Bacterial blight(BB),caused by Xanthomonas oryzae pathovar oryzae(Xoo),poses a significant threat to rice production,particularly in Asia and West Africa.Breeding resistance against BB in elite rice varieties is cruci...Bacterial blight(BB),caused by Xanthomonas oryzae pathovar oryzae(Xoo),poses a significant threat to rice production,particularly in Asia and West Africa.Breeding resistance against BB in elite rice varieties is crucial to advancing rice breeding program and supporting smallholder farmers.Transcription Activator-Like effectors(TALes)are key virulence factors in Xoo,with some targeting the susceptibility(S)genes such as the sugar transporter SWEET genes in rice.Among these,SWEET14 is an important S gene,with its promoter bound by the TALe TalC which exists across all sequenced African Xoo isolates.In the present study,we utilized CRISPR/Cas9-based cytidine and adenine base editors to alter the effector binding element(EBE)of TalC in the promoter of SWEET14 in rice cultivars Kitaake,IR24,and Zhonghua 11.Mutations with C to T changes in EBE led to reduced SWEET14 induction by TalC-containing Xoo strains,resulting in resistance to African Xoo isolates reliant on TalC for virulence.Conversely,A to G changes retained SWEET14 inducibility and susceptibility to Xoo in edited lines.Importantly,no off-target mutations were detected at predicted sites,and the edited lines exhibited no obvious defects in major agronomic traits in Kitaake.These results underscore the effectiveness of base editing systems for both molecular biology research and crop improvement endeavors.展开更多
Male gametes are produced in the anthers and are essential for fertilization and seed setting.A transverse section of the anther reveals four layers:the epidermis,endothecium,middle layer,and tapetum.The tapetum,being...Male gametes are produced in the anthers and are essential for fertilization and seed setting.A transverse section of the anther reveals four layers:the epidermis,endothecium,middle layer,and tapetum.The tapetum,being the innermost layer,plays a critical role in supplying nutrients,enzymes,and protection to microspores.Detailed microscopic and ultrastructural analyses have revealed highly active and well-organized structures within the tapetum,referred to as tapetal organelles.Molecular studies have highlighted the significance of tapetal cell death and the nurturing role of the tapetum for microspores.However,the mechanisms by which these processes are mediated by tapetal organelles at the cellular level remain elusive.The discovery of mutants defective in tapetal organelles has enabled further investigations into their structure,morphology,and function.This review discusses the molecular and functional roles of various tapetal organelles,such as plastids(amyloplasts and elaioplasts),mitochondria,tapetosomes,endoplasmic reticulum,and lipid bodies.We provide an overview of their roles,highlight key organelles in the tapetum,and address recent challenges and potential applications of genes regulating tapetal organelles in enhancing crop fertility.展开更多
Small RNAs(sRNAs)are essential regulatory molecules,and there are three major sRNA classes in plants:microRNAs(miRNAs),phased small interfering RNAs(phased siRNAs or phasiRNAs),and heterochromatic siRNAs(hc-siRNAs).Ex...Small RNAs(sRNAs)are essential regulatory molecules,and there are three major sRNA classes in plants:microRNAs(miRNAs),phased small interfering RNAs(phased siRNAs or phasiRNAs),and heterochromatic siRNAs(hc-siRNAs).Excluding miRNAs,the other two classes are not well annotated or available in public databases for most sequenced plant genomes.We performed a comprehensive sRNA annotation of 143 plant species that have fully sequenced genomes and next-generation sequencing sRNA data publicly available.The results are available via an online repository called sRNAanno(www.plantsRNAs.org).Compared with other public plant sRNA databases,we obtained was much more miRNA annotations,which are more complete and reliable because of the consistent and highly stringent criteria used in our miRNA annotations.sRNAanno also provides free access to genomic information for>22,721 PHAS loci and>22 million hc-siRNA loci annotated from these 143 plant species.Both miRNA and PHAS loci can be easily browsed to view their main features,and a collection of archetypal trans-acting siRNA 3(TAS3)genes were annotated separately for quick access.To facilitate the ease of sRNA annotation,sRNAanno provides free service for sRNA annotations to the community.In summary,the sRNAanno database is a great resource to facilitate genomic and genetic research on plant small RNAs.展开更多
Cellular signaling mediated by heterotrimeric G-proteins,comprised of Gα,Gβ,and Gγsubunits,is a major theme in eukaryotic signal transduction pathways(Oldham and Hamm,2008;Pandey,2019).According to the conventional...Cellular signaling mediated by heterotrimeric G-proteins,comprised of Gα,Gβ,and Gγsubunits,is a major theme in eukaryotic signal transduction pathways(Oldham and Hamm,2008;Pandey,2019).According to the conventional paradigm,the guanine nucleotide(GTP or GDP)-bound status of the Gαprotein determines the active versus inactive state of G-protein signaling:the complex stays in an inactive,heterotrimeric form when the Gαis GDP bound.Signal perception or ligand binding to a G-protein-coupled receptor(GPCR)causes an exchange of GDP for GTP on its cognate Gαsubunit;the GPCR thus acts as a guanine-nucleotide exchange factor(GEF).Upon GTP binding,the Gαdissociates from the Gβγsubunits,and both of these entities can interact with downstream effectors to relay information.The Gαprotein has an inherent GTPase activity,which hydrolyzes the bound GTP,and the protein returns to its GDP-bound form,in complex with Gβγ.Therefore,the GEF activity of GPCRs dictates the active(GTP-bound)versus inactive(GDP-bound)stages of G-protein signaling(Oldham and Hamm,2008;Pandey,2019).展开更多
Phosphatidic acid(PA)is an important class of signaling lipids involved in various biological processes in plants.Functional characterization of mutants of PA-metabolizing enzymes,combined with lipidomics and protein...Phosphatidic acid(PA)is an important class of signaling lipids involved in various biological processes in plants.Functional characterization of mutants of PA-metabolizing enzymes,combined with lipidomics and protein–lipid interaction analyses,has revealed the key role of PA signaling in plant responses to biotic and abiotic stresses.Moreover,PA and its metabolizing enzymes influence several reproductive processes,including gametogenesis,pollen tube growth,self-incompatibility,haploid embryo formation,embryogen-esis,and seed development.They also play a significant role in shaping plant reproductive and root archi-tecture.Recent studies have shed light on the diverse mechanisms of PA’s action,though much remains to be elucidated.Here,we summarize recent advances in the study of PA and its metabolizing enzymes,emphasizing their roles in plant sexual reproduction and architecture.We also explore potential mecha-nisms underlying PA’s functions and discuss future research directions.展开更多
Three kinds of plant growth regulators, gibberellinA 4/7 （GA 4/7 ）, 6-benzylaminopurine （BA）, and chlormequat chloride （CCC）, were evaluated for their ability to promote strobilus and cone production in a Chines...Three kinds of plant growth regulators, gibberellinA 4/7 （GA 4/7 ）, 6-benzylaminopurine （BA）, and chlormequat chloride （CCC）, were evaluated for their ability to promote strobilus and cone production in a Chinese pine （Pinus tabuliformis Carr.） clonal seed orchard. Treatments （0, 250, 500, or 1000 mg L -1 ） were applied during three periods （June- July, July-August and August-September） in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed with GA 4/7 （500 mg L -1 ） from June to September had significantly more female strobili and immature cones than controls and other treatments （p≤0.0001）. The best time to apply GA 4/7 was in June. BA at 500 mg L -1 significantly increased female flower and immature cone production, compared to other treatments and controls （p≤0.0001）, while promotion of male strobili was unchanged. Chlormequat chloride at 1000 mg L -1 significantly increased the number of male strobili, compared to the other treatments （p≤0.0001）. Spraying CCC at500 mg L -1 significantly increased the number of female strobili, compared to controls （p0.05）, but it had no effect on immature cone production （p0.05）. These results are important for improving seed production and seed orchard management of Chinese pine.展开更多
Black raspberry(Rubus occidentalis L.)is a niche fruit crop valued for its flavor and potential health benefits.The improvement of fruit and cane characteristics via molecular breeding technologies has been hindered b...Black raspberry(Rubus occidentalis L.)is a niche fruit crop valued for its flavor and potential health benefits.The improvement of fruit and cane characteristics via molecular breeding technologies has been hindered by the lack of a high-quality reference genome.The recently released draft genome for black raspberry(ORUS 4115-3)lacks assembly of scaffolds to chromosome scale.We used high-throughput chromatin conformation capture(Hi-C)and Proximity-Guided Assembly(PGA)to cluster and order 9650 out of 11,936 contigs of this draft genome assembly into seven pseudo-chromosomes.The seven pseudo-chromosomes cover~97.2%of the total contig length(~223.8 Mb).Locating existing genetic markers on the physical map resolved multiple discrepancies in marker order on the genetic map.Centromeric regions were inferred from recombination frequencies of genetic markers,alignment of 303 bp centromeric sequence with the PGA,and heat map showing the physical contact matrix over the entire genome.We demonstrate a high degree of synteny between each of the seven chromosomes of black raspberry and a high-quality reference genome for strawberry(Fragaria vesca L.)assembled using only PacBio long-read sequences.We conclude that PGA is a cost-effective and rapid method of generating chromosome-scale assemblies from Illumina short-read sequencing data.展开更多
SWEET transporters are a unique class of sugar transporters that play vital roles in various developmental and physiological processes in plants.While the functions of SWEETs have been well established in model plants...SWEET transporters are a unique class of sugar transporters that play vital roles in various developmental and physiological processes in plants.While the functions of SWEETs have been well established in model plants such as Arabidopsis,their functions in economically important fruit crops like pineapple have not been well studied.Here we aimed to investigate the substrate specificity of pineapple SWEETs by comparing the protein sequences of known glucose and sucrose transporters in Arabidopsis with those in pineapple.Our genome-wide approach and 3D structure comparison showed that the Arabidopsis SWEET8 homolog in pineapple,AcSWEET10,shares similar sequences and protein properties responsible for glucose transport.To determine the functional conservation of AcSWEET10,we tested its ability to complement glucose transport mutants in yeast and analyzed its expression in stamens and impact on the microspore phenotype and seed set in transgenic Arabidopsis.The results showed that AcSWEET10 is functionally equivalent to AtSWEET8 and plays a critical role in regulating microspore formation through the regulation of the Callose synthase5(CalS5),which highlights the importance of SWEET transporters in pineapple.This information could have important implications for improving fruit crop yield and quality by manipulating SWEET transporter activity.展开更多
Understanding how root systems modulate shoot system phenotypes is a fundamental question in plant biology and will be useful in developing resilient agricultural crops.Grafting is a common horticultural practice that...Understanding how root systems modulate shoot system phenotypes is a fundamental question in plant biology and will be useful in developing resilient agricultural crops.Grafting is a common horticultural practice that joins the roots(rootstock)of one plant to the shoot(scion)of another,providing an excellent method for investigating how these two organ systems affect each other.In this study,we used the French-American hybrid grapevine‘Chambourcin’(Vitis L.)as a model to explore the rootstock–scion relationship.We examined leaf shape,ion concentrations,and gene expression in‘Chambourcin’grown ungrafted as well as grafted to three different rootstocks(‘SO4’,‘1103P’and‘3309C’)across 2 years and three different irrigation treatments.We found that a significant amount of the variation in leaf shape could be explained by the interaction between rootstock and irrigation.For ion concentrations,the primary source of variation identified was the position of a leaf in a shoot,although rootstock and rootstock by irrigation interaction also explained a significant amount of variation for most ions.Lastly,we found rootstock-specific patterns of gene expression in grafted plants when compared to ungrafted vines.Thus,our work reveals the subtle and complex effect of grafting on‘Chambourcin’leaf morphology,ionomics,and gene expression.展开更多
Lipid phosphorylation by diacylglycerol kinase(DGK)that produces phosphatidic acid(PA)plays important roles in various biological processes,including stress responses,but the underlying mechanisms remain elusive.Here,...Lipid phosphorylation by diacylglycerol kinase(DGK)that produces phosphatidic acid(PA)plays important roles in various biological processes,including stress responses,but the underlying mechanisms remain elusive.Here,we show that DGK5 and its lipid product PA suppress ABA biosynthesis by interacting withABA-DEFICIENT2(ABA2),a key ABA biosynthesis enzyme,to negatively modulate plant responseto abiotic stress tested in Arabidopsis thaliana.Loss of DGK5 function rendered plants less damaged,whereas overexpression(OE)of DGK5 enhanced plant damage to water and salt stress.The dgk5 mutant plants exhibited decreased total cellular and nuclear levels of PA with increased levels of diacylglycerol,whereas DGK5-OE plants displayed the opposite effect.Interestingly,we found that both DGK5 and PA bind to the ABA-synthesizing enzyme ABA2 and suppress its enzymatic activity.Consistently,the dgk5 mutant plants exhibited increased levels of ABA,while DGK5-OE plants showed reduced ABA levels.In addition,we showed that both DGK5 and ABA2 are detected in and outside the nuclei,and loss of DGK5 function decreased the nuclear association of ABA2.We found that both DGK5 activity and PA promote nuclear association of ABA2.Taken together,these results indicate that both DGK5 and PA interact with ABA2 to inhibit its enzymatic activity and promote its nuclear sequestration,thereby sup-pressing ABA production in response to abiotic stress.Our study reveals a sophisticated mechanism by which DGK5 and PA regulate plant stress responses.展开更多
Plants respond to low-nutrient conditions through metabolic and morphology changes that increase their ability to survive and grow. The transcription factor RAP2.11 was identified as a component in the response to low...Plants respond to low-nutrient conditions through metabolic and morphology changes that increase their ability to survive and grow. The transcription factor RAP2.11 was identified as a component in the response to low potassium through regulation of the high-affinity K＋ uptake transporter AtHAK5 and other components of the low- potassium signal transduction pathway. RAP2.11 was identified through the activation tagging of Arabidopsis lines that contained a luciferase marker driven by the AtHAK5 promoter that is normally only induced by low potassium. This factor bound to a GCC-box of the AtHAK5 promoter in vitro and in vivo. Transcript profiling revealed that a large number of genes were up-regulated in roots by RAP2.11 overexpression. Many regulated genes were identified to be in functional cate- gories that are important in Iow-K＋ signaling. These categories included ethylene signaling, reactive oxygen species pro- duction, and calcium signaling. Promoter regions of the up-regulated genes were enriched in the GCCGGC motif also contained in the AtHAK5 promoter. These results suggest that RAP2.11 regulates AtHAK5 expression under Iow-K＋ con- ditions and also contributes to a coordinated response to low-potassium conditions through the regulation of other genes in the Iow-K＋ signaling cascade.展开更多
Plant sphingolipids are not only structural components of the plasma membrane and other endomembrane systems but also act as signaling molecules during biotic and abiotic stresses.However,the roles of sphingolipids in...Plant sphingolipids are not only structural components of the plasma membrane and other endomembrane systems but also act as signaling molecules during biotic and abiotic stresses.However,the roles of sphingolipids in plant signal transduction in response to environmental cues are yet to be investigated in detail. In this review,we discuss the signaling roles of sphingolipid metabolites with a focus on plant sphingolipids.We also mention some microbial sphingolipids that initiate signals during their interaction with plants, because of the limited literatures on their plant analogs.The equilibrium of nonphosphorylated and phosphorylated sphingolipid species determine the destiny of plant cells,whereas molecular connections among the enzymes responsible for this equilibrium in a coordinated signaling network are poorly understood.A mechanistic link between the phytohormone-sphingolipid interplay has also not yet been fully understood and many key participants involved in this complex interaction operating under stress conditions await to be identified.Future research is needed to fill these gaps and to better understand the signal pathways of plant sphingolipids and their interplay with other signals in response to environmental stresses.展开更多
Sulfur is essential for plant growth and development, and the molecular systems for maintaining sulfur and thiol metabolism are tightly controlled. From a biochemical perspective, the regulation of plant thiol metabol...Sulfur is essential for plant growth and development, and the molecular systems for maintaining sulfur and thiol metabolism are tightly controlled. From a biochemical perspective, the regulation of plant thiol metabolism high- lights nature＇s ability to engineer pathways that respond to multiple inputs and cellular demands under a range of con- ditions. In this review, we focus on the regulatory mechanisms that form the molecular basis of biochemical sulfur sensing in plants by translating the intracellular concentration of sulfur-containing compounds into control of key metabolic steps. These mechanisms range from the simple （substrate availability, thermodynamic properties of reactions, feedback inhi- bition, and organelle localization） to the elaborate （formation of multienzyme complexes and thiol-based redox switches）. Ultimately, the dynamic interplay of these regulatory systems is critical for sensing and maintaining sulfur assimilation and thiol metabolism in plants.展开更多
Cereal crops including maize,rice,wheat,sorghum,barley,millet,oats and rye are the major calorie sources in our daily life and also important bioenergy sources of the world.The rapidly advancing and state-of-the-art g...Cereal crops including maize,rice,wheat,sorghum,barley,millet,oats and rye are the major calorie sources in our daily life and also important bioenergy sources of the world.The rapidly advancing and state-of-the-art genome-editing tools such as zinc finger nucleases,TAL effector nucleases,and clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated systems(CRISPR-Cas9-,CRISPR-Cas12a-and CRISPR/Cas-derived base editors)have accelerated the functional genomics and have promising potential for precision breeding of grass crops.With the availability of annotated genomes of the major cereal crops,application of these established genome-editing toolkits to grass plants holds promise to increase the nutritional value and productivity.Furthermore,these easy-to-use and robust genome-editing toolkits have advanced the reverse genetics for discovery of novel gene functions in crop plants.In this review,we document some of important progress in development and utilization of genome-editing tool sets in grass plants.We also highlight present and future uses of genome-editing toolkits that can sustain and improve the quality of cereal grain for food consumption.展开更多
基金supported by a sub-award to the University of Missouri from the Heinrich Heine University of Dusseldorf funded by the Bill&Melinda Gates Foundation(OPP1155704)(Bing Yang)and the China Scholar Council(Chenhao Li,as a joint Ph.D.student).
文摘Bacterial blight(BB),caused by Xanthomonas oryzae pathovar oryzae(Xoo),poses a significant threat to rice production,particularly in Asia and West Africa.Breeding resistance against BB in elite rice varieties is crucial to advancing rice breeding program and supporting smallholder farmers.Transcription Activator-Like effectors(TALes)are key virulence factors in Xoo,with some targeting the susceptibility(S)genes such as the sugar transporter SWEET genes in rice.Among these,SWEET14 is an important S gene,with its promoter bound by the TALe TalC which exists across all sequenced African Xoo isolates.In the present study,we utilized CRISPR/Cas9-based cytidine and adenine base editors to alter the effector binding element(EBE)of TalC in the promoter of SWEET14 in rice cultivars Kitaake,IR24,and Zhonghua 11.Mutations with C to T changes in EBE led to reduced SWEET14 induction by TalC-containing Xoo strains,resulting in resistance to African Xoo isolates reliant on TalC for virulence.Conversely,A to G changes retained SWEET14 inducibility and susceptibility to Xoo in edited lines.Importantly,no off-target mutations were detected at predicted sites,and the edited lines exhibited no obvious defects in major agronomic traits in Kitaake.These results underscore the effectiveness of base editing systems for both molecular biology research and crop improvement endeavors.
基金supported by the National Natural Science Foundation of China(Grant Nos.32272191 and 32350410428).
文摘Male gametes are produced in the anthers and are essential for fertilization and seed setting.A transverse section of the anther reveals four layers:the epidermis,endothecium,middle layer,and tapetum.The tapetum,being the innermost layer,plays a critical role in supplying nutrients,enzymes,and protection to microspores.Detailed microscopic and ultrastructural analyses have revealed highly active and well-organized structures within the tapetum,referred to as tapetal organelles.Molecular studies have highlighted the significance of tapetal cell death and the nurturing role of the tapetum for microspores.However,the mechanisms by which these processes are mediated by tapetal organelles at the cellular level remain elusive.The discovery of mutants defective in tapetal organelles has enabled further investigations into their structure,morphology,and function.This review discusses the molecular and functional roles of various tapetal organelles,such as plastids(amyloplasts and elaioplasts),mitochondria,tapetosomes,endoplasmic reticulum,and lipid bodies.We provide an overview of their roles,highlight key organelles in the tapetum,and address recent challenges and potential applications of genes regulating tapetal organelles in enhancing crop fertility.
基金the National Key Research and Developmental Program of China(2018YFD1000104)the National Natural Science Foundation of China(#31872063)+4 种基金the Special Support Program of Guangdong Province(2019TX05N193)the Guangzhou Science and Technology Key Project(201804020063)the Innovation Team Project of the Department of Education of Guangdong Province(2016KCXTD011)the Key Areas of Science and Technology Planning Project of Guangdong Province(2018B020202011)the Guangdong Innovative and Entrepreneurial Research Team Program(2016ZT06S172)。
文摘Small RNAs(sRNAs)are essential regulatory molecules,and there are three major sRNA classes in plants:microRNAs(miRNAs),phased small interfering RNAs(phased siRNAs or phasiRNAs),and heterochromatic siRNAs(hc-siRNAs).Excluding miRNAs,the other two classes are not well annotated or available in public databases for most sequenced plant genomes.We performed a comprehensive sRNA annotation of 143 plant species that have fully sequenced genomes and next-generation sequencing sRNA data publicly available.The results are available via an online repository called sRNAanno(www.plantsRNAs.org).Compared with other public plant sRNA databases,we obtained was much more miRNA annotations,which are more complete and reliable because of the consistent and highly stringent criteria used in our miRNA annotations.sRNAanno also provides free access to genomic information for>22,721 PHAS loci and>22 million hc-siRNA loci annotated from these 143 plant species.Both miRNA and PHAS loci can be easily browsed to view their main features,and a collection of archetypal trans-acting siRNA 3(TAS3)genes were annotated separately for quick access.To facilitate the ease of sRNA annotation,sRNAanno provides free service for sRNA annotations to the community.In summary,the sRNAanno database is a great resource to facilitate genomic and genetic research on plant small RNAs.
基金supported by National Science Foundation grants(MCB-2207012 and IOS-2421468)to S.P.
文摘Cellular signaling mediated by heterotrimeric G-proteins,comprised of Gα,Gβ,and Gγsubunits,is a major theme in eukaryotic signal transduction pathways(Oldham and Hamm,2008;Pandey,2019).According to the conventional paradigm,the guanine nucleotide(GTP or GDP)-bound status of the Gαprotein determines the active versus inactive state of G-protein signaling:the complex stays in an inactive,heterotrimeric form when the Gαis GDP bound.Signal perception or ligand binding to a G-protein-coupled receptor(GPCR)causes an exchange of GDP for GTP on its cognate Gαsubunit;the GPCR thus acts as a guanine-nucleotide exchange factor(GEF).Upon GTP binding,the Gαdissociates from the Gβγsubunits,and both of these entities can interact with downstream effectors to relay information.The Gαprotein has an inherent GTPase activity,which hydrolyzes the bound GTP,and the protein returns to its GDP-bound form,in complex with Gβγ.Therefore,the GEF activity of GPCRs dictates the active(GTP-bound)versus inactive(GDP-bound)stages of G-protein signaling(Oldham and Hamm,2008;Pandey,2019).
基金supported by grants from the National Institute of General Medical Sciences of the National Institutes of Health under award no.R01GM141374the National Science Foundation under grant nos.2222157 and 2302424the USDA National Institute of Food and Agriculture 2020-67013-30908/project accession no.1022148.
文摘Phosphatidic acid(PA)is an important class of signaling lipids involved in various biological processes in plants.Functional characterization of mutants of PA-metabolizing enzymes,combined with lipidomics and protein–lipid interaction analyses,has revealed the key role of PA signaling in plant responses to biotic and abiotic stresses.Moreover,PA and its metabolizing enzymes influence several reproductive processes,including gametogenesis,pollen tube growth,self-incompatibility,haploid embryo formation,embryogen-esis,and seed development.They also play a significant role in shaping plant reproductive and root archi-tecture.Recent studies have shed light on the diverse mechanisms of PA’s action,though much remains to be elucidated.Here,we summarize recent advances in the study of PA and its metabolizing enzymes,emphasizing their roles in plant sexual reproduction and architecture.We also explore potential mecha-nisms underlying PA’s functions and discuss future research directions.
基金Partial funding for this research was provided by The State Forestry Administration of China(No.2006-85)
文摘Three kinds of plant growth regulators, gibberellinA 4/7 （GA 4/7 ）, 6-benzylaminopurine （BA）, and chlormequat chloride （CCC）, were evaluated for their ability to promote strobilus and cone production in a Chinese pine （Pinus tabuliformis Carr.） clonal seed orchard. Treatments （0, 250, 500, or 1000 mg L -1 ） were applied during three periods （June- July, July-August and August-September） in 2005. Of the three plant growth regulators, GA 4/7 was the best for promoting flower and cone production. Trees sprayed with GA 4/7 （500 mg L -1 ） from June to September had significantly more female strobili and immature cones than controls and other treatments （p≤0.0001）. The best time to apply GA 4/7 was in June. BA at 500 mg L -1 significantly increased female flower and immature cone production, compared to other treatments and controls （p≤0.0001）, while promotion of male strobili was unchanged. Chlormequat chloride at 1000 mg L -1 significantly increased the number of male strobili, compared to the other treatments （p≤0.0001）. Spraying CCC at500 mg L -1 significantly increased the number of female strobili, compared to controls （p0.05）, but it had no effect on immature cone production （p0.05）. These results are important for improving seed production and seed orchard management of Chinese pine.
文摘Black raspberry(Rubus occidentalis L.)is a niche fruit crop valued for its flavor and potential health benefits.The improvement of fruit and cane characteristics via molecular breeding technologies has been hindered by the lack of a high-quality reference genome.The recently released draft genome for black raspberry(ORUS 4115-3)lacks assembly of scaffolds to chromosome scale.We used high-throughput chromatin conformation capture(Hi-C)and Proximity-Guided Assembly(PGA)to cluster and order 9650 out of 11,936 contigs of this draft genome assembly into seven pseudo-chromosomes.The seven pseudo-chromosomes cover~97.2%of the total contig length(~223.8 Mb).Locating existing genetic markers on the physical map resolved multiple discrepancies in marker order on the genetic map.Centromeric regions were inferred from recombination frequencies of genetic markers,alignment of 303 bp centromeric sequence with the PGA,and heat map showing the physical contact matrix over the entire genome.We demonstrate a high degree of synteny between each of the seven chromosomes of black raspberry and a high-quality reference genome for strawberry(Fragaria vesca L.)assembled using only PacBio long-read sequences.We conclude that PGA is a cost-effective and rapid method of generating chromosome-scale assemblies from Illumina short-read sequencing data.
基金We especially thank Dr Binghua Wu(Fujian Agriculture and Forestry University,China)for kindly providing the yeast mutant strain EBY.VW4000 and Prof.Zhong-Nan Yang(Shanghai Normal University,China)for sharing Atsweet8 seeds.This work was supported by the Science and Technology Major Project of Guangxi(Gui Ke AA22068096)the Science and Technology Innovation Project of Pingtan Science and Technology Research Institute(PT2021007,PT2021003)+2 种基金the General Project of Fujian Natural Science Foundation(2020 J01594)the Project of Guangxi Featured Fruit Innovation Team on Pineapple Breeding and Cultivation Post under the National Modern Agricultural Industry Technology System(nycytxgxcxtd-17-05)the Guangxi Academy of Agricultural Sciences Basic Research Project(Gui Nong Ke 2021YT046).The funding bodies played no role in the design of the study and collection,analysis and interpretation of the data,and writing the manuscript.
文摘SWEET transporters are a unique class of sugar transporters that play vital roles in various developmental and physiological processes in plants.While the functions of SWEETs have been well established in model plants such as Arabidopsis,their functions in economically important fruit crops like pineapple have not been well studied.Here we aimed to investigate the substrate specificity of pineapple SWEETs by comparing the protein sequences of known glucose and sucrose transporters in Arabidopsis with those in pineapple.Our genome-wide approach and 3D structure comparison showed that the Arabidopsis SWEET8 homolog in pineapple,AcSWEET10,shares similar sequences and protein properties responsible for glucose transport.To determine the functional conservation of AcSWEET10,we tested its ability to complement glucose transport mutants in yeast and analyzed its expression in stamens and impact on the microspore phenotype and seed set in transgenic Arabidopsis.The results showed that AcSWEET10 is functionally equivalent to AtSWEET8 and plays a critical role in regulating microspore formation through the regulation of the Callose synthase5(CalS5),which highlights the importance of SWEET transporters in pineapple.This information could have important implications for improving fruit crop yield and quality by manipulating SWEET transporter activity.
基金supported by appropriated funds to USDAARS-GGRU for project 8060-21220-006-00Dsupported by the USDA National Institute of Food and Agriculture,and by Michigan State University AgBioResearchsupport from National Science Foundation(NSF)Plant Genome Research Program award DBI#154689,NSF/EPSCoR Cooperative Agreement#IIA-1355423 and BioSNTR which is funded in part by the South Dakota Research and Innovation Center that supported this research.
文摘Understanding how root systems modulate shoot system phenotypes is a fundamental question in plant biology and will be useful in developing resilient agricultural crops.Grafting is a common horticultural practice that joins the roots(rootstock)of one plant to the shoot(scion)of another,providing an excellent method for investigating how these two organ systems affect each other.In this study,we used the French-American hybrid grapevine‘Chambourcin’(Vitis L.)as a model to explore the rootstock–scion relationship.We examined leaf shape,ion concentrations,and gene expression in‘Chambourcin’grown ungrafted as well as grafted to three different rootstocks(‘SO4’,‘1103P’and‘3309C’)across 2 years and three different irrigation treatments.We found that a significant amount of the variation in leaf shape could be explained by the interaction between rootstock and irrigation.For ion concentrations,the primary source of variation identified was the position of a leaf in a shoot,although rootstock and rootstock by irrigation interaction also explained a significant amount of variation for most ions.Lastly,we found rootstock-specific patterns of gene expression in grafted plants when compared to ungrafted vines.Thus,our work reveals the subtle and complex effect of grafting on‘Chambourcin’leaf morphology,ionomics,and gene expression.
基金Research reported in this article was supported by the National Institute of General Medical Sciences of the National Institutes of Health under award number R01GM141374 and the National Science Foundation grants 2222157 and 2302424.
文摘Lipid phosphorylation by diacylglycerol kinase(DGK)that produces phosphatidic acid(PA)plays important roles in various biological processes,including stress responses,but the underlying mechanisms remain elusive.Here,we show that DGK5 and its lipid product PA suppress ABA biosynthesis by interacting withABA-DEFICIENT2(ABA2),a key ABA biosynthesis enzyme,to negatively modulate plant responseto abiotic stress tested in Arabidopsis thaliana.Loss of DGK5 function rendered plants less damaged,whereas overexpression(OE)of DGK5 enhanced plant damage to water and salt stress.The dgk5 mutant plants exhibited decreased total cellular and nuclear levels of PA with increased levels of diacylglycerol,whereas DGK5-OE plants displayed the opposite effect.Interestingly,we found that both DGK5 and PA bind to the ABA-synthesizing enzyme ABA2 and suppress its enzymatic activity.Consistently,the dgk5 mutant plants exhibited increased levels of ABA,while DGK5-OE plants showed reduced ABA levels.In addition,we showed that both DGK5 and ABA2 are detected in and outside the nuclei,and loss of DGK5 function decreased the nuclear association of ABA2.We found that both DGK5 activity and PA promote nuclear association of ABA2.Taken together,these results indicate that both DGK5 and PA interact with ABA2 to inhibit its enzymatic activity and promote its nuclear sequestration,thereby sup-pressing ABA production in response to abiotic stress.Our study reveals a sophisticated mechanism by which DGK5 and PA regulate plant stress responses.
文摘Plants respond to low-nutrient conditions through metabolic and morphology changes that increase their ability to survive and grow. The transcription factor RAP2.11 was identified as a component in the response to low potassium through regulation of the high-affinity K＋ uptake transporter AtHAK5 and other components of the low- potassium signal transduction pathway. RAP2.11 was identified through the activation tagging of Arabidopsis lines that contained a luciferase marker driven by the AtHAK5 promoter that is normally only induced by low potassium. This factor bound to a GCC-box of the AtHAK5 promoter in vitro and in vivo. Transcript profiling revealed that a large number of genes were up-regulated in roots by RAP2.11 overexpression. Many regulated genes were identified to be in functional cate- gories that are important in Iow-K＋ signaling. These categories included ethylene signaling, reactive oxygen species pro- duction, and calcium signaling. Promoter regions of the up-regulated genes were enriched in the GCCGGC motif also contained in the AtHAK5 promoter. These results suggest that RAP2.11 regulates AtHAK5 expression under Iow-K＋ con- ditions and also contributes to a coordinated response to low-potassium conditions through the regulation of other genes in the Iow-K＋ signaling cascade.
基金the National Natural Science Foundation of China (31570808)the Fundamental Research Funds for the Central Universities (2662015PY090).
文摘Plant sphingolipids are not only structural components of the plasma membrane and other endomembrane systems but also act as signaling molecules during biotic and abiotic stresses.However,the roles of sphingolipids in plant signal transduction in response to environmental cues are yet to be investigated in detail. In this review,we discuss the signaling roles of sphingolipid metabolites with a focus on plant sphingolipids.We also mention some microbial sphingolipids that initiate signals during their interaction with plants, because of the limited literatures on their plant analogs.The equilibrium of nonphosphorylated and phosphorylated sphingolipid species determine the destiny of plant cells,whereas molecular connections among the enzymes responsible for this equilibrium in a coordinated signaling network are poorly understood.A mechanistic link between the phytohormone-sphingolipid interplay has also not yet been fully understood and many key participants involved in this complex interaction operating under stress conditions await to be identified.Future research is needed to fill these gaps and to better understand the signal pathways of plant sphingolipids and their interplay with other signals in response to environmental stresses.
基金This work was funded by grants from the US Department of Agriculture （NRI-2005-02518） and the National Science Foundation （MCB-0824492）. No conflict of interest declared.
文摘Sulfur is essential for plant growth and development, and the molecular systems for maintaining sulfur and thiol metabolism are tightly controlled. From a biochemical perspective, the regulation of plant thiol metabolism high- lights nature＇s ability to engineer pathways that respond to multiple inputs and cellular demands under a range of con- ditions. In this review, we focus on the regulatory mechanisms that form the molecular basis of biochemical sulfur sensing in plants by translating the intracellular concentration of sulfur-containing compounds into control of key metabolic steps. These mechanisms range from the simple （substrate availability, thermodynamic properties of reactions, feedback inhi- bition, and organelle localization） to the elaborate （formation of multienzyme complexes and thiol-based redox switches）. Ultimately, the dynamic interplay of these regulatory systems is critical for sensing and maintaining sulfur assimilation and thiol metabolism in plants.
基金The authors gratefully acknowledge grant support from the National Science Foundation(1936492 to B.Y.)a subaward to MU from Heinrich Heine University of Dusseldorf,which was funded by the Bill&Melinda Gates Foundation[OPP1155704](B.Y.).
文摘Cereal crops including maize,rice,wheat,sorghum,barley,millet,oats and rye are the major calorie sources in our daily life and also important bioenergy sources of the world.The rapidly advancing and state-of-the-art genome-editing tools such as zinc finger nucleases,TAL effector nucleases,and clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated systems(CRISPR-Cas9-,CRISPR-Cas12a-and CRISPR/Cas-derived base editors)have accelerated the functional genomics and have promising potential for precision breeding of grass crops.With the availability of annotated genomes of the major cereal crops,application of these established genome-editing toolkits to grass plants holds promise to increase the nutritional value and productivity.Furthermore,these easy-to-use and robust genome-editing toolkits have advanced the reverse genetics for discovery of novel gene functions in crop plants.In this review,we document some of important progress in development and utilization of genome-editing tool sets in grass plants.We also highlight present and future uses of genome-editing toolkits that can sustain and improve the quality of cereal grain for food consumption.
