关键词：
Coumarins;Biosynthesis;O-Methyltransferase;Catalytic promiscuity and fidelity;Angelica decursiva
摘要：
Angelica decursiva, an important traditional medicinal plant, possesses a unique pharmacological activity. Its principal active ingredients are coumarins, including scopoletin, bergapten, and imperatorin. However, the enzymes catalyzing the critical step of coumarins biosynthesis pathway remain unidentified. This study initially screened 14 candidate O-methyltransferases (OMTs) through transcriptomics and metabolic determination. Combined with gene expression profile and biochemical assays, two OMTs (AdOMT1 and AdOMT2) were identified to be responsible for the O-methylation of coumarins in A. decursiva. AdOMT1 showed higher catalytic efficiency for bergaptol (Kcat/Km = 3123.70), while AdOMT2 exhibited higher substrate and catalytic pro-miscuity, allowing it to catalyze the methylation of various coumarins, phenylpropanes, and flavonoids. Based on molecular docking and site-specific mutagenesis determined that His126/Asn132, Phe171/Phe177, Trp261/ Trp267, and Asn312/Ile317 were the key catalytic residues of AdOMT1 and AdOMT2 for the O-methylation of bergaptol and xanthotoxol. Further phylogenetic analysis confirmed the reasons for the catalytic functional differentiation of AdOMT1 and AdOMT2. This study provides a basis for exploring the coumarins O-methylation mechanism and plays a critical role in diversifying the structures used in coumarins drug discovery.
摘要：
The tea plant is a vital strategic forest resource in China. Dark tea produced from its leaves is an indispensable health-promoting product in western China due to its unique lipid-lowering function. Eurotium cristatum is the dominant strain in Fuzhuan brick tea (a variety of Anhua dark tea) and could produce many functional components, including lovastatin, a lipid-lowering compound. In this study, the lovastatin yield of dark tea was improved by breeding Eurotium cristatum using the protoplast fusion method. The experiments were carried out by inducing a fusion between inactivated Eurotium cristatum JH1205 and Monascus CICC5031. Among the 92 fusants screened the HPLC method, four strains (A4, A36, A54, and A76) with higher lovastatin production (more than three times as high) were obtained. The A76 strain had the highest lovastatin yield, which was 23.93 mu g/mL. The location of the tea forest strongly influenced the lovastatin yield of loose dark tea. The strain bred in this study improved the lovastatin yield of loose dark tea by more than three times when compared to wild Eurotium cristatum. These results are promising for the development of tea forest resources.
摘要：
Protoplast-based engineering has become an important tool for basic plant molecular biology research and developing genome-edited crops. Uncaria rhynchophylla is a traditional Chinese medicinal plant with a variety of pharmaceutically important indole alkaloids. In this study, an optimized protocol for U. rhynchophylla protoplast isolation, purification, and transient gene expression was developed. The best protoplast separation protocol was found to be 0.8 M D-mannitol, 1.25% Cellulase R-10, and 0.6% Macerozyme R-10 enzymolysis for 5 h at 26 degrees C in the dark with constant oscillation at 40 rpm/min. The protoplast yield was as high as 1.5 x 10(7) protoplasts/g fresh weight, and the survival rate of protoplasts was greater than 90%. Furthermore, polyethylene glycol (PEG)-mediated transient transformation of U. rhynchophylla protoplasts was investigated by optimizing different crucial factors affecting transfection efficiency, including plasmid DNA amount, PEG concentration, and transfection duration. The U. rhynchophylla protoplast transfection rate was highest (71%) when protoplasts were transfected overnight at 24 degrees C with the 40 mu g of plasmid DNA for 40 min in a solution containing 40% PEG. This highly efficient protoplast-based transient expression system was used for subcellular localization of transcription factor UrWRKY37. Finally, a dual-luciferase assay was used to detect a transcription factor promoter interaction by co-expressing UrWRKY37 with a UrTDC-promoter reporter plasmid. Taken together, our optimized protocols provide a foundation for future molecular studies of gene function and expression in U. rhynchophylla.
摘要：
Long-term consumption of tea with high fluoride (F) content has a potential threat to human health. The application of different amounts of biochar to reduce F accumulation in tea leaves has been little studied. In this study, a pot experiment was conducted to investigate the effect of biochar amounts (0, 0.5%, 2.5%, 5.0%, 8.0%, and 10.0%, w/w) on tea F content during the tea plant growth. Changes in tea quality, soil F fraction, and soil properties caused by biochar and the relationship with tea F accumulation were also considered. The results showed that the application of biochar amendment significantly reduced water-soluble F contents in tea leaves compared to CK (without biochar), especially in the 8.0% treatment (72.55%). Overall, biochar contributed to improving tea polyphenols and caffeine, but had no significant impact on free amino acids and water leachate. Compared with CK, 5.0-10.0% biochar significantly increased soil water-soluble F content due to the substitution of F- with OH- under high pH. Additionally, biochar applied to tea garden soil was effective in decreasing the soil exchangeable aluminum (Ex-Al) content (46.37-91.90%) and increasing the soil exchangeable calcium (Ca2+) content (12.02-129.74%) compared to CK, and correlation analysis showed that this may help reduce F enrichment of tea leaves. In general, the application of 5.0-8.0% biochar can be suggested as an optimal application dose to decrease tea F contents while simultaneously improving tea quality.
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.
摘要：
Light is a crucial environmental component for plant growth, and light intensity plays a crucial function in controlling pigment anabolism in plants. We performed physiological characterisation, transcriptome, and metabolome investigations on purple leaf peppers treated with different light intensities to evaluate the effect on plant leaf colour. The results showed that the leaves of the peppers became significantly purplish under high light, with significantly higher anthocyanin, chlorophyll a, and carotenoid contents. A total of 44,263 genes were quantified using RNA-Seq, with the photoprotein-related genes LRP and LIP maintaining high expression levels under high and medium light. The anthocyanin synthesis pathway was variously enriched among the comparison groups, according to KEGG. The expression of the genes involved in the anthocyanin synthesis pathway, such as CHI, F3H, DFR, and BZ1, was significantly higher under high light. In addition, MYB and bHLH gene families were the most abundant, and MYB1R1, MYB113-like, and bHLH90-like were significantly expressed under high light and highly positively correlated with the above anthocyanin synthesis genes. According to our metabolomic analysis, delphinidin-3-O-rutinoside and delphinidin-3-O-glucoside accumulated in significant concentrations in purple leaves under high light. This study is useful for understanding the process of anthocyanin synthesis and metabolism in pepper leaves that is generated and regulated by varied light intensity.
摘要：
Primary bud necrosis of grape buds is a physiological disorder that leads to decreased berry yield and has a catastrophic impact on the double cropping system in sub-tropical areas. The pathogenic mechanisms and potential solutions remain unknown. In this study, the progression and irreversibility patterns of primary bud necrosis in 'Summer Black' were examined via staining and transmission electron microscopy observation. Primary bud necrosis was initiated at 60 days after bud break and was characterized by plasmolysis, mitochondrial swelling, and severe damage to other organelles. To reveal the underlying regulatory networks, winter buds were collected during primary bud necrosis progression for integrated transcriptome and metabolome analysis. The accumulation of reactive oxygen species and subsequent signaling cascades disrupted the regulation systems for cellular protein quality. ROS cascade reactions were related to mitochondrial stress that can lead to mitochondrial dysfunction, lipid peroxidation causing damage to membrane structure, and endoplasmic reticulum stress leading to misfolded protein aggregates. All these factors ultimately resulted in primary bud necrosis. Visible tissue browning was associated with the oxidation and decreased levels of flavonoids during primary bud necrosis, while the products of polyunsaturated fatty acids and stilbenes exhibited an increasing trend, leading to a shift in carbon flow from flavonoids to stilbene. Increased ethylene may be closely related to primary bud necrosis, while auxin accelerated cell growth and alleviated necrosis by co-chaperone VvP23-regulated redistribution of auxin in meristem cells. Altogether, this study provides important clues for further study on primary bud necrosis.
作者机构：
[Distefano, Gaetano; Bennici, Stefania; Gentile, Alessandra; Di Guardo, Mario; La Malfa, Stefano; Seminara, Sebastiano] Univ Catania, Dept Agr Food & Environm Di3A, Via Valdisavoia 5, I-95123 Catania, Italy.;[Caruso, Marco] Res Ctr Ol, Council Agr Res & Econ CREA, Fruit & Citrus Crops, Corso Savoia 190, I-95024 Acireale, Italy.;[Gentile, Alessandra] Hunan Agr Univ, Coll Hort & Landscape, Changsha 410128, Peoples R China.
通讯机构：
[Stefano La Malfa] D;Department of Agriculture, Food and Environment (Di3A), University of Catania, Via Valdisavoia 5, 95123 Catania, Italy<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Among Citrus species, the sweet orange (Citrus sinensis (L.) Osbeck) is the most important in terms of production volumes and cultivated areas. Oranges are particularly appreciated for the organoleptic characteristics and the high nutraceutical value of the fruits (thanks especially to their high content of antioxidants). Recent advances in citrus genetic and genomic resources, such as the release of the reference genomes of several sweet orange cultivars, have contributed to (i) understanding the diversification of C. sinensis and its relation with other citrus species, (ii) assessing the molecular mechanisms underlying traits of interest, (iii) identifying and characterizing the candidate genes responsible for important phenotypic traits, and (iv) developing biotechnological methods to incorporate these traits into different citrus genotypes. It has been clarified that all the genetic diversity within the sweet orange species was derived from subsequent mutations starting from a single ancestor and was derived from complex cycles of hybridization and backcrossing between the mandarin (Citrus reticulata Blanco) and the pummelo (Citrus maxima (Burm.) Merr.). This paper provides an overview of the varietal panorama together with a description of the main driving forces in present and future sweet orange breeding. In fact, for the sweet orange, as well as for other citrus species, the release of novel varieties with improved characteristics is being pursued thanks to the employment of conventional and/or innovative (molecular-based) methods. The state of the art methods together with the innovations in genomics and biotechnological tools leading to the so-called new plant breeding technologies were also reviewed and discussed.
作者机构：
[Zhang, Donglin; Zhang, Yifan; Yu, Xiaoying; Li, Yanlin; Xiong, Xingyao; Liu, Yang; Li, YL] Hunan Agr Univ, Coll Hort, Hunan Midsubtrop Qual Plant Breeding & Utilizat En, Engn Res,Ctr Hort Crop Germplasm Creat & New Varie, Changsha 410128, Peoples R China.;[Lin, Ling] Hunan Agr Univ, Sch Econ, Changsha 410128, Peoples R China.;[Xiong, Xingyao] Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Shenzhen 518120, Peoples R China.;[Li, Yanlin; Xiong, Xingyao; Li, YL] Kunpeng Inst Modern Agr, Foshan 528225, Peoples R China.;[Zhang, Donglin] Univ Georgia, Dept Hort, Athens, GA 30602 USA.
通讯机构：
[Yu, XY; Li, YL ] H;Hunan Agr Univ, Coll Hort, Hunan Midsubtrop Qual Plant Breeding & Utilizat En, Engn Res,Ctr Hort Crop Germplasm Creat & New Varie, Changsha 410128, Peoples R China.;Kunpeng Inst Modern Agr, Foshan 528225, Peoples R China.;Nanyang Technol Univ, Sch Biol Sci, 60 Nanyang Dr, Singapore 637551, Singapore.
关键词：
Loropetalumchinense var. rubrum;WRKY;expression pattern;genome-wide analysis;light quality
摘要：
The WRKY gene family plays important roles in plant growth and development, as well as in the responses to biotic and abiotic stresses. Loropetalum chinense var. rubrum has high ornamental and medicinal value. However, few WRKY genes have been reported in this plant, and their functions remain unknown. To explore the roles that the WRKY genes play in L. chinense var. rubrum, we identified and characterized 79 LcWRKYs through BLAST homology analysis and renamed them (as LcWRKY1-79) based on their distribution on the chromosomes of L. chinense var. rubrum. In this way, according to their structural characteristics and phylogenetic analysis, they were divided into three groups containing 16 (Group I), 52 (Group II), and 11 (Group III) WRKYs, respectively. LcWRKYs in the same group have similar motifs and gene structures; for instance, Motifs 1, 2, 3, 4, and 10 constitute the WRKY domain and zinc-finger structure. The LcWRKY promoter region contains light response elements (ACE, G-box), stress response elements (TC-rich repeats), hormone response elements (TATC-box, TCA-element), and MYB binding sites (MBS, MBSI). Synteny analysis of LcWRKYs allowed us to establish orthologous relationships among the WRKY gene families of Arabidopsis thaliana, Oryza sativa, Solanum lycopersicum L., Vitis vinifera L., Oryza sativa L., and Zea mays L.; furthermore, analysis of the transcriptomes of mature leaves and flowers from different cultivars demonstrated the cultivar-specific LcWRKY gene expression. The expression levels of certain LcWRKY genes also presented responsive changes from young to mature leaves, based on an analysis of the transcriptome in leaves at different developmental stages. White light treatment led to a significant decrease in the expression of LcWRKY6, 18, 24, 34, 36, 44, 48, 61, 62, and 77 and a significant increase in the expression of LcWRKY41, blue light treatment led to a significant decrease in the expression of LcWRKY18, 34, 50, and 77 and a significant increase in the expression of LcWRKY36 and 48. These results enable a better understanding of LcWRKYs, facilitating the further exploration of their genetic functions and the molecular breeding of L. chinense var. rubrum.
摘要：
The actin-depolymerizing factor (ADF) gene family regulates changes in actin. However, the entire ADF family in the sweet orange Citrus sinensis has not been systematically identified, and their expressions in different organs and biotic stress have not been determined. In this study, through phylogenetic analysis of the sweet orange ADF gene family, seven CsADFs were found to be highly conserved and sparsely distributed across the four chromosomes. Analysis of the cis-regulatory elements in the promoter region showed that the CsADF gene had the potential to impact the development of sweet oranges under biotic or abiotic stress. Quantitative fluorescence analysis was then performed. Seven CsADFs were differentially expressed against the invasion of Xcc and CLas pathogens. It is worth noting that the expression of CsADF4 was significantly up-regulated at 4 days post-infection. Subcellular localization results showed that CsADF4 was localized in both the nucleus and the cytoplasm. Overexpression of CsADF4 enhanced the sensitivity of sweet orange leaves to Xcc. These results suggest that CsADFs may regulate the interaction of C. sinensis and bacterial pathogens, providing a way to further explore the function and mechanisms of ADF in the sweet orange.
摘要：
To explore the effects of different water levels on competition of submerged plants, we selected the canopy submerged plant Potamogeton malaianus Miq. and the erect submerged plant Hydrilla verticillata (L. f.) Royle as study materials. Four water level gradients (25, 50, 75, 100 cm) were chosen to simulate the hydrological environment of shallow depressions in the main distribution area of submerged plants in the field. The competition between P. malaianus and H. verticillata under different water levels was investigated by measuring plant height, root length, stem thickness, number of leaves, nodal thrift, nodal spacing, above-ground biomass, below-ground biomass, and canopy whole-plant biomass. The results show that P. malaianus and H. verticillata increased in height as the water level rose. In most treatments, above-ground parts grew better than below ground parts. In the 25 cm water level, relative yields (RYs) of the above-and below-ground parts, and whole plant of P. malaianus displayed different patterns. At the water level of 25 cm, the RY values of the above-ground part, below-ground part, and whole plant of P. malaianus were greater than 1. At the low water level of 25 cm, all treatments had relative yield total (RYT) values greater than 1, and at 50 cm water level, the RYT value of P4H8 was greater than 1. RYT was less than 1 at both 75 and 100 cm at 75 and 100 cm water levels, the growth of each species was limited by the other species. In low water level environments, submerged plants switch from a competitive relationship to a facilitative relationship as the water level decreases (stress increases).
摘要：
Grapevines possess a hierarchy of buds, and the fruitful winter bud forms the foundation of the two-crop-a-year cultivation system, yielding biannual harvests. Throughout its developmental stages, the winter bud sequentially undergoes paradormancy, endodormancy, and ecodormancy to ensure survival in challenging environmental conditions. Releasing the endodormancy of winter bud results in the first crop yield, while breaking the paradormancy of winter bud allows for the second crop harvest. Hydrogen cyanamide serves as an agent to break endodormancy, which counteracting the inhibitory effects of ABA, while H2O2 and ethylene function as signaling molecules in the process of endodormancy release. In the context of breaking paradormancy, common agronomic practices include short pruning and hydrogen cyanamide treatment. However, the mechanism of hydrogen cyanamide contributes to this process remains unknown. This study confirms that hydrogen cyanamide treatment significantly improved both the speed and uniformity of bud sprouting, while short pruning proved to be an effective method for releasing paradormancy until August. This observation highlights the role of apical dominance as a primary inhibitory factor in suppressing the sprouting of paradormant winter bud. Comparative transcriptome analysis revealed that the sixth node winter bud convert to apical tissue following short pruning and established a polar auxin transport canal through the upregulated expression of VvPIN3 and VvTIR1. Moreover, short pruning induced the generation of reactive oxygen species, and wounding, ethylene, and H2O2 collectively acted as stimulating signals and amplified effects through the MAPK cascade. In contrast, hydrogen cyanamide treatment directly disrupted mitochondrial function, resulting in ROS production and an extended efficacy of the growth hormone signaling pathway induction.
通讯机构：
[Qin Li] N;National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Collaborative Innovation Centre of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Author to whom correspondence should be addressed.
通讯机构：
[Zhao-Ying Liu; Qi Tang] A;Authors to whom correspondence should be addressed.<&wdkj&>College of Horticulture, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Hunan Engineering Technology Research Center of Veterinary Drugs, Hunan Agricultural University, Changsha 410128, China
摘要：
Obesity is regarded to be correlated with disorders of lipid metabolism, bile acid metabolism and dysbiosis of the gut microbiota. Moringa-Fu brick tea (MFBT), a functional food, has a significant anti-obesity effect. However, the effectiveness and mechanisms of MFBT in preventing obesity require further investigation. Here, our results show that moringa-Fu brick tea extract (MFTE) displays anti-obesity effects by reducing high-fat diet-induced weight gain and adipose tissue accumulation in rats, and attenuating visceral adiposity index, oxidative stress and inflammation. In addition, MFTE could regulate gut microbiota diversity, reduce the relative abundance of microbioa associated with bile salt hydrolase (BSH) activity, such as Blautia, Ruminococcaceae, Coprococcus and Roseburia. Moreover, MFTE could improve the expression of the main rate-limiting enzymes CYP7A1 and CYP27A1 in the process of bile acid synthesis, downregulate the expression of intestinal FXR protein, promote the serum bile acid level, and reduce the accumulation of cholesterol in serum and liver. Taken together, these results suggested that MFBT could serve as a functional food for prevention of obesity and hyperlipidemia in association with regulating bile acid metabolism and gut microbiota.
作者机构：
[Guangming Yuan; Yao Yuan] College of Science, Central South University of Forestry and Technology, Changsha 410004, China;College of Horticulture, Hunan Agricultural University, Changsha 410128, China;Author to whom correspondence should be addressed.;[Fuxiang Cao] College of Science, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>College of Horticulture, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Author to whom correspondence should be addressed.
通讯机构：
[Fuxiang Cao] C;College of Science, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>College of Horticulture, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Amino acid is the main transport form of reduced nitrogen in plants. To investigate the uptake and source–sink translocation process of plants to help understand their physiological roles and transport mechanisms, we designed and synthesized three fluorescent-dye-labeled amino acids as tools to visualize amino acid transportation in Arabidopsis thaliana; these amino acids consist of amino acids linked to the fluorophore nitrobenzoxadiazole (NBD) with excellent optical properties. Furthermore, we incubated Arabidopsis thaliana with these NBD fluorescent-dye-labeled amino acids for real-time imaging along with fluorescence enhancement for 24 h. The results showed that Arabidopsis thaliana could absorb them directly from the roots to the leaves. Therefore, our fluorescent-dye-labeled amino acids provide a de novo tool and strategy for visualizing amino acid absorption and transportation in plants.
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.
