cZOGT1 interacts with TaZIP to regulate senescence by affecting cytokinin and abscisic acid levels in wheat.

Premature senescence is an important factor affecting wheat yield and quality. Wheat yield can be increased by delaying senescence and prolonging the effective photosynthetic time. Previously, we found that the cis-Zeatin-O-glucosyltransferase (cZOGT1) gene plays an important role in the stay-green wheat phenotype. In this study, cZOGT1-overexpressing lines exhibited a delayed senescence phenotype, despite a significant reduction in the total cytokinin content. Further, we found that cZOGT1 interacted with TaZIP, and that a high level of cZOGT1 expression led to the suppression of TaZIP expression, which in turn, reduced abscisic acid (ABA) content. The synergistic reduction in cytokinins and ABA levels eventually caused the stay-green phenotype in cZOGT1-OE lines. This study provides a new theoretical basis to explain the mechanism underlying the wheat stay-green phenotype and provides an excellent genetic resource for wheat molecular-design breeding.