Phenome analysis in multiple combinations of G-protein alpha and beta in Arabidopsis  (Plant J)

Heterotrimeric G-proteins are implicated in a large number of signalling pathways. As their name indicates, they are composed of three different subunits, Gα, Gβ, and Gγ. The Arabidopsis genome has genes encoding four Gα, one Gβ and two Gγ protein subunits, as compared to the multiple members that occur in human G-protein subunit families (23 Gα, 5 Gβ, 12 Gγ). Choudhury et al. generated different combinations of higher order mutants in the four Gα (including single Gα, GPA1 and three extra-large Gα, XLG1/2/3) and single Gβ (AGB1) subunits and compared these combinations of quadruple and quintuple mutants to the representative single, double and triple mutants. The authors summarise that G-protein subunits affect the plant phenotypes in a subunit-dependent manner and propose several mechanistic modes (Mode 1 to 4) to explain the complexity of the phenome network in G-protein signalling. This phenome analysis demonstrates the presence of various interactions between the Gα and the sole Gβ could influence specific pathways and contribute to the plant adaptation to different environmental changes. It would be interesting to do a similar study in a plant such as soybean that has multiple Gβ subunit. (Summary by Min May Wong) Plant Journal 10.1111/tpj.14714