Back to Search Start Over

OsTKPR2 is part of a sporopollenin-producing metabolon required for exine formation in rice.

Authors :
Yang, Huiting
Liu, Feng
Wang, Wang
Rui, Qingchen
Li, Ge
Tan, Xiaoyun
Ye, Jie
Shen, Haodong
Liu, Yanping
Liu, Wenlong
Tang, Rong
Hu, Jingru
Liu, Kai
Zhang, Yunhui
Zhan, Huadong
Wang, Yihua
Bao, Yiqun
Source :
Journal of Experimental Botany. 3/28/2023, Vol. 74 Issue 6, p1911-1925. 15p.
Publication Year :
2023

Abstract

The sporopollenin polymer is a major component of the pollen exine. Fatty acid derivatives synthesized in the tapetum are among the precursors of sporopollenin. Progress has been made to understand sporopollenin metabolism in rice; however, the underlying molecular mechanisms remain elusive. We found that OsTKPR2 and OsTKPR1 share a similar expression pattern, and their coding proteins have a similar subcellular localization and enzyme activities towards reduced tetraketide α-pyrone and hydroxylated tetraketide α-pyrone. Unexpectedly, OsTKPR1 pro : OsTKPR2-eGFP could not rescue the phenotype of ostkpr1-4. Three independent ostkpr2 mutant lines generated by CRISPR/Cas9 displayed reduced male fertility to various extents which were correlated with the severity of gene disruptions. Notably, the anther cuticle, Ubisch bodies, and pollen development were affected in the ostkpr2-1 mutant, where a thinner pollen exine was noticed. OsTKPR1 and OsTKPR2 were integrated into a metabolon including OsACOS12 and OsPKS2, which resulted in a significant increased enzymatic efficiency when both OsTKPR1 and OsTKPR2 were present, indicating the mutual dependence of OsTKPR2 and OsTKPR1 for their full biochemical activities. Thus, our results demonstrated that OsTKPR2 is required for anther and pollen development where an OsTKPR2-containing metabolon is functional during rice sporopollenin synthesis. Furthermore, the cooperation and possible functional divergence between OsTKPR2 and OsTKPR1 is also discussed. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00220957
Volume :
74
Issue :
6
Database :
Academic Search Index
Journal :
Journal of Experimental Botany
Publication Type :
Academic Journal
Accession number :
163005821
Full Text :
https://doi.org/10.1093/jxb/erad016