Rhizosphere colonization is a key requirement for the application of plant growth-promoting rhizobacteria(PGPR)as a bioferilizer.Signaling molecules are often exchanged between PGPR and plants,and genes in plants may ...Rhizosphere colonization is a key requirement for the application of plant growth-promoting rhizobacteria(PGPR)as a bioferilizer.Signaling molecules are often exchanged between PGPR and plants,and genes in plants may respond to the action of PGPR.Here,the luciferase luxAB gene was electrotransformed into Pseudomonas sp.strain TK35,a PGPR with an afinity for tobacco,and the labelled TK35(TK35-L)was used to monitor colonization dynamics in the tobacco rhizosphere and evaluate the effects of colonization on tobacco growth and root development.The transcript levels of the hydroxyproline rich glycoprotein HRGPnt3 gene,a lateral root induction indicator,in tobacco roots were examined by qPCR.The results showed that TK35-L could survive for long periods in the tobacco rhizosphere and colonize new spaces in the tobacco rhizosphere following tobacco root extension,exhibiting significant increases in root development,seedling growth and potassium accumulation in tobacco plants.The upregulation of HRGPnt3 transcription in the inoculated tobacco suggested that TK35-L can promote tobacco root development by upregulating the transcript levels of the HRGPnt3 gene,which promotes tobacco seedling growth.These findings lay a foundation for future studies on the molecular mechanism underlying the plant growth-promoting activities of PGPR.Futhermore,this work provided an ideal potential strain for biofertilizer production.展开更多
Nanosilver(10−9 m)refers to particles comprising 20–15,000 silver atoms,exhibiting high stability and specific surface area.At present,nanosilver has been used in agricultural cultivation and production.This study ex...Nanosilver(10−9 m)refers to particles comprising 20–15,000 silver atoms,exhibiting high stability and specific surface area.At present,nanosilver has been used in agricultural cultivation and production.This study examined the effects of nanosilver on growth and development of rice root systems.Study results showed that fresh weight of rice belowground organs and root length both increased significantly by 5%and 25%,respectively,after rice radicles were treated with 2 ppm of nanosilver for three days.However,the H_(2)O_(2) level reached its peak at 2 days from treatment,but the activities of the antioxidant enzymes CAT,APX,and GR were inhibited by 2 ppm of nanosilver treatment.The results showed that nanosilver treatment inhibited the antioxidant enzyme activity of rice roots.The treatment of rice radicles with 5μM H_(2)O_(2) promoted root development and the same was observed when nanosilver was used for treatment.Moreover,ascorbic acid(AsA)is a H_(2)O_(2) scavenger and therefore rice root development was inhibited when AsA was added to rice radicles together with either treatment of nanosilver or H_(2)O_(2).In summary,nanosilver treatment of rice radicles promoted root growth and development via the regulation of H_(2)O_(2) and not the O2−pathway.展开更多
Roots are fundamental for plants to adapt to variable environmental conditions.The development of a robust root system is orchestrated by numerous genetic determinants and,among them,the MADS-box gene ANR1 has garnere...Roots are fundamental for plants to adapt to variable environmental conditions.The development of a robust root system is orchestrated by numerous genetic determinants and,among them,the MADS-box gene ANR1 has garnered substantial attention.Prior research has demonstrated that,in chrysanthemum,CmANR1positively regulates root system development.Nevertheless,the upstream regulators involved in the CmANR1-mediated regulation of root development remain unidentified.In this study,we successfully identified bric-a-brac,tramtrack and broad(BTB)and transcription adapter putative zinc finger(TAZ)domain protein CmBT1 as the interacting partner of CmANR1 through a yeasttwo-hybrid(Y2H)screening library.Furthermore,we validated this physical interaction through bimolecular fluorescence complementation and pull-down assays.Functional assays revealed that CmBT1 exerted a negative influence on root development in chrysanthemum.In both in vitro and in vivo assays,it was evident that CmBT1mediated the ubiquitination of CmANR1 through the ubiquitin/26S proteasome pathway.This ubiquitination subsequently led to the degradation of the CmANR1 protein and a reduction in the transcription of CmANR1-targeted gene CmPIN2,which was crucial for root development in chrysanthemum.Genetic analysis suggested that CmBT1 modulated root development,at least in part,by regulating the level of CmANR1 protein.Collectively,these findings shed new light on the regulatory role of CmBT1 in degrading CmANR1 through ubiquitination,thereby repressing the expression of its targeted gene and inhibiting root development in chrysanthemum.展开更多
INDETERMINATE-DOMAIN proteins(IDDs)are a plant-specific transcription factor family characterized by a conserved ID domain with four zinc finger motifs.Previous studies have demonstrated that IDDs coordinate a diversi...INDETERMINATE-DOMAIN proteins(IDDs)are a plant-specific transcription factor family characterized by a conserved ID domain with four zinc finger motifs.Previous studies have demonstrated that IDDs coordinate a diversity of physiological processes and functions in plant growth and development,including floral transition,plant architecture,seed and root development,and hormone signaling.In this review,we especially summarized the latest knowledge on the functions and working models of IDD members in Arabidopsis,rice,and maize,particularly focusing on their role in the regulatory network of biotic and abiotic environmental responses,such as gravity,temperature,water,and pathogens.Understanding these mechanisms underlying the function of IDD proteins in these processes is important for improving crop yields by manipulating their activity.Overall,the review offers valuable insights into the functions and mechanisms of IDD proteins in plants,providing a foundation for further research and potential applications in agriculture.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
Plant architecture determines grain production in rice(Oryza sativa) and is affected by important agronomic traits such as tillering,plant height,and panicle morphology.Many key genes involved in controlling the initi...Plant architecture determines grain production in rice(Oryza sativa) and is affected by important agronomic traits such as tillering,plant height,and panicle morphology.Many key genes involved in controlling the initiation and outgrowth of axillary buds,the elongation of stems,and the architecture of inflorescences have been isolated and analyzed.Previous studies have shown that SiPf40,which was identified from a foxtail millet(Setaria italica) immature seed cDNA library,causes extra branches and tillers in SiPf40-transgenic tobacco and foxtail millet,respectively.To reconfirm its function,we generated transgenic rice plants overexpressing SiPf40 under the control of the ubiquitin promoter.SiPf40-overexpressing transgenic plants have a greater tillering number and a wider tiller angle than wild-type plants.Their root architecture is modified by the promotion of lateral root development,and the distribution of xylem and phloem in the vascular bundle is affected.Analysis of hormone levels showed that the ratios of indole-3-acetic acid/zeatin(IAA/ZR) and IAA/gibberellic acid(IAA/GA) decreased in SiPf40-transgenic plants compared with wild-type plants.These findings strongly suggest that SiPf40 plays an important role in plant architecture.展开更多
Alfalfa(Medicago sativa L.) is an important forage crop worldwide. However, little is known about the effects of breeding status and different geographical populations on alfalfa improvement. Here, we sequenced 220 al...Alfalfa(Medicago sativa L.) is an important forage crop worldwide. However, little is known about the effects of breeding status and different geographical populations on alfalfa improvement. Here, we sequenced 220 alfalfa core germplasms and determined that Chinese alfalfa cultivars form an independent group, as evidenced by comparisons of FSTvalues between different subgroups, suggesting that geographical origin plays an important role in group differentiation. By tracing the influence of geographical regions on the genetic diversity of alfalfa varieties in China, we identified 350 common candidate genetic regions and 548 genes under selection. We also defined 165 loci associated with 24 important traits from genome-wide association studies. Of those, 17 genomic regions closely associated with a given phenotype were under selection, with the underlying haplotypes showing significant differences between subgroups of distinct geographical origins. Based on results from expression analysis and association mapping,we propose that 6-phosphogluconolactonase(MsPGL) and a gene encoding a protein with NHL domains(MsNHL) are critical candidate genes for root growth. In conclusion, our results provide valuable information for alfalfa improvement via molecular breeding.展开更多
Root architecture is one of the most important agronomic traits that determines rice crop yield. The primary root(PR) absorbs mineral nutrients and provides mechanical support;however, the molecular mechanisms of PR e...Root architecture is one of the most important agronomic traits that determines rice crop yield. The primary root(PR) absorbs mineral nutrients and provides mechanical support;however, the molecular mechanisms of PR elongation remain unclear in rice. Here, the two loss-of-function T-DNA insertion mutants of root length regulator 4(Os RLR4), osrlr4-1 and osrlr4-2 with longer PR, and three Os RLR4 overexpression lines, OE-Os RLR4-1/-2/-3 with shorter PR compared to the wild type/Hwayoung(WT/HY), were identified. Os RLR4 isone of five members of the PRAF subfamily of the regulator chromosome condensation1(RCC1) family. Phylogenetic analysis of Os RLR4 from wild and cultivated rice indicated that it is under selective sweeps, suggesting its potential role in domestication. Os RLR4 controls PR development by regulating auxin accumulation in the PR tip and thus the root apical meristem activity. A series of biochemical and genetic analyses demonstrated that Os RLR4 functions directly upstream of the auxin transporter Os AUX1. Moreover, Os RLR4 interacts with the TRITHORAX-like protein Os Trx1 to promote H3 K4 me3 deposition at the Os AUX1 promoter, thus altering its transcription level. This work provides insight into the cooperation of auxin and epigenetic modifications in regulating root architecture and provides a genetic resource for plant architecture breeding.展开更多
Drought stress caused by insufficient irrigation or precipitation impairs agricultural production worldwide.In this study,a two-year field experiment was conducted to investigate the effect of coronatine(COR),a functi...Drought stress caused by insufficient irrigation or precipitation impairs agricultural production worldwide.In this study,a two-year field experiment was conducted to investigate the effect of coronatine(COR),a functional analog of jasmonic acid(JA),on maize drought resistance.The experiment included two water treatments(rainfed and irrigation),four COR concentrations(mock,0μmol L^(-1);A1,0.1μmol L^(-1);A2,1μmol L^(-1);A3,10μmol L^(-1))and two maize genotypes(Fumin 985(FM985),a drought-resistant cultivar and Xianyu 335(XY335),a drought-sensitive cultivar).Spraying 1μmol L^(-1)COR at seedling stage increased surface root density and size,including root dry matter by 12.6%,projected root area by 19.0%,average root density by 51.9%,and thus root bleeding sap by 28.2%under drought conditions.COR application also increased leaf area and SPAD values,a result attributed to improvement of the root system and increases in abscisic acid(ABA),JA,and salicylic acid(SA)contents.The improvement of leaves and roots laid the foundation for increasing plant height and dry matter accumulation.COR application reduced anthesis and silking interval,increasing kernel number per ear.COR treatment at 1μmol L^(-1)increased the yield of XY335 and FM985 by 7.9%and 11.0%,respectively.Correlation and path analysis showed that grain yields were correlated with root dry weight and projected root area,increasing maize drought resistance mainly via leaf area index and dry matter accumulation.Overall,COR increased maize drought resistance mainly by increasing root dry weight and root area,with 1μmol L-^(-1)COR as an optimal concentration.展开更多
Root cap not only protects root meristem,but also detects and transduces the signals of environmental changes to affect root development.The symplastic communication is an important way for plants to transduce signals...Root cap not only protects root meristem,but also detects and transduces the signals of environmental changes to affect root development.The symplastic communication is an important way for plants to transduce signals to coordinate the development and physiology in response to the changing enviroments.However,it is unclear how the symplastic communication between root cap cells affects root growth.Here we exploit an inducible system to specifically block the symplastic communication in the root cap.Transient blockage of plasmodesmata(PD)in differentiated collumella cells severely impairs the root development in Arabidopsis,in particular in the stem cell niche and the proximal meristem.The neighboring stem cell niche is the region that is most sensitive to the disrupted symplastic communication and responds rapidly via the alteration of auxin distribution.In the later stage,the cell division in proximal meristem is inhibited,presumably due to the reduced auxin level in the root cap.Our results reveal the essential role of the differentiated collumella cells in the root cap mediated signaling system that directs root development.展开更多
Efficient use of natural resources(e.g.,light,water,and nutrients)can be improved with a tailored developmental program that maximizes the lifetime and fitness of plants.In plant shoots,a developmental phase represent...Efficient use of natural resources(e.g.,light,water,and nutrients)can be improved with a tailored developmental program that maximizes the lifetime and fitness of plants.In plant shoots,a developmental phase represents a time window in which the meristem triggers the development of unique morphological and physiological traits,leading to the emergence of leaves,flowers,and fruits.Whereas developmental phases in plant shoots have been shown to enhance food production in crops,this phenomenon has remained poorly investigated in roots.In light of recent advances,we suggest that root development occurs in three main phases:root apical meristem appearance,foraging,and senescence.We provide compelling evidence suggesting that these phases are regulated by at least four developmental pathways:autonomous,non-autonomous,hormonal,and periodic.Root developmental pathways differentially coordinate organ plasticity,promoting morphological alterations,tissue regeneration,and cell death regulation.Furthermore,we suggest how nutritional checkpoints may allow progression through the developmental phases,thus completing the root life cycle.These insights highlight novel and exciting advances in root biology that may help maximize the productivity of crops through more sustainable agriculture and the reduced use of chemical fertilizers.展开更多
The auxin polar transporter,PIN-FORMED 2(PIN2)plays an important role in root development.However,it remains unclear whether PIN2 genes form two Liriodendron species,L.chinense(LcPIN2)and L.tulipifera(LtPIN2),are both...The auxin polar transporter,PIN-FORMED 2(PIN2)plays an important role in root development.However,it remains unclear whether PIN2 genes form two Liriodendron species,L.chinense(LcPIN2)and L.tulipifera(LtPIN2),are both involved in root development and whether and to what extent these two genes diverge in function.Here,we cloned and overexpressed LcPIN2 and LtPIN2 in Arabidopsis thaliana wild-type(WT)and Atpin2 mutant.Phylogenetic and sequence analysis showed a small degree of differentiation between these two Liriodendron PIN2 genes.Tissue-specific gene expression analysis indicated that both Liriodendron PIN2 genes were highly expressed in roots,implying a potential role in root development.Finally,heterologous overexpression of LcPIN2 and LtPIN2 in Arabidopsis both significantly increased the root length compared to wild-type and empty vector.Furthermore,the root length defect in Atpin2 was complemented both by LcPIN2 and LtPIN2.However,heterologous overexpression of LcPIN2 and LtPIN2 cannot rescue the defect in root gravitropism of Atpin2 mutants.Taken together,ourfindings unravel PIN2 genes from the magnoliids plant Liriodendron were functionally conserved with AtPIN2 in the dicotyledonous plant Arabidopsis in regard to the regulation of root length,but not root gravitropism.This study also provides a potential target for genetic improvement of the root system in these valuable forest trees Liriodendron.展开更多
Upland rice shows dryland adaptation in the form of a deeper and denser root system and greater drought resistance than its counterpart,irrigated rice.Our previous study revealed a difference in the frequency of the O...Upland rice shows dryland adaptation in the form of a deeper and denser root system and greater drought resistance than its counterpart,irrigated rice.Our previous study revealed a difference in the frequency of the OsNCED2 gene between upland and irrigated populations.A nonsynonymous mutation(C to T,from irrigated to upland rice)may have led to functional variation fixed by artificial selection,but the exact biological function in dryland adaptation is unclear.In this study,transgenic and association analysis indicated that the domesticated fixed mutation caused functional variation in OsNCED2,increasing ABA levels,root development,and drought tolerance in upland rice under dryland conditions.OsNCED2-overexpressing rice showed increased reactive oxygen species-scavenging abilities and transcription levels of many genes functioning in stress response and development that may regulate root development and drought tolerance.OsNCED2^(T)-NILs showed a denser root system and drought resistance,promoting the yield of rice under dryland conditions.OsNCED2^(T)may confer dryland adaptation in upland rice and may find use in breeding dryland-adapted,water-saving rice.展开更多
Root system architecture is influenced by gravity.How the root senses gravity and directs its orientation,so-called gravitropism,is not only a fundamental question in plant biology but also theoretically important for...Root system architecture is influenced by gravity.How the root senses gravity and directs its orientation,so-called gravitropism,is not only a fundamental question in plant biology but also theoretically important for genetic improvement of crop root architecture.However,the mechanism has not been elucidated in most crops.We characterized a rice agravitropism allele,wavy root 1(war1),a loss-of-function allele in OsPIN2,which encodes an auxin efflux transporter.With loss of OsPIN2 function,war1 leads to altered root system architecture including wavy root,larger root distribution angle,and shallower root system due to the loss of gravitropic perception in root tips.In the war1 mutant,polar auxin transport was disrupted in the root tip,leading to abnormal auxin levels and disturbed auxin transport and distribution in columella cells.Amyloplast sedimentation,an important process in gravitropic sensing,was also decreased in root tip columella cells.The results indicated that OsPIN2 controls gravitropism by finely regulating auxin transport,distribution and levels,and amyloplast sedimentation in root tips.We identified a novel role of OsPIN2 in regulating ABA biosynthesis and response pathways.Loss of OsPIN2 function in the war1 resulted in increased sensitivity to ABA in seed germination,increased ABA level,changes in ABA-associated genes in roots,and decreased drought tolerance in the seedlings.These results suggest that the auxin transporter OsPIN2 not only modulates auxin transport to control root gravitropism,but also functions in ABA signaling to affect seed germination and root development,probably by mediating crosstalk between auxin and ABA pathways.展开更多
Rubber[Hevea brasiliensis(Willd.ex A.Juss.)Müll.Arg.]plantations are the largest cultivated forest type in tropical China.Returning organic materials to the soil will help to maintain the quality and growth of ru...Rubber[Hevea brasiliensis(Willd.ex A.Juss.)Müll.Arg.]plantations are the largest cultivated forest type in tropical China.Returning organic materials to the soil will help to maintain the quality and growth of rubber trees.Although many studies have demonstrated that organic waste materials can be used to improve soil fertility and structure to promote root growth,few studies have studied the eff ects of organic amendments on soil fertility and root growth in rubber tree plantations.Here,bagasse,coconut husk or biochar were applied with a chemical fertilizer to test their eff ects on soil properties after 6 months and compared with the eff ects of only the chemical fertilizer.Results showed that the soil organic matter content,total nitrogen,available phosphorus and available potassium after the chemical fertilizer(F)treatment were all signifi cantly lower than after the chemical fertilizer+bagasse(Fba),chemical fertilizer+coconut husk(Fco)or chemical fertilizer+biochar(Fbi)(p<0.05).Soil pH in all organic amendments was higher than in the F treatment,but was only signifi cantly higher in the Fbi treatment.In contrast,soil bulk density in the F treatment was signifi cantly higher than in treatments with the organic amendments(p<0.05).When compared with the F treatment,soil root dry mass increased signifi-cantly by 190%,176%and 33%in Fba,Fco and Fbi treatments,respectively(p<0.05).Similar results were found for root activity,number of root tips,root length,root surface area and root volume.Conclusively,the application of bagasse,coconut husk and biochar increased soil fertility and promoted root growth of rubber trees in the short term.However,bagasse and coconut husk were more eff ective than biochar in improving root growth of rubber trees.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 reacti...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
The rol genes cloned from Agrobacterium rhizogenes were transferred to the cotton genomevia Agrobacterium-mediated transformation. Molecular analyses and developmentalidentification of the putative transgenic plants w...The rol genes cloned from Agrobacterium rhizogenes were transferred to the cotton genomevia Agrobacterium-mediated transformation. Molecular analyses and developmentalidentification of the putative transgenic plants were carried out by means of PCR,Southern blotting and field characterization. The results showed that the expression ofrol genes greatly increased the rooting ability of the transgenic plants, and changed theplant development. Highly male-sterile plants with strong apical dominance and fertileplants with short internodes, stunted growth and improved economic characteristics weresegregated from the T1 transgenic lines of wild rol B gene and the rol B gene driven by35S promoter. The transgenic lines of rol ABC construct usually had normal boll settingand slow growth. Therefore we concluded that the rol genes, modified in suitable ways,could be used to create new cotton varieties with some highly valuable characteristics.展开更多
基金Supported by the National Natural Science Foundation of China(41401269)the Key Project of the University Natural Science Research Project of Anhui Province,China(KJ2019A0183)+1 种基金the Open Fund of Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention(FECPP201902)the Key Research Project of China National Tobacco Corporation Hubei Company(027Y2020-011).
文摘Rhizosphere colonization is a key requirement for the application of plant growth-promoting rhizobacteria(PGPR)as a bioferilizer.Signaling molecules are often exchanged between PGPR and plants,and genes in plants may respond to the action of PGPR.Here,the luciferase luxAB gene was electrotransformed into Pseudomonas sp.strain TK35,a PGPR with an afinity for tobacco,and the labelled TK35(TK35-L)was used to monitor colonization dynamics in the tobacco rhizosphere and evaluate the effects of colonization on tobacco growth and root development.The transcript levels of the hydroxyproline rich glycoprotein HRGPnt3 gene,a lateral root induction indicator,in tobacco roots were examined by qPCR.The results showed that TK35-L could survive for long periods in the tobacco rhizosphere and colonize new spaces in the tobacco rhizosphere following tobacco root extension,exhibiting significant increases in root development,seedling growth and potassium accumulation in tobacco plants.The upregulation of HRGPnt3 transcription in the inoculated tobacco suggested that TK35-L can promote tobacco root development by upregulating the transcript levels of the HRGPnt3 gene,which promotes tobacco seedling growth.These findings lay a foundation for future studies on the molecular mechanism underlying the plant growth-promoting activities of PGPR.Futhermore,this work provided an ideal potential strain for biofertilizer production.
文摘Nanosilver(10−9 m)refers to particles comprising 20–15,000 silver atoms,exhibiting high stability and specific surface area.At present,nanosilver has been used in agricultural cultivation and production.This study examined the effects of nanosilver on growth and development of rice root systems.Study results showed that fresh weight of rice belowground organs and root length both increased significantly by 5%and 25%,respectively,after rice radicles were treated with 2 ppm of nanosilver for three days.However,the H_(2)O_(2) level reached its peak at 2 days from treatment,but the activities of the antioxidant enzymes CAT,APX,and GR were inhibited by 2 ppm of nanosilver treatment.The results showed that nanosilver treatment inhibited the antioxidant enzyme activity of rice roots.The treatment of rice radicles with 5μM H_(2)O_(2) promoted root development and the same was observed when nanosilver was used for treatment.Moreover,ascorbic acid(AsA)is a H_(2)O_(2) scavenger and therefore rice root development was inhibited when AsA was added to rice radicles together with either treatment of nanosilver or H_(2)O_(2).In summary,nanosilver treatment of rice radicles promoted root growth and development via the regulation of H_(2)O_(2) and not the O2−pathway.
基金supported by grants from the National Natural Science Foundation of China(31902049)the National Natural Science Foundation of China(32122080)Shandong Province(ZR2020YQ25)。
文摘Roots are fundamental for plants to adapt to variable environmental conditions.The development of a robust root system is orchestrated by numerous genetic determinants and,among them,the MADS-box gene ANR1 has garnered substantial attention.Prior research has demonstrated that,in chrysanthemum,CmANR1positively regulates root system development.Nevertheless,the upstream regulators involved in the CmANR1-mediated regulation of root development remain unidentified.In this study,we successfully identified bric-a-brac,tramtrack and broad(BTB)and transcription adapter putative zinc finger(TAZ)domain protein CmBT1 as the interacting partner of CmANR1 through a yeasttwo-hybrid(Y2H)screening library.Furthermore,we validated this physical interaction through bimolecular fluorescence complementation and pull-down assays.Functional assays revealed that CmBT1 exerted a negative influence on root development in chrysanthemum.In both in vitro and in vivo assays,it was evident that CmBT1mediated the ubiquitination of CmANR1 through the ubiquitin/26S proteasome pathway.This ubiquitination subsequently led to the degradation of the CmANR1 protein and a reduction in the transcription of CmANR1-targeted gene CmPIN2,which was crucial for root development in chrysanthemum.Genetic analysis suggested that CmBT1 modulated root development,at least in part,by regulating the level of CmANR1 protein.Collectively,these findings shed new light on the regulatory role of CmBT1 in degrading CmANR1 through ubiquitination,thereby repressing the expression of its targeted gene and inhibiting root development in chrysanthemum.
基金the National Natural Science Foundation of China(31800225 and 32370363)the Natural Science Foundation of Shandong Province(ZR2020MC027 and ZR2021QC213).
文摘INDETERMINATE-DOMAIN proteins(IDDs)are a plant-specific transcription factor family characterized by a conserved ID domain with four zinc finger motifs.Previous studies have demonstrated that IDDs coordinate a diversity of physiological processes and functions in plant growth and development,including floral transition,plant architecture,seed and root development,and hormone signaling.In this review,we especially summarized the latest knowledge on the functions and working models of IDD members in Arabidopsis,rice,and maize,particularly focusing on their role in the regulatory network of biotic and abiotic environmental responses,such as gravity,temperature,water,and pathogens.Understanding these mechanisms underlying the function of IDD proteins in these processes is important for improving crop yields by manipulating their activity.Overall,the review offers valuable insights into the functions and mechanisms of IDD proteins in plants,providing a foundation for further research and potential applications in agriculture.
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.
基金supported by the National Transgenic Major Program of China (Grant Nos. 2008ZX003-002 and 2009ZX08009-093B)the National High-Tech Research and Development Program of China (Grant No.2008AA10Z158-2)+1 种基金the National Natural Science Foundation of China (Grant Nos. 30971555 and 30671124)and the State Key Laboratory for Agrobiotechnology in China (Grant No. 2010SKLAB05-12)
文摘Plant architecture determines grain production in rice(Oryza sativa) and is affected by important agronomic traits such as tillering,plant height,and panicle morphology.Many key genes involved in controlling the initiation and outgrowth of axillary buds,the elongation of stems,and the architecture of inflorescences have been isolated and analyzed.Previous studies have shown that SiPf40,which was identified from a foxtail millet(Setaria italica) immature seed cDNA library,causes extra branches and tillers in SiPf40-transgenic tobacco and foxtail millet,respectively.To reconfirm its function,we generated transgenic rice plants overexpressing SiPf40 under the control of the ubiquitin promoter.SiPf40-overexpressing transgenic plants have a greater tillering number and a wider tiller angle than wild-type plants.Their root architecture is modified by the promotion of lateral root development,and the distribution of xylem and phloem in the vascular bundle is affected.Analysis of hormone levels showed that the ratios of indole-3-acetic acid/zeatin(IAA/ZR) and IAA/gibberellic acid(IAA/GA) decreased in SiPf40-transgenic plants compared with wild-type plants.These findings strongly suggest that SiPf40 plays an important role in plant architecture.
基金This work was supported by the Collaborative Research Key Project between China and EU(2017YFE0111000)the National Natural Science Foundation of China(31971758,31772656)the Innovation Program of CAAS(ASTIP-IAS14)。
文摘Alfalfa(Medicago sativa L.) is an important forage crop worldwide. However, little is known about the effects of breeding status and different geographical populations on alfalfa improvement. Here, we sequenced 220 alfalfa core germplasms and determined that Chinese alfalfa cultivars form an independent group, as evidenced by comparisons of FSTvalues between different subgroups, suggesting that geographical origin plays an important role in group differentiation. By tracing the influence of geographical regions on the genetic diversity of alfalfa varieties in China, we identified 350 common candidate genetic regions and 548 genes under selection. We also defined 165 loci associated with 24 important traits from genome-wide association studies. Of those, 17 genomic regions closely associated with a given phenotype were under selection, with the underlying haplotypes showing significant differences between subgroups of distinct geographical origins. Based on results from expression analysis and association mapping,we propose that 6-phosphogluconolactonase(MsPGL) and a gene encoding a protein with NHL domains(MsNHL) are critical candidate genes for root growth. In conclusion, our results provide valuable information for alfalfa improvement via molecular breeding.
基金funded by grants from the National Natural Science Foundation of China(32060451)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ19C020001)+2 种基金Inner Mongolia Applied Technology Research and Development Foundation to Y.H.Q.the National Natural Science Foundation of China(31801064)to D.M.L.grants from the Swiss National Funds(31003A-165877/1)to M.G.
文摘Root architecture is one of the most important agronomic traits that determines rice crop yield. The primary root(PR) absorbs mineral nutrients and provides mechanical support;however, the molecular mechanisms of PR elongation remain unclear in rice. Here, the two loss-of-function T-DNA insertion mutants of root length regulator 4(Os RLR4), osrlr4-1 and osrlr4-2 with longer PR, and three Os RLR4 overexpression lines, OE-Os RLR4-1/-2/-3 with shorter PR compared to the wild type/Hwayoung(WT/HY), were identified. Os RLR4 isone of five members of the PRAF subfamily of the regulator chromosome condensation1(RCC1) family. Phylogenetic analysis of Os RLR4 from wild and cultivated rice indicated that it is under selective sweeps, suggesting its potential role in domestication. Os RLR4 controls PR development by regulating auxin accumulation in the PR tip and thus the root apical meristem activity. A series of biochemical and genetic analyses demonstrated that Os RLR4 functions directly upstream of the auxin transporter Os AUX1. Moreover, Os RLR4 interacts with the TRITHORAX-like protein Os Trx1 to promote H3 K4 me3 deposition at the Os AUX1 promoter, thus altering its transcription level. This work provides insight into the cooperation of auxin and epigenetic modifications in regulating root architecture and provides a genetic resource for plant architecture breeding.
基金funded by National Key Research and Development Program of China(2017YFD0300405-2)。
文摘Drought stress caused by insufficient irrigation or precipitation impairs agricultural production worldwide.In this study,a two-year field experiment was conducted to investigate the effect of coronatine(COR),a functional analog of jasmonic acid(JA),on maize drought resistance.The experiment included two water treatments(rainfed and irrigation),four COR concentrations(mock,0μmol L^(-1);A1,0.1μmol L^(-1);A2,1μmol L^(-1);A3,10μmol L^(-1))and two maize genotypes(Fumin 985(FM985),a drought-resistant cultivar and Xianyu 335(XY335),a drought-sensitive cultivar).Spraying 1μmol L^(-1)COR at seedling stage increased surface root density and size,including root dry matter by 12.6%,projected root area by 19.0%,average root density by 51.9%,and thus root bleeding sap by 28.2%under drought conditions.COR application also increased leaf area and SPAD values,a result attributed to improvement of the root system and increases in abscisic acid(ABA),JA,and salicylic acid(SA)contents.The improvement of leaves and roots laid the foundation for increasing plant height and dry matter accumulation.COR application reduced anthesis and silking interval,increasing kernel number per ear.COR treatment at 1μmol L^(-1)increased the yield of XY335 and FM985 by 7.9%and 11.0%,respectively.Correlation and path analysis showed that grain yields were correlated with root dry weight and projected root area,increasing maize drought resistance mainly via leaf area index and dry matter accumulation.Overall,COR increased maize drought resistance mainly by increasing root dry weight and root area,with 1μmol L-^(-1)COR as an optimal concentration.
基金This work is supported by the National Key Research and Development Program of China(2018YFD1000800)the grant from the National Natural Science Foundation of China(31900169).
文摘Root cap not only protects root meristem,but also detects and transduces the signals of environmental changes to affect root development.The symplastic communication is an important way for plants to transduce signals to coordinate the development and physiology in response to the changing enviroments.However,it is unclear how the symplastic communication between root cap cells affects root growth.Here we exploit an inducible system to specifically block the symplastic communication in the root cap.Transient blockage of plasmodesmata(PD)in differentiated collumella cells severely impairs the root development in Arabidopsis,in particular in the stem cell niche and the proximal meristem.The neighboring stem cell niche is the region that is most sensitive to the disrupted symplastic communication and responds rapidly via the alteration of auxin distribution.In the later stage,the cell division in proximal meristem is inhibited,presumably due to the reduced auxin level in the root cap.Our results reveal the essential role of the differentiated collumella cells in the root cap mediated signaling system that directs root development.
基金This work was made possible through financial support from the Serrapilheira Institute(grant Serra-1812-27067)the Fundac¸ao de Amparo a`Pesquisa do Estado de Minas Gerais(FAPEMIG-Brazil,projects CRARED-00053-16 and CAG-APQ-00772-19)Scholarships granted by FAPEMIG-Brazil to J.A.S.and research fellowships granted by the National Council for Scientific and Technological Development(CNPq-Brazil)to W.C.O.and W.L.A.are gratefully acknowledged.
文摘Efficient use of natural resources(e.g.,light,water,and nutrients)can be improved with a tailored developmental program that maximizes the lifetime and fitness of plants.In plant shoots,a developmental phase represents a time window in which the meristem triggers the development of unique morphological and physiological traits,leading to the emergence of leaves,flowers,and fruits.Whereas developmental phases in plant shoots have been shown to enhance food production in crops,this phenomenon has remained poorly investigated in roots.In light of recent advances,we suggest that root development occurs in three main phases:root apical meristem appearance,foraging,and senescence.We provide compelling evidence suggesting that these phases are regulated by at least four developmental pathways:autonomous,non-autonomous,hormonal,and periodic.Root developmental pathways differentially coordinate organ plasticity,promoting morphological alterations,tissue regeneration,and cell death regulation.Furthermore,we suggest how nutritional checkpoints may allow progression through the developmental phases,thus completing the root life cycle.These insights highlight novel and exciting advances in root biology that may help maximize the productivity of crops through more sustainable agriculture and the reduced use of chemical fertilizers.
基金supported by the Youth Foundation of the Natural Science Foundation of Jiangsu Province(BK20210614)the Nature Science Foundation of China(32071784)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_0921).
文摘The auxin polar transporter,PIN-FORMED 2(PIN2)plays an important role in root development.However,it remains unclear whether PIN2 genes form two Liriodendron species,L.chinense(LcPIN2)and L.tulipifera(LtPIN2),are both involved in root development and whether and to what extent these two genes diverge in function.Here,we cloned and overexpressed LcPIN2 and LtPIN2 in Arabidopsis thaliana wild-type(WT)and Atpin2 mutant.Phylogenetic and sequence analysis showed a small degree of differentiation between these two Liriodendron PIN2 genes.Tissue-specific gene expression analysis indicated that both Liriodendron PIN2 genes were highly expressed in roots,implying a potential role in root development.Finally,heterologous overexpression of LcPIN2 and LtPIN2 in Arabidopsis both significantly increased the root length compared to wild-type and empty vector.Furthermore,the root length defect in Atpin2 was complemented both by LcPIN2 and LtPIN2.However,heterologous overexpression of LcPIN2 and LtPIN2 cannot rescue the defect in root gravitropism of Atpin2 mutants.Taken together,ourfindings unravel PIN2 genes from the magnoliids plant Liriodendron were functionally conserved with AtPIN2 in the dicotyledonous plant Arabidopsis in regard to the regulation of root length,but not root gravitropism.This study also provides a potential target for genetic improvement of the root system in these valuable forest trees Liriodendron.
基金This work was supported by the National Natural Science Foundation of China(U1602266,32060474,and 31601274)grants from the Yunnan Provincial Science and Technology Department(202005AF150009 and 202101AS070001).
文摘Upland rice shows dryland adaptation in the form of a deeper and denser root system and greater drought resistance than its counterpart,irrigated rice.Our previous study revealed a difference in the frequency of the OsNCED2 gene between upland and irrigated populations.A nonsynonymous mutation(C to T,from irrigated to upland rice)may have led to functional variation fixed by artificial selection,but the exact biological function in dryland adaptation is unclear.In this study,transgenic and association analysis indicated that the domesticated fixed mutation caused functional variation in OsNCED2,increasing ABA levels,root development,and drought tolerance in upland rice under dryland conditions.OsNCED2-overexpressing rice showed increased reactive oxygen species-scavenging abilities and transcription levels of many genes functioning in stress response and development that may regulate root development and drought tolerance.OsNCED2^(T)-NILs showed a denser root system and drought resistance,promoting the yield of rice under dryland conditions.OsNCED2^(T)may confer dryland adaptation in upland rice and may find use in breeding dryland-adapted,water-saving rice.
基金supported by the National Natural Science Foundation of China(32070197,31570181 and 31200148)Chinese Universities Scientific Fund(2452018149)。
文摘Root system architecture is influenced by gravity.How the root senses gravity and directs its orientation,so-called gravitropism,is not only a fundamental question in plant biology but also theoretically important for genetic improvement of crop root architecture.However,the mechanism has not been elucidated in most crops.We characterized a rice agravitropism allele,wavy root 1(war1),a loss-of-function allele in OsPIN2,which encodes an auxin efflux transporter.With loss of OsPIN2 function,war1 leads to altered root system architecture including wavy root,larger root distribution angle,and shallower root system due to the loss of gravitropic perception in root tips.In the war1 mutant,polar auxin transport was disrupted in the root tip,leading to abnormal auxin levels and disturbed auxin transport and distribution in columella cells.Amyloplast sedimentation,an important process in gravitropic sensing,was also decreased in root tip columella cells.The results indicated that OsPIN2 controls gravitropism by finely regulating auxin transport,distribution and levels,and amyloplast sedimentation in root tips.We identified a novel role of OsPIN2 in regulating ABA biosynthesis and response pathways.Loss of OsPIN2 function in the war1 resulted in increased sensitivity to ABA in seed germination,increased ABA level,changes in ABA-associated genes in roots,and decreased drought tolerance in the seedlings.These results suggest that the auxin transporter OsPIN2 not only modulates auxin transport to control root gravitropism,but also functions in ABA signaling to affect seed germination and root development,probably by mediating crosstalk between auxin and ABA pathways.
文摘Rubber[Hevea brasiliensis(Willd.ex A.Juss.)Müll.Arg.]plantations are the largest cultivated forest type in tropical China.Returning organic materials to the soil will help to maintain the quality and growth of rubber trees.Although many studies have demonstrated that organic waste materials can be used to improve soil fertility and structure to promote root growth,few studies have studied the eff ects of organic amendments on soil fertility and root growth in rubber tree plantations.Here,bagasse,coconut husk or biochar were applied with a chemical fertilizer to test their eff ects on soil properties after 6 months and compared with the eff ects of only the chemical fertilizer.Results showed that the soil organic matter content,total nitrogen,available phosphorus and available potassium after the chemical fertilizer(F)treatment were all signifi cantly lower than after the chemical fertilizer+bagasse(Fba),chemical fertilizer+coconut husk(Fco)or chemical fertilizer+biochar(Fbi)(p<0.05).Soil pH in all organic amendments was higher than in the F treatment,but was only signifi cantly higher in the Fbi treatment.In contrast,soil bulk density in the F treatment was signifi cantly higher than in treatments with the organic amendments(p<0.05).When compared with the F treatment,soil root dry mass increased signifi-cantly by 190%,176%and 33%in Fba,Fco and Fbi treatments,respectively(p<0.05).Similar results were found for root activity,number of root tips,root length,root surface area and root volume.Conclusively,the application of bagasse,coconut husk and biochar increased soil fertility and promoted root growth of rubber trees in the short term.However,bagasse and coconut husk were more eff ective than biochar in improving root growth of rubber trees.
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the National Natural science Fundationof china(39970386)
文摘The rol genes cloned from Agrobacterium rhizogenes were transferred to the cotton genomevia Agrobacterium-mediated transformation. Molecular analyses and developmentalidentification of the putative transgenic plants were carried out by means of PCR,Southern blotting and field characterization. The results showed that the expression ofrol genes greatly increased the rooting ability of the transgenic plants, and changed theplant development. Highly male-sterile plants with strong apical dominance and fertileplants with short internodes, stunted growth and improved economic characteristics weresegregated from the T1 transgenic lines of wild rol B gene and the rol B gene driven by35S promoter. The transgenic lines of rol ABC construct usually had normal boll settingand slow growth. Therefore we concluded that the rol genes, modified in suitable ways,could be used to create new cotton varieties with some highly valuable characteristics.