| Abstract: As the main staple food for over one-third of the world’s population, rice (Oryza sativa L.) is the crucial
material foundation and guarantee for human survival and productivity. However, most of rice-producing regions are facing
serious water scarcity issues, which severely restrict rice growth, leading to a sharp decrease in rice yield and posing a threat
to food security. Therefore, studies of drought resistance mechanisms as well as breeding and application of water-saving
and drought-resistant rice varieties are not only beneficial for utilizing freshwater resources in a sustainable manner, it also holds significant importance for ensuring food security. Breeders have screened and bred water-saving and drought-resistant
varieties through the evaluation of morphological traits, physiological-biochemical and yield indexes, and even have promoted
them. Researchers have identified many drought genes related to transcription factors, transport proteins, ubiquitin ligases,
proteases and protein kinases by using genetic mapping, GWAS, expression profiling and multi-omics integrative analysis,
indicating that drought resistance of rice is a complex quantitative trait controlled by multiple genes. They also demonstrated the
mechanisms including hormone regulation, reactive oxygen scavenging, osmotic regulation, cuticular wax deposition and root
architecture improvement. However, the number of water-saving and drought-resistant varieties cannot meet the urgent need for
our country, the drought resistant genes are still need to be mined and demonstrated. In this article, we collected and reviewed
literature related to rice drought resistance over the past two decades in China and abroad. And then summarized three types of
conventional identification indexes for rice drought resistance, and comprehensively analyzed the latest progress of important
mechanisms and key genes (QTLs) for rice drought resistance. |
