Induction of male-sterility by controlling of gibberellin biosynthesis in rice (Oryza sativa)

Abstract

Gibberellins (GAs) are important hormones at every plant developmental stage including vegetative and reproductive. It is reported in many plant species that many dwarfism and male sterile mutants have defective GA biosynthesis genes. RNA interference (RNAi) technology can reduce expression of specific genes at the transcription level. Also, promoters can control the spatial and temporal expression of genes. Specific promoters containing the RNAi vector can control specific genes' spatial and temporal expression at the transcriptional level. In this study, at first, five anther specific promoters were chosen and verified by examining their tissue specific expression using promoter::GUS transgenic analysis. RNAi vectors, which contain five anther specific promoters and one constitutive promoter fused to GA biosynthesis related genes, were constructed for controlling of GA biosynthesis in stem and floral tissue. OsAct1 promoter containing OsGA20ox1 and OsGA3ox2 RNAi T1 plants showed reduced gene expression and short plant height phenotype compare to wild type plant. OsGA20ox and OsGA3ox RNAi transformants also showed reduced fertility or sterile phenotype.