查看更多>>摘要：Powdery mildew(PM),a common disease of many major crop species,including melon(Cucumis melo L.),affects plant growth and fruit quality and seriously reduces production.Using a combined morphological and molecular approach,we attribute the PM pathogen that naturally occurs in melon to Podosphaera xanthii,and specifically to physiological race 1.An investigation into the genetic basis of PM resistance in melon using the resistant accession'PI 164637'and susceptible counterpart'HDZ'reveals dominant inheritance of PM resistance at the seedling stage,supported by F2 and backcross population segregation ratios.Adult plant assessments indicate a major gene with an additive effect for PM resistance.Bulk segregant analysis coupled with high-throughput sequencing identified a significant quantitative trait locus on chromosome 6 that is associated with PM resistance.Genetic mapping narrowed down the candidate region to 63.5 kb using InDel molecular markers,harboring 12 candidate genes.The marker chr06_indel_5 047127 demonstrated high accuracy in screening PM resistance in an F2 segregating population and 30 inbred lines as natural populations.Functional annotation and expression analysis of candidate genes revealed that MYB transcription factor MELO3C006700,GATA transcription factor MELO3C028829 and heparanase-like protein MELO3C006697 are promising candidate genes for PM resistance in melon.The genetic architecture underlying this resistance in melon offers valuable insights for breeding programs,and the identified markers,especially chr06_indel_5 047127,may enable practical applications for marker-assisted selection in developing PM-resistant melon varieties.
查看更多>>摘要：Cytoplasmic male sterility(CMS)is pivotal in plant breeding and widely employed in various crop hybrids,including pepper.However,the functional validation of the restorer of fertility(Rf)gene in pepper has been lacking until now.This study identifies and characterizes CaRf,a single dominant locus crucial for restoring CMS in the pepper strong recovery inbred line Zhangshugang.The CaRf gene encodes a mitochondria-targeted pentatricopeptide repeat protein,validated through the induction of male sterility upon its silencing in hybrid F1 plants.To enhance pepper breeding efficiency,176 important pepper breeding parent materials were resequenced,and a PepperSNP50K liquid-phase breeding chip was developed,comprising 51172 markers.Integration of CaRf functional characterization and PepperSNP50K facilitated the development of a high-quality red pepper hybrid.These findings provide significant insights and practical strategies for advancing molecular-designed breeding in peppers.
查看更多>>摘要：The circadian system of plants is a complex physiological mechanism,a biological process in which plants can adjust themselves according to the day and night cycle.To understand the effects of different photoperiods on the biological clock of tea plants,we analyzed the expression levels of core clock genes(CCA1,PRR9,TOC1,ELF4)and photosynthesis-related genes(Lhcb,RbcS,atpA)under normal light(light/dark=12 h/12 h,12L12D)and took the cost function defined by cycle and phase errors as the basic model parameter.In the continuous light environment(24 h light,24L),the peak activity and cycle of key genes that control the biological clock and photosynthesis were delayed by 1-2 h.Under a skeleton photoperiod(6L6D,3L3D),the expression profiles of clock genes and photosynthesis-related genes in tea plants were changed and stomatal opening showed a circadian rhythm.These observations suggest that a skeleton photoperiod may have an effect on the circadian rhythm,photosynthetic efficiency and stomatal regulation of tea plants.Our study and model analyzed the components of circadian rhythms under different photoperiodic pathways,and also revealed the underlying mechanisms of circadian regulation of photosynthesis in tea plants.
Alana R.BrinleyPatrick J.ConnerFahong YuAli Sarkhosh...
185-198页
查看更多>>摘要：Muscadines face limitations to fresh market production due to high manual labor costs.Mechanical harvesting holds promise for reducing the costs associated with muscadine production but requires cultivars with easily detached fruit at maturity.This study aimed to determine muscadine fruit and pedicel characteristics influencing fruit detachment force(FDF)and to unravel the genes,hormones,and regulatory networks governing muscadine abscission.We characterized the FDF of muscadine fruit across 18 genotypes and at four developmental stages.Following this,we performed a transcriptome analysis using the mature pedicel tissue of two genotypes,a genotype with high FDF at maturity and a genotype with low FDF at maturity,to identify differentially expressed and uniquely expressed genes contributing to fruit detachment.We found that pedicel length,pedicel-fruit junction area,and fruit diameter positively correlated with FDF.This study also identified novel candidate genes,transcription factor families,and pathways associated with muscadine fruit abscission.These findings provide valuable knowledge on the progression of fruit abscission and insights for reducing FDF,particularly in developing machine-harvestable muscadine cultivars and fostering sustainability and efficiency in muscadine production.
查看更多>>摘要：Terpene trilactones(TTLs)have important medicinal value,but their low content in Ginkgo biloba leaves makes their exploitation extremely costly,thereby limiting the development of TTL-related industries.It was found that exogenous methyl jasmonate(MeJA)treatment increased the accumulation of TTLs,but the molecular mechanism is still unclear.Here,we identified two bHLH transcription factors in G.biloba,with the protein subcellular localizations in the nucleus.Expression of GbMYC2s was strongly induced by MeJA treatment,and the interactions between GbJAZs and GbMYC2s were demonstrated by yeast two-hybrid and bimolecular fluorescence complementation experiments.Overexpression of GbMYC2_4 and GbMYC2_5 enhanced Arabidopsis root sensitivity and significantly increased TTL content.In addition,GbGGPPS was found to be a common target of GbMYC2_4 and GbMYC2_5 by yeast one-hybrid,electrophoretic mobility shift,and dual-luciferase reporter assays and DAP-seq,and they achieved regulation of GbGGPPS by binding to the G-box.Further findings revealed that GbMYC2_4 and GbMYC2_5 bind the G-box not universally but selectively.Our study revealed that jasmonic acid signaling mediates TTL biosynthesis through the GbJAZ-GbMYC2-GbGGPPS module,which enriches the terpenoid biosynthesis regulatory networks and provides a research basis and target genes for enhancing TTL content through genetic engineering.
查看更多>>摘要：Sugar beet(Beta vulgaris)has emerged as one of the two primary crops,alongside sugarcane,for global sugar production.Com-prehensively understanding sucrose synthesis,transport,and accumulation in sugar beet holds great significance for enhancing sugar production.In this study,we collected a diverse set of 269 sugar beet accessions worldwide and measured 12 phenotypes,comprising biomass,soluble sugar content,and 10 taproot-related traits.We re-sequenced 207 accessions to explore genetic diversity and population structure.Then we employed a genome-wide association study(GWAS)and RNA-seq to identify single-nucleotide polymorphisms and genes associated with natural phenotypic variations.Our findings revealed a panel of genes potentially regulating biomass and sugar accumulation,notably the dual-role gene UDP-glucose 4-epimerase,which genetically balances sugar accumulation and cell wall synthesis.In summary,this study provides a foundation for molecular breeding in sugar beet.
查看更多>>摘要：Salicylic acid(SA)plays a role in the regulation of grafting-induced cold tolerance.However,the molecular mechanism behind it is still unknown.Here,we established that the phenylalanine ammonia-lyase(PAL)pathway-dependent elevate in SA content in grafted cucumber leaves was not only synthesized in the leaves but also transported from the roots under chilling stress.RNAi-CsPAL with low SA content as rootstock reduced SA accumulation in grafted seedling leaves while decreasing rootstock-induced cold tolerance,as evidenced by higher electrolyte leakage(EL),hydrogen peroxide(H2O2),and superoxide anion(O2-)contents and lower expression of cold-responsive genes(CsICE1,CsDREB1A,CsDREB1B,and CsCOR47),whereas OE-CsPAL with high SA content as rootstock improved the cold tolerance of grafted plants in comparison with the wild type(WT).In addition,CsNPR1 was significantly upregulated in grafted cucumber under chilling stress,with exogenous and endogenous overexpressed SA inducing its transcriptional expression and protein stability,which exhibited higher expression in grafted plants than in self-root plants.While CsNPR1-overexpression(OE-CsNPR1)seedlings as scions were more tolerant to chilling stress than WT seedlings,CsNPR1-suppression(Anti-CsNPR1)seedlings as scions were more vulnerable to chilling stress.Notably,CsNPR1-CsICE1 interactions alleviated ROS accumulation and activated the expression of CsDREB1A,CsDREB1B,CsCOR47,CsCOR15,CsCOR413,and CsKIN1 to enhance SA-mediated chilling tolerance in grafted cucumber.Overall,our findings reveal that SA enhances chilling tolerance in grafted cucumbers via the model of the CsNPR1-CsICE1 transcriptional regulatory cascade.
Luis Felipe V.FerrãoCamila AzevedoJuliana BenevenutoMolla Fentie Mengist...
239-250页
查看更多>>摘要：The global production and consumption of blueberry(Vaccinium spp.),a specialty crop known for its abundant bioactive and antioxidant compounds,has more than doubled over the last decade.To hold this momentum,plant breeders have begun to use quantitative genetics and molecular breeding to guide their decisions and select new cultivars that are improved for fruit quality.In this study,we leveraged our inferences on the genetic basis of fruit texture and chemical components by surveying large breeding populations from northern highbush blueberries(NHBs)and southern highbush blueberries(SHBs),the two dominant cultivated blueberries.After evaluating 1065 NHB genotypes planted at the Oregon State University,and 992 SHB genotypes maintained at the University of Florida for 17 texture-related traits,evaluated over multiple years,our contributions consist of the following:(i)we drew attention to differences between NHB and SHB materials and showed that both blueberry types can be differentiated using texture traits;(ii)we computed genetic parameters and shed light on the genetic architecture of important texture attributes,indicating that most traits had a complex nature with low to moderate heritability;(iii)using molecular breeding,we emphasized that prediction could be performed across populations;and finally(iv)the genomic association analyses pinpointed some genomic regions harboring potential candidate genes for texture that could be used for further validation studies.Altogether,the methods and approaches used here can guide future breeding efforts focused on maximizing texture improvements in blueberries.
查看更多>>摘要：Cucumber(Cucumis sativus)fruit spines are a classic material for researching the development of multicellular trichomes.Some key genes that influence trichome development have been confirmed to be associated with cuticle biosynthesis and secondary metabolism.However,the biological mechanisms underlying trichome development,cuticle biosynthesis,and secondary metabolism in cucumber remain poorly understood.CsTs,a C-type lectin receptor-like kinase gene,reportedly causes a tender trichome phenotype in cucumber when it mutates.In this study,the role of CsTs in cucumber fruit spines morphogenesis was confirmed using gene editing technology.Sectioning and cell wall component detection were used to analyse the main reason of tender fruit spines in the ts mutant.Subsequently,transcriptome data and a series of molecular biology experiments were used to further investigate the relationship between CsTs and cytoskeletal homeostasis in cucumber.CsTs overexpression partially compensated for the abnormal trichome phenotype of an Arabidopsis homolog mutant.Genetic hybridization and metabolic analysis indicated that CsTs and CsMict can affect trichome development and cuticle biosynthesis in the same pathway.Our findings provide important background information for further researching on the molecular mechanism underlying cucumber trichome development and contribute to understanding the biological function of C-type lectin receptor-like kinases.
查看更多>>摘要：Benzenoids/phenylpropanoids,the second most diverse group of plant volatiles,exhibit significant structural diversity and play crucial roles in attracting pollinators and protecting against pathogens,insects,and herbivores.This review summarizes their complex biosynthetic pathways and regulatory mechanisms,highlighting their links to plant growth,development,hormone levels,circadian rhythms,and flower coloration.External factors like light,humidity,and temperature also influence their biosynthesis.Their ecological value is discussed,offering insights for enhancing floral scent,pollinator attraction,pest resistance,and metabolic engineering through genetic modification.
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