J Integr Plant Biol. ›› 2023, Vol. 65 ›› Issue (10): 2395-2406.DOI: 10.1111/jipb.13547

• Plant Reproductive Biology • Previous Articles    

SD-RLK28 positively regulates pollen hydration on stigmas as a PCP-Bβ receptor in Arabidopsis thaliana

Li Guo1,2, Ziya Huang1,2, Xingyu Chen1,2, Min Yang1,2, Miaomiao Yang1,2, Ziwei Liu1,2, Xuejie Han1,2, Xiangjie Ma1,2, Xiaoli Wang1,2 and Qiguo Gao1,2*   

  1. 1. College of Horticulture and Landscape Architecture, Chongqing 400716, China;
    2. Ministry of Education, Key Laboratory of Horticulture Science for Southern Mountainous Regions, Chongqing 400716, China
    *Correspondence: Qiguo Gao (gaoqg031@swu.edu.cn)
  • Received:2023-01-03 Accepted:2023-07-24 Online:2023-07-24 Published:2023-10-01

Abstract: Pollen hydration on dry stigmas is strictly regulated by pollen–stigma interactions in Brassicaceae. Although several related molecular events have been described, the molecular mechanism underlying pollen hydration remains elusive. Multiple B-class pollen coat proteins (PCP-Bs) are involved in pollen hydration. Here, by analyzing the interactions of two PCP-Bs with three Arabidopsis thaliana stigmas strongly expressing S-domain receptor kinase (SD-RLK), we determined that SD-RLK28 directly interacts with PCP-Bβ. We investigated pollen hydration, pollen germination, pollen tube growth, and stigma receptivity in the sd-rlk28 and pcp-bβ mutants. PCP-Bβ acts in the pollen to regulate pollen hydration on stigmas. Loss of SD-RLK28 had no effect on pollen viability, and sd-rlk28 plants had normal life cycles without obvious defects. However, pollen hydration on sd-rlk28 stigmas was impaired and pollen tube growth in sd-rlk28 pistils was delayed. The defect in pollen hydration on sd-rlk28 stigmas was independent of changes in reactive oxygen species levels in stigmas. These results indicate that SD-RLK28 functions in the stigma as a PCP-Bβ receptor to positively regulate pollen hydration on dry stigmas.

Key words: Arabidopsis thaliana, PCP-B, pollen hydration, pollen–stigma interaction, reactive oxygen species, SD-RLK

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2022 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q