通讯机构：
[Zou, XX; Ou, LJ ; Liu, ZB] H;[Zou, XX ] N;Hunan Agr Univ, Coll Hort, Engn Res Ctr Hort Crop Germplasm Creat & New Varie, Key Lab Vegetable Biol Hunan Prov,Minist Educ, Changsha 410125, Peoples R China.;Nanjing Agr Univ, Coll Hort, 1 Weigang, Nanjing 210095, Peoples R China.;Yuelushan Lab, Changsha 410128, Peoples R China.
摘要：
Carotenoids play indispensable roles in the ripening process of fleshy fruits. Capsanthin is a widely distributed and utilized natural red carotenoid. However, the regulatory genes involved in capsanthin biosynthesis remain insufficient. Here, we identified the MADS-box transcription factor RIPENING INHIBITOR (MADS-RIN) in pepper (Capsicum annuum), which regulates ripening in climacteric tomato (Solanum lycopersicum) fruits, using weighted gene co-expression network analysis. We found MADS-RIN can directly bind to the promoters of carotenoid biosynthetic genes phytoene synthase 1 (PSY1) and capsanthin/capsorubin synthase (CCS) and the promoter of DIVARICATA1 to activate their expression, thereby regulating carotenoid biosynthesis directly or indirectly. The physical interaction between MADS-RIN and DIVARICATA1 enhances the transactivation effect on PSY1 and CCS. The self-transactivation of MADS-RIN demonstrates its capability to expedite the above process under specific conditions. Interestingly, chromatin immunoprecipitation sequencing assays revealed consistency and divergence of potential targets of MADS-RIN in climacteric tomato and nonclimacteric pepper fruits, suggesting potential conservation and variation of MADS-RIN in regulating ripening and carotenoid metabolism. The present study illustrates the regulatory mechanism of the MADS-RIN-DIVARICATA1 module in capsanthin biosynthesis in pepper, providing targets for breeding high-quality peppers. These findings enrich our understanding of the regulatory network of carotenoid biosynthesis and offer insights into the complex mechanisms of MADS-RIN in climacteric/nonclimacteric fruit ripening and carotenoid biosynthesis. A MADS-box transcription factor, RIPENING INHIBITOR (MADS-RIN), regulates carotenoid biosynthesis in nonclimacteric pepper fruits through its dominant MADS-RIN-DIVARICATA1 module.
摘要：
Pepper (Capsicum annuum L.), recognized as a globally preeminent vegetable, holds substantial economic and nutritional value. The BTB (broad-complex, tramtrack, and bric-a-brac) family of proteins, characterized by a highly conserved BTB domain, also denoted as the POZ domain, are intricately involved in a diverse array of biological processes. However, the existing corpus of research regarding pepper BTB genes remains relatively meager. In this study, a total of 72 CaBTB gene members were meticulously identified from the entire genome of pepper. Phylogenetic analysis illuminated the presence of conspicuous collinear relationships between the CaBTB genes and those of its closely affiliated species. Gene expression profiling and RT-qPCR analysis revealed that multiple CaBTB genes exhibited pronounced differential expression under diverse treatment regimens. Expression pattern analysis unveiled that CaBTB25 manifested a remarkably elevated abundance in leaves. Moreover, its promoters were replete with an abundance of light-responsive cis-elements. Our comprehensive and in-depth explorations into subcellular localization revealed that CaBTB25 was predominantly detected to localize within the nucleus and lacked transcriptional activation. This research provides a crucial theoretical edifice, enabling a more profound understanding of the biological functions of the BTB gene family in pepper, thereby underscoring its potential significance within the intricate network of gene-environment interactions.
作者机构：
College of Horticulture, Hunan Agricultural University, International Collaborative Joint Laboratory for Germplasm Innovation, Molecular Breeding of Horticultural Crops, Ministry of Education, Engineering Research Center of Germplasm Innovation, New Variety Breeding for Horticultural Crops, Changsha, 410128, China;Yuelushan Laboratory, Changsha, 410128, China;[朱凡; 胡博文; 杨莎; 熊程; 欧立军; 刘熠; 刘峰; 戴雄泽] 湖南农业大学园艺学院,教育部园艺作物种质创新与分子育种国际合作联合实验室,园艺作物种质创新与新品种选育教育部工程研究中心;[王中一; 邹学校] 湖南农业大学园艺学院,教育部园艺作物种质创新与分子育种国际合作联合实验室,园艺作物种质创新与新品种选育教育部工程研究中心<&wdkj&>岳麓山实验室
通讯机构：
[Liu, F; Wang, ZY ] H;Hunan Agr Univ, Coll Hort, Engn Res Ctr Hort Crop Germplasm Creat & New Varie, Key Lab Vegetable Biol Hunan Prov, Changsha 410128, Peoples R China.;Yuelushan Lab, Changsha 410128, Peoples R China.
关键词：
YABBY transcription factor;pepper;expression pattern;CaYABBY5;CaSEP3;flower organs development
摘要：
Pepper fruit is highly favored for its spicy taste, diverse flavors, and significant nutritional benefits. The proper development of flowers and fruits directly determines the quality of pepper fruit. The YABBY gene family exhibits diverse functions in growth and development, which is crucial to the identity of flower organs. However, the specific functions of these genes in pepper remain unclear. In this study, nine CaYABBY genes were identified and characterized in pepper. Most CaYABBY genes were highly expressed in reproductive organs, albeit with varying expression patterns. The CaYABBY5 gene, uniquely expressed in petals and carpels, has been demonstrated to modulate floral organ determinacy and fruit shape through gene silencing in pepper and ectopic expression in tomato. Protein interaction analysis revealed an interacting protein SEPALLATA3-like protein (SEP3), exhibiting a similar expression profile to CaYABBY5 . These findings suggest that CaYABBY5 may modulate the morphogenesis of floral organs and fruits by interacting with CaSEP3. This study provided valuable insights into the classification and function of CaYABBY genes in pepper.
Pepper fruit is highly favored for its spicy taste, diverse flavors, and significant nutritional benefits. The proper development of flowers and fruits directly determines the quality of pepper fruit. The YABBY gene family exhibits diverse functions in growth and development, which is crucial to the identity of flower organs. However, the specific functions of these genes in pepper remain unclear. In this study, nine CaYABBY genes were identified and characterized in pepper. Most CaYABBY genes were highly expressed in reproductive organs, albeit with varying expression patterns. The CaYABBY5 gene, uniquely expressed in petals and carpels, has been demonstrated to modulate floral organ determinacy and fruit shape through gene silencing in pepper and ectopic expression in tomato. Protein interaction analysis revealed an interacting protein SEPALLATA3-like protein (SEP3), exhibiting a similar expression profile to CaYABBY5 . These findings suggest that CaYABBY5 may modulate the morphogenesis of floral organs and fruits by interacting with CaSEP3. This study provided valuable insights into the classification and function of CaYABBY genes in pepper.
摘要：
Pepper ( Capsicum annuum L.) is a typical self-pollinating crop with obvious heterosis in hybrids. Consequently, the use of morphological markers during the pepper seedling stage is crucial for pepper breeding. The color of hypocotyl is widely used as a phenotypic marker in crossing studies of pepper. Pepper accessions generally have purple hypocotyls, which are mainly due to the anthocyanin accumulation in seedlings, and green hypocotyls are rarely observed in pepper. Here we reported the characterization of a green hypocotyl mutant of pepper, Cha1 , which was identified from a pepper ethyl methanesulfonate (EMS) mutant library. Fine mapping revealed that the causal gene, CaTTG1 , belonging to the WD40 repeat family, controlled the green hypocotyl phenotype of the mutant. Virus-induced gene silencing (VIGS) confirmed that CaTTG1 regulated anthocyanin accumulation. RNA-seq data showed that expression of structural genes CaDFR , CaANS , and CaUF3GT in the anthocyanin biosynthetic pathway was significantly decreased in Cha1 compared to the wild type. Yeast two-hybrid (Y2H) experiments also confirmed that CaTTG1 activated the synthesis of anthocyanin structural genes by forming a MBW complex with CaAN1 and CaGL3. In summary, this study provided a green hypocotyl mutant of pepper, and the Kompetitive Allele Specific PCR (KASP) marker developed based on the mutation site of the underlying gene would be helpful for pepper breeding.
Pepper ( Capsicum annuum L.) is a typical self-pollinating crop with obvious heterosis in hybrids. Consequently, the use of morphological markers during the pepper seedling stage is crucial for pepper breeding. The color of hypocotyl is widely used as a phenotypic marker in crossing studies of pepper. Pepper accessions generally have purple hypocotyls, which are mainly due to the anthocyanin accumulation in seedlings, and green hypocotyls are rarely observed in pepper. Here we reported the characterization of a green hypocotyl mutant of pepper, Cha1 , which was identified from a pepper ethyl methanesulfonate (EMS) mutant library. Fine mapping revealed that the causal gene, CaTTG1 , belonging to the WD40 repeat family, controlled the green hypocotyl phenotype of the mutant. Virus-induced gene silencing (VIGS) confirmed that CaTTG1 regulated anthocyanin accumulation. RNA-seq data showed that expression of structural genes CaDFR , CaANS , and CaUF3GT in the anthocyanin biosynthetic pathway was significantly decreased in Cha1 compared to the wild type. Yeast two-hybrid (Y2H) experiments also confirmed that CaTTG1 activated the synthesis of anthocyanin structural genes by forming a MBW complex with CaAN1 and CaGL3. In summary, this study provided a green hypocotyl mutant of pepper, and the Kompetitive Allele Specific PCR (KASP) marker developed based on the mutation site of the underlying gene would be helpful for pepper breeding.
摘要：
The OVATE FAMILY PROTEIN (OFP) genes encode transcription factors pivotal for plant growth and reproductive development. In pepper ( Capsicum annuum L.), previous research has primarily focused on OFP’s role in regulating fruit shape; however, the mechanism by which OFP influences floral development and fertility in pepper remains unclear. In this study, we investigated the functional role of CaOFP20 , a member of the OFP family in pepper, in regulating floral development and fertility. Results showed that the overexpression of CaOFP20 in tomato ( Solanum lycopersicum L.) resulted in evident phenotypic alterations, including aberrant floral architecture and reduced fertility. Male sterility was evident through a significant decrease in viable pollen grains and abnormalities in pollen development, while female fertility was impaired by anomalous ovule development and seed abortion. Transcriptomic analysis via RNA sequencing demonstrated that CaOFP20 overexpression significantly altered the expression of genes associated with floral morphogenesis, hormonal signaling pathways, and lipid metabolism. Notably, CaOFP20 was observed to interact with CaAG , suggesting a regulatory module governing flower development and fertility. The upregulated expression of gibberellin oxidase genes indicated that CaOFP20 modulates gibberellin homeostasis via the gibberellin catabolic pathway. These findings elucidate a regulatory mechanism by which CaOFP20 influences reproductive development in pepper, providing insights into its broader role in plant fertility.
The OVATE FAMILY PROTEIN (OFP) genes encode transcription factors pivotal for plant growth and reproductive development. In pepper ( Capsicum annuum L.), previous research has primarily focused on OFP’s role in regulating fruit shape; however, the mechanism by which OFP influences floral development and fertility in pepper remains unclear. In this study, we investigated the functional role of CaOFP20 , a member of the OFP family in pepper, in regulating floral development and fertility. Results showed that the overexpression of CaOFP20 in tomato ( Solanum lycopersicum L.) resulted in evident phenotypic alterations, including aberrant floral architecture and reduced fertility. Male sterility was evident through a significant decrease in viable pollen grains and abnormalities in pollen development, while female fertility was impaired by anomalous ovule development and seed abortion. Transcriptomic analysis via RNA sequencing demonstrated that CaOFP20 overexpression significantly altered the expression of genes associated with floral morphogenesis, hormonal signaling pathways, and lipid metabolism. Notably, CaOFP20 was observed to interact with CaAG , suggesting a regulatory module governing flower development and fertility. The upregulated expression of gibberellin oxidase genes indicated that CaOFP20 modulates gibberellin homeostasis via the gibberellin catabolic pathway. These findings elucidate a regulatory mechanism by which CaOFP20 influences reproductive development in pepper, providing insights into its broader role in plant fertility.
作者机构：
Hunan Vegetable Research Institute, Hunan, Changsha, 410125, China;Hunan Engineering Research Center on Excavation and Utilization of the Endophytic Microbial Resources of Plants, Hunan, Changsha, 410125, China;College of Horticulture, Hunan Agricultural University, Hunan, Changsha, 410125, China;[陶禹; 董志雪; 张竹青; 李雪峰; 陈文超; 周池; 李鑫; 周诗晶] 湖南省蔬菜研究所<&wdkj&>植物内生微生物资源挖掘与利用湖南省工程研究中心;[姚苏航] 湖南省蔬菜研究所<&wdkj&>植物内生微生物资源挖掘与利用湖南省工程研究中心<&wdkj&>湖南农业大学园艺学院
关键词：
辣椒;内生微生物;群落结构;生态位;溯源分析
摘要：
【目的】探究辣椒不同生态位间内生微生物群落的差异及其潜在关联，以期为辣椒内生微生物资源的挖掘和应用提供理论依据。【方法】采用16SrRNA基因和内转录间隔区(internal transcribed spacer, ITS)基因测序技术，比较分析91份辣椒材料不同生态位(根、茎、叶和果)内生细菌和真菌的群落结构特征，并进行功能注释；此外，针对内生细菌群落进行共现网络分析和溯源分析。【结果】四个生态位点内生微生物群落的操作分类单元(operational taxonomic unit, OTU)高度共享，其中，细菌的共享OTUs占比46.36%，真菌的共享OTUs占比29.66%。不同生态位间，辣椒内生细菌和真菌群落的多样性差异显著，根部的内生细菌和真菌群落与其他3个生态位显著分离(P<0.05)；内生细菌群落的Shannon指数在不同生态位间差异显著，而内生真菌则相对稳定。辣椒中的优势内生细菌为变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidota)，其中，变形菌门在根部富集，而厚壁菌门和拟杆菌门则在果中占据优势。子囊菌门(Ascomycota)和担子菌门(Basidiomycota)作为主要的内生真菌优势菌群，在4个生态位中的相对丰度差异较小。功能注释结果显示，辣椒含有多种具有次生代谢物生物合成和抗生素生物合成功能的内生细菌；而在真菌群落中，病原真菌的相对丰度最高。此外，辣椒中超过80%的内生细菌来源于与其直接相连的形态学下方生态位，具有复杂的相互作用网络、较强的群落稳定性和模块结构。【结论】相较于内生真菌，辣椒内生细菌的群落组成对生态位的变化更为敏感，而真菌的生态位特异性较弱。辣椒各生态位的内生细菌主要源自其形态学下方生态位，表现出显著的生态位富集作用，且根部在内生细菌群落塑造中起着至关重要的作用。
摘要：
Environmental temperature significantly affects plant growth and development, particularly flower development. In pepper (Capsicum annuum), the molecular mechanisms underlying temperature-mediated floral organ development remain unclear. Gibberellins (GAs) are key plant hormones regulating growth and development, including flower development, and the CaGA20ox gene family may play a crucial role in this process due to its involvement in GA biosynthesis. In this study, we comprehensively analyzed the CaGA20ox gene family across six pepper genomes ('Zhangshugang', 'Zunla', 'Chiltepin', 'CM334', 'Ca59', and 'T2T') to explore their roles in flower development and temperature stress response, identifying five to six genes per genome. These genes exhibited distinct expression patterns across different tissues and developmental stages, with some members showing higher expression in specific floral organs, particularly pistils. Our results revealed that temperature significantly impacts pepper flower development and GA content, with lower temperatures enhancing antioxidant capacity and increasing GA levels. Specifically, the expression levels of four CazGA20ox genes (CazGA20ox1, CazGA20ox2, CazGA20ox4, and CazGA20ox6) were significantly influenced by temperature changes. Our systematic analysis of the role of the CaGA20ox gene family in temperature-mediated pepper flower development provides a foundation for further studies on the molecular mechanisms as well as the development of improved pepper varieties.
摘要：
Natural genetic variation can be used to improve important crop agronomic traits, and understanding the genetic basis of natural variation in fruit shape can help breeders develop pepper varieties that meet market demand. In this study, we identified a QTL controlling fruit length-width ratio by conventional genetic mapping, encoding a previously uncharacterized gene CaIQD1. Reduced CaIQD1 expression resulted in short and wide fruits in pepper, whereas heterologous overexpression of CaIQD1 resulted in narrower fruits in tomato. Further experiments suggested that CaIQD1 regulates fruit shape in pepper by affecting cell proliferation, expansion and morphological changes. CaIQD1 also has a direct protein interaction with CaOFP20 in CaTRM-like-CaOFP20. Reduced CaOFP20 expression caused pepper fruits to become elongated and curved, whereas reduced CaTRM-like expression led to the formation of rounder fruits. These gene expression changes had a significant effect on the expression of genes related to the cell cycle and cell expansion. The CaTRM-like-CaOFP20-CaIQD1 module may thus represent a conserved regulatory pathway for controlling pepper fruit shape. CaIQD1 also showed direct interactions with the pepper calmodulin CaCaM7, the tubulin CaMAP70-2 and the microtubule motor protein CaKLCR1, suggesting that the regulation of fruit shape by CaIQD1 is related to changes in microtubule dynamics mediated by Ca(2+)-CaM. We also found that CaIQD1 interacts with several homologues of genes that typically regulate fruit shape in other plant species. In summary, our results show that CaIQD1 acts as a core hub in regulating pepper fruit shape through interactions with multiple proteins.
摘要：
Pepper is a major horticultural crop cultivated extensively worldwide. Among its various agronomic characteristics, fruit length is a key trait influencing both yield and visual quality. Despite its importance, the genetic mechanisms regulating fruit length in Capsicum remain insufficiently characterized, hindering the development of high-yielding and aesthetically desirable cultivars. In this study, fruits at three developmental stages (0, 15, and 30 days after flowering) were sampled from the long-fruit mutant fe1 and its wild-type progenitor LY0. Phenotypic characterization and transcriptomic sequencing were conducted to identify candidate genes associated with fruit length regulation. Morphological analysis revealed that the most pronounced difference in fruit length occurred at 30 days after flowering. RNA-seq analysis identified 41,194 genes, including 13,512 differentially expressed genes (DEGs). Enrichment analysis highlighted key pathways, such as plant-pathogen interaction, plant hormone signal transduction, and the MAPK signaling pathway. DEG classification suggested that several downregulated genes related to early auxin responses may contribute to the regulation of fruit elongation. Notably, the gibberellin signaling gene SCL13 (Caz12g26660), transcription factors MYB48 (Caz11g07190) and ERF3-like (Caz10g00810), and the cell-wall-modifying gene XTH15-like (Caz07g19100) showed significantly elevated expression in 30-day-old fruits of fe1. Weighted gene co-expression network analysis (WGCNA) further revealed a strong positive correlation among these genes. Quantitative RT-PCR analysis of eight selected DEGs confirmed the RNA-seq results. This study provides a foundational framework for dissecting the molecular regulatory network of fruit length in Capsicum, offering valuable insights for breeding programs.
通讯机构：
[Zou, XX; Ou, LJ ] H;[Hou, XL; Zou, XX ] N;Nanjing Agr Univ, Coll Hort, 1 Weigang, Nanjing 210095, Peoples R China.;Hunan Agr Univ, Coll Hort, Engn Res Ctr Hort Crop Germplasm Creat & New Varie, Key Lab Vegetable Biol Hunan Prov,Minist Educ, Changsha 410125, Peoples R China.;Yuelushan Lab, Changsha 410128, Peoples R China.
关键词：
Red pepper;Metabolomics;Transcriptomics;Natural pigment;Flavonoid;Carotenoid;Regulatory gene
摘要：
Pepper is highly popular as a vegetable, spice, and natural red pigment material. However, little is known about metabolite accumulation dynamics in red pepper pericarp, which limits the full utilization of nutrients at different stages of pepper pericarp development. Moreover, few regulatory genes responsible for natural pigment flavonoids and carotenoids biosynthesis were reported in peppers, resulting in a constrained understanding of the molecular mechanisms that contribute to their formation. Here, we identified 1429 metabolites for the first time during the development and ripening processes of three color-transition types of red peppers (white/purple/green transition to red, respectively), by widely-targeted and carotenoid-targeted metabolomics analysis. Metabolites’ weighted gene co-expression network analysis (mWGCNA) was performed to analyze the accumulation patterns of metabolites in widely-targeted metabolomics. Among them, 290 flavonoids and 68 carotenoids were identified, revealing the material basis of the natural purple color and red color peppers. The formation of the purple color in '5' is crucially dependent on delphinidin-3-O-(2′''-O-p-coumaroyl) rutinoside-5-O-glucoside and delphinidin-3-O-(2′''-O-p-coumaroyl) rutinoside-7-O-glucoside, especially the former, while capsanthin plays a crucial role in the appearance of the red color in peppers. Integrating transcriptome and metabolome data for WGCNA, potential regulatory genes MYB113, TT8, TT8 - like, TTG1 , and BRF for anthocyanins biosynthesis, and DIVARICATA1, MADS - RIN, AGL9 - like , and Y subunit for capsanthin biosynthesis were identified. Our research is crucial for maximizing the edible and industrial application of pepper. The identified potential regulatory genes for anthocyanins and capsanthin provide a reference for an in-depth study of natural pigment biosynthetic mechanisms in pepper.
Pepper is highly popular as a vegetable, spice, and natural red pigment material. However, little is known about metabolite accumulation dynamics in red pepper pericarp, which limits the full utilization of nutrients at different stages of pepper pericarp development. Moreover, few regulatory genes responsible for natural pigment flavonoids and carotenoids biosynthesis were reported in peppers, resulting in a constrained understanding of the molecular mechanisms that contribute to their formation. Here, we identified 1429 metabolites for the first time during the development and ripening processes of three color-transition types of red peppers (white/purple/green transition to red, respectively), by widely-targeted and carotenoid-targeted metabolomics analysis. Metabolites’ weighted gene co-expression network analysis (mWGCNA) was performed to analyze the accumulation patterns of metabolites in widely-targeted metabolomics. Among them, 290 flavonoids and 68 carotenoids were identified, revealing the material basis of the natural purple color and red color peppers. The formation of the purple color in '5' is crucially dependent on delphinidin-3-O-(2′''-O-p-coumaroyl) rutinoside-5-O-glucoside and delphinidin-3-O-(2′''-O-p-coumaroyl) rutinoside-7-O-glucoside, especially the former, while capsanthin plays a crucial role in the appearance of the red color in peppers. Integrating transcriptome and metabolome data for WGCNA, potential regulatory genes MYB113, TT8, TT8 - like, TTG1 , and BRF for anthocyanins biosynthesis, and DIVARICATA1, MADS - RIN, AGL9 - like , and Y subunit for capsanthin biosynthesis were identified. Our research is crucial for maximizing the edible and industrial application of pepper. The identified potential regulatory genes for anthocyanins and capsanthin provide a reference for an in-depth study of natural pigment biosynthetic mechanisms in pepper.
通讯机构：
[Xiong, C; Zhu, F; Liu, F ] H;Hunan Agr Univ, Coll Hort, Engn Res Ctr Germplasm Innovat & New Varieties Bre, Key Lab Vegetable Biol Hunan Prov, Changsha 410128, Peoples R China.
摘要：
Chlorophylls and carotenoids are 2 pivotal photosynthetic pigments directly influencing the economic value of pepper (Capsicum annuum L.) fruits. However, the coordinated regulatory mechanisms governing the accumulation of both chlorophylls and carotenoids during pepper fruit development remain elusive. In this study, pepper B-box 10 (CaBBX10), a candidate hub transcription factor, was found to play dual roles in the early development of pepper fruit. CaBBX10 virus-induced gene silencing and overexpression experiments demonstrated that the encoded transcription factor promotes both chlorophyll and carotenoid accumulation in pepper fruit. Further comprehensive analyses showed that CaBBX10 directly binds to the promoter of magnesium chelatase subunit D subunit (CaCHLD) and phytoene synthase 1 (CaPSY1), thereby activating their expression in the chlorophyll and carotenoid biosynthesis pathways, respectively. Additionally, the photomorphogenic factor CaCOP1 was found to physically interact with CaBBX10 and lead to its degradation. Therefore, CaBBX10 may serve as a critical link connecting chlorophyll and carotenoid biosynthesis to light signaling. Altogether, our findings reveal a mechanism for the complex transcriptional regulation that simultaneously promotes chlorophyll and carotenoid accumulation in pepper fruit.
关键词：
CaAFR1;CaMYB61;Khib;cellulose and hemicellulose;histone deacetylases;stem lodging
摘要：
Plant stems constitute the most abundant renewable resource on earth. The function of lysine (K)-2-hydroxyisobutyrylation (K(hib)), a novel post-translational modification (PTM), has not yet been elucidated in plant stem development. Here, by assessing typical pepper genotypes with straight stem (SS) and prostrate stem (PS), we report the first large-scale proteomics analysis for protein K(hib) to date. K(hib)-modifications influenced central metabolic processes involved in stem development, such as glycolysis/gluconeogenesis and protein translation. The high K(hib) level regulated gene expression and protein accumulation associated with cell wall formation in the pepper stem. Specially, we found that CaMYB61 knockdown lines that exhibited prostrate stem phenotypes had high K(hib) levels. Most histone deacetylases (HDACs, e.g., switch-independent 3 associated polypeptide function related 1, AFR1) potentially function as the "erasing enzymes" involved in reversing K(hib) level. CaMYB61 positively regulated CaAFR1 expression to erase K(hib) and promote cellulose and hemicellulose accumulation in the stem. Therefore, we propose a bidirectional regulation hypothesis of "K(hib) modifications" and "K(hib) erasing" in stem development, and reveal a novel epigenetic regulatory network in which the CaMYB61-CaAFR1 molecular module participating in the regulation of K(hib) levels and biosynthesis of cellulose and hemicellulose for the first time.
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 F(1) plants. To enhance pepper breeding efficiency, 176 important pepper breeding parent materials were resequenced, and a PepperSNP50K liquid-phase breeding chip was developed, comprising 51 172 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.
