Crc1,6RhaT is involved in the synthesis of hesperidin of the main bioactive substance in the Citrus reticulata ‘Chachi' fruit  

作　　者：Na Shang Panpan Tong Peng Ye Jianmu Su Mei Bai Hong Wu 

机构地区：[1]State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,Guangdong Laboratory for Lingnan Modern Agriculture,College of Life Sciences,South China Agricultural University,Guangzhou,Guangdong 510642,China [2]Guangdong Technology Research Center for Traditional Chinese Veterinary Medicine and Natural Medicine,South China Agricultural University,Guangzhou,Guangdong 510642,China

出　　处：《Horticultural Plant Journal》2024年第6期1321-1335,共15页园艺学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.32270381);Natural Science Foundation of Guangdong (Grant No.2022A1515011086);Key Realm R&D Program of Guangdong Province (Grant No.2020B020221001);Provincial Special Fund for Modern Agriculture Industry Technology Innovation Teams (Grant No.2019KJ125);Research Fund of Maoming Branch,Guangdong Laboratory for Lingnan Modern Agriculture (Grant No.2022KF009)。

摘　　要：Hesperidin is a dihydroflavonoids, accounting for more than 50% of the total flavonoids in Citri Reticulatae Pericarpium(CRP) of traditional Chinese medicine. It is an effective antioxidant and free radical scavenger that has anti-inflammatory, antiviral and hypoglycemic properties.The latest studies reported that hesperidin has a potential for novel coronavirus resistance. However, little is known about the synthesis regulation and accumulation site of hesperidin in plants. In this study, hesperidin synthase gene Crc1,6RhaT was cloned, and the protein can be completely transformed flavanone-7-O-glucoside into hesperidin in vitro and in vivo. Studies on biological characteristics of ovary walls and exocarps showed that the relative expression levels of the Crc1,6RhaT gene and protein decreased gradually with the development of citrus fruits, and the relative content of hesperidin firstly increased, then sequentially decreased. In situ hybridization results further revealed that Crc1,6RhaT transcription was mainly concentrated in the secretory cavity cells, which are revealed to be the site of flavonoid synthesis.Immunocytochemistry localization results showed that the Crc1,6RhaT was mainly located in the endoplasmic reticulum, nucleus and vacuole of secretory cells. We inferred that the Crc1,6RhaT was synthesized in the endoplasmic reticulum, then was transported into the vacuoles through enlarged vesicles at the end of the endoplasmic reticulum. Our results not only revealed that Crc1,6RhaT may be involved in the synthesis of hesperidin of the main bioactive substance in the medicinal plant Citrus reticulata ‘Chachi' fruit, but also provided novel insights into the main subcellular sites of hesperidin biosynthesis in vacuoles.

关 键 词：Citri Reticulatae Pericarpium CITRUS HESPERIDIN FLAVONOIDS Crc1 6RhaT Secretory cavity 

分 类 号：S666[农业科学—果树学]