Sequence analysis and expression profiles of TaABI5, a pre-harvest sprouting resistance gene in wheat

Pre-harvest sprouting (PHS) is the germination of grains in the spike under wet conditions before harvest, which causes a severe reduction in crop yield and flour quality. The phytohormone abscisic acid plays a key role in regulating seed dormancy, which inhibits pre-harvest spouting or vivipary for many important crops. TaABI5, belonging to a family of basic leucine zipper transcription factors could regulate a subset of late embryogenesis abundant genes during seed development, was isolated and characterized. Phylogenetic analysis revealed that TaABI5 homologous gene belonged to the ABI5 subgroup of the ABF/AREB/ABI5 subfamily. TaABI5 consist of four conserved domains and one bZip domain. The expression pattern of TaABI5 indicated that it was seed-specific and accumulated at late stages of seed development. Accumulation of TaABI5 in synthetic hexaploid wheat SHW-L1 (PHS resistance) was 8.93-fold higher than that in wheat cultivar Chuanmai 32 (PHS susceptible) at 25 days post anthesis. Four expression quantitative trait loci (eQTL) of TaABI5 on chromosome 2DS, 4DS, 6DS, and 7DL were characterized from SHW-L1/Chuanmai 32 derived recombinant inbred line population.