Genomic analysis of the core components of ABA signaling reveals their possible role in abiotic stress response in cassava

Abstract

Abscisic acid (ABA) signaling plays an important role in plants development and response to environmental stimuli. Currently, the PYL-PP2C-SnRK2 families, as the core components of ABA signaling, are not well understood in cassava, a drought tolerant crop. In this study, we identified 13 PYLs, 80 PP2Cs, and 10 SnRK2s from the cassava genome, supported by evolutionary relationship, protein motif, and gene structure analyses. Generally, most of the PYL-PP2C-SnRK2s had similar expression profiles in different tissues between Arg7 and W14. Comparative expression analyses showed less activation of MePP2Cs in wild subspecies W14, compared with cultivated varieties Arg7 and SC124, which may contributed to the strong tolerance of W14. Interaction networks and co-expression assays demonstrated that less Group A PP2C-mediated network showed transcriptional changes in leaves and roots of W14 than that in Arg7. Expression of several selected PYL-PP2C-SnRK2 genes indicated their significant upregulation upon ABA and multiple abiotic stresses. Taken together, this study provides new insights into PYL-PP2C-SnRK2-mediated drought adaption at transcription levels in cassava and identifies some candidates for genetic improvement of crop tolerance to abiotic stress.