Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes ...Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.展开更多
Strigolactones(SLs)are a new class of phytohormones that not only act as signalling molecules with external rhizospheric fungus and stimulate the seed germination of root parasite weeds,but also regulate many aspects ...Strigolactones(SLs)are a new class of phytohormones that not only act as signalling molecules with external rhizospheric fungus and stimulate the seed germination of root parasite weeds,but also regulate many aspects of plant development,such as regulating root and shoot architecture.These intriguing properties,which in turn,make SLs great potency for applications in agriculture.In this review,we highlight the recent advancements in applying SLs and their agonists or antagonists for agricultural applications,including controlling root parasite weeds,improving plant nutrient availability,and regulating abiotic stress responses.Although many SL agonists or antagonists have been synthesized since the first isolation of SL,strigol,in 1966,there is still no commercial application of this class of molecule.We also present an overview of the possible challenges for the practical application of SL agonists or antagonists.展开更多
Plant growth is controlled by integration of hormonal and light-signaling pathways. BZS1 is a B-box zinc finger protein previously characterized as a negative regulator in the brassinosteroid （BR）-signaling pathway ...Plant growth is controlled by integration of hormonal and light-signaling pathways. BZS1 is a B-box zinc finger protein previously characterized as a negative regulator in the brassinosteroid （BR）-signaling pathway and a positive regulator in the light-signaling pathway. However, the mechanisms by which BZS1/BBX20 integrates light and hormonal pathways are not fully understood. Here, using a quantitative proteomic workflow, we identified several BZSl-associated proteins, including light-signaling compo- nents COP1 and HY5. Direct interactions of BZS1 with COPI and HY5 were verified by yeast two-hybrid and co-immunoprecipitation assays. Overexpression of BZS1 causes a dwarf phenotype that is sup- pressed by the by5 mutation, while overexpression of BZSI fused with the SRDX transcription repressor domain （BZS1-SRDX） causes a long-hypocotyl phenotype similar to by5, indicating that BZSI＇s function requires HY5. BZSI positively regulates HY5 expression, whereas HY5 negatively regulates BZS1 protein level, forming a feedback loop that potentially contributes to signaling dynamics. In contrast to BR, strigolactone （SL） increases BZS1 level, whereas the SL responses of hypocoryl elongation, chlorophyll and HY5 accumulation are diminished in the BZSI-SRDX seedlings, indicating that BZS1 is involved in these SL responses. These results demonstrate that BZS1 interacts with HY5 and plays a central role in integrating light and multiple hormone signals for photomorphogenesis in Arabidopsis.展开更多
Strigolactones(SLs),which are biosynthesized mainly in roots,modulate various aspects of plant growth and development.Here,we review recent research on the role of SLs and their cross-regulation with auxin,cytokinin,a...Strigolactones(SLs),which are biosynthesized mainly in roots,modulate various aspects of plant growth and development.Here,we review recent research on the role of SLs and their cross-regulation with auxin,cytokinin,and ethylene in the modulation of root growth and development.Under nutrientsufficient conditions,SLs regulate the elongation of primary roots and inhibit adventitious root formation in eudicot plants.SLs promote the elongation of seminal roots and increase the number of adventitious roots in grass plants in the short term,while inhibiting lateral root development in both grass and eudicot plants.The effects of SLs on the elongation of root hairs are variable and depend on plant species,growth conditions,and SL concentration.Nitrogen or phosphate deficiency induces the accumulation of endogenous SLs,modulates root growth and development.Genetic analyses indicate cross-regulation of SLs with auxin,cytokinin,and ethylene in regulation of root growth and development.We discuss the implications of these studies and consider their potential for exploiting the components of SL signaling for the design of crop plants with more efficient soil-resource utilization.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
Strigolactones （SLs） are a class of plant hormones that control plant development in response to environmental conditions. In rice, mesocotyl elongation is regulated by SLs in the dark, while mesocotyls are longer i...Strigolactones （SLs） are a class of plant hormones that control plant development in response to environmental conditions. In rice, mesocotyl elongation is regulated by SLs in the dark, while mesocotyls are longer in SL deficient or insensitive mutants. SLs are perceived by DWARF14 （D14）, which is a member of a small gene family. In this study, we examined the function of another D14 family gene in rice, D14 LIKE （D14L）, focusing on mesocotyl growth. The mesocotyls of D14L RNAi lines are longer than those of WT in the dark. This phenotype is enhanced when the D14L RNAi lines are combined with the d14 mutation, suggesting that D14 and D14L work independently to inhibit mesocotyl elongation. This phenotype is alleviated by the exogenous supply of GR24, a synthetic SL, suggesting that D14L is not necessary for SL signaling. D14L mRNA is predominantly expressed in vascular bundles and crown root primordia. Our results suggest that D14L and D14 confer their effects via an SL independent pathway and an SL signaling pathway respectively.展开更多
Strigolactones(SLs)are classified into plant hormones,playing a key role as a mediator of plant growth in response to several abiotic stresses.Cadmium(Cd),a common heavy metal and soil pollutant,can suppress plant gro...Strigolactones(SLs)are classified into plant hormones,playing a key role as a mediator of plant growth in response to several abiotic stresses.Cadmium(Cd),a common heavy metal and soil pollutant,can suppress plant growth and development.In this work,we explored the effects of exogenous SLs on root formation in response to Cd stress using melon seeds subjected to seven germination treatments:CK(control),Cd(300 μmol·L^(-1) CdCl_(2)),and SL1-SL5(CdCl_(2)-stressed seeds pretreated with 0.1,0.5,1,2,and 3 μmol·L^(-1) GR24 solutions).The results indicated that SLs increased the antioxidant enzyme activities and root vigor and decreased the malondialdehyde(MDA)contents in the roots of Cdstressed melon seedlings.Then we used transcriptomic and metabolomic analyses to explore the mechanisms by which exogenous SLs protect against Cd stress.There were 242 significant differentially expressed genes(DEGs)(78 upregulated,164 downregulated)and 247 significantly differentially expressed metabolites(DEMs)(222 upregulated,25 downregulated)between the Cd and SL3 treatments.SLs altered the expression of genes related to redox formation processes,including peroxidase(POD),lipoxygenase(LOX),glutamate dehydrogenase(GDH),and glutathione S-transferase(GST).In addition,we found that SLs regulated the expression of the MYB,AP2/ERF,bHLH,and WRKY transcription factor families.The combined transcriptomic and metabolomic analyses revealed that the DEGs and DEMs involved in Cd stress alleviation were mainly related to the gene expression of jasmonic acid(JA)and flavonoid biosynthesis.SLs might induce LOX-related genes to regulate JA biosynthesis.Moreover,SLs might promote flavonoid biosynthesis by regulating eleven flavonoid-related genes and eight metabolites.The results provide a new perspective for studying the adaptation of plants to Cd stress.展开更多
A homologous gene of strigolactones repressor protein gene SMXL7/D53,MdSMXL8.2(GenBank accession No.:MD07G1222400),was cloned from‘Royal Gala’apple(Malus×domestica Borkh.)in this study.The sequence analysis rev...A homologous gene of strigolactones repressor protein gene SMXL7/D53,MdSMXL8.2(GenBank accession No.:MD07G1222400),was cloned from‘Royal Gala’apple(Malus×domestica Borkh.)in this study.The sequence analysis revealed that the length of this gene was 3243 bp,which encoded 1080 amino acids,and had a protein molecular mass of∼110 kD.The phylogenetic tree analysis indicated that the MdSMXL8.2 exhibited the highest sequence similarity with Arabidopsis AtSMXL7.The protein conserved domain analysis revealed that the MdSMXL8.2 contained two ClpA domains.The prediction of the secondary and tertiary structures of the MdSMXL8.2 indicated that it contained 34.54%αhelix,3.43%β-sheet,and 11.76%extended chain.The in-silico analysis suggested that the promoter sequence of MdSMXL8.2 contained several typical cisacting elements,including abscisic acid(ABA),gibberellin(GA),ethylene,auxin,jasmonic acid(JA),salicylic acid(SA),drought,and heat stressresponsive elements.Quantitative real-time(qRT)-PCR analyses revealed that MdSMXL8.2 was expressed in different apple tissues,with the highest transcript level found in the stem.The expression of MdSMXL8.2 was significantly induced by exogenous ABA,PEG and mannitol,while exogenous NaCl significantly inhibited MdSMXL8.2 expression.The growing status of MdSMXL8.2-overexpressed Orin apple callus was worse than the wild type(WT)after NaCl treatment and had a higher malondialdehyde(MDA)content and relative conductance(REC).Additionally,MdSMXL8.2-overexpressed Arabidopsis exhibited shorter root length and a reduction in fresh weight under salt stress,indicating that MdSMXL8.2 negatively regulated salt tolerance in apples.展开更多
Strigolactones are plant hormones with multiple functions, including regulating various aspects of plant architecture such as shoot branching, facilitating the colonization of plant roots by arbuscular mycorrhizal fun...Strigolactones are plant hormones with multiple functions, including regulating various aspects of plant architecture such as shoot branching, facilitating the colonization of plant roots by arbuscular mycorrhizal fungi, and acting as seed germination stimulants for certain parasitic plants of the family Orobanchaceae. The obligate parasitic species Phelipanche aegyptiaca and Striga hermonthica require strigolactones for germination, while the facultative parasite Triphysaria versicolor does not. It has been hypothesized that P. aegyptiaca and S. hermonthica would have undergone evolutionary loss of strigolactone biosynthesis as a part of their mechanism to enable specific detection of exogenous strigolactones. We analyzed the transcriptomes of P. aegyptiaca, S. hermonthica and T. versicolor and identified genes known to act in strigolactone synthesis (D27, CCD7, CCD8, and MAX1), perception (MAX2 and D14) and transport (PDR12). These genes were then analyzed to assess likelihood of function. Transcripts of all strigolactone-related genes were found in P. aegyptiaca and S. hermonthica, and evidence points to their encoding functional proteins. Gene open reading frames were consistent with homologs from Arabidopsis and other strigolactone-producing plants, and all genes were expressed in parasite tissues. In general, the genes related to strigolactone synthesis and perception appeared to be evolving under codon-based selective constraints in strigolactone-dependent species. Bioassays of S. hermonthica root extracts indicated the presence of strigolactone class stimulants on germination of P. aegyptiaca seeds. Taken together, these results indicate that Phelipanche aegyptiaca and S. hermonthica have retained functional genes involved in strigolactone biosynthesis, suggesting that the parasites use both endogenous and exogenous strigolactones and have mechanisms to differentiate the two.展开更多
Tea(Camellia sinensis[L.]O.Kuntze.)is an important cash crop,which mainly uses tender shoots and young leaves for manufacturing.Due to the marketing characteristic that earlier made tea has higher price,the time of th...Tea(Camellia sinensis[L.]O.Kuntze.)is an important cash crop,which mainly uses tender shoots and young leaves for manufacturing.Due to the marketing characteristic that earlier made tea has higher price,the time of the breaking of winter dormancy buds in spring is extremely important in tea industry.Strigolactones are a group of carotenoids-derived metabolites which regulates bud outgrowth,shoot branching,tiller angle and environmental stress responses.The role of strigolactones in tea plant was briefly summarized in the current review,with an emphasis of the association of strigolactones on bud ecodormancy and shoot branching.The involvement of strigolactones on the biosynthesis of the tea characteristic metabolites flavonoids,caffeine and theanine were also discussed.Moreover,recent advances on the biosynthesis of strigolactones and its regulation by microRNAs and environmental stresses were also presented.This review provides a basis for future investigations underlying the mechanisms of strigolactones on bud winter dormancy and tea secondary metabolism.展开更多
Parasitic weeds of the Orobanchaceae family cause substantial economic losses and pose significant threats to global agriculture.However,management of such parasitism is challenging,and very few resistance genes have ...Parasitic weeds of the Orobanchaceae family cause substantial economic losses and pose significant threats to global agriculture.However,management of such parasitism is challenging,and very few resistance genes have been cloned and characterized in depth.Here,we performed a genome-wide association study using 152 tomato accessions and identified SlABCG45 as a key gene that mediates host resistance to Phelipanche aegyptiaca by affecting the level of strigolactones(SLs)in root exudates.SLs are synthesized and released by host plants and act as germination stimulants for parasitic weeds.We found that SlABCG45 and its close homolog SlABCG44 were membrane-localized SL transporters with essential roles in exudation of SLs to the rhizosphere,resistance to Phelipanche and Orobanche,and upward transport of SLs from roots to shoots.As a predominant environmental stimulant exacerbates parasitism,phosphorus deficiency dramatically induced SlABCG45 expression and weakly induced SlABCG44 expression via the transcription factors SlNSP1 and SlNSP2.Knockout of SlABCG45 in tomato had little effect on yield traits in a broomrape-free field,but conferred increased resistance to different Phelipanche and Orobanche species,resulting in an30%yield increase in a Phelipanche-infested field.Our findings reveal that targeting a single gene by genome editing can confer broad-spectrum parasite resistance in tomato,providing an effective strategy for the sustainable control of parasitic plants in agriculture.展开更多
The phytoparasites of the Orobanchaceae family invade the root systems of host plants such as sorghum(Sorghum bicolor),maize(Zea mays),and tomato(Solanum lycopersicum)by producing haustoria,which competitively take up...The phytoparasites of the Orobanchaceae family invade the root systems of host plants such as sorghum(Sorghum bicolor),maize(Zea mays),and tomato(Solanum lycopersicum)by producing haustoria,which competitively take up water and nutrients from the host,ultimately causing serious yield losses(Li et al.,2023).Seed germination of phytoparasitic species is triggered by the specific perception of host-derived strigolactones(SLs),a class of phytohormone biosynthesized through the carotenoid pathway,which activate downstream signal transduction by interacting with the DWARF14(D14)receptor and its homologs,regulating critical physiological processes,such as branch development,nutrient uptake,and stress responses in various plants(Hu et al.,2024).展开更多
Coordinated morphogenic adaptation of growing plants is critical for their survival and propagation under fluctuating environments.Plant morphogenic responses to light and warm temperatures,termed photomorphogenesis a...Coordinated morphogenic adaptation of growing plants is critical for their survival and propagation under fluctuating environments.Plant morphogenic responses to light and warm temperatures,termed photomorphogenesis and thermomorphogenesis,respectively,have been extensively studied in recent decades.During photomorphogenesis,plants actively reshape their growth and developmental patterns to cope with changes in light regimes.Accordingly,photomorphogenesis is closely associated with diverse growth hormonal cues.Notably,accumulating evidence indicates that light-directed morphogenesis is profoundly affected by two recently identified phytochemicals,karrikins(KARs)and strigolactones(SLs).KARs and SLs are structurally related butenolides acting as signaling molecules during a variety of developmental steps,including seed germination.Their receptors and signaling mediators have been identified,and associated working mechanisms have been explored using gene-deficient mutants in various plant species.Of particular interest is that the KAR and SL signaling pathways play important roles in environmental responses,among which their linkages with photomorphogenesis are most comprehensively studied during seedling establishment.In this review,we focus on how the phytochemical and light signals converge on the optimization of morphogenic fitness.We also discuss molecular mechanisms underlying the signaling crosstalks with an aim of developing potential ways to improve crop productivity under climate changes.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
Researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences,with collaborators,identified two sorghum genes(SbSLT1 and SbSLT2)that block Striga-a parasitic plant,also k...Researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences,with collaborators,identified two sorghum genes(SbSLT1 and SbSLT2)that block Striga-a parasitic plant,also known as“witchweed,”that causes$1.5 billion annual losses in Africa by draining crop nutrients.Published in Cell(February 12,2025),the study shows that these genes regulate strigolactones(SLs).展开更多
With the discovery of strigolactones as root exudate signals that trigger parasitic weed seed germination, and then as a branching inhibitor and plant hormone, the next phase of strigolactone research has quickly reve...With the discovery of strigolactones as root exudate signals that trigger parasitic weed seed germination, and then as a branching inhibitor and plant hormone, the next phase of strigolactone research has quickly revealed this hormone class as a major player in optimizing plant growth and development. From the early stages of plant evolution, it seems that strigolactones were involved in enabling plants to modify growth in order to gain advantage in competi- tion with neighboring organisms for limited resources. For example, a moss plant can alter its growth in response to strigolactones emanating from a neighbor. Within a higher plant, strigolactones appear to be involved in controlling the balance of resource distribution via strategic modification of growth and development. Most notably, higher plants that encounter phosphate deficiency increase strigolactone production, which changes root growth and promotes fungal symbiosis to enhance phosphate intake. The shoot also changes by channeling resources away from unessential leaves and branches and into the main stem and root system. This hormonal response is a key adaption that radically alters whole-plant architecture in order to optimize growth and development under diverse environmental conditions.展开更多
Rice tillering,a key architecture trait determ ining grain yield,is highly regulated by a class of newly identified phytohorm ones,strigolactones(SLs).How ever,the whole SL signaling pathw ay from the receptor to dow ...Rice tillering,a key architecture trait determ ining grain yield,is highly regulated by a class of newly identified phytohorm ones,strigolactones(SLs).How ever,the whole SL signaling pathw ay from the receptor to dow nstream transcription factors to finally inhibit tillering remains unrevealed.In this study,we first found that brassinosteroids(BRs)strongly enhance tillering by prom oting bud outgrow th in rice,which is largely different from the function of BRs in Arabidopsis.Genetic and biochem ical analyses indicated that both the SL and BR signaling pathw ays control rice tillering by regulating the stability of D53 and/or the OsBZR1 RLA1-DLT module,a transcriptional complex in the rice BR signaling pathway.We further found that D53 interacts with OsBZR1 to inhibit the expression of FC1,a local inhibitor of tillering,and that this inhibition depends on direct DNA binding by OsBZR1,which recruits D53 to the FC1 promoter in rice buds.Taken together,these findings uncover a mechanism illustrating how SLs and BRs coordinately regulate rice tillering via the early responsive gene FC1.展开更多
Lodging has been a major roadblock to attaining increased crop productivity. In an attempt to understand the mechanism for culm strength in rice, we isolated an effective quantitative trait locus （QTL）, STRONG CULM3...Lodging has been a major roadblock to attaining increased crop productivity. In an attempt to understand the mechanism for culm strength in rice, we isolated an effective quantitative trait locus （QTL）, STRONG CULM3 （SCM3）, the causal gene of which is identical to rice TEOSINTE BRANCHED1 （OsTB1）, a gene previously reported to positively control strigolactone （SL） signaling. A near-isogenic line （NIL） carrying SCM3 showed enhanced culm strength and increased spikelet number despite the expected decrease in tiller number, indicating that SL also has a positive role in enhancing culm strength and spikelet number. We produced a pyramiding line carrying SCM3 and SCM2, another QTL encoding AP01 involved in panicle development. The NIL-SCM2＋SCM3 showed a much stronger culm than NIL-SCM2 and NIL-SCM3 and an increased spikelet number caused by the additive effect of these QTLs. We discuss the importance of utilizing suitable alleles of these STRONG CULM QTLs without inducing detrimental traits for breeding.展开更多
Because plants are sessile organisms,the ability to adapt to a wide range of environmental conditions is critical for their survival.As a consequence,plants use hormones to regulate growth,mitigate biotic and abiotic ...Because plants are sessile organisms,the ability to adapt to a wide range of environmental conditions is critical for their survival.As a consequence,plants use hormones to regulate growth,mitigate biotic and abiotic stresses,and to communicate with other organisms.Many plant hormones function plei-otropically in vivo,and often work in tandem with other hormones that are chemically distinct.A newly-defined class of plant hormones,the strigolactones,cooperate with auxins and cytokinins to control shoot branching and the outgrowth of lateral buds.Strigolactones were originally identified as compounds that stimulated the germination of parasitic plant seeds,and were also demonstrated to induce hyphal branching in arbuscular mycorrhizal(AM) fungi.AM fungi form symbioses with higher plant roots and mainly facilitate the absorption of phosphate from the soil.Conforming to the classical definition of a plant hormone,strigolactones are produced in the roots and translocated to the shoots where they inhibit shoot outgrowth and branching.The biosynthesis of this class of compounds is regulated by soil nutrient availability,i.e.the plant will increase its production of strigolactones when the soil phosphate concentration is limited,and decrease production when phosphates are in ample supply.Strigolactones that affect plant shoot branching,AM fungal hyphal branching,and seed germination in parasitic plants facilitate chemical synthesis of similar compounds to control these and other biological processes by exogenous application.展开更多
基金supported by the National Natural Science Foundation of China (32170367 and 32000146)the Fundamental Research Funds for the Central Universities, China (2021TS066 and GK202103063)the Excellent Graduate Training Program of Shaanxi Normal University, China (LHRCCX23181).
文摘Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.
基金funding support by the National Natural Science Foundation of China(No.22077072 and 21837001)the Frontiers Science Center for New Organic Matter of Nankai University(No.63181206)the Haihe Laboratory of Sustainable Chemical Transformations(No.YYJC202102).
文摘Strigolactones(SLs)are a new class of phytohormones that not only act as signalling molecules with external rhizospheric fungus and stimulate the seed germination of root parasite weeds,but also regulate many aspects of plant development,such as regulating root and shoot architecture.These intriguing properties,which in turn,make SLs great potency for applications in agriculture.In this review,we highlight the recent advancements in applying SLs and their agonists or antagonists for agricultural applications,including controlling root parasite weeds,improving plant nutrient availability,and regulating abiotic stress responses.Although many SL agonists or antagonists have been synthesized since the first isolation of SL,strigol,in 1966,there is still no commercial application of this class of molecule.We also present an overview of the possible challenges for the practical application of SL agonists or antagonists.
基金supported by a grant from National Institute of Health (NIH, R01GM066258)“One-hundred Talents Project” of Hebei province, China (E2013100004)supported by the China Scholarship Council
文摘Plant growth is controlled by integration of hormonal and light-signaling pathways. BZS1 is a B-box zinc finger protein previously characterized as a negative regulator in the brassinosteroid （BR）-signaling pathway and a positive regulator in the light-signaling pathway. However, the mechanisms by which BZS1/BBX20 integrates light and hormonal pathways are not fully understood. Here, using a quantitative proteomic workflow, we identified several BZSl-associated proteins, including light-signaling compo- nents COP1 and HY5. Direct interactions of BZS1 with COPI and HY5 were verified by yeast two-hybrid and co-immunoprecipitation assays. Overexpression of BZS1 causes a dwarf phenotype that is sup- pressed by the by5 mutation, while overexpression of BZSI fused with the SRDX transcription repressor domain （BZS1-SRDX） causes a long-hypocotyl phenotype similar to by5, indicating that BZSI＇s function requires HY5. BZSI positively regulates HY5 expression, whereas HY5 negatively regulates BZS1 protein level, forming a feedback loop that potentially contributes to signaling dynamics. In contrast to BR, strigolactone （SL） increases BZS1 level, whereas the SL responses of hypocoryl elongation, chlorophyll and HY5 accumulation are diminished in the BZSI-SRDX seedlings, indicating that BZS1 is involved in these SL responses. These results demonstrate that BZS1 interacts with HY5 and plays a central role in integrating light and multiple hormone signals for photomorphogenesis in Arabidopsis.
基金funded by the National Natural Science Foundation of China(31601821 and 31770300)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA28110100)+1 种基金the National Key Research and Development Program of China(2018YFE0194000,2018YFD0100304,2016YFD0101006)the Special Fund for Henan Agriculture Research System(HARS-22-03-G3)。
文摘Strigolactones(SLs),which are biosynthesized mainly in roots,modulate various aspects of plant growth and development.Here,we review recent research on the role of SLs and their cross-regulation with auxin,cytokinin,and ethylene in the modulation of root growth and development.Under nutrientsufficient conditions,SLs regulate the elongation of primary roots and inhibit adventitious root formation in eudicot plants.SLs promote the elongation of seminal roots and increase the number of adventitious roots in grass plants in the short term,while inhibiting lateral root development in both grass and eudicot plants.The effects of SLs on the elongation of root hairs are variable and depend on plant species,growth conditions,and SL concentration.Nitrogen or phosphate deficiency induces the accumulation of endogenous SLs,modulates root growth and development.Genetic analyses indicate cross-regulation of SLs with auxin,cytokinin,and ethylene in regulation of root growth and development.We discuss the implications of these studies and consider their potential for exploiting the components of SL signaling for the design of crop plants with more efficient soil-resource utilization.
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.
基金supported by a grant from the Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN) of Japan to J.K
文摘Strigolactones （SLs） are a class of plant hormones that control plant development in response to environmental conditions. In rice, mesocotyl elongation is regulated by SLs in the dark, while mesocotyls are longer in SL deficient or insensitive mutants. SLs are perceived by DWARF14 （D14）, which is a member of a small gene family. In this study, we examined the function of another D14 family gene in rice, D14 LIKE （D14L）, focusing on mesocotyl growth. The mesocotyls of D14L RNAi lines are longer than those of WT in the dark. This phenotype is enhanced when the D14L RNAi lines are combined with the d14 mutation, suggesting that D14 and D14L work independently to inhibit mesocotyl elongation. This phenotype is alleviated by the exogenous supply of GR24, a synthetic SL, suggesting that D14L is not necessary for SL signaling. D14L mRNA is predominantly expressed in vascular bundles and crown root primordia. Our results suggest that D14L and D14 confer their effects via an SL independent pathway and an SL signaling pathway respectively.
基金supported by the National Key Research and Development ProgramofChina(GrantNo.2020YFD1000300)China Agriculture Research System of MOF and MARA(Grant No.CARS-25)+1 种基金the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(Grant No.CAASASTIP-IVFCAAS)Central Public-interest Scientific Institution Basal Research Fund(Grant No.IVF-BRF2022006).
文摘Strigolactones(SLs)are classified into plant hormones,playing a key role as a mediator of plant growth in response to several abiotic stresses.Cadmium(Cd),a common heavy metal and soil pollutant,can suppress plant growth and development.In this work,we explored the effects of exogenous SLs on root formation in response to Cd stress using melon seeds subjected to seven germination treatments:CK(control),Cd(300 μmol·L^(-1) CdCl_(2)),and SL1-SL5(CdCl_(2)-stressed seeds pretreated with 0.1,0.5,1,2,and 3 μmol·L^(-1) GR24 solutions).The results indicated that SLs increased the antioxidant enzyme activities and root vigor and decreased the malondialdehyde(MDA)contents in the roots of Cdstressed melon seedlings.Then we used transcriptomic and metabolomic analyses to explore the mechanisms by which exogenous SLs protect against Cd stress.There were 242 significant differentially expressed genes(DEGs)(78 upregulated,164 downregulated)and 247 significantly differentially expressed metabolites(DEMs)(222 upregulated,25 downregulated)between the Cd and SL3 treatments.SLs altered the expression of genes related to redox formation processes,including peroxidase(POD),lipoxygenase(LOX),glutamate dehydrogenase(GDH),and glutathione S-transferase(GST).In addition,we found that SLs regulated the expression of the MYB,AP2/ERF,bHLH,and WRKY transcription factor families.The combined transcriptomic and metabolomic analyses revealed that the DEGs and DEMs involved in Cd stress alleviation were mainly related to the gene expression of jasmonic acid(JA)and flavonoid biosynthesis.SLs might induce LOX-related genes to regulate JA biosynthesis.Moreover,SLs might promote flavonoid biosynthesis by regulating eleven flavonoid-related genes and eight metabolites.The results provide a new perspective for studying the adaptation of plants to Cd stress.
基金This study was financially supported by the Shandong Province(Grant No.2019LZGC007,SDAIT-06-03)National Natural Science Foundation of China(Grant No.31430074,U1706202)National Modern Apple Industry Technology System of China(Grant No.CARS-27).
文摘A homologous gene of strigolactones repressor protein gene SMXL7/D53,MdSMXL8.2(GenBank accession No.:MD07G1222400),was cloned from‘Royal Gala’apple(Malus×domestica Borkh.)in this study.The sequence analysis revealed that the length of this gene was 3243 bp,which encoded 1080 amino acids,and had a protein molecular mass of∼110 kD.The phylogenetic tree analysis indicated that the MdSMXL8.2 exhibited the highest sequence similarity with Arabidopsis AtSMXL7.The protein conserved domain analysis revealed that the MdSMXL8.2 contained two ClpA domains.The prediction of the secondary and tertiary structures of the MdSMXL8.2 indicated that it contained 34.54%αhelix,3.43%β-sheet,and 11.76%extended chain.The in-silico analysis suggested that the promoter sequence of MdSMXL8.2 contained several typical cisacting elements,including abscisic acid(ABA),gibberellin(GA),ethylene,auxin,jasmonic acid(JA),salicylic acid(SA),drought,and heat stressresponsive elements.Quantitative real-time(qRT)-PCR analyses revealed that MdSMXL8.2 was expressed in different apple tissues,with the highest transcript level found in the stem.The expression of MdSMXL8.2 was significantly induced by exogenous ABA,PEG and mannitol,while exogenous NaCl significantly inhibited MdSMXL8.2 expression.The growing status of MdSMXL8.2-overexpressed Orin apple callus was worse than the wild type(WT)after NaCl treatment and had a higher malondialdehyde(MDA)content and relative conductance(REC).Additionally,MdSMXL8.2-overexpressed Arabidopsis exhibited shorter root length and a reduction in fresh weight under salt stress,indicating that MdSMXL8.2 negatively regulated salt tolerance in apples.
文摘Strigolactones are plant hormones with multiple functions, including regulating various aspects of plant architecture such as shoot branching, facilitating the colonization of plant roots by arbuscular mycorrhizal fungi, and acting as seed germination stimulants for certain parasitic plants of the family Orobanchaceae. The obligate parasitic species Phelipanche aegyptiaca and Striga hermonthica require strigolactones for germination, while the facultative parasite Triphysaria versicolor does not. It has been hypothesized that P. aegyptiaca and S. hermonthica would have undergone evolutionary loss of strigolactone biosynthesis as a part of their mechanism to enable specific detection of exogenous strigolactones. We analyzed the transcriptomes of P. aegyptiaca, S. hermonthica and T. versicolor and identified genes known to act in strigolactone synthesis (D27, CCD7, CCD8, and MAX1), perception (MAX2 and D14) and transport (PDR12). These genes were then analyzed to assess likelihood of function. Transcripts of all strigolactone-related genes were found in P. aegyptiaca and S. hermonthica, and evidence points to their encoding functional proteins. Gene open reading frames were consistent with homologs from Arabidopsis and other strigolactone-producing plants, and all genes were expressed in parasite tissues. In general, the genes related to strigolactone synthesis and perception appeared to be evolving under codon-based selective constraints in strigolactone-dependent species. Bioassays of S. hermonthica root extracts indicated the presence of strigolactone class stimulants on germination of P. aegyptiaca seeds. Taken together, these results indicate that Phelipanche aegyptiaca and S. hermonthica have retained functional genes involved in strigolactone biosynthesis, suggesting that the parasites use both endogenous and exogenous strigolactones and have mechanisms to differentiate the two.
基金This work was financially supported by the China Postdoctoral Science Foundation(2018M632821)the Open Fund of State Key Laboratory of Tea Plant Biology and Utilization(SKLTOF 20180105)+3 种基金China agriculture research system(CARS-19)Hubei Natural Science Foundation Project(2019CFB178)Natural Science Foundation of Hubei Academy of Agricultural Sciences(2021NKYJJ13)the Agricultural Science and Technology Innovation Project of Hubei Province(2019-620-000-001-24).
文摘Tea(Camellia sinensis[L.]O.Kuntze.)is an important cash crop,which mainly uses tender shoots and young leaves for manufacturing.Due to the marketing characteristic that earlier made tea has higher price,the time of the breaking of winter dormancy buds in spring is extremely important in tea industry.Strigolactones are a group of carotenoids-derived metabolites which regulates bud outgrowth,shoot branching,tiller angle and environmental stress responses.The role of strigolactones in tea plant was briefly summarized in the current review,with an emphasis of the association of strigolactones on bud ecodormancy and shoot branching.The involvement of strigolactones on the biosynthesis of the tea characteristic metabolites flavonoids,caffeine and theanine were also discussed.Moreover,recent advances on the biosynthesis of strigolactones and its regulation by microRNAs and environmental stresses were also presented.This review provides a basis for future investigations underlying the mechanisms of strigolactones on bud winter dormancy and tea secondary metabolism.
基金supported by grants from the National Natural Science Foundation of China(32122012,31788103)CAS Project for Young Scientists in Basic Research(YSBR-078)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB1090201)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2023025).
文摘Parasitic weeds of the Orobanchaceae family cause substantial economic losses and pose significant threats to global agriculture.However,management of such parasitism is challenging,and very few resistance genes have been cloned and characterized in depth.Here,we performed a genome-wide association study using 152 tomato accessions and identified SlABCG45 as a key gene that mediates host resistance to Phelipanche aegyptiaca by affecting the level of strigolactones(SLs)in root exudates.SLs are synthesized and released by host plants and act as germination stimulants for parasitic weeds.We found that SlABCG45 and its close homolog SlABCG44 were membrane-localized SL transporters with essential roles in exudation of SLs to the rhizosphere,resistance to Phelipanche and Orobanche,and upward transport of SLs from roots to shoots.As a predominant environmental stimulant exacerbates parasitism,phosphorus deficiency dramatically induced SlABCG45 expression and weakly induced SlABCG44 expression via the transcription factors SlNSP1 and SlNSP2.Knockout of SlABCG45 in tomato had little effect on yield traits in a broomrape-free field,but conferred increased resistance to different Phelipanche and Orobanche species,resulting in an30%yield increase in a Phelipanche-infested field.Our findings reveal that targeting a single gene by genome editing can confer broad-spectrum parasite resistance in tomato,providing an effective strategy for the sustainable control of parasitic plants in agriculture.
基金supported by the National Natural Science Foundation of China(32470364 and 32370321)the Natural Science Basic Research Program of Shaanxi(2025JC-JCQN-056 and 2024JC-YBMS-151)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2025A1515012749)the Shaanxi Fundamental Science Research Project for Chemistry&Biology(22JHQ054 and 22JHZ007)the Fundamental Research Funds for the Central Universities(D5000230089).
文摘The phytoparasites of the Orobanchaceae family invade the root systems of host plants such as sorghum(Sorghum bicolor),maize(Zea mays),and tomato(Solanum lycopersicum)by producing haustoria,which competitively take up water and nutrients from the host,ultimately causing serious yield losses(Li et al.,2023).Seed germination of phytoparasitic species is triggered by the specific perception of host-derived strigolactones(SLs),a class of phytohormone biosynthesized through the carotenoid pathway,which activate downstream signal transduction by interacting with the DWARF14(D14)receptor and its homologs,regulating critical physiological processes,such as branch development,nutrient uptake,and stress responses in various plants(Hu et al.,2024).
基金supported by the Leaping Research Program(NRF-2021R1A2B5B03001476 to C.M.P.)provided by the National Research Foundation(NRF)of Koreaa grant from Kyung Hee University in 2023(KHU-20230886 to Y.J.P.).
文摘Coordinated morphogenic adaptation of growing plants is critical for their survival and propagation under fluctuating environments.Plant morphogenic responses to light and warm temperatures,termed photomorphogenesis and thermomorphogenesis,respectively,have been extensively studied in recent decades.During photomorphogenesis,plants actively reshape their growth and developmental patterns to cope with changes in light regimes.Accordingly,photomorphogenesis is closely associated with diverse growth hormonal cues.Notably,accumulating evidence indicates that light-directed morphogenesis is profoundly affected by two recently identified phytochemicals,karrikins(KARs)and strigolactones(SLs).KARs and SLs are structurally related butenolides acting as signaling molecules during a variety of developmental steps,including seed germination.Their receptors and signaling mediators have been identified,and associated working mechanisms have been explored using gene-deficient mutants in various plant species.Of particular interest is that the KAR and SL signaling pathways play important roles in environmental responses,among which their linkages with photomorphogenesis are most comprehensively studied during seedling establishment.In this review,we focus on how the phytochemical and light signals converge on the optimization of morphogenic fitness.We also discuss molecular mechanisms underlying the signaling crosstalks with an aim of developing potential ways to improve crop productivity under climate changes.
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.
文摘Researchers from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences,with collaborators,identified two sorghum genes(SbSLT1 and SbSLT2)that block Striga-a parasitic plant,also known as“witchweed,”that causes$1.5 billion annual losses in Africa by draining crop nutrients.Published in Cell(February 12,2025),the study shows that these genes regulate strigolactones(SLs).
文摘With the discovery of strigolactones as root exudate signals that trigger parasitic weed seed germination, and then as a branching inhibitor and plant hormone, the next phase of strigolactone research has quickly revealed this hormone class as a major player in optimizing plant growth and development. From the early stages of plant evolution, it seems that strigolactones were involved in enabling plants to modify growth in order to gain advantage in competi- tion with neighboring organisms for limited resources. For example, a moss plant can alter its growth in response to strigolactones emanating from a neighbor. Within a higher plant, strigolactones appear to be involved in controlling the balance of resource distribution via strategic modification of growth and development. Most notably, higher plants that encounter phosphate deficiency increase strigolactone production, which changes root growth and promotes fungal symbiosis to enhance phosphate intake. The shoot also changes by channeling resources away from unessential leaves and branches and into the main stem and root system. This hormonal response is a key adaption that radically alters whole-plant architecture in order to optimize growth and development under diverse environmental conditions.
基金This work was supported by grants from NNSFC(31430046 to X.W.),NKRDP(2016YFD0100403 to S.S.,2016YFD0100700 to Z.F.),ICPNNSFC(31661143024 to X.W.),MAITP(0120150092 to X.W.)School Independent Scientific and Technological Innovation Foundation and Research Startup Foundation of Huazhong Agricultural University(2662015PY020,2014RC002 to X.W.).
文摘Rice tillering,a key architecture trait determ ining grain yield,is highly regulated by a class of newly identified phytohorm ones,strigolactones(SLs).How ever,the whole SL signaling pathw ay from the receptor to dow nstream transcription factors to finally inhibit tillering remains unrevealed.In this study,we first found that brassinosteroids(BRs)strongly enhance tillering by prom oting bud outgrow th in rice,which is largely different from the function of BRs in Arabidopsis.Genetic and biochem ical analyses indicated that both the SL and BR signaling pathw ays control rice tillering by regulating the stability of D53 and/or the OsBZR1 RLA1-DLT module,a transcriptional complex in the rice BR signaling pathway.We further found that D53 interacts with OsBZR1 to inhibit the expression of FC1,a local inhibitor of tillering,and that this inhibition depends on direct DNA binding by OsBZR1,which recruits D53 to the FC1 promoter in rice buds.Taken together,these findings uncover a mechanism illustrating how SLs and BRs coordinately regulate rice tillering via the early responsive gene FC1.
文摘Lodging has been a major roadblock to attaining increased crop productivity. In an attempt to understand the mechanism for culm strength in rice, we isolated an effective quantitative trait locus （QTL）, STRONG CULM3 （SCM3）, the causal gene of which is identical to rice TEOSINTE BRANCHED1 （OsTB1）, a gene previously reported to positively control strigolactone （SL） signaling. A near-isogenic line （NIL） carrying SCM3 showed enhanced culm strength and increased spikelet number despite the expected decrease in tiller number, indicating that SL also has a positive role in enhancing culm strength and spikelet number. We produced a pyramiding line carrying SCM3 and SCM2, another QTL encoding AP01 involved in panicle development. The NIL-SCM2＋SCM3 showed a much stronger culm than NIL-SCM2 and NIL-SCM3 and an increased spikelet number caused by the additive effect of these QTLs. We discuss the importance of utilizing suitable alleles of these STRONG CULM QTLs without inducing detrimental traits for breeding.
基金Supported by the National Natural Science Foundation of China (Grant No. 30623011)
文摘Because plants are sessile organisms,the ability to adapt to a wide range of environmental conditions is critical for their survival.As a consequence,plants use hormones to regulate growth,mitigate biotic and abiotic stresses,and to communicate with other organisms.Many plant hormones function plei-otropically in vivo,and often work in tandem with other hormones that are chemically distinct.A newly-defined class of plant hormones,the strigolactones,cooperate with auxins and cytokinins to control shoot branching and the outgrowth of lateral buds.Strigolactones were originally identified as compounds that stimulated the germination of parasitic plant seeds,and were also demonstrated to induce hyphal branching in arbuscular mycorrhizal(AM) fungi.AM fungi form symbioses with higher plant roots and mainly facilitate the absorption of phosphate from the soil.Conforming to the classical definition of a plant hormone,strigolactones are produced in the roots and translocated to the shoots where they inhibit shoot outgrowth and branching.The biosynthesis of this class of compounds is regulated by soil nutrient availability,i.e.the plant will increase its production of strigolactones when the soil phosphate concentration is limited,and decrease production when phosphates are in ample supply.Strigolactones that affect plant shoot branching,AM fungal hyphal branching,and seed germination in parasitic plants facilitate chemical synthesis of similar compounds to control these and other biological processes by exogenous application.
