Identification of P-type plasma membrane H+-ATPases in common wheat and characterization of TaHA7 associated with seed dormancy and germination

The P-type plasma membrane (PM) H+-ATPases (HAs) are central to plant development, growth, and defense. The HAs are thoroughly characterized in diverse plants. However, despite their importance, the functions of Has in germination and seed dormancy (SD) have not been validated in wheat. Here, we identified 28 TaHA genes (TaHA1-28) in common wheat, which were divided into five subfamilies. Examination of gene expression in strong- and weak-SD wheat varieties led to the discovery of six candidate genes (TaHA7/-12/-14/-16/-18/-20). Based on a single nucleotide polymorphism (SNP) mutation (C/T) in the TaHA7 coding region, a CAPS marker (HA7) was developed and validated in 168 wheat varieties and 171 Chinese mini-core collections exhibiting diverse germination and SD phenotypes. We further verified the roles of the two allelic variations of TaHA7 in germination and SD using wheat mutants mutagenized with ethyl methane sulphonate (EMS) in 'Jimai 22' and 'Jing 411' backgrounds, and in transgenic Arabidopsis lines. TaHA7 appears to regulate germination and SD by mediating GA and ABA signaling, metabolism, and biosynthesis. The results presented here will be beneficial for future research regarding TaHAs in wheat.