A bHLH Transcription Factor Regulates Anther Development and Dehiscence in Rice
Rajeev Ranjan1, Reema Khurana2, Akhilesh K. Tyagi1, 2
1. National Institute of Plant Genome Research, New Delhi, India
2. Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
Anther development and its dehiscence are important for the reproductive success of the
flowering plants. bHLH class of transcription factors are known to regulate several plant
growth and development processes. Here, we are describing cellular and molecular functions
of a bHLH transcription factor during anther development process in rice. Previously, by
using microarray, qRT-PCR and promoter-reporter assay in transgenic system we reported
OsbHLH142 as an anther specific gene in rice. Expression analysis of OsbHLH142
transcripts through qPCR and its protein profiling through immune-blot and immunolocalization during different stages of anther development showed delayed accumulation of
its protein compared to transcripts. Overexpression of OsbHLH142 in transgenic rice results
in complete male sterility owing to indehisced anthers as well as production of non-viable,
shrunken and abnormal shaped pollen. Electron microscopic and paraffin based tissue section
analysis revealed detailed reason for these defects. RNA-Seq based transcriptome analysis of
early and mature transgenics anthers has identified direct/indirect target of OsbHLH142
associated with anther functions. Moreover, through yeast two-hybrid and BiFC assays we
have identified some OsbHLH142 interacting proteins which gives more insight on its
molecular functions. Therefore, this study has explored novel functions of OsbHLH142 in
rice anthers which will essentially help in the control of male fertility in crop plants for the
hybrid seed production.