The transcription factor IbNAC29 positively regulates the carotenoid accumulation in sweet potato  

作　　者：Shihan Xing Ruijie Li Haoqiang Zhao Hong Zhai Shaozhen He Huan Zhang Yuanyuan Zhou Ning Zhao Shaopei Gao Qingchang Liu 

机构地区：[1]Key Laboratory of Sweet Potato Biology and Biotechnology,Ministry of Agriculture and Rural Affairs/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization,Ministry of Education,College of Agronomy&Biotechnology,China Agricultural University,Beijing 100193,China

出　　处：《Horticulture Research》2023年第3期189-200,共12页园艺研究（英文）

基　　金：supported by the National Natural Science Foundation of China(31872878);the earmarked fund for CARS-10-Sweetpotato.

摘　　要：Carotenoid is a tetraterpene pigment beneficial for human health.Although the carotenoid biosynthesis pathway has been extensively studied in plants,relatively little is known about their regulation in sweet potato.Previously,we conducted the transcriptome database of differentially expressed genes between the sweet potato(Ipomoea batatas)cultivar‘Weiduoli’and its high-carotenoid mutant‘HVB-3’.In this study,we selected one of these candidate genes,IbNAC29,for subsequent analyses.IbNAC29 belongs to the plant-specific NAC(NAM,ATAF1/2,and CUC2)transcription factor family.Relative IbNAC29 mRNA level in the HVB-3 storage roots was∼1.71-fold higher than Weiduoli.Additional experiments showed that the contents ofα-carotene,lutein,β-carotene,zeaxanthin,and capsanthin are obviously increased in the storage roots of transgenic sweet potato plants overexpressing IbNAC29.Moreover,the levels of carotenoid biosynthesis genes in transgenic plants were also up-regulated.Nevertheless,yeast one-hybrid assays indicated that IbNAC29 could not directly bind to the promoters of these carotenoid biosynthesis genes.Furthermore,the level of IbSGR1 was down-regulated,whose homologous genes in tomato can negatively regulate carotene accumulation.Yeast three-hybrid analysis revealed that the IbNAC29-IbMYB1R1-IbAITR5 could form a regulatory module.Yeast one-hybrid,electrophoretic mobility shift assay,quantitative PCR analysis of chromatin immunoprecipitation and dual-luciferase reporter assay showed that IbAITR5 directly binds to and inhibits the promoter activity of IbSGR1,up-regulating carotenoid biosynthesis gene IbPSY.Taken together,IbNAC29 is a potential candidate gene for the genetic improvement of nutritive value in sweet potato.

关 键 词：ROOTS SWEET POTATO 

分 类 号：S531[农业科学—作物学]