Pangenome analysis provides insight into the evolution of the orange subfamily and a key gene for citric acid accumulation in citrus fruits.
Yue HuangJiaxian HeYuantao XuWeikang ZhengShaohua WangPeng ChenBin ZengShuizhi YangXiaolin JiangZishuang LiuLun WangXia WangShengjun LiuZhihao LuZiang LiuHuiwen YuJianqiang YueJunyan GaoXianyan ZhouChunrui LongXiuli ZengYong-Jie GuoWen-Fu ZhangZongzhou XieChunlong LiZhaocheng MaWen-Biao JiaoFei ZhangRobert M LarkinRobert R KruegerMalcolm W SmithRay MingXiu-Xin DengQiang XuPublished in: Nature genetics (2023)
The orange subfamily (Aurantioideae) contains several Citrus species cultivated worldwide, such as sweet orange and lemon. The origin of Citrus species has long been debated and less is known about the Aurantioideae. Here, we compiled the genome sequences of 314 accessions, de novo assembled the genomes of 12 species and constructed a graph-based pangenome for Aurantioideae. Our analysis indicates that the ancient Indian Plate is the ancestral area for Citrus-related genera and that South Central China is the primary center of origin of the Citrus genus. We found substantial variations in the sequence and expression of the PH4 gene in Citrus relative to Citrus-related genera. Gene editing and biochemical experiments demonstrate a central role for PH4 in the accumulation of citric acid in citrus fruits. This study provides insights into the origin and evolution of the orange subfamily and a regulatory mechanism underpinning the evolution of fruit taste.