通讯机构：
[Wei Liu; Xuexiao Zou] C;[Zhuqing Zhang] V;College of Horticulture, Hunan Agricultural University, Changsha, Hunan 410128, China<&wdkj&>Longping Branch, Graduate School of Hunan University, Changsha, Hunan 410125, Chin<&wdkj&>College of Life Sciences and Environment, Hengyang Normal University, Hengyang, Henan 421008, China<&wdkj&>Vegetable Institution of Hunan Academy of Agricultural Science, Changsha, Hunan 410125, China
摘要：
The stay-green trait is of considerable importance in extending the shelf life of green pepper fruit (Capsicum annuum L.) and in enhancing the appearance of ornamental plants. The study revealed the genetic and regulatory mechanisms of the stay-green trait in pepper, which will aid in the selection of ornamental pepper varieties. In this study, a pepper mutant with stay-green fruit named TNX348 was identified from a germplasm resource bank. Two segregating populations were constructed using the stay-green mutant TNX348 and then used in bulked segre-gant analysis combined with RNA sequencing and linkage analyses. The causal gene of the stay-green trait was mapped to an approximately 131-kb region, and a senescence-induced chloroplast protein gene, CaSGR1 (Capana01g000359), was identified as a candidate gene. Sequencing analysis revealed a G -> A single-base mutation of CaSGR1 in TNX348 that led to early termination of translation. Based on the single-base mu-tation, a single nucleotide polymorphism (SNP) marker co-segregating with the stay-green trait was developed. Furthermore, in transcriptome analysis, expression patterns of 11 hormone transduction-related transcription factors, such as abscisic acid-insensitive (ABI), abscisic acid-responsive element-binding factor (ABF), and NAC transcription factor, were similar or opposite to that of CaSGR1. The results indicated that the transcription factors might mediate chlorophyll degradation by regulating the expression of CaSGR1.
通讯机构：
[Liu, F ] H;Hunan Agr Univ, Coll Hort, Engn Res Ctr, Key Lab Vegetable Biol Hunan Prov,Educ Minist,Germ, Changsha 410125, Peoples R China.;Hunan Univ, Longping Branch, Grad Sch, Changsha 410125, Hunan, Peoples R China.
关键词：
Pepper;Transcriptome;Flower development;Period-specific expression;Transcription factor;ABCDE model
摘要：
An analysis of genome-wide gene expression profiles during floral organ development can provide important clues about the molecular basis of gene functions and developmental processes. In this study, we analyzed the transcriptome data of 36 samples obtained during floral organ development from pepper ‘6421’ and detected 30 016 genes that were expressed in at least one sample. K-means clustering analysis was used to classify the data into 16 clusters based on the similarities between the dynamic expression profiles of genes. Of these, 15 clusters exhibited notable up-regulation or down-regulation trends in different developmental stages or tissues of floral organs. We identified transcription factors expressed at the early, medium, and late stages of bud development (F1, F5, F9). Transcription factor families such as AP2-ERF, MADS-box, MYB, bHLH, and NAC showed significant levels of enrichment. In comparison with genes expressed in vegetative tissues at different stages, certain genes were specifically up-regulated during flower development; among these, the number of genes specifically up-regulated during the stamen (Sta10) and bud tetrad development (F4) stages was the highest. Through extensive studies of the ABCDE model of flower development in Arabidopsis, we identified 17 ABCDE model candidate genes in pepper, most of which were up-regulated at specific stages of flower bud development. The expression data provided in this study is the most comprehensive dataset available for pepper to date and will serve as a resource for identifying the functions of many specific genes involved in flower development in pepper and other Solanaceae plants.
摘要：
The leaf is an important plant organ and is closely related to agricultural yield. Photosynthesis plays a critical role in promoting plant growth and development. Understanding the mechanism of leaf photosynthesis regulation will help improve crop yield. In this study, the pepper yellowing mutant was used as the experimental material, and the photosynthetic changes of pepper leaves (yl1 and 6421) under different light intensities were analyzed by chlorophyll fluorimeter and photosynthesis meter. Changes in proteins and enrichment of phosphopeptides in pepper leaves were determined. The results showed that different light intensities had significant effects on the chlorophyll fluorescence and photosynthetic parameters of pepper leaves. The differentially expressed proteins (DEPs) and differentially expressed phosphorylated proteins (DEPPs) were mainly involved in photosynthesis, photosynthesis-antenna proteins, and carbon fixation in photosynthetic organisms. In yl1 leaves, the phosphorylation levels of photosynthesis and photosynthesis-antenna proteins LHCA2, LHCA3, PsbC, PsbO, and PsbP were lower under low light treatment, but significantly higher under high light intensity compared with wild-type leaves. In addition, many proteins involved in the carbon assimilation pathway, including TKT, Rubisco, and PGK, were phosphorylated, and this modification level was significantly higher in yl1 than in the wild type under high light intensity. These results provide a new perspective for studying the photosynthesis mechanism of pepper under different light intensities.
通讯机构：
[Yang, S ; Ou, LJ] H;Hunan Agr Univ, Coll Hort, Engn Res Ctr Educ, Key Lab Vegetable Biol Hunan Prov,Minist Germplasm, Changsha 410125, Peoples R China.
摘要：
Light quality and intensity can have a significant impact on plant health and crop productivity. Chlorophylls and carotenoids are classes of plant pigments that are responsible for harvesting light energy and protecting plants from the damaging effects of intense light. Our understanding of the role played by plant pigments in light sensitivity has been aided by light-sensitive mutants that change colors upon exposure to light of variable intensity. In this study, we conducted transcriptomic, metabolomic, and hormone analyses on a novel yellowing mutant of pepper (yl1) to shed light on the molecular mechanism that regulates the transition from green to yellow leaves in this mutant upon exposure to high-intensity light. Our results revealed greater accumulation of the carotenoid precursor phytoene and the carotenoids phytofluene, antheraxanthin, and zeaxanthin in yl1 compared with wild-type plants under high light intensity. A transcriptomic analysis confirmed that enzymes involved in zeaxanthin and antheraxanthin biosynthesis were upregulated in yl1 upon exposure to high-intensity light. We also identified a single basic helix-loop-helix (bHLH) transcription factor, bHLH71-like, that was differentially expressed and positively correlated with light intensity in yl1. Silencing of bHLH71-like in pepper plants suppressed the yellowing phenotype and led to reduced accumulation of zeaxanthin and antheraxanthin. We propose that the yellow phenotype of yl1 induced by high light intensity could be caused by an increase in yellow carotenoid pigments, concurrent with a decrease in chlorophyll accumulation. Our results also suggest that bHLH71-like functions as a positive regulator of carotenoid biosynthesis in pepper.
期刊：
Theoretical and Applied Genetics,2023年136(3):1-15 ISSN：0040-5752
通讯作者：
Xuexiao Zou<&wdkj&>Cheng Xiong<&wdkj&>Feng Liu
作者机构：
[Zhou, Xiaoxun; Shan, Qingyun; Yi, Ting; Ma, Yanqing; Wang, Jin; Zou, Xuexiao; Liu, Feng; Xiong, Cheng; Pan, Luzhao] Hunan Agr Univ, Coll Hort, Engn Res Ctr Germplasm Innovat & New Varieties Bre, Key Lab Vegetable Biol Hunan Prov, Changsha, Hunan, Peoples R China.;[Wang, Jin; Zou, Xuexiao; Pan, Luzhao] Nanjing Agr Univ, Coll Hort, Nanjing, Peoples R China.;[Miao, Wu] Hunan Xiangyan Seed Ind Co LTD, Changsha, Peoples R China.
通讯机构：
[Xuexiao Zou; Cheng Xiong; Feng Liu] E;Engineering Research Center for Germplasm Innovation and New Varieties Breeding of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha, China<&wdkj&>College of Horticulture, Nanjing Agricultural University, Nanjing, China<&wdkj&>Engineering Research Center for Germplasm Innovation and New Varieties Breeding of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha, China<&wdkj&>Engineering Research Center for Germplasm Innovation and New Varieties Breeding of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, College of Horticulture, Hunan Agricultural University, Changsha, China
摘要：
CaFCD1 gene regulates pepper cuticle biosynthesis. Pepper (Capsicum annuum L.) is an economically important vegetable crop that easily loses water after harvesting, which seriously affects the quality of its product. The cuticle is the lipid water-retaining layer on the outside of the fruit epidermis, which regulates the biological properties and reduces the rate of water-loss. However, the key genes involved in pepper fruit cuticle development are poorly understood. In this study, a pepper fruit cuticle development mutant fcd1 (fruit cuticle deficiency 1) was obtained by ethyl methanesulfonate mutagenesis. The mutant has great defects in fruit cuticle development, and the fruit water-loss rate of fcd1is significantly higher than that of the wild-type '8214' line. Genetic analysis suggested that the phenotype of the mutant fcd1 cuticle development defect was controlled by a recessive candidate gene CaFCD1 (Capsicum annuum fruit cuticle deficiency 1) on chromosome 12, which is mainly transcribed during fruit development. In fcd1, a base substitution within the CaFCD1 domain resulted in the premature termination of transcription, which affected cutin and wax biosynthesis in pepper fruit, as revealed by the GC-MS and RNA-seq analysis. Furthermore, the yeast one-hybrid and dual-luciferase reporter assays verified that the cutin synthesis protein CaCD2 was directly bound to the promoter of CaFCD1, suggesting that CaFCD1 may be a hub node in the cutin and wax biosynthetic regulatory network in pepper. This study provides a reference for candidate genes of cuticle synthesis and lays a foundation for breeding excellent pepper varieties.
摘要：
辣椒(Capsicum annuum)是茄科辣椒属一年生或有限多年生草本植物。DNA损伤结合蛋白1(damaged DNA binding protein 1,DDB1)基因在番茄(Solanum lycopersicu...展开更多 辣椒(Capsicum annuum)是茄科辣椒属一年生或有限多年生草本植物。DNA损伤结合蛋白1(damaged DNA binding protein 1,DDB1)基因在番茄(Solanum lycopersicum)和拟南芥(Arabidopsis thaliana)等模式植物中已有一定研究,但该基因在辣椒中的功能尚不明确。本研究在辣椒中克隆了番茄DDB1同源基因,命名为CaDDB1(GenBank No.XM_016701551)。采用病毒诱导基因沉默(virus-induced gene silencing,VIGS)技术获得了辣椒CaDDB1基因沉默植株,通过观察其表型,初步鉴定了CaDDB1的生物学功能。研究结果表明,CaDDB1基因沉默后辣椒植株极显著矮化(P<0.01),第3~6片真叶花青素含量极显著升高(P<0.01),说明CaDDB1基因影响辣椒的生长发育并在花青素合成方面起负调控作用。本研究结果为辣椒生长发育调控及品种改良提供一定的理论指导。收起
通讯机构：
[Yanqing Ma] V;[Xuexiao Zou] C;Vegetable Institution of Hunan Academy of Agricultural Science, Changsha 410125, China<&wdkj&>College of Horticulture, Hunan Agricultural University, Changsha 410128, China
摘要：
Leaf color is directly related to altered photosynthesis. Hence, leaf yellowing mutants can be widely used for the researching plant phys-iology and functional genomes, for cultivating new varieties of popular horticultural plants, and for identifying hybrid purity (as markers). Here, we constructed a 60Co-g F2 population from the leaf-yellowing mutant R24 via radiation mutation with the inbred line WT21 of pepper. Genetic analysis showed that the leaf-yellowing of the mutant was controlled by a single recessive gene. By applying the Bulk Segregation Analysis and Kompetitive Allele Specific PCR markers, the leaf-yellowing gene CaLY1 (Capsicum annuum Leaf yellow 1) was mapped on chromosome 9, SNP5791587-SNP6011215, with a size of 214.5 kb. One non-synonymous mutated gene Capana09g000166 was found in the interval. The gene encoded a PsbX, which is the core complex of PSII. Transcriptome analysis further showed that 2301 differentially expressed genes were identified under shading treatment for 24 h in R24. The Gene Ontology enrichment pathways were related to photosynthesis light harvesting, cell wall, activity of quercetin 3-O-glucosyltransferase and flavonoid metabolic process, which likely regulate the response of pepper leaves to different light levels. Functional enrichment analysis indicated that the most abundant pathways were photosynthesis antenna proteins and metabolic.
摘要：
Pepper (Capsicum annuum L.) is one of the most widely grown vegetable crops in China, with widespread cultivation worldwide. Fruit weight (size) is a complex trait controlled by multiple factors and is an essential determinant of pepper yield. In this study, we analyzed the transcriptome of two pepper recombinant lines with different fruit weights, 'B302' and 'B400', at five developmental stages to reveal some of the differentially expressed genes and mechanisms controlling fruit weight. The results showed that 21,878 differential genes were identified between the two specimens. Further analysis of the differentially expressed genes revealed that Boron transporter 4 was significantly highly expressed in the large-fruited pepper and almost not expressed at all in the small-fruited pepper. CaAUX1, CaAUX/IAA, CaGH3, CaSAUR, and other related genes in the Auxin signal transduction pathway were highly expressed in the large-fruited pepper but significantly reduced in the small-fruited pepper. In addition, a comparison of differentially expressed transcription factors at different times revealed that transcription factors such as CaMADS3, CaAGL8, CaATHB13, and CaATHB-40 were highly differentially expressed in the large-fruited pepper, and these transcription factors may be related to pepper fruit expansion. Through weighted gene co-expression network analysis (WGCNA), the MEorangered4 module was shown to have a highly significant correlation with fruit weight, and the key modules were analyzed by constructing the hub core gene network interactions map and core genes regulating fruit weight such as APETALA 2 were found. In conclusion, we find that the expression of relevant genes at different developmental stages was different in 'B302' and 'B400', and it was hypothesized that these genes play essential roles in the development of fruit size and that the interactions occurring between transcription factors and phytohormones may regulate the development of fruit size.
摘要：
Pepper is among the most economically important solanaceous vegetable crops worldwide. The shape and spatial distribution of leaves affect the light energy use efficiency of the plant, which strongly affects the yield and quality of pepper fruit. However, the molecular mechanisms underlying pepper leaf development are unknown. In this study, we demonstrated that the CaSRM1 gene regulates pepper leaf morphology. Virus-induced gene silencing was used to reveal that silencing of CaSRM1 caused development of uneven leaf margins and curling of pepper leaves. Overexpression of CaSRM1 in tomato led to leaf morphological defects, but was accompanied by improved vegetative growth and larger fruit. The expression level of CaSRM1 in mature tissues was higher than that in young tissues of pepper plant, and its expression was induced by auxin. Analysis of phytohormone contents and expression of leaf shape-related genes revealed that the auxin content showed an opposite trend to CaSRM1 expression, and certain leaf shape-related genes were affected by CaSRM1 expression, especially auxin-related genes. The results provide important information for functional research on other SRM1 genes and offer a novel perspective to the mechanism of plant leaf and fruit development.
