Title:

Cytological and transcriptional insights of late-acting self-incompatibility in tea plants (Camellia sinensis)

Authors:

Shengrui Liu, Rui Guo, Jingjuan Zhao, Enhua Xia, Yongning Tao, Qianqian Zhou, Zhipeng Chen, Hui Xie, Junyan Zhu & Chaoling Wei*

Journal:

Beverage Plant Research

DOI:

https://doi.org/10.48130/BPR-2023-0019

Abstract:

Self-incompatibility (SI) is a kind of plant fertilization obstacle, which can prevent the harmful effects of inbreeding decline, but it hinders the breeding of inbred lines. Tea plants have SI and long-term cross-pollination, which limits the progress of genetic research and variety improvement. However, the mechanism of SI in tea plants is still a mystery. Herein, microscopic observation showed that the pollen tube could pass through the base of style and enter the ovary cavity after 48 h of self-pollination at different flowering stages, and the SI intensity at bud stage and full bloom stage was lower than initial bloom stage. RNA-seq analysis showed that 1,463 and 1,409 differentially expressed genes (DEGs) were associated with low SI at bud stage and full bloom stage, respectively, and 507 DEGs were associated with SI at initial bloom stage. The results of qRT-PCR validation of 20 DEGs were consistent with the RNA-seq data. Furthermore, CsRNS, CsSRKL5 and CsSRKL8 specifically expressed in style, which may be related to the low SI at bud stage, and three CsACC genes may be related to the low SI at full bloom stage. The results provide useful information for understanding the mechanism of SI in tea plants.