Fine mapping of the flavonoid 3',5'-hydroxylase gene controlling anthocyanin biosynthesis in pepper anthers and stems

Yixin Wang; Zheng Wang; Heshan Du; Bin Chen; Guoyun Wang; Qian Wang; Sansheng Geng; Xiaofen Zhang

doi:10.3389/fpls.2023.1232755

Fine mapping of the flavonoid 3',5'-hydroxylase gene controlling anthocyanin biosynthesis in pepper anthers and stems

Front Plant Sci. 2023 Jul 27:14:1232755. doi: 10.3389/fpls.2023.1232755. eCollection 2023.

Authors

Yixin Wang^{1

2}, Zheng Wang¹, Heshan Du¹, Bin Chen¹, Guoyun Wang¹, Qian Wang², Sansheng Geng¹, Xiaofen Zhang¹

Affiliations

¹ Beijing Key Laboratory of Vegetable Germplasms Improvement, Key Laboratory of Biology and Genetics Improvement of Horticultural Crops (North China), National Engineering Research Center for Vegetables, State Key Laboratory of Vegetable Biobreeding, Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China.
² Department of Vegetable Science, College of Horticulture, China Agricultural University, Beijing, China.

Abstract

Pepper (Capsicum annuum L) is one of the most important vegetables grown worldwide. Nevertheless, the key structural and regulatory genes involved in anthocyanin accumulation in pepper have not been well understood or fine mapped yet. In this study, F₁, F₂, BC₁P₁, and BC₁P₂ pepper populations were analyzed and these populations were derived from a cross between line 14-Z4, which has yellow anthers and green stems, and line 14-Z5, which has purple anthers and stems. The results showed that the yellow anthers and green stems were determined by a single recessive locus called to as ayw. While, using preliminary and fine mapping techniques, ayw locus was located between markers aywSNP120 and aywSNP124, with physical distance of 0.2 Mb. The CA11g18550 gene was identified as promising candidate for the ayw locus, as it co-segregated with the yellow anthers and green stems phenotypes. CA11g18550 encodes a homolog of the F3'5'H (flavonoid 3',5'-hydroxylase) anthocyanin synthesis structure gene. The missense mutation of CA11g18550 possibly resulted in a loss-of-function. The expression analysis showed that CA11g18550 was significantly expressed in the stems, leaves, anthers and petals in 14-Z5, and it's silencing caused the stems changing from purple to green. This study provides a theoretical basis for using yellow anthers and green stems in pepper breeding and helps to advance the understanding of anthocyanin synthesis.

Keywords: CA11g18550; Capsicum annuum L; F3’5’H; anthocyanins; ayw; delphinidin.

Grants and funding

This research was funded by the General Program of National Natural Science Foundation of China (32072566), the Innovation Ability Construction Projects of Beijing Academy of Agriculture and Forest Sciences (KJCX20200113 and KJCX20230813), and the Beijing Innovation Consortium of Agriculture Research System (BAIC01).