The key contribution of OsGHD7 in controlling flowering time, grain yield, and abiotic stress tolerance in photoperiod-insensitive rice.

Abstract

Developing rice types with shorter life cycle without compromising yield is vital for sustainable agriculture, as it can significantly reduce water and fertilizer consumption while enabling early harvest. Despite recent advancements in identifying the genes associated with heading date, the intricate regulatory network governing this process remains largely unexplored. In rice, one such gene, GHD7 (QTL for grain-heading-date on chromosome 7), encodes a CCT (CONSTANS, CONSTANS-LIKE and TIMING OF CAB1) domain protein and plays a pivotal role in regulating flowering time and associated developmental processes. To gain insight into the role of OsGHD7 in improving yield, we have overexpressed OsGHD7 in the widely cultivated and photoperiod-insensitive rice variety IR64. This led to notable phenotypic changes in rice, including tiller number and grain number (66% increase), along with the promotion of early flowering (8-9 days preponement). Interestingly, these plants also exhibited enhanced tolerance to drought and salinity stress and showed better post-stress recovery. This study emphasizes the potential of manipulating the multifaceted genetic determinants of key traits to optimize rice productivity under changing climate conditions.