Zhencheng Xie*, Lichao Zhang*, Qiang Zhang, Yan Lu, Chunhao Dong, Danping Li, Xu Liu,Chuan Xia, Xiuying Kong.

New Phytologist, 2023, IF 9.4

DOI:10.1111/nph.19246

SUMMARY:

Plant height and grain size are two important agronomic traits that are closely related tocrop yield. Numerous dwarf and grain-shape mutants have been studied to identify genesthat can be used to increase crop yield and improve breeding programs.In this study, we characterized a dominant mutant,dwarf and round grain 1(drg1-D), inbread wheat (Triticum aestivumL.).drg1-Dplants exhibit multiple phenotypic changes,including dwarfism, round grains, and insensitivity to brassinosteroids (BR). Cell structureobservation indrg1-Dmutant plants showed that the reduced organ size is due to irregularcell shape.

Using map-based cloning and verification in transgenic plants, we found that a Glu209Lyssubstitution in the DRG1 protein is responsible for the irregular cell size and arrangement inthedrg1-Dmutant.DRG1/TaACT7encodes an actin family protein that is essential for poly-merization stability and microfilament (MF) formation. In addition, the BR response and vesi-cular transport were altered by the abnormal actin cytoskeleton indrg1-Dmutant plants.

Our study demonstrates that DRG1/TaACT7 plays an important role in wheat cell shapedetermination by modulating actin organization and intracellular material transport, whichcould in the longer term provide tools to better understand the polymerization of actin and itsassembly into filaments and array