水稻耐盐分子机制研究进展

Research Progress on Molecular Mechanism of Salt Tolerance in Rice

水稻是世界上重要的粮食作物之一,对盐胁迫比较敏感,土壤盐碱化对水稻的安全生产造成潜在风险。盐胁迫会引起水稻的渗透胁迫和离子毒害,还会在植株中引起氧化胁迫,导致水稻品质和产量下降。由于水稻根系能吸收盐分分泌有机酸,同时具有田间持水和排水晒田的生长特性,因此水稻也是一种改良盐渍土的优良作物。因此培育耐盐水稻新品种,提高水稻耐盐性,可有效提高盐渍化耕地的生产潜力,对保障我国乃至全球粮食安全具有重要意义。近年来,数量遗传学和分子标记技术不断发展,通过遗传、生化及分子生物学等手段,挖掘出大量耐盐相关QTL和基因,对于解析水稻耐盐分子机制,利用分子标记辅助选择、基因编辑等提高耐盐水稻育种效率,均具有非常重要的意义。但目前克隆的耐盐相关基因大多采用反向遗传学方法获得,且大多是在过表达条件下表现出耐盐性,或者耐盐基因为隐性,难以在耐盐水稻育种中应用。总结近年来水稻耐盐相关基因的鉴定和挖掘研究中所取得的进展,从有机物渗透调节、离子吸收转运调节、抗氧化系统清除活性氧调节、激素调节4个方面综述水稻耐盐分子机制的研究进展,并探讨未来水稻耐盐性研究面临的挑战,为开展水稻耐盐分子育种提供建议。

Rice is one of the important grain crops in the world and is sensitive to salt stress.The increasingly serious salinization of paddy soils is becoming a potential risk to the safe production of rice.Salt stress can cause osmotic stress,ion toxicity and oxidative stress in rice plant,ultimately leading to a decrease in rice quality and yield.Due to the ability of rice roots to absorb salt and secrete organic acids as well as the growth characteristics of water holding in the early stage and drainage in rice paddies in the later stage,rice is also an excellent crop for improving saline soil.Therefore,cultivating new rice varieties of salt tolerant and improving rice salt tolerance can effectively enhance the production potential of saline farmland,which is important to food security in China and the world.In recent years,quantitative genetics and molecular marker technology have been continuously developed.Through genetic,biochemical and molecular biology methods,a large number of salt-tolerant related QTLs and genes have been excavated,which is of great benefit to analyze the molecular mechanism of salt tolerance in rice and improve the breeding efficiency of salt-tolerant rice through molecular marker-assisted selection,gene editing and other molecular means.Nevertheless,many cloned genes related to salt tolerance are difficult to be applied in rice breeding currently as most of them are obtained through reverse genetics methods and exhibit salt tolerance only under overexpression conditions,or these genes are recessive genes.The study summarized the recent progress in the identification and mining of salt-tolerant genes in rice,and reviewed the research progress on molecular mechanisms of salt tolerance in rice from four aspects:osmotic regulation of organic matter,regulation of ion absorption and transport,regulation of reactive oxygen removal by antioxidant system and regulation of hormone.The challenges of future researches on salt tolerance of rice were also discussed in order to provide some suggestions for molecular breeding of salt tolerance of rice in the future.