ABA-Mediated Flexibility of Female Stigmatic Papillae Development in Arabidopsis thaliana

In order to survive and inherit against biotic and abiotic stresses, plants need to adapt to environment. There are many genes in the A. thaliana genome, and more than 15,000 genes are expressed in Arabidopsis stigmatic papillae for sustaining a reproduction and developmental functions, which includes a diversity of molecular players particularly those involved in metabolic, transcription and signaling processes. In this study, we report a developmental flexibility of papillae in response to abiotic stress. By in vitro culture analysis of papillae, we found that the stigmatic papillae of A. thaliana changed their length rapidly in response to ambient conditions such as high humidity and salinity: NaCl treatment reduced the papillae length and ABA treatment induced papillae elongation. Through reverse genetic and transcriptome analyses, we suggest that the key mechanism for the rapid response of papillae elongation is mediated by ABA pathway, and ABA-mediated response in papillae can be launched only when synthesized ABA precursor from the primary biosynthesis pathway is converted to an active form of ABA by activation of the downstream biosynthesis pathway. This is one of plant adaptations to the environment to raise the chance of successful pollination.