[Xinhua News, February 9]On the 7th, the Shenzhen Agricultural Genomics Institute of the Chinese Academy of Agricultural Sciences (Shenzhen Sub-Center of the Guangdong Provincial Laboratory of Modern Agricultural Science and Technology in Lingnan), in collaboration with Yazhouwan National Laboratory, the Institute of Wetland Agriculture and Ecology of the Shandong Provincial Academy of Agricultural Sciences, the China Rice Research Institute and others, successfully mapped gene expression profiles of rice super pan-genome populations under salt stress and identified a new excellent gene, STG5, which is key to salt tolerance. The research results, which have important significance for the breeding and improvement of salt-tolerant rice, were published in the scientific journal National Science Review (NSR) on the 6th Beijing time.

According to Shang Lianguang, a researcher at the Shenzhen Agricultural Genomics Institute and head of the project, China has about 1.5 billion mu (100 million hectares) of saline and alkaline soil, of which about 500 million mu (about 33.33 million hectares) has the potential for development and utilization. How to awaken this dormant reserve arable land resource is one of China’s most pressing issues.

According to Shang, salt stress causes varying degrees of harm to different stages of rice growth and development, resulting in reduced yields. The selection and breeding of salt-tolerant rice is an important measure for the development and utilization of saline and alkaline soils. By thoroughly identifying the salt tolerance of various rice germplasm resources and analyzing the alleles and molecular mechanisms of superior salt tolerance, a good theoretical basis and germplasm materials can be provided for the cultivation of salt-tolerant varieties.

In this study, gene expression profiles of rice super pan-genome populations under normal conditions and salt stress were constructed, and salt tolerance at the seedling stage was systematically analyzed. Evaluations were conducted based on many salt tolerance indicators, and genome-wide association studies (GWAS) combined with the super pan-genome were used to identify many new loci related to salt tolerance, and the major gene STG5, which affects salt tolerance, was identified. In addition, the STG5 allele of the highly salt-tolerant variety “Seaweed 86” was introduced into the less salt-tolerant “Nipponbare”, and it was found that the salt tolerance of Nipponbare was significantly improved. The gene is mainly involved in regulating the steady-state balance of sodium ions (Na+) and potassium ions (K+), which may be of great use in breeding salt-tolerant organisms. The study has provided abundant resources for the extraction of highly salt-tolerant alleles. In the future, it will provide genetic resources and theoretical support for the development and cultivation of salt-tolerant rice varieties. (c)Xinhua News/AFPBB News