Activation tagging of an Arabidopsis SHI-RELATED SEQUENCE gene produces abnormal anther dehiscence and floral development

• Published in: Plant molecular biology Vol. 74; no. 4-5; pp. 337 - 351
• Main Authors: Kim, Sang-Gyu, Lee, Sangmin, Kim, Youn-Sung, Yun, Dae-Jin, Woo, Je-Chang, Park, Chung-Mo
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01-11-2010; Springer Netherlands; Springer Nature B.V
• Subjects: Anther dehiscence; Arabidopsis; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biochemistry; Biomedical and Life Sciences; Biosynthesis; Botany; Cell Enlargement; Cyclopentanes - metabolism; Fertility; Floral development; Flowers; Flowers & plants; Flowers - genetics; Flowers - growth & development; Flowers - metabolism; Genes, Plant - genetics; Genes, Plant - physiology; Gibberellins - pharmacology; jasmonic acid; Life Sciences; Male sterility; Molecular biology; Mutants; Mutation; Oxylipins - metabolism; Phospholipases A1 - genetics; Phospholipases A1 - metabolism; Plant biology; Plant Pathology; Plant Sciences; Plant Shoots - genetics; Plant Shoots - growth & development; Plant Shoots - metabolism; Pollen; Pollen - genetics; Pollen - physiology; Pollen - ultrastructure; RNA Interference; RNA, Messenger - metabolism; SRS7; Tapetum; Transcriptional Activation; Tapetum; Jasmonic acid; Anther dehiscence; Floral development
• ISSN: 0167-4412; 1573-5028
• DOI: 10.1007/s11103-010-9677-5

The tapetum is a layer of cells covering the inner surface of pollen sac wall. It contributes to anther development by providing enzymes and materials for pollen coat biosynthesis and nutrients for pollen development. At the end of anther development, the tapetum is degenerated, and the anther is dehisced, releasing mature pollen grains. In Arabidopsis, several genes are known to regulate tapetum formation and pollen development. However, little is known about how tapetum degeneration and anther dehiscence are regulated. Here, we show that an activation-tagged mutant of the S HI-R ELATED S EQUENCE 7 (SRS7) gene exhibits disrupted anther dehiscence and abnormal floral organ development in addition to its dwarfed growth with small, curled leaves. In the mutant hypocotyls, cell elongation was reduced, and gibberellic acid sensitivity was diminished. Whereas anther development was normal, its dehiscence was suppressed in the dominant srs7-1D mutant. In wild-type anthers, the tapetum disappeared at anther development stages 11 and 12. In contrast, tapetum degeneration was not completed at these stages, and anther dehiscence was inhibited, causing male sterility in the mutant. The SRS7 gene was expressed mainly in the filaments of flowers, where the DEFECTIVE-IN-ANTHER-DEHISCENCE 1 (DAD1) enzyme catalyzing jasmonic acid (JA) biosynthesis is accumulated immediately before flower opening. The DAD1 gene was induced in the srs7-1D floral buds. In fully open flowers, the SRS7 gene was also expressed in pollen grains. It is therefore possible that the abnormal anther dehiscence and floral development of the srs7-1D mutant would be related with JA.