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Gibberellin regulates post‐microsporogenesis processes in petunia anthers
Author(s) -
Izhaki Anat,
Borochov Amihud,
Zamski Eliezer,
Weiss David
Publication year - 2002
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2002.1150314.x
Subject(s) - petunia , stamen , tapetum , biology , arabidopsis , pollen , gibberellin , paclobutrazol , botany , meiosis , gynoecium , microbiology and biotechnology , gene , genetics , microspore , mutant
Previous studies have suggested that gibberellins (GAs) are produced in petunia anthers and transported to the corolla to induce growth and pigmentation. In this work, we studied the role of GA in the regulation of anther development. When petunia plants were treated with the GA‐biosynthesis inhibitor paclobutrazol, anther development was arrested. Microscopic analysis of these anthers revealed that paclobutrazol inhibits post‐meiotic developmental processes. The treated anthers contained pollen grains but the connective tissue and tapetum cells were degenerated. A similar phenotype was obtained when the Arabidopsis GA‐signal repressor, SPY, was over‐expressed in transgenic petunia plants, i.e. anther development was arrested following microsporogenesis. The expression of the GA‐induced gene, GIP , can be used in petunia as a molecular marker to study GA responses. GA 3 treatment of young anthers promoted, and paclobutrazol inhibited, GIP expression, suggesting that the hormone controls the natural activation of the gene in the anthers. Analyses of GIP expression during anther development revealed that the gene is induced only after microsporogenesis. This observation further suggests a role for GA in the regulation of post‐meiotic processes during petunia anther development.