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Brassinosteroid‐mediated reactive oxygen species are essential for tapetum degradation and pollen fertility in tomato
Author(s) -
Yan MengYu,
Xie DongLing,
Cao JiaJian,
Xia XiaoJian,
Shi Kai,
Zhou YanHong,
Zhou Jie,
Foyer Christine H.,
Yu JingQuan
Publication year - 2020
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14672
Subject(s) - pollen , brassinosteroid , tapetum , reactive oxygen species , biology , mutant , microbiology and biotechnology , programmed cell death , botany , solanum , arabidopsis , stamen , gene , genetics , apoptosis , microspore
Summary Phytohormone brassinosteroids (BRs) are essential for plant growth and development, but the mechanisms of BR‐mediated pollen development remain largely unknown. In this study, we show that pollen viability, pollen germination and seed number decreased in the BR‐deficient mutant d ^im , which has a lesion in the BR biosynthetic gene DWARF ( DWF ), and in the bzr1 mutant, which is deficient in BR signaling regulator BRASSINAZOLE RESISTANT 1 ( BZR1 ), compared with those in wild‐type plants, whereas plants overexpressing DWF or BZR1 exhibited the opposite effects. Loss or gain of function in the DWF or BZR1 genes altered the timing of reactive oxygen species (ROS) production and programmed cell death (PCD) in tapetal cells, resulting in delayed or premature tapetal degeneration, respectively. Further analysis revealed that BZR1 could directly bind to the promoter of RESPIRATORY BURST OXIDASE HOMOLOG 1 ( RBOH1 ), and that RBOH1 ‐mediated ROS promote pollen and seed development by triggering PCD and tapetal cell degradation. In contrast, the suppression of RBOH1 compromised BR signaling‐mediated ROS production and pollen development. These findings provide strong evidence that BZR1‐dependent ROS production plays a critical role in the BR‐mediated regulation of tapetal cell degeneration and pollen development in Solanum lycopersicum (tomato) plants.