Genetic and molecular regulation of increased photosynthetic cell number contributes to leaf size heterosis in Arabidopsis

Wenwen Liu; Diqiu Ren; Wenyi Yang; Miqi Xu; Yi Zhang; Xingwei Wang; Guangming He; Xing Wang Deng

doi:10.1016/j.isci.2023.107366

Genetic and molecular regulation of increased photosynthetic cell number contributes to leaf size heterosis in Arabidopsis

iScience. 2023 Jul 13;26(8):107366. doi: 10.1016/j.isci.2023.107366. eCollection 2023 Aug 18.

Authors

Wenwen Liu¹, Diqiu Ren¹, Wenyi Yang¹, Miqi Xu¹, Yi Zhang¹, Xingwei Wang¹, Guangming He¹, Xing Wang Deng^{1

2}

Affiliations

¹ School of Advanced Agricultural Sciences and School of Life Sciences, State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
² Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang, Shandong 261325, China.

Abstract

Heterosis is an important genetic phenomenon that has been observed and widely utilized in agriculture. However, the genetic and molecular bases of heterosis are unclear. Through transcriptome-wide association studies (TWAS) and expression quantitative trait locus (eQTL) analysis to integrate genome, transcriptome, and heterotic phenotype of a half-sibling Arabidopsis hybrid population, we report that the genetic and molecular bases of variations in leaf growth heterosis can be explained by the varied expression levels of growth-regulating genes resulting from distinct sets of heterozygous eQTLs carried by the half-sibling hybrids. In F₁ versus parent, the degree of up-regulated gene expression in the cell cycle pathway in the shoot apex and the photosynthesis pathway in true leaf positively correlates with true leaf area heterosis level, and this is affected by the accumulation of superior heterozygous eQTLs. This was further corroborated by the major contribution of increased photosynthetic cell number to leaf area heterosis.

Keywords: Genomics; Plant Genetics; Plant development.