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
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
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
Lateral roots play essential roles in drought tolerance in maize(Zea mays L.). However, the genetic basis for the variation in the number of lateral roots in maize remains elusive. Here, we identified a major quantita...Lateral roots play essential roles in drought tolerance in maize(Zea mays L.). However, the genetic basis for the variation in the number of lateral roots in maize remains elusive. Here, we identified a major quantitative trait locus(QTL),q LRT5-1, controlling lateral root number using a recombinant inbred population from a cross between the maize lines Zong3(with many lateral roots) and 87-1(with few lateral roots).Fine-mapping and functional analysis determined that the candidate gene for qLRT5-1,ZmLRT, expresses the primary transcript for the microRNA miR166a. ZmLRT was highly expressed in root tips and lateral root primordia,and knockout and overexpression of ZmLRT increased and decreased lateral root number,respectively. Compared with 87-1, the ZmLRT gene model of Zong3 lacked the second and third exons and contained a 14 bp deletion at the junction between the first exon and intron,which altered the splicing site. In addition,ZmLRT expression was significantly lower in Zong3 than in 87-1, which might be attributed to the insertions of a transposon and over large DNA fragments in the Zong3 ZmLRT promoter region. These mutations decreased the abundance of mature miR166a in Zong3, resulting in increased lateral roots at the seedling stage.Furthermore, miR166a post-transcriptionally repressed five development-related class-Ⅲ homeodomain-leucine zipper genes. Moreover,knockout of ZmLRT enhanced drought tolerance of maize seedlings. Our study furthers our understanding of the genetic basis of lateral root number variation in maize and highlights ZmLRT as a target for improving drought tolerance in maize.展开更多
Objective: The content of saikosaponins in genus Bupleurum is increased with numbers of lateral root, but the genetic mechanisms are largely unknown. This study aims to identify the heme oxygenase(HO) gene family memb...Objective: The content of saikosaponins in genus Bupleurum is increased with numbers of lateral root, but the genetic mechanisms are largely unknown. This study aims to identify the heme oxygenase(HO) gene family members of B. chinense and B. scorzonerifolium, and assess their role in the root development in Bupleurum.Methods: The gene sequences of HO family were selected from iso-seq full-length transcriptome data of B. chinense and B. scorzonerifolium, and were analyzed in physicochemical properties, conserved domains,motifs and phylogenetic relationship. In addition, the expression patterns of HO gene in different parts of roots were compared via transcriptome sequencing and qRT-PCR in the two species.Results: Five Bupleurum HO genes(BcHO1-BcHO5) belonging to the HO1 subfamily were identified from the transcriptome data, whereas the HO_(2) subfamily member was not identified. The expression levels of BcHO1 and BcHO_(2) were significantly higher than those of other three HO members in the transcriptome analysis. In addition, the expression profile of BcHO1 showed consistency with lateral root development in B. chinense and B. scorzonerifolium.Conclusion: Hos might participate in the auxin-induced morphogenesis of lateral roots. The yield of saikosaponin may be improved by manipulating expression of these genes.展开更多
Plant root system morphology is dramatically influenced by various environmental cues. The adaptation of root system architecture to environmental constraints, which mostly depends on the formation and growth of later...Plant root system morphology is dramatically influenced by various environmental cues. The adaptation of root system architecture to environmental constraints, which mostly depends on the formation and growth of lateral roots, is an important agronomic trait. Lateral root development is regulated by the external signals coordinating closely with intrinsic signaling pathways. MADS-box transcription factors are known key regulators of the transition to flowering and flower development. However, their functions in root development are still poorly understood. Here we report that AGL21, an AGL17-clade MADS-box gene, plays a crucial role in lateral root development. AGL21 was highly expressed in root, particularly in the root central cylinder and lateral root primordia. AGL21 overexpression plants produced more and longer lateral roots while ag121 mutants showed impaired lateral root development, especially under nitrogen-deficient conditions. AGL21 was induced by many plant hormones and environmental stresses, suggesting a function of this gene in root system plasticity in response to various signals. Furthermore, AGL21 was found positively regulating auxin accumulation in lateral root primordia and lateral roots by enhancing local auxin biosynthesis, thus stimulating lateral root initiation and growth. We propose that AGL21 may be involved in various environmental and physiological signals-mediated lateral root development and growth.展开更多
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
Lateral roots are important to plants for the uptake of nutrients and water. Several members of the Aux/IAA family have been shown to play crucial roles in lateral root development. Here, a member of the rice Aux/IAA ...Lateral roots are important to plants for the uptake of nutrients and water. Several members of the Aux/IAA family have been shown to play crucial roles in lateral root development. Here, a member of the rice Aux/IAA family genes, OslAA 11 (LOC_Os03g43400), was isolated from a rice mutant defective in lateral root development. The gain-of-function mutation in OslAAll strictly blocks the initiation of lateral root primordia, but it does not affect crown root development. The expression of OslAAll is defined in root tips, lateral root caps, steles, and lateral root primordia. The auxin reporter DR5-GUS (^-glucuronidase) was expressed at lower levels in the mutant than in wild-type, indicating that OslAAll is involved in auxin signaling in root caps. The transcript abundance of both OsPINlb and OsPIN10a was diminished in root tips of the Osiaa 11 mutant. Taken together, the results indicate that the gain-of-function mutation in OslAA 11 caused the inhibition of lateral root development in rice.展开更多
Auxin plays a critical role in lateral root(LR)formation.The signaling module composed of auxin-response factors(ARFs)and lateral organ boundaries domain transcription factors mediates auxin signaling to control almos...Auxin plays a critical role in lateral root(LR)formation.The signaling module composed of auxin-response factors(ARFs)and lateral organ boundaries domain transcription factors mediates auxin signaling to control almost every stage of LR development.Here,we show that auxin-induced degradation of the APETALA2/Ethylene Responsive Factor(AP2/ERF)transcription factor ERF13,dependent on MITOGENACTIVATED PROTEIN KINASE MPK14-mediated phosphorylation,plays an essential role in LR development.Overexpression of ERF13 results in restricted passage of the LR primordia through the endodermal layer,greatly reducing LR emergence,whereas the erf13 mutants showed an increase in emerged LR.ERF13 inhibits the expression of 3-ketoacyl-CoA synthase16(KCS16),which encodes a fatty acid elongase involved in very-long-chain fatty acid(VLCFA)biosynthesis.Overexpression of KCS16 or exogenous VLCFA treatment rescues the LR emergence defects in ERF13 overexpression lines,indicating a role downstream of the auxin-MPK14-ERF13 signaling module.Collectively,our study uncovers a novel molecular mechanism by which MPK14-mediated auxin signaling modulates LR development via ERF13-regulated VLCFA biosynthesis.展开更多
Carbon monoxide (CO), an odorless, tasteless and colorless gas, has recently proved to be an important bioactive or signal molecule in mammalian cells, with its effects mediated mainly by nitric oxide (NO). In the...Carbon monoxide (CO), an odorless, tasteless and colorless gas, has recently proved to be an important bioactive or signal molecule in mammalian cells, with its effects mediated mainly by nitric oxide (NO). In the present report, we show that exogenous CO induces lateral root (LR) formation, an NO-dependent process. Administration of the CO donor hematin to rapeseed (Brassica napus L. Yangyou 6) seedlings for 3 days, dose-dependently promoted the total length and number of LRs. These responses were also seen following the application of gaseous CO aqueous solutions of different saturated concentrations. Furthermore, the actions of CO on seedlings were fully reversed when the CO scavenger hemoglobin (Hb) or the CO-specific synthetic inhibitor zinc protoporphyrin-IX(ZnPPIX) were added. Interestingly, depletion of endogenous NO using its specific scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO) or the nitric oxide synthase (NOS) inhibitor N^G-nitro-L-arginine methyl ester (L-NAME), led to the complete abolition of LR development, illustrating an important role for endogenous NO in the action of CO on LR formation. However, the induction of LR development by 200 μmol/L sodium nitroprusside (SNP), an NO donor, was not affected by the presence or absence of ZnPPIX. Furthermore, using an anatomical approach combined with laser scanning confocal microscopy with the NO-specific fluorophore 4,5-diaminofluorescein diacetate, we observed that both hematin and SNP increased NO release compared with control samples and that the NO signal was mainly distributed in the LR primordia (LRP), especially after 36 h treatment. The LRP were found to have similar morphology in control, SNP- and hematin-treated seedlings. Similarly, the enhancement of the NO signal by CO at 36 h was differentially quenched by the addition of cPTIO, L-NAME, ZnPPIX and Hb. In contrast, the induction of NO caused by SNP was not affected by the application of ZnPPIX. Therefore, we further deduced that CO induces LR formation probably mediated by the NO/NOS pathway and NO may act downstream of CO signaling, which has also been shown to occur in animals.展开更多
Root branching or lateral root formation is crucial to maximize a root system acquiring nutrients and water from soil. A lateral root (LR) arises from asymmetric cell division of founder cells (FCs) in a pre-branc...Root branching or lateral root formation is crucial to maximize a root system acquiring nutrients and water from soil. A lateral root (LR) arises from asymmetric cell division of founder cells (FCs) in a pre-branch site of the primary root, and FC establishment is essential for lateral root formation. FCs are known to be specified from xylem pole pericycle cells, but the molecular genetic mechanisms underlying FC establishment are unclear. Here, we report that, in Arabidopsis thaliana, a PRC2 (for Polycomb repressive complex 2) histone H3 lysine-27 (H3K27) methyltransferase complex, functions to inhibit FC establishment during LR initiation. We found that functional loss of the PRC2 subunits EMF2 (for EMBRYONIC FLOWER 2) or CLF (for CURLY LEAF) leads to a great increase in the number of LRs formed in the primary root. The CLF H3K27 methyltransferase binds to chromatin of the auxin efflux carrier gene PIN FORMED 1 (PIN1), deposits the repres- sive mark H3K27me3 to repress its expression, and functions to down-regulate auxin maxima in root tissues and inhibit FC establishment. Our findings collectively suggest that EMF2-CLF PRC2 acts to down-regulate root auxin maxima and show that this complex represses LR formation in Arabidopsis.展开更多
Abstract: Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition. Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under condi...Abstract: Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition. Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under conditions of low phosphorus availability, the length of cells in the meristem zone of the lateral roots was longer, but the length of cells in the elongation and mature zones of the lateral roots was shorter, compared with seedlings grown under conditions of high phosphorus availability. The elongation rates of primary roots increased as phosphorus availability increased, but the elongation rates of the branched zones of the primary roots decreased. The number of lateral root primordia and the length of the lateral roots decreased as phosphorus availability increased. The topological index (altitude slope) decreased as phosphorus availability increased, suggesting that root architecture tended to be herringbone-like when seedlings were grown under conditions of low phosphate availability. Herringbone-like root systems exploit nutrients more efficiently, but they have higher construction costs than root systems with a branching pattern.展开更多
Root architecture is crucial for plants to absorb water and nutrients. We previously reported edtl (edtlD) mutant with altered root architecture that contributes significantly to drought resistance. However, the und...Root architecture is crucial for plants to absorb water and nutrients. We previously reported edtl (edtlD) mutant with altered root architecture that contributes significantly to drought resistance. However, the underlying molecular mechanisms are not well understood. Here we report one of the mechanisms underlying EDT1/HDGll- conferred altered root architecture. Root transcriptome comparison between the wild type and edtlD revealed that the upregulated genes involved in jasmonate biosynthesis and signaling pathway were enriched in edtlD root, which were confirmed by quantitative RT-PCR. Further analysis showed that EDT1/HDG11, as a transcription factor, bound directly to the HD binding sites in the promoters of AOS, AOC3, OPR3, and OPCL1, which encode four key enzymes in JA biosynthesis. We found that the jasmonic acid level was significantly elevated in edtlD root compared with that in the wild type subsequently. In addition, more auxin accumulation was observed in thelateral root primordium of edtlD compared with that of wild type. Genetic analysis of edtlD opcl1 double mutant also showed that HDGll was partially dependent on JA in regulating LR formation. Taken together, overexpression of EDT1/HDGll increases JA level in the root of edtlD by directly upregulating the expressions of several genes encoding JA biosynthesis enzymes to activate auxin signaling and promote lateral root formation.展开更多
Sugars promote lateral root formation at low levels but become inhibitory at high C/N or C/P ratios. How sugars suppress lateral root formation is unclear, however. Here we report that WOX7, a member of the WUSCHEL re...Sugars promote lateral root formation at low levels but become inhibitory at high C/N or C/P ratios. How sugars suppress lateral root formation is unclear, however. Here we report that WOX7, a member of the WUSCHEL related homeobox (WOX) family transcription factors, inhibits lateral root development in a sugar-dependent manner. The number of lateral root primordia increased in wox7 mutants but decreased in plants over-expressing WOX7o Plants expressing the WOX7-VP16 fusion protein produced even more lateral roots than wox7, suggesting that WOX7 acts as a transcriptional repressor in lateral root develop- ment. WOX7 is expressed at all stages of lateral root development, but it is primarily involved in lateral root initiation. Consistent with this, the wox7 mutant had a higher mitotic activity only at early stages of lateral root development. Further studies suggest that WOX7 regulates lateral root development through direct repression of cell cycle genes, particularly CYCD6;1. WOX7 expression was enhanced by sugar, reduced by auxin, but did not respond to salt and mannitoh In the wox7 mutant, the effect of sugar on lateral root formation was mitigated. These results together suggest that WOX7 plays an important role in coupling the lateral root development program and sugar status in plants.展开更多
Plants show an unparalleled regenerative capacity,allowing them to survive severe stress conditions,such as injury,herbivory attack,and harsh weather conditions.This potential not only replenishes tissues and restores...Plants show an unparalleled regenerative capacity,allowing them to survive severe stress conditions,such as injury,herbivory attack,and harsh weather conditions.This potential not only replenishes tissues and restores damaged organs but can also give rise to whole plant bodies.Despite the intertwined nature of development and regeneration,common upstream cues and signaling mechanisms are largely unknown.Here,we demonstrate that in addition to being activators of regeneration,ETHYLENE RESPONSE FACTOR 114(ERF114)and ERF115 govern developmental growth in the absence of wounding or injury.Increased ERF114 and ERF115 activity enhances auxin sensitivity,which is correlated with enhanced xylem maturation and lateral root formation,whereas their knockout results in a decrease in lateral roots.Moreover,we provide evidence that mechanical cues contribute to ERF114 and ERF115 expression in correlation with BZR1-mediated brassinosteroid signaling under both regenerative and developmental conditions.Antagonistically,cell wall integrity surveillance via mechanosensory FERONIA signaling suppresses their expression under both conditions.Taken together,our data suggest a molecular framework in which cell wall signals and mechanical strains regulate organ development and regenerative responses via ERF114-and ERF115-mediated auxin signaling.展开更多
Plants' developmental plasticity plays a pivotal role in responding to environmental conditions. One of the most plastic plant organs is the root system. Different environmental stimuli such as nutrients and water de...Plants' developmental plasticity plays a pivotal role in responding to environmental conditions. One of the most plastic plant organs is the root system. Different environmental stimuli such as nutrients and water deficiency may induce lateral root formation to compensate for a low level of water and/or nutrients. It has been shown that the hor- mone auxin tunes lateral root development and components for its signaling pathway have been identified. Using chemi- cal biology, we discovered an Arabidopsis thaliana lateral root formation mechanism that is independent of the auxin receptor SCFTM. The bioactive compound Sortin2 increased lateral root occurrence by acting upstream from the morpho- logical marker of lateral root primordium formation, the mitotic activity. The compound did not display auxin activity. At the cellular level, Sortin2 accelerated endosomal trafficking, resulting in increased trafficking of plasma membrane recy- cling proteins to the vacuole. Sortin2 affected Late endosome/PVC/MVB trafficking and morphology. Combining Sortin2 with well-known drugs showed that endocytic trafficking of Late E/PVC/MVB towards the vacuole is pivotal for Sortin2- induced SCFTm-independent lateral root initiation. Our results revealed a distinctive role for endosomal trafficking in the promotion of lateral root formation via a process that does not rely on the auxin receptor complex SCFTM.展开更多
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 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financially supported by the National Key Research and Development Program of China (Grant No. 2016YFD0100801)the National Transgenic Key Project of the Ministry of Agriculture of China (Grant No. 2016ZX08009002)the Natural Science Foundation of Shandong Province (Grant No. ZR2018PC017)。
文摘Lateral roots play essential roles in drought tolerance in maize(Zea mays L.). However, the genetic basis for the variation in the number of lateral roots in maize remains elusive. Here, we identified a major quantitative trait locus(QTL),q LRT5-1, controlling lateral root number using a recombinant inbred population from a cross between the maize lines Zong3(with many lateral roots) and 87-1(with few lateral roots).Fine-mapping and functional analysis determined that the candidate gene for qLRT5-1,ZmLRT, expresses the primary transcript for the microRNA miR166a. ZmLRT was highly expressed in root tips and lateral root primordia,and knockout and overexpression of ZmLRT increased and decreased lateral root number,respectively. Compared with 87-1, the ZmLRT gene model of Zong3 lacked the second and third exons and contained a 14 bp deletion at the junction between the first exon and intron,which altered the splicing site. In addition,ZmLRT expression was significantly lower in Zong3 than in 87-1, which might be attributed to the insertions of a transposon and over large DNA fragments in the Zong3 ZmLRT promoter region. These mutations decreased the abundance of mature miR166a in Zong3, resulting in increased lateral roots at the seedling stage.Furthermore, miR166a post-transcriptionally repressed five development-related class-Ⅲ homeodomain-leucine zipper genes. Moreover,knockout of ZmLRT enhanced drought tolerance of maize seedlings. Our study furthers our understanding of the genetic basis of lateral root number variation in maize and highlights ZmLRT as a target for improving drought tolerance in maize.
基金financially supported by China Agriculture Research System of MOF and MARA,the CAMS Innovation Fund for Medical Sciences(CIFMS)(No.2016-I2M-2-003)Opening Project Fund of Key Laboratory of Rubber Biology and Genetic Resource Utilization,Ministry of Agriculture/State Key Laboratory Breeding Base of Cultivation&Physiology for Tropical Crops/Danzhou Investigation&Experiment Station of Tropical Crops,Ministry of Agriculture(No.RRL-KLOF202201)。
文摘Objective: The content of saikosaponins in genus Bupleurum is increased with numbers of lateral root, but the genetic mechanisms are largely unknown. This study aims to identify the heme oxygenase(HO) gene family members of B. chinense and B. scorzonerifolium, and assess their role in the root development in Bupleurum.Methods: The gene sequences of HO family were selected from iso-seq full-length transcriptome data of B. chinense and B. scorzonerifolium, and were analyzed in physicochemical properties, conserved domains,motifs and phylogenetic relationship. In addition, the expression patterns of HO gene in different parts of roots were compared via transcriptome sequencing and qRT-PCR in the two species.Results: Five Bupleurum HO genes(BcHO1-BcHO5) belonging to the HO1 subfamily were identified from the transcriptome data, whereas the HO_(2) subfamily member was not identified. The expression levels of BcHO1 and BcHO_(2) were significantly higher than those of other three HO members in the transcriptome analysis. In addition, the expression profile of BcHO1 showed consistency with lateral root development in B. chinense and B. scorzonerifolium.Conclusion: Hos might participate in the auxin-induced morphogenesis of lateral roots. The yield of saikosaponin may be improved by manipulating expression of these genes.
基金This work was supported by the Chinese Academy of Science (grant no. KSCX3-YW-N-007), the Ministry of Science and Technology of China (grant no. 2012CBl14304), and the National Nature Science Foundation of China (grant no. 30830075).
文摘Plant root system morphology is dramatically influenced by various environmental cues. The adaptation of root system architecture to environmental constraints, which mostly depends on the formation and growth of lateral roots, is an important agronomic trait. Lateral root development is regulated by the external signals coordinating closely with intrinsic signaling pathways. MADS-box transcription factors are known key regulators of the transition to flowering and flower development. However, their functions in root development are still poorly understood. Here we report that AGL21, an AGL17-clade MADS-box gene, plays a crucial role in lateral root development. AGL21 was highly expressed in root, particularly in the root central cylinder and lateral root primordia. AGL21 overexpression plants produced more and longer lateral roots while ag121 mutants showed impaired lateral root development, especially under nitrogen-deficient conditions. AGL21 was induced by many plant hormones and environmental stresses, suggesting a function of this gene in root system plasticity in response to various signals. Furthermore, AGL21 was found positively regulating auxin accumulation in lateral root primordia and lateral roots by enhancing local auxin biosynthesis, thus stimulating lateral root initiation and growth. We propose that AGL21 may be involved in various environmental and physiological signals-mediated lateral root development and growth.
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.
文摘Lateral roots are important to plants for the uptake of nutrients and water. Several members of the Aux/IAA family have been shown to play crucial roles in lateral root development. Here, a member of the rice Aux/IAA family genes, OslAA 11 (LOC_Os03g43400), was isolated from a rice mutant defective in lateral root development. The gain-of-function mutation in OslAAll strictly blocks the initiation of lateral root primordia, but it does not affect crown root development. The expression of OslAAll is defined in root tips, lateral root caps, steles, and lateral root primordia. The auxin reporter DR5-GUS (^-glucuronidase) was expressed at lower levels in the mutant than in wild-type, indicating that OslAAll is involved in auxin signaling in root caps. The transcript abundance of both OsPINlb and OsPIN10a was diminished in root tips of the Osiaa 11 mutant. Taken together, the results indicate that the gain-of-function mutation in OslAA 11 caused the inhibition of lateral root development in rice.
基金This research was supported by the National Natural Science Foundation of China(Projects 31670275,31470371,31500227,and 31900246)the Shandong Province Natural Science Foundation Major Basic Research Program(2017C03)+1 种基金the China Postdoctoral Science Foundation(2019M662332,2019T120582)the Special Support for Post-doc Creative Funding in Shandong(201901010).
文摘Auxin plays a critical role in lateral root(LR)formation.The signaling module composed of auxin-response factors(ARFs)and lateral organ boundaries domain transcription factors mediates auxin signaling to control almost every stage of LR development.Here,we show that auxin-induced degradation of the APETALA2/Ethylene Responsive Factor(AP2/ERF)transcription factor ERF13,dependent on MITOGENACTIVATED PROTEIN KINASE MPK14-mediated phosphorylation,plays an essential role in LR development.Overexpression of ERF13 results in restricted passage of the LR primordia through the endodermal layer,greatly reducing LR emergence,whereas the erf13 mutants showed an increase in emerged LR.ERF13 inhibits the expression of 3-ketoacyl-CoA synthase16(KCS16),which encodes a fatty acid elongase involved in very-long-chain fatty acid(VLCFA)biosynthesis.Overexpression of KCS16 or exogenous VLCFA treatment rescues the LR emergence defects in ERF13 overexpression lines,indicating a role downstream of the auxin-MPK14-ERF13 signaling module.Collectively,our study uncovers a novel molecular mechanism by which MPK14-mediated auxin signaling modulates LR development via ERF13-regulated VLCFA biosynthesis.
文摘Carbon monoxide (CO), an odorless, tasteless and colorless gas, has recently proved to be an important bioactive or signal molecule in mammalian cells, with its effects mediated mainly by nitric oxide (NO). In the present report, we show that exogenous CO induces lateral root (LR) formation, an NO-dependent process. Administration of the CO donor hematin to rapeseed (Brassica napus L. Yangyou 6) seedlings for 3 days, dose-dependently promoted the total length and number of LRs. These responses were also seen following the application of gaseous CO aqueous solutions of different saturated concentrations. Furthermore, the actions of CO on seedlings were fully reversed when the CO scavenger hemoglobin (Hb) or the CO-specific synthetic inhibitor zinc protoporphyrin-IX(ZnPPIX) were added. Interestingly, depletion of endogenous NO using its specific scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO) or the nitric oxide synthase (NOS) inhibitor N^G-nitro-L-arginine methyl ester (L-NAME), led to the complete abolition of LR development, illustrating an important role for endogenous NO in the action of CO on LR formation. However, the induction of LR development by 200 μmol/L sodium nitroprusside (SNP), an NO donor, was not affected by the presence or absence of ZnPPIX. Furthermore, using an anatomical approach combined with laser scanning confocal microscopy with the NO-specific fluorophore 4,5-diaminofluorescein diacetate, we observed that both hematin and SNP increased NO release compared with control samples and that the NO signal was mainly distributed in the LR primordia (LRP), especially after 36 h treatment. The LRP were found to have similar morphology in control, SNP- and hematin-treated seedlings. Similarly, the enhancement of the NO signal by CO at 36 h was differentially quenched by the addition of cPTIO, L-NAME, ZnPPIX and Hb. In contrast, the induction of NO caused by SNP was not affected by the application of ZnPPIX. Therefore, we further deduced that CO induces LR formation probably mediated by the NO/NOS pathway and NO may act downstream of CO signaling, which has also been shown to occur in animals.
文摘Root branching or lateral root formation is crucial to maximize a root system acquiring nutrients and water from soil. A lateral root (LR) arises from asymmetric cell division of founder cells (FCs) in a pre-branch site of the primary root, and FC establishment is essential for lateral root formation. FCs are known to be specified from xylem pole pericycle cells, but the molecular genetic mechanisms underlying FC establishment are unclear. Here, we report that, in Arabidopsis thaliana, a PRC2 (for Polycomb repressive complex 2) histone H3 lysine-27 (H3K27) methyltransferase complex, functions to inhibit FC establishment during LR initiation. We found that functional loss of the PRC2 subunits EMF2 (for EMBRYONIC FLOWER 2) or CLF (for CURLY LEAF) leads to a great increase in the number of LRs formed in the primary root. The CLF H3K27 methyltransferase binds to chromatin of the auxin efflux carrier gene PIN FORMED 1 (PIN1), deposits the repres- sive mark H3K27me3 to repress its expression, and functions to down-regulate auxin maxima in root tissues and inhibit FC establishment. Our findings collectively suggest that EMF2-CLF PRC2 acts to down-regulate root auxin maxima and show that this complex represses LR formation in Arabidopsis.
文摘Abstract: Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition. Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under conditions of low phosphorus availability, the length of cells in the meristem zone of the lateral roots was longer, but the length of cells in the elongation and mature zones of the lateral roots was shorter, compared with seedlings grown under conditions of high phosphorus availability. The elongation rates of primary roots increased as phosphorus availability increased, but the elongation rates of the branched zones of the primary roots decreased. The number of lateral root primordia and the length of the lateral roots decreased as phosphorus availability increased. The topological index (altitude slope) decreased as phosphorus availability increased, suggesting that root architecture tended to be herringbone-like when seedlings were grown under conditions of low phosphate availability. Herringbone-like root systems exploit nutrients more efficiently, but they have higher construction costs than root systems with a branching pattern.
基金supported by grants from the Ministry of Science and Technology of China (MOST, 2012CB114304, 2011ZX08005-004)the Chinese Academy of Science (CAS, KSCX3-YW-N-007)the National Nature Science Foundation of China (NNSFC, 30830075, 90917004)
文摘Root architecture is crucial for plants to absorb water and nutrients. We previously reported edtl (edtlD) mutant with altered root architecture that contributes significantly to drought resistance. However, the underlying molecular mechanisms are not well understood. Here we report one of the mechanisms underlying EDT1/HDGll- conferred altered root architecture. Root transcriptome comparison between the wild type and edtlD revealed that the upregulated genes involved in jasmonate biosynthesis and signaling pathway were enriched in edtlD root, which were confirmed by quantitative RT-PCR. Further analysis showed that EDT1/HDG11, as a transcription factor, bound directly to the HD binding sites in the promoters of AOS, AOC3, OPR3, and OPCL1, which encode four key enzymes in JA biosynthesis. We found that the jasmonic acid level was significantly elevated in edtlD root compared with that in the wild type subsequently. In addition, more auxin accumulation was observed in thelateral root primordium of edtlD compared with that of wild type. Genetic analysis of edtlD opcl1 double mutant also showed that HDGll was partially dependent on JA in regulating LR formation. Taken together, overexpression of EDT1/HDGll increases JA level in the root of edtlD by directly upregulating the expressions of several genes encoding JA biosynthesis enzymes to activate auxin signaling and promote lateral root formation.
文摘Sugars promote lateral root formation at low levels but become inhibitory at high C/N or C/P ratios. How sugars suppress lateral root formation is unclear, however. Here we report that WOX7, a member of the WUSCHEL related homeobox (WOX) family transcription factors, inhibits lateral root development in a sugar-dependent manner. The number of lateral root primordia increased in wox7 mutants but decreased in plants over-expressing WOX7o Plants expressing the WOX7-VP16 fusion protein produced even more lateral roots than wox7, suggesting that WOX7 acts as a transcriptional repressor in lateral root develop- ment. WOX7 is expressed at all stages of lateral root development, but it is primarily involved in lateral root initiation. Consistent with this, the wox7 mutant had a higher mitotic activity only at early stages of lateral root development. Further studies suggest that WOX7 regulates lateral root development through direct repression of cell cycle genes, particularly CYCD6;1. WOX7 expression was enhanced by sugar, reduced by auxin, but did not respond to salt and mannitoh In the wox7 mutant, the effect of sugar on lateral root formation was mitigated. These results together suggest that WOX7 plays an important role in coupling the lateral root development program and sugar status in plants.
基金grants G007218N and G010820N and a pre-doctoral fllowship(to FL.)from the Research Foundation-Flanders.A.Z.S.M.and C.W.M.were supported by a Wallenberg Academy Fllowship(2016-0274)a Vetenskapsradet grant(2017-05122).
文摘Plants show an unparalleled regenerative capacity,allowing them to survive severe stress conditions,such as injury,herbivory attack,and harsh weather conditions.This potential not only replenishes tissues and restores damaged organs but can also give rise to whole plant bodies.Despite the intertwined nature of development and regeneration,common upstream cues and signaling mechanisms are largely unknown.Here,we demonstrate that in addition to being activators of regeneration,ETHYLENE RESPONSE FACTOR 114(ERF114)and ERF115 govern developmental growth in the absence of wounding or injury.Increased ERF114 and ERF115 activity enhances auxin sensitivity,which is correlated with enhanced xylem maturation and lateral root formation,whereas their knockout results in a decrease in lateral roots.Moreover,we provide evidence that mechanical cues contribute to ERF114 and ERF115 expression in correlation with BZR1-mediated brassinosteroid signaling under both regenerative and developmental conditions.Antagonistically,cell wall integrity surveillance via mechanosensory FERONIA signaling suppresses their expression under both conditions.Taken together,our data suggest a molecular framework in which cell wall signals and mechanical strains regulate organ development and regenerative responses via ERF114-and ERF115-mediated auxin signaling.
文摘Plants' developmental plasticity plays a pivotal role in responding to environmental conditions. One of the most plastic plant organs is the root system. Different environmental stimuli such as nutrients and water deficiency may induce lateral root formation to compensate for a low level of water and/or nutrients. It has been shown that the hor- mone auxin tunes lateral root development and components for its signaling pathway have been identified. Using chemi- cal biology, we discovered an Arabidopsis thaliana lateral root formation mechanism that is independent of the auxin receptor SCFTM. The bioactive compound Sortin2 increased lateral root occurrence by acting upstream from the morpho- logical marker of lateral root primordium formation, the mitotic activity. The compound did not display auxin activity. At the cellular level, Sortin2 accelerated endosomal trafficking, resulting in increased trafficking of plasma membrane recy- cling proteins to the vacuole. Sortin2 affected Late endosome/PVC/MVB trafficking and morphology. Combining Sortin2 with well-known drugs showed that endocytic trafficking of Late E/PVC/MVB towards the vacuole is pivotal for Sortin2- induced SCFTm-independent lateral root initiation. Our results revealed a distinctive role for endosomal trafficking in the promotion of lateral root formation via a process that does not rely on the auxin receptor complex SCFTM.