通讯机构：
[Ou, LJ ; Qin, D; Qin, D ] H;Hunan Agr Univ, Coll Hort, Changsha 410128, Peoples R China.;Hunan Agr Univ, Engn Res Ctr Hort Crop Germplasm Creat & New Varie, Minist Educ, Changsha 410128, Peoples R China.;Hunan Agr Univ, Coll Food Sci & Technol, Changsha 410128, Peoples R China.
关键词：
fresh chili pepper;fermented chopped chili pepper;process adaptability;quality appraisal;sensory appraisal
摘要：
Fermented chopped chili pepper (FCCP) is the most important fermented and processed chili pepper product, and most pepper varieties can be processed with obvious flavor differences. Many studies have tried to explain these differences using the results of component analysis, processing technology, the microbes involved, etc., but few have examined the characteristics of these varieties along with the flavor of products. We conducted a physiochemical characteristic analysis of 35 kinds of fresh chili peppers with different genotypes and made fermented products from 17 varieties, using principal component analysis (PCA) and cluster analysis (CA) to correlate their components with FCCP products. The results were as follows: (1) Protein, total acids, a* (representation of the object's red and green color), protopectin, and fruit thickness are the five key indexes that affect the quality of fresh chili peppers the most. (2) Protein, total acids, a*, protopectin, and fruit thickness are also the key indexes that affect the quality of FCCP. (3) Suitable ranges of fresh chili pepper to manufacture FCCP are 1.3-2.0 g/100 g for protein, 2.5-4.0 g/kg for total acids, 10-15 g/100 g for protopectin, 30-39 for a*, and 1.2-2.0 mm for fruit thickness. (4) Sensory appraisal shows crispness is the most important mouthfeel sensation and can decrease during the process. The varieties with the top three scores were A12 (21G675), A13 (20Z663), and A14 (21Z698) with scores of 87.92, 74.08, and 74.15, respectively. The varieties in the top three scores are pod peppers. The PCA and CA showed that pod peppers were the most suitable materials for making FCCP. Our results will benefit others in selecting fresh chili peppers for making FCCP and provide data support for directing processable variety breeding.
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.
摘要：
Higher plants survive terrestrial water deficiency and fluctuation by arresting cellular activities (dehydration) and resuscitating processes (rehydration). However, how plants monitor water availability during rehydration is unknown. Although increases in hypo-osmolarity-induced cytosolic Ca2+ concentration (HOSCA) have long been postulated to be the mechanism for sensing hypo-osmolarity in rehydration1,2, the molecular basis remains unknown. Because osmolarity triggers membrane tension and the osmosensing specificity of osmosensing channels can only be determined in vivo3–5, these channels have been classified as a subtype of mechanosensors. Here we identify bona fide cell surface hypo-osmosensors in Arabidopsis and find that pollen Ca2+ spiking is controlled directly by water through these hypo-osmosensors—that is, Ca2+ spiking is the second messenger for water status. We developed a functional expression screen in Escherichia coli for hypo-osmosensitive channels and identified OSCA2.1, a member of the hyperosmolarity-gated calcium-permeable channel (OSCA) family of proteins6. We screened single and high-order OSCA mutants, and observed that the osca2.1/osca2.2 double-knockout mutant was impaired in pollen germination and HOSCA. OSCA2.1 and OSCA2.2 function as hypo-osmosensitive Ca2+-permeable channels in planta and in HEK293 cells. Decreasing osmolarity of the medium enhanced pollen Ca2+ oscillations, which were mediated by OSCA2.1 and OSCA2.2 and required for germination. OSCA2.1 and OSCA2.2 convert extracellular water status into Ca2+ spiking in pollen and may serve as essential hypo-osmosensors for tracking rehydration in plants. Screening in Escherichia coli and biochemical experiments show that in Arabidopsis thaliana, OSCA2.1 and OSCA2.2 function as plant sensors of hypo-osmolarity, utilize Ca2+ oscillations as second messengers and have crucial roles in pollen germination.
摘要：
Chili pepper is an important spice and a model plant for fruit development studies. Large-scale omics information on chili pepper plant development continues to be gathered for understanding development as well as capsaicin biosynthesis. In this study, a full-spectrum transcriptome data of eight chili pepper tissues at five growth stages using the Oxford Nanopore long-read sequencing approach was generated. Of the 485 351 transcripts, 35 336 were recorded as reference transcripts (genes), while 450 015 were novel including coding, lnc, and other non-coding RNAs. These novel transcripts belonged to unknown/intergenic (347703), those retained introns (26336), and had multi-exons with at least one junction match (20333). In terms of alternative splicing, retained intron had the highest proportion (14795). The number of tissue-specific expressed transcripts ranged from 22 925 (stem) to 40 289 (flower). The expression changes during fruit and placenta development are discussed in detail. Integration of gene expression and capsaicin content quantification throughout the placental development clarifies that capsaicin biosynthesis in pepper is mainly derived from valine, leucin, and isoleucine degradation as well as citrate cycle and/or pyrimidine metabolism pathways. Most importantly, a user-friendly Pepper Full-Length Transcriptome Variation Database (PFTVD 1.0) (http://pepper-database.cn/) has been developed. PFTVD 1.0 provides transcriptomics and genomics information and allows users to analyse the data using various tools implemented. This work highlights the potential of long-read sequencing to discover novel genes and transcripts and their diversity in plant developmental biology.
作者机构：
[Yang, Bozhi; Li, Qing; Fu, Canfang; Ou, Lijun; Yu, Huiyang; He, Huan; Zou, Xuexiao; Hu, Bowen; Xu, Qing] Hunan Agr Univ, Coll Hort, Engn Res Ctr Educ, Minist Germplasm Innovat & Breeding New Variet Hor, Changsha 410125, Peoples R China.;[Yang, Bozhi; Li, Qing; Fu, Canfang; Ou, Lijun; Yu, Huiyang; He, Huan; Zou, Xuexiao; Hu, Bowen; Xu, Qing] Yuelushan Lab, Changsha 410128, Peoples R China.;[Li, Qing] Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Shenzhen Branch, Guangdong Lab Lingnan Modern Agr,Key Lab Synthet B, Shenzhen 518120, Peoples R China.;[Miao, Wu; Liu, Rongyun] Hunan Xiangyan Seed Ind Co Ltd, Changsha 410100, Peoples R China.;[Chen, Wenchao; Zhang, Zhuqing] Hunan Acad Agr Sci, Vegetable Res Inst, Changsha 410125, Peoples R China.
通讯机构：
[Zou, XX; Hu, BW; Ou, LJ ] H;Hunan Agr Univ, Coll Hort, Engn Res Ctr Educ, Minist Germplasm Innovat & Breeding New Variet Hor, Changsha 410125, Peoples R China.;Yuelushan Lab, Changsha 410128, Peoples R China.
摘要：
Lodging presents a significant challenge in cultivating high-yield crops with extensive above-ground biomass, yet the molecular mechanisms underlying this phenomenon in the Solanaceae family remain largely unexplored. In this study, we identified a gene, CaSLR1 (Capsicum annuum Stem Lodging Resistance 1), which encodes a MYELOBLASTOSIS (MYB) family transcription factor, from a lodging-affected C. annuum EMS mutant. The suppression of CaSLR1 expression in pepper led to notable stem lodging, reduced thickness of the secondary cell wall, and decreased stem strength. A similar phenotype was observed in tomato with the knockdown of SlMYB61, the orthologous gene to CaSLR1. Further investigations demonstrated that CaNAC6, a gene involved in secondary cell wall (SCW) formation, is co-expressed with CaSLR1 and acts as a positive regulator of its expression, as confirmed through yeast one-hybrid, dual-luciferase reporter assays, and electrophoretic mobility shift assays. These findings elucidate the CaNAC6-CaSLR1 module that contributes to lodging resistance, emphasizing the critical role of CaSLR1 in the lodging resistance regulatory network.
摘要：
Capsaicinoids are produced uniquely in pepper fruits, and its level determines the commercial quality and health-promoting properties of pepper. So, it is particularly important to increase capsaicinoids content in pepper. Rhizosphere microbiota is critical to plant growth and performance, and affected by plant varieties. However, the impact of pepper varieties with different capsaicinoids yields on the rhizosphere microbiota is poorly understood. Using high-throughput sequencing of the 16S rRNA and internal transcribed spacer (ITS) region, we investigated the rhizosphere microbial community among five pepper varieties containing different capsaicinoids. Our results demonstrated that pepper variety significantly influenced the diversity and structure of rhizosphere microbial community. Bacterial diversity in varieties with high capsaicinoids content was significantly higher than in varieties with low capsaicinoids content, while fungal diversity was opposite to bacterial diversity. The correlation analysis revealed that 19 dominant bacterial genera (e.g., Chujaibacter, Rhodanobacter, and Gemmatimonas) were significantly correlated with capsaicinoids content, and nine of them were also significantly associated with soil nutrients, whereas only one fungal genus (Podospora) was significantly correlated with capsaicinoids content. Additionally, almost all genera which significantly correlated to capsaicinoids content were biomarkers of the five pepper varieties and the correlation was well corresponding to the capsaicinoids content. Overall, our results confirmed that the variety of pepper significantly affected the rhizosphere microbial community in the fields, and bacteria and fungi responded differently to capsaicinoids, which may affect the biosynthesis of capsaicinoids and contribute to further improvement of capsaicinoids production in pepper fruits.
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 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.
