TaACTIN7-D Regulates Plant Height and Grain Shape in Bread Wheat
Published:31 Oct.2023 Source:Journal of Genetics and Genomics
Exploitation of new gene resources and genetic networks contributing to the control of crop yield-related traits, such as plant height and grain size and shape, may enable us to breed modern high-yielding wheat varieties through molecular methods. In this study, via ethylmethanesulfonate (EMS) mutagenesis, we identified a wheat mutant plant, mu-597, that shows semi-dwarf plant architecture and round grain shape.
Through bulked segregant RNA-seq and map-based cloning, the causal gene for the semi-dwarf phenotype of mu-597 was located. We found that a single-base mutation in the coding region of TaACTIN7-D (TaACT7-D), leading to a Gly-to-Ser (G65S) amino acid mutation at the 65th residue of the deduced TaACT7-D protein, can explain the semi-dwarfism and round grain shape of mu-597.
Further evidence shows that the G65S mutation in TaACT7-D hinders the polymerization of actin from monomeric (G-actin) to filamentous (F-actin) status while attenuates wheat responses to multiple phytohormones, including brassinosteroids, auxin, and gibberellin. Together, these findings not only define a new semi-dwarfing gene resource that can be potentially used to design plant height and grain shape of bread wheat but also establish a direct link between actin structure modulation and phytohormone signal transduction.