots were consistent with the changes In endogenous H2O2 levels. These results suggest that the development of soybean lateral roots Is associated with the oxidative degradation of polyamlnes, and that their products, especially H2O2, are likely to play an Important role In the growth of soybean lateral roots.展开更多
Monocot root systems comprise a large number of lateral roots to allow them to survive and colonize land.Auxin signaling pathways centered on Aux/IAA play a crucial role in lateral root development.However,in non-mode...Monocot root systems comprise a large number of lateral roots to allow them to survive and colonize land.Auxin signaling pathways centered on Aux/IAA play a crucial role in lateral root development.However,in non-model monocot plants,the effects of Aux/IAA on lateral root initiation and number remain largely unknown.The present study transformed PheIAA17,a member of the Aux/IAA family of Moso bamboo,into rice and found that it significantly drove plants to produce lateral roots and improved the rooting rate.Quantitative experiments showed that PheIAA17 overexpression significantly affected the expression of ARF family members.Phylogenetic and promoter analyses indicate that PheARF3-2 belongs to class B ARF,and the promoter region contains auxin response elements.The results of yeast one-hybrid and dual-luciferase reporter assays confirmed that PheIAA17 bound specific fragments of the PheARF3-2 promoter to repress its transcriptional activity.Y2H and BiFC assay have shown that PheIAA17 and PheIAA30-3 could physically interact in vitro and in vivo.Taken together,this study reports a new molecular module centered on PheIAA17,which directs plants to alter root morphology through an increase in lateral roots.展开更多
Lateral root is primary organ for plant to explore and utilize soil nutrient efficiently. The development of lateral roots (LR) is controlled by both genetic factors and nutrient status in environment. To investigate ...Lateral root is primary organ for plant to explore and utilize soil nutrient efficiently. The development of lateral roots (LR) is controlled by both genetic factors and nutrient status in environment. To investigate the effects of nitrate (NO3-) on rice lateral root growth and nitrogen (N) uptake efficiency under upland condition, three treatments, including root-split culture and whole plant culture in N sufficient and deficient conditions, were used in a vermiculite culture experiment. Root-split treatment showed that the growth of lateral roots was stimulated by localized nitrate supply. However, in whole plant culture, elongation of lateral roots was induced by NO3- deficiency. The effects of NO3- on rice lateral root growth were genotype-dependent. Similar N concentration, soluble sugar concentration and N content in shoot were observed in both root-split treatment and whole plant culture under NO3- sufficient condition, suggesting that the nitrogen requirement for rice normal growth could be satisfied with only half of roots supplied with NO3-. In the root-split treatment, N uptake was positively correlated with the average of lateral root length (ALRL) in NO3--supplied side, suggesting that the ALRL is important for rice root N uptake in the environment where the nitrogen nutrient is limiting factor. No significant correlation was observed between N uptake and ALRL in whole plant culture under N sufficient condition, which implies that the length of lateral roots may not be the main factor to determine tire rice root N uptake in nutrient-rich zone. Morphological and metabolic evidence in this study provided some prospects for genetic improvement of root system characters to improve the efficiency of nutrient absorption in rice.展开更多
Strigolactones(SLs)are newly discovered plant hormones which regulate the normal development of different plant organs,especially root architecture.Lateral root formation of rapeseed seedlings before winter has great ...Strigolactones(SLs)are newly discovered plant hormones which regulate the normal development of different plant organs,especially root architecture.Lateral root formation of rapeseed seedlings before winter has great effects on the plant growth and seed yield.Here,we treated the seedlings of Zhongshuang 11(ZS11),an elite conventional rapeseed cultivar,with different concentrations of GR24(a synthetic analogue of strigolactones),and found that a low concentration(0.18μmol L–1)of GR24 could significantly increase the lateral root growth,shoot growth,and root/shoot ratio of seedlings.RNA-Seq analysis of lateral roots at 12 h,1 d,4 d,and 7 d after GR24 treatment showed that 2301,4626,1595,and 783 genes were significantly differentially expressed,respectively.Function enrichment analysis revealed that the plant hormone transduction pathway,tryptophan metabolism,and the phenylpropanoid biosynthesis pathway were over-represented.Moreover,transcription factors,including AP2/ERF,AUX/IAA,NAC,MYB,and WRKY,were up-regulated at 1 d after GR24 treatment.Metabolomics profiling further demonstrated that the amounts of various metabolites,such as indole-3-acetic acid(IAA)and cis-zeatin were drastically altered.In particular,the concentrations of endogenous IAA significantly decreased by 52.4 and 75.8%at 12 h and 1 d after GR24 treatment,respectively.Our study indicated that low concentrations of exogenous SLs could promote the lateral root growth of rapeseed through interaction with other phytohormones,which provides useful clues for the effects of SLs on root architecture and crop productivity.展开更多
Mutants with increased resistance to toxic anxin concentrations were first isolated in rice.The present report describes their isolation,genetics and physiological characterization.
Pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)is an essential layer of plant disease resistance.Robust bioassays for PTI are pre-required to dissect its molecular mechanism.In this study,we establ...Pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)is an essential layer of plant disease resistance.Robust bioassays for PTI are pre-required to dissect its molecular mechanism.In this study,we established that lateral root growth inhibition as a simple and robust measurement of PTI in rice seedlings.Specifically,flg22,a well-characterized PAMP from bacterial flagellin,was used to induce PTI in rice seedlings.While flg22 treatment induced PR gene expression and mitogen-activated protein kinase activation in the roots of rice seedlings to support the PTI triggered,this treatment substantially repressed lateral root growth,but it did not alter primary root growth.Moreover,treatments with chitin(i.e.,a fungal PAMP)and oligogalacturonides(i.e.,classical damage-associated molecular pattern)clearly inhibited the lateral root growth,although a priming step involving ulvan was required for the chitin treatment.The bioassay developed was applicable to various rice cultivars and wild species.Thus,lateral root growth inhibition represents a simple and reliable assay for studying PTI in rice plants.展开更多
A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are sti...A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are still unclear.Here,maize seedlings were grown hydroponically with three N supplied in three different forms (NO_(3)^(–)only,75/25 NO_(3)^(–)/NH_(4)^(+)and NH_(4)^(+)only).Compared with sole NO_(3)^(–)or NH_(4)^(+),the mixed N supply increased the total root length of maize but did not affect the number of axial roots.The main reason was the increased total lateral root length,while the average lateral root (LR) length in each axle was only slightly increased.In addition,the average LR density of 2nd whorl crown root under mixed N was also increased.Compared with sole nitrate,mixed N could improve the N metabolism of roots (such as the N influx rate,nitrate reductase (NR) and glutamine synthase (GS)enzyme activities and total amino content of the roots).Experiments with exogenously added NR and GS inhibitors suggested that the increase in the average LR length under mixed N was related to the process of N assimilation,and whether the NR mediated NO synthesis participates in this process needs further exploration.Meanwhile,an investigation of the changes in root-shoot ratio and carbon (C) concentration showed that C transportation from shoots to roots may not be the key factor in mediating lateral root elongation,and the changes in the sugar concentration in roots further proved this conclusion.Furthermore,the synthesis and transportation of auxin in axial roots may play a key role in lateral root elongation,in which the expression of ZmPIN1B and ZmPIN9 may be involved in this pathway.This study preliminarily clarified the changes in root morphology and explored the possible physiological mechanism under a mixed N supply in maize,which may provide some theoretical basis for the cultivation of crop varieties with high N efficiency.展开更多
Rice roots include seminal roots, adventitious roots, lateral roots and root hairs, At present, progresses in the research of rice roots have been achieved in many aspects, such as root morphology, root activity, root...Rice roots include seminal roots, adventitious roots, lateral roots and root hairs, At present, progresses in the research of rice roots have been achieved in many aspects, such as root morphology, root activity, root reaction to various environmental factors as a contribution of root growth and rice yield, the relationship between root growth and stems/leaves/flowers/rice, genetic laws of root characters, etc. However, there are very few researches on lateral root mutant. This paper reviewed progresses of the lateral root mutant of rice from the perspectives of phytomorphology to plant physiology and biochemistry to the gene mapping, consisting of mechanism of developing lateral root of rice, gene cloning and functional analysis of lateral root development, the relationship between auxin and lateral roots, agronomic traits of lateral roots mutant, structure and morphology of root hairs, gravity anomaly of root, redox metabolism and proteomics researches of the mutation in lateral root of rice.展开更多
Background:The lateral root is one of the most important organs that constitute the root architecture system in plants.It can directly affect the contact area between plants and soil and plays an important role in pla...Background:The lateral root is one of the most important organs that constitute the root architecture system in plants.It can directly affect the contact area between plants and soil and plays an important role in plant structural support and nutrient absorption.Optimizing root architecture systems can greatly increase crop yields.This study was designed to identify the molecular markers and candidate genes associated with lateral root development in cotton and to evaluate correlations with yield and disease traits.Result:The number of lateral roots for 14-day old seedlings was recorded for 215 Gossypium arboreum accessions.A correlation analysis showed that the number of lateral roots positively correlates with the sympodial branch node and seed index traits,but negatively correlates with lint percentage.A Genome-wide association study(GWAS)identified 18 significant SNPs with 19 candidate genes associated with the lateral root number.Expression analysis identified three genes(FLA 12,WRKY29,and RBOHA)associated with lateral root development.Conclusion:GWAS an alysis identified key SNPs and candidate gen esfor lateral root number,a nd gen es of FLA 12,WRKY29,and RBOHA may play a pivotal role in lateral root development in Asian cotton.展开更多
Lateral root perforations are unfortunate procedures during endodontic treatment and often lead to tooth extraction. Conditioning factors such as time, size, location, inappropriate disinfection and sealing, are indis...Lateral root perforations are unfortunate procedures during endodontic treatment and often lead to tooth extraction. Conditioning factors such as time, size, location, inappropriate disinfection and sealing, are indispensable to achieve acceptable long-term outcomes. Calcium silicate cements are bioactive materials used for perforation repair. They can be set in moist environments such as blood, saliva and dentinal fluid making them a reliable material for clinical applications. This case report describes the treatment and repair after a 16-month follow-up of a lateral root perforation of the maxillary lateral incisor.展开更多
The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 ...The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 mmol L^-1） and three NO^-3 levels （0.05, 5, and 10 mmol L^-1） in solution culture for 30 d. Addition of NO^-3 at 10 mmol L^-1 significantly improved the shoot （P 〈 0.001） and root （P 〈 0.001） growth and the promotive effect of NO^-3 was more pronounced on root dry weight despite the high NaCl concentration in the culture solution, leading to a significant increase in the root：shoot ratio （P 〈 0.01）. Lateral root length, but not primary root length, considerably increased with increasing NaCl salinity and NO^-3 levels （P 〈 0.001）, implying that Na^＋ and NO3^- in the culture solution simultaneously stimulated lateral root growth. Concentrations of Na^＋ in plant tissues were also significantly increased by higher NaCl treatments （P 〈 0.001）. At 10 mmol L^-1 NO^-3, the concentrations of NO^-3 and total nitrogen and nitrate reductase activities in the roots were remarkably reduced by increasing salinity （P 〈 0.001）, but were unaffected in the shoots. The results indicated that the fine lateral root development and effective nitrogen uptake of the shoots might contribute to high salt tolerance of S. physophora under adequate NO^-3 supply.展开更多
The potential of Plant Growth Promoting Rhizobacteria(PGPR)has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield.A.brasilense produces a wide variety of mo...The potential of Plant Growth Promoting Rhizobacteria(PGPR)has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield.A.brasilense produces a wide variety of molecules,including the natural auxin indole-3-acetic acid(IAA),as well as other phytoregulators.However,several studies have suggested that auxin induces changes in plant development during their interaction with the bacteria.The effects of A.brasilense Sp245 on the development of Arabidopsis thaliana root were investigated to help explain the molecular basis of the interaction.The results obtained showed a decrease in primary root length from the first day and remained so throughout the exposure,accompanied by a stimulation of initiation and maturation of lateral root primordia and an increase of lateral roots.An enhanced auxin response was evident in the vascular tissue and lateral root meristems of inoculated plants.However,after five days of bacterization,the response disappeared in the primary root meristems.The role of polar auxin transport(PAT)in auxins relocation involved the PGP1,AXR4-1,and BEN2 proteins,which apparently mediated A.brasilense-induced root branching of Arabidopsis seedlings.展开更多
[Objective]The aim was to research the function of AtGEF1 in Rac/Rop GTPses mediate auxin signal passway.[Method]Using the transgenic plants of AtGEF1 promotor fused with GUS reporter gene and the over-expression plan...[Objective]The aim was to research the function of AtGEF1 in Rac/Rop GTPses mediate auxin signal passway.[Method]Using the transgenic plants of AtGEF1 promotor fused with GUS reporter gene and the over-expression plants of Rac/Rop GEF1 under the control of 35S promoter as materials,which were constructed from our lab,the expression pattern of GEF1 was analyzed by GUS assay using histochemical staining,and the development of seedling roots of over-expression plant of GEF1 was observed.[Result]GEF1 expression was mainly detected in root meristem,root vascular tissue,lateral roots and root hair.Furthermore,the expression level of GEF1 was highly increased with the induction of NAA.Over-expression of GEF1 was observed to enhance lateral root formation.[Conclusion]GEF1 may be involved in the regulation of development of root and root hair,and it may have redundant function in the control of lateral root development.展开更多
WRKY transcription factors have many regulatory roles we isolated a rice WRKY gene （OsWRKY31） that is induced in response to biotic and abiotic stresses. In this study, by the rice blast fungus Magnaporthe grisea an...WRKY transcription factors have many regulatory roles we isolated a rice WRKY gene （OsWRKY31） that is induced in response to biotic and abiotic stresses. In this study, by the rice blast fungus Magnaporthe grisea and auxin. This gene encodes a polypeptide of 211 amino-acid residues and belongs to a subgroup of the rice WRKY gene family that probably originated after the divergence of monocot and dicot plants. OsWRKY31 was found to be localized to the nucleus of onion epidermis cells to transiently express OsWRKY31-eGFP fusion protein. Analysis of OsWRKY31 and its mutants fused with a Gal4 DNA-binding domain indicated that OsWRKY31 has transactivation activity in yeast. Overexpression of the OsWRKY31 gene was found to enhance resistance against infection with M. grisea, and the transgenic lines exhibited reduced lateral root formation and elongation compared with wild-type and RNAi plants. The lines with overexpression showed constitutive expression of many defense-related genes, such as PBZI and OsSci2, as well as early auxin-response genes, such as OslAA4 and OsCrll genes. Furthermore, the plants with overexpression were less sensitive to exogenously supplied IBA, NAA and 2,4-1） at high concentrations, suggesting that overexpression of the OsWRKY31 gene might alter the auxin response or transport. These results also suggest that OsWRKY31 might be a common component in the signal transduction pathways of the auxin response and the defense response in rice.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 MT10 mutant plants had resistances to auxin.Under light and dark culture,the roots of MT10 seedlings had shown less lateral roots and short lateral roots.In soil,MT10 seedlings had shown not only no changed agrono...The MT10 mutant plants had resistances to auxin.Under light and dark culture,the roots of MT10 seedlings had shown less lateral roots and short lateral roots.In soil,MT10 seedlings had shown not only no changed agronomic characteristics but also no significant difference with WT.展开更多
MicroRNAs(miRNAs) are small(ca. 20-24 nucleotides) non-coding RNAs that have recently been recognized as key post-transcriptional modulators of gene expression;and they are involved in many biological processes in pla...MicroRNAs(miRNAs) are small(ca. 20-24 nucleotides) non-coding RNAs that have recently been recognized as key post-transcriptional modulators of gene expression;and they are involved in many biological processes in plants, such as root growth and development. The miRNAs regulate root elongation, lateral root(LR) formation and adventitious root(AR) development in response to hormone signaling, nutrient uptake and biotic/abiotic stress. This review provides multiple perspectives on the involvement of miRNAs in regulating root growth and development in plants. We also discuss several crucial mechanisms of miRNAs, their relationships with transcription factors and the target gene-mediated hormone signaling interactions in the regulation of root growth and development.展开更多
Given the consistent release of zinc oxide(ZnO)nanoparticles into the environment,it is urgent to study their impact on plants in depth.In this study,grains of rice were treated with two different concentrations of Zn...Given the consistent release of zinc oxide(ZnO)nanoparticles into the environment,it is urgent to study their impact on plants in depth.In this study,grains of rice were treated with two different concentrations of ZnO nanoparticles(NP-ZnO,10 and 100 mg/L),and their bulk counterpart(B-ZnO)were used to evaluate whether ZnO action could depend on particle size.To test this hypothesis,root growth and development assessment,oxidative stress parameters,indole-3-acetic acid(IAA)content and molecules/enzymes involved in IAA metabolism were analyzed.In situ localization of Zn in control and treated roots was also performed.Though Zn was visible inside root cells only following nanoparticle treatment,both materials(NP-ZnO and B-ZnO)were able to affect seedling growth and root morphology,with alteration in the concentration/pattern of localization of oxidative stress markers and with a different action depending on particle size.In addition,only ZnO supplied as bulk material induced a significant increase in both IAA concentration and lateral root density,supporting our hypothesis that bulk particles might enhance lateral root development through the rise of IAA concentration.Apparently,IAA concentration was influenced more by the activity of the catabolic peroxidases than by the protective action of phenols.展开更多
Poplar is one of the fastest-growing temperate trees in the world and is widely used in ornamental horticulture for shade.The root is essential for tree growth and development and its utilization potential is huge.Cal...Poplar is one of the fastest-growing temperate trees in the world and is widely used in ornamental horticulture for shade.The root is essential for tree growth and development and its utilization potential is huge.Calcium(Ca),as a signaling molecule,is involved in the regulation of plant root development.However,the detailed underlying regulatory mechanism is elusive.In this study,we analyzed the morphological and transcriptomic variations of 84K poplar(Populus alba×P.glandulosa)in response to different calcium concentrations and found that low Ca^(2+)(1 mmol·L^(-1))promoted lateral root development,while deficiency(0.1 mmol·L^(-1)Ca^(2+))inhibited lateral root development.Co-expression analysis showed that Ca^(2+)channel glutamate receptors(GLRs)were present in various modules with significance for root development.Two GLR paralogous genes,PagGLR3.3a and Pag GLR3.3b,were mainly expressed in roots and up-regulated under Ca^(2+)deficiency.The CRISPR/Cas9-mediated signal gene(crispr-PagGLR3.3a,PagGLR3.3b)and double gene(crispr-PagGLR3.3ab)mutants presented more and longer lateral roots.Anatomical analysis showed that crispr-PagGLR3.3ab plants had more xylem cells and promoted the development of secondary vascular tissues.Further transcriptomic analysis suggested that knockout of PagGLR3.3a and PagGLR3.3b led to the up-regulation of several genes related to protein phosphorylation,auxin efflux,lignin and hemicellulose biosynthesis as well as transcriptional regulation,which might contribute to lateral root growth.This study not only provides novel insight into how the Ca^(2+)channels mediated root growth and development in trees,but also provides a directive breeding of new poplar species for biofuel and bioenergy production.展开更多
基金the Scientific Research Foundation Especially for Doctoral Programs at Chinese Universities （20020307004） and the National Natural Science Foundation of China （30370850 and 30400280）.
文摘In order to determine whether hydrogen peroxide （H2O2） generated by polyamlne oxidative degradation Is Involved In the development of lateral roots In soybean, the length and the number of lateral roots, the actlvltlea of polyamlne oxldases and dlamlne oxldases, and the endogenous free polyamlne and H2O2 content were analyzed In soybean （Giycine max （Linn.） Merr.） main roots of 2-d-old seedlings after treatments for 2 d with exogenous β-hydroxyethylhydrazine （an Inhibitor of polyamlne oxldases）, H202, putresclne, cyclohexylamlne （an Inhibitor of spermidine synthase） or N,N＇-dimethylthlourea （a scavenger of hydrogen peroxide）.β-hydroxyethylhydrazlne treatment strongly Inhibited the development of lateral roots In soybean seedlings, reduced the activities of polyamine oxldases and dlamlne oxidases, decreased H2O2 levels, and led to the accumulation of endogenous polyamlnes In the main roots. The inhibitory effect of β-hydroxyethylhydrazlne on root development could be alleviated by exogenously applied 10 μmol/L H2O2 （a major product of polyamlne oxidation）. Treatment with cyclohexylamlne and putresclne promoted root growth slightly, but treatment with cyclohexylamlne plus N,N＇dlmethylthlourea or putresclne plus N,N＇-dlmethylthlourea prevented the development of soybean lateral roots. The effects of these treatments on the development of soybean lateral roots were consistent with the changes In endogenous H2O2 levels. These results suggest that the development of soybean lateral roots Is associated with the oxidative degradation of polyamlnes, and that their products, especially H2O2, are likely to play an Important role In the growth of soybean lateral roots.
基金supported by the National Key Research and Development Program of China(2021YFD2200505)the National Natural Science Foundation of China(32071849)。
文摘Monocot root systems comprise a large number of lateral roots to allow them to survive and colonize land.Auxin signaling pathways centered on Aux/IAA play a crucial role in lateral root development.However,in non-model monocot plants,the effects of Aux/IAA on lateral root initiation and number remain largely unknown.The present study transformed PheIAA17,a member of the Aux/IAA family of Moso bamboo,into rice and found that it significantly drove plants to produce lateral roots and improved the rooting rate.Quantitative experiments showed that PheIAA17 overexpression significantly affected the expression of ARF family members.Phylogenetic and promoter analyses indicate that PheARF3-2 belongs to class B ARF,and the promoter region contains auxin response elements.The results of yeast one-hybrid and dual-luciferase reporter assays confirmed that PheIAA17 bound specific fragments of the PheARF3-2 promoter to repress its transcriptional activity.Y2H and BiFC assay have shown that PheIAA17 and PheIAA30-3 could physically interact in vitro and in vivo.Taken together,this study reports a new molecular module centered on PheIAA17,which directs plants to alter root morphology through an increase in lateral roots.
文摘Lateral root is primary organ for plant to explore and utilize soil nutrient efficiently. The development of lateral roots (LR) is controlled by both genetic factors and nutrient status in environment. To investigate the effects of nitrate (NO3-) on rice lateral root growth and nitrogen (N) uptake efficiency under upland condition, three treatments, including root-split culture and whole plant culture in N sufficient and deficient conditions, were used in a vermiculite culture experiment. Root-split treatment showed that the growth of lateral roots was stimulated by localized nitrate supply. However, in whole plant culture, elongation of lateral roots was induced by NO3- deficiency. The effects of NO3- on rice lateral root growth were genotype-dependent. Similar N concentration, soluble sugar concentration and N content in shoot were observed in both root-split treatment and whole plant culture under NO3- sufficient condition, suggesting that the nitrogen requirement for rice normal growth could be satisfied with only half of roots supplied with NO3-. In the root-split treatment, N uptake was positively correlated with the average of lateral root length (ALRL) in NO3--supplied side, suggesting that the ALRL is important for rice root N uptake in the environment where the nitrogen nutrient is limiting factor. No significant correlation was observed between N uptake and ALRL in whole plant culture under N sufficient condition, which implies that the length of lateral roots may not be the main factor to determine tire rice root N uptake in nutrient-rich zone. Morphological and metabolic evidence in this study provided some prospects for genetic improvement of root system characters to improve the efficiency of nutrient absorption in rice.
基金Funds were provided by the National Key Research and Development Program of China (2018YFD1000900)
文摘Strigolactones(SLs)are newly discovered plant hormones which regulate the normal development of different plant organs,especially root architecture.Lateral root formation of rapeseed seedlings before winter has great effects on the plant growth and seed yield.Here,we treated the seedlings of Zhongshuang 11(ZS11),an elite conventional rapeseed cultivar,with different concentrations of GR24(a synthetic analogue of strigolactones),and found that a low concentration(0.18μmol L–1)of GR24 could significantly increase the lateral root growth,shoot growth,and root/shoot ratio of seedlings.RNA-Seq analysis of lateral roots at 12 h,1 d,4 d,and 7 d after GR24 treatment showed that 2301,4626,1595,and 783 genes were significantly differentially expressed,respectively.Function enrichment analysis revealed that the plant hormone transduction pathway,tryptophan metabolism,and the phenylpropanoid biosynthesis pathway were over-represented.Moreover,transcription factors,including AP2/ERF,AUX/IAA,NAC,MYB,and WRKY,were up-regulated at 1 d after GR24 treatment.Metabolomics profiling further demonstrated that the amounts of various metabolites,such as indole-3-acetic acid(IAA)and cis-zeatin were drastically altered.In particular,the concentrations of endogenous IAA significantly decreased by 52.4 and 75.8%at 12 h and 1 d after GR24 treatment,respectively.Our study indicated that low concentrations of exogenous SLs could promote the lateral root growth of rapeseed through interaction with other phytohormones,which provides useful clues for the effects of SLs on root architecture and crop productivity.
文摘Mutants with increased resistance to toxic anxin concentrations were first isolated in rice.The present report describes their isolation,genetics and physiological characterization.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFD0100602)the National Natural Science Foundation of China(Grant No.31901868)。
文摘Pathogen-associated molecular pattern(PAMP)-triggered immunity(PTI)is an essential layer of plant disease resistance.Robust bioassays for PTI are pre-required to dissect its molecular mechanism.In this study,we established that lateral root growth inhibition as a simple and robust measurement of PTI in rice seedlings.Specifically,flg22,a well-characterized PAMP from bacterial flagellin,was used to induce PTI in rice seedlings.While flg22 treatment induced PR gene expression and mitogen-activated protein kinase activation in the roots of rice seedlings to support the PTI triggered,this treatment substantially repressed lateral root growth,but it did not alter primary root growth.Moreover,treatments with chitin(i.e.,a fungal PAMP)and oligogalacturonides(i.e.,classical damage-associated molecular pattern)clearly inhibited the lateral root growth,although a priming step involving ulvan was required for the chitin treatment.The bioassay developed was applicable to various rice cultivars and wild species.Thus,lateral root growth inhibition represents a simple and reliable assay for studying PTI in rice plants.
基金supported by the National Natural Science Foundation of China(31421092)the Central Publicinterest Scientific Institution Basal Research Fund,China(1610232023023)。
文摘A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are still unclear.Here,maize seedlings were grown hydroponically with three N supplied in three different forms (NO_(3)^(–)only,75/25 NO_(3)^(–)/NH_(4)^(+)and NH_(4)^(+)only).Compared with sole NO_(3)^(–)or NH_(4)^(+),the mixed N supply increased the total root length of maize but did not affect the number of axial roots.The main reason was the increased total lateral root length,while the average lateral root (LR) length in each axle was only slightly increased.In addition,the average LR density of 2nd whorl crown root under mixed N was also increased.Compared with sole nitrate,mixed N could improve the N metabolism of roots (such as the N influx rate,nitrate reductase (NR) and glutamine synthase (GS)enzyme activities and total amino content of the roots).Experiments with exogenously added NR and GS inhibitors suggested that the increase in the average LR length under mixed N was related to the process of N assimilation,and whether the NR mediated NO synthesis participates in this process needs further exploration.Meanwhile,an investigation of the changes in root-shoot ratio and carbon (C) concentration showed that C transportation from shoots to roots may not be the key factor in mediating lateral root elongation,and the changes in the sugar concentration in roots further proved this conclusion.Furthermore,the synthesis and transportation of auxin in axial roots may play a key role in lateral root elongation,in which the expression of ZmPIN1B and ZmPIN9 may be involved in this pathway.This study preliminarily clarified the changes in root morphology and explored the possible physiological mechanism under a mixed N supply in maize,which may provide some theoretical basis for the cultivation of crop varieties with high N efficiency.
基金Supported by Guangxi Natural Science Funds (GSR0731021)National 863 Funds (2006AA02Z189)
文摘Rice roots include seminal roots, adventitious roots, lateral roots and root hairs, At present, progresses in the research of rice roots have been achieved in many aspects, such as root morphology, root activity, root reaction to various environmental factors as a contribution of root growth and rice yield, the relationship between root growth and stems/leaves/flowers/rice, genetic laws of root characters, etc. However, there are very few researches on lateral root mutant. This paper reviewed progresses of the lateral root mutant of rice from the perspectives of phytomorphology to plant physiology and biochemistry to the gene mapping, consisting of mechanism of developing lateral root of rice, gene cloning and functional analysis of lateral root development, the relationship between auxin and lateral roots, agronomic traits of lateral roots mutant, structure and morphology of root hairs, gravity anomaly of root, redox metabolism and proteomics researches of the mutation in lateral root of rice.
基金supported by Central Public-interest Scientific Institution Basal Research Fund,Chinese Academy of Agricultural Science(No.1610162021012)funded by DU Xiongming.
文摘Background:The lateral root is one of the most important organs that constitute the root architecture system in plants.It can directly affect the contact area between plants and soil and plays an important role in plant structural support and nutrient absorption.Optimizing root architecture systems can greatly increase crop yields.This study was designed to identify the molecular markers and candidate genes associated with lateral root development in cotton and to evaluate correlations with yield and disease traits.Result:The number of lateral roots for 14-day old seedlings was recorded for 215 Gossypium arboreum accessions.A correlation analysis showed that the number of lateral roots positively correlates with the sympodial branch node and seed index traits,but negatively correlates with lint percentage.A Genome-wide association study(GWAS)identified 18 significant SNPs with 19 candidate genes associated with the lateral root number.Expression analysis identified three genes(FLA 12,WRKY29,and RBOHA)associated with lateral root development.Conclusion:GWAS an alysis identified key SNPs and candidate gen esfor lateral root number,a nd gen es of FLA 12,WRKY29,and RBOHA may play a pivotal role in lateral root development in Asian cotton.
文摘Lateral root perforations are unfortunate procedures during endodontic treatment and often lead to tooth extraction. Conditioning factors such as time, size, location, inappropriate disinfection and sealing, are indispensable to achieve acceptable long-term outcomes. Calcium silicate cements are bioactive materials used for perforation repair. They can be set in moist environments such as blood, saliva and dentinal fluid making them a reliable material for clinical applications. This case report describes the treatment and repair after a 16-month follow-up of a lateral root perforation of the maxillary lateral incisor.
基金Supported by the Key Technology Program of the Xinjiang Uygur Autonomous Region, China (No.200733144-1)the Knowledge Innovation Project of the Chinese of Academy of Sciences (No.KSCX2-YW-N-41)
文摘The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 mmol L^-1） and three NO^-3 levels （0.05, 5, and 10 mmol L^-1） in solution culture for 30 d. Addition of NO^-3 at 10 mmol L^-1 significantly improved the shoot （P 〈 0.001） and root （P 〈 0.001） growth and the promotive effect of NO^-3 was more pronounced on root dry weight despite the high NaCl concentration in the culture solution, leading to a significant increase in the root：shoot ratio （P 〈 0.01）. Lateral root length, but not primary root length, considerably increased with increasing NaCl salinity and NO^-3 levels （P 〈 0.001）, implying that Na^＋ and NO3^- in the culture solution simultaneously stimulated lateral root growth. Concentrations of Na^＋ in plant tissues were also significantly increased by higher NaCl treatments （P 〈 0.001）. At 10 mmol L^-1 NO^-3, the concentrations of NO^-3 and total nitrogen and nitrate reductase activities in the roots were remarkably reduced by increasing salinity （P 〈 0.001）, but were unaffected in the shoots. The results indicated that the fine lateral root development and effective nitrogen uptake of the shoots might contribute to high salt tolerance of S. physophora under adequate NO^-3 supply.
基金supported by the Coordinación de la Investigación Científica UMSNH.E.C.-F.and J.A.-R.were fellows of CONACYT-México.
文摘The potential of Plant Growth Promoting Rhizobacteria(PGPR)has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield.A.brasilense produces a wide variety of molecules,including the natural auxin indole-3-acetic acid(IAA),as well as other phytoregulators.However,several studies have suggested that auxin induces changes in plant development during their interaction with the bacteria.The effects of A.brasilense Sp245 on the development of Arabidopsis thaliana root were investigated to help explain the molecular basis of the interaction.The results obtained showed a decrease in primary root length from the first day and remained so throughout the exposure,accompanied by a stimulation of initiation and maturation of lateral root primordia and an increase of lateral roots.An enhanced auxin response was evident in the vascular tissue and lateral root meristems of inoculated plants.However,after five days of bacterization,the response disappeared in the primary root meristems.The role of polar auxin transport(PAT)in auxins relocation involved the PGP1,AXR4-1,and BEN2 proteins,which apparently mediated A.brasilense-induced root branching of Arabidopsis seedlings.
基金Supported by Natural Science Foundation of Guangdong Province" Study on Molecular Mechanism of Auxin Signal Transduction "(06025819)~~
文摘[Objective]The aim was to research the function of AtGEF1 in Rac/Rop GTPses mediate auxin signal passway.[Method]Using the transgenic plants of AtGEF1 promotor fused with GUS reporter gene and the over-expression plants of Rac/Rop GEF1 under the control of 35S promoter as materials,which were constructed from our lab,the expression pattern of GEF1 was analyzed by GUS assay using histochemical staining,and the development of seedling roots of over-expression plant of GEF1 was observed.[Result]GEF1 expression was mainly detected in root meristem,root vascular tissue,lateral roots and root hair.Furthermore,the expression level of GEF1 was highly increased with the induction of NAA.Over-expression of GEF1 was observed to enhance lateral root formation.[Conclusion]GEF1 may be involved in the regulation of development of root and root hair,and it may have redundant function in the control of lateral root development.
文摘WRKY transcription factors have many regulatory roles we isolated a rice WRKY gene （OsWRKY31） that is induced in response to biotic and abiotic stresses. In this study, by the rice blast fungus Magnaporthe grisea and auxin. This gene encodes a polypeptide of 211 amino-acid residues and belongs to a subgroup of the rice WRKY gene family that probably originated after the divergence of monocot and dicot plants. OsWRKY31 was found to be localized to the nucleus of onion epidermis cells to transiently express OsWRKY31-eGFP fusion protein. Analysis of OsWRKY31 and its mutants fused with a Gal4 DNA-binding domain indicated that OsWRKY31 has transactivation activity in yeast. Overexpression of the OsWRKY31 gene was found to enhance resistance against infection with M. grisea, and the transgenic lines exhibited reduced lateral root formation and elongation compared with wild-type and RNAi plants. The lines with overexpression showed constitutive expression of many defense-related genes, such as PBZI and OsSci2, as well as early auxin-response genes, such as OslAA4 and OsCrll genes. Furthermore, the plants with overexpression were less sensitive to exogenously supplied IBA, NAA and 2,4-1） at high concentrations, suggesting that overexpression of the OsWRKY31 gene might alter the auxin response or transport. These results also suggest that OsWRKY31 might be a common component in the signal transduction pathways of the auxin response and the defense response in rice.
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）.
文摘The MT10 mutant plants had resistances to auxin.Under light and dark culture,the roots of MT10 seedlings had shown less lateral roots and short lateral roots.In soil,MT10 seedlings had shown not only no changed agronomic characteristics but also no significant difference with WT.
基金funded by the Science and Technology Department of Henan Province,China(212102110046)the State Tobacco Monopoly Administration of China(110202101005(JY-05))+1 种基金the Science and Technology Project of China National Tobacco Corporation Henan Tobacco Company,China(2018410000270095)the Undergraduate Innovation and Entrepreneurship Project of Henan Province,China(202110466042)。
文摘MicroRNAs(miRNAs) are small(ca. 20-24 nucleotides) non-coding RNAs that have recently been recognized as key post-transcriptional modulators of gene expression;and they are involved in many biological processes in plants, such as root growth and development. The miRNAs regulate root elongation, lateral root(LR) formation and adventitious root(AR) development in response to hormone signaling, nutrient uptake and biotic/abiotic stress. This review provides multiple perspectives on the involvement of miRNAs in regulating root growth and development in plants. We also discuss several crucial mechanisms of miRNAs, their relationships with transcription factors and the target gene-mediated hormone signaling interactions in the regulation of root growth and development.
基金financed by local funding of the University of Pisa。
文摘Given the consistent release of zinc oxide(ZnO)nanoparticles into the environment,it is urgent to study their impact on plants in depth.In this study,grains of rice were treated with two different concentrations of ZnO nanoparticles(NP-ZnO,10 and 100 mg/L),and their bulk counterpart(B-ZnO)were used to evaluate whether ZnO action could depend on particle size.To test this hypothesis,root growth and development assessment,oxidative stress parameters,indole-3-acetic acid(IAA)content and molecules/enzymes involved in IAA metabolism were analyzed.In situ localization of Zn in control and treated roots was also performed.Though Zn was visible inside root cells only following nanoparticle treatment,both materials(NP-ZnO and B-ZnO)were able to affect seedling growth and root morphology,with alteration in the concentration/pattern of localization of oxidative stress markers and with a different action depending on particle size.In addition,only ZnO supplied as bulk material induced a significant increase in both IAA concentration and lateral root density,supporting our hypothesis that bulk particles might enhance lateral root development through the rise of IAA concentration.Apparently,IAA concentration was influenced more by the activity of the catabolic peroxidases than by the protective action of phenols.
基金supported by the National Natural Science Foundation of China(Grant Nos.32371902,31901327)National Key Research and Development Program of China(Grant Nos.2019YFE0119100,2021YFD2200205)+1 种基金Overseas Expertise Introduction Project for Discipline Innovation(111 Project D18008)The researches foundation of Zhejiang A&F University(Grant No.2018FR013)。
文摘Poplar is one of the fastest-growing temperate trees in the world and is widely used in ornamental horticulture for shade.The root is essential for tree growth and development and its utilization potential is huge.Calcium(Ca),as a signaling molecule,is involved in the regulation of plant root development.However,the detailed underlying regulatory mechanism is elusive.In this study,we analyzed the morphological and transcriptomic variations of 84K poplar(Populus alba×P.glandulosa)in response to different calcium concentrations and found that low Ca^(2+)(1 mmol·L^(-1))promoted lateral root development,while deficiency(0.1 mmol·L^(-1)Ca^(2+))inhibited lateral root development.Co-expression analysis showed that Ca^(2+)channel glutamate receptors(GLRs)were present in various modules with significance for root development.Two GLR paralogous genes,PagGLR3.3a and Pag GLR3.3b,were mainly expressed in roots and up-regulated under Ca^(2+)deficiency.The CRISPR/Cas9-mediated signal gene(crispr-PagGLR3.3a,PagGLR3.3b)and double gene(crispr-PagGLR3.3ab)mutants presented more and longer lateral roots.Anatomical analysis showed that crispr-PagGLR3.3ab plants had more xylem cells and promoted the development of secondary vascular tissues.Further transcriptomic analysis suggested that knockout of PagGLR3.3a and PagGLR3.3b led to the up-regulation of several genes related to protein phosphorylation,auxin efflux,lignin and hemicellulose biosynthesis as well as transcriptional regulation,which might contribute to lateral root growth.This study not only provides novel insight into how the Ca^(2+)channels mediated root growth and development in trees,but also provides a directive breeding of new poplar species for biofuel and bioenergy production.
