文献类型： 外文期刊

作者： Tian, Shulin ¹ ; Yang, Yuyan ¹ ; Fang, Bo ³ ; Uddin, Saleem ¹ ; Liu, Xiaogang ¹ ;

作者机构： 1.Southwest Univ, Coll Hort & Landscape Architecture, Chongqing 400715, Peoples R China

2.Southwest Univ, Key Lab Agr Biosafety & Green Prod Upper Yangtze R, Minist Educ, Chongqing 400715, Peoples R China

3.Chongqing Acad Agr Sci, Chongqing 401329, Peoples R China

关键词： Citrus; Carotenoid; Chlorophyll; Fruit ripening; MYB transcription factor; Transcriptional; Regulation

期刊名称：PLANT PHYSIOLOGY AND BIOCHEMISTRY （ 影响因子：6.1； 五年影响因子：6.2 ）

ISSN： 0981-9428

年卷期： 2024 年 209 卷

页码：

收录情况： SCI

摘要： Citrus, cultivated extensively across the globe, possesses considerable economic importance and nutritional value. With the degradation of chlorophyll and accumulation of carotenoids, mature citrus fruits develop an orange-yellow peel, enhancing fruit value and consumer preference. MYB transcription factors (TFs) exert a significant role in diverse plant developmental processes and investigating their involvement in fruit coloration is crucial for developing new cultivars. This work aimed to characterize a citrus TF, CrMYB33, whose expression was found to be positively correlated with carotenoid biosynthesis during fruit ripening. The interference of CrMYB33 expression in citrus fruit resulted in inhibition of carotenoid accumulation, down-regulation of carotenoid biosynthetic genes, and a slower rate of chlorophyll degradation. Conversely, overexpression of CrMYB33 in tomato (Solanum lycopersicum) enhanced chlorophyll degradation and carotenoid biosynthesis, resulting in a deeper red coloration of the fruits. Furthermore, the transcription of associated genes was upregulated in CrMYB33-overexpressing tomato fruits. Additional assays reveal that CrMYB33 exhibits direct links and activation of the promoters of lycopene fl-cyclase 2 (CrLCYb2), and fl-carotene hydroxylases 2 (CrBCH2), both crucial genes in the carotenoid biosynthetic pathway. Additionally, it was found to inhibit chlorophyllase (CrCLH), a gene essential in chlorophyll degradation. These findings provide insight into the observed changes in LCYb2, BCH2, and CLH expression in the transgenic lines under investigation. In conclusion, our study revealed that CrMYB33 modulates carotenoid accumulation and chlorophyll degradation in citrus fruits through transcriptionally activating genes involved in metabolic pathways.