Drought priming enhances wheat grain starch and protein quality under drought stress during grain filling

The impact of drought stress on crop yield and quality is substantial. Drought priming during the early growth stage of plants has been shown to improve tolerance to drought stress during the reproductive stage, although its effects on grain quality remains elusive. This study aimed to investigate the influence of drought priming on starch and protein levels in grains under drought stress during grain filling. Our results reveal that drought stress results in a reduction in starch content and its constituents, while simultaneously increasing glutenin macropolymers and protein fractons. Notably, drought primed plants under drought stress (PD) exhibit mitigated declines in starch content and its components, leading to improvements in starch swelling power and pasting properties. Additionally, PD results in a slight increase in protein fractions, limiting the overall rise in total protein content compared to drought stress alone. Collectively, our study underscores the efficacyof drought priming as a strategy to counteract the negative effects of drought stress on grain quality, particularly by minimizing starch losses and restraining protein content elevation.