过表达一个疣粒野生稻的Ricin_B凝集素基因OmR40c1增强水稻耐盐性

Over-expression of OmR40c1,a Ricin_B Lectin from Oryza meyeriana L. Enhances Salt Tolerance in Transgenic Plants

盐胁迫是影响盐/碱稻区水稻产量的主要逆境因素。研究耐盐相关基因,对于培育水稻抗逆品种具有重要意义。OmR40c1是从疣粒野生稻(Oryza meyeriana)中分离获得cDNA序列,与已报道的受脱落酸与盐诱导的OsR40c1的CDS序列完全相同,但在5′端UTR和3′端UTR区域有差别。有关OmR40c1基因功能的研究还未见报道。本研究的主要目的是初步分析OmR40c1在水稻耐盐性中的作用。对栽培稻日本晴(Oryza sativa L.var.Nipponbare)进行脱落酸(abscisic acid,ABA)和盐胁迫处理,OsR40c1基因均上调表达。构建基因定位载体并注射烟草表皮细胞,其结果表明OmR40c1定位于细胞质膜和细胞核上。构建超表达载体并转染日本晴,PCR及qRT-PCR结果均显示OmR40c1在转基因材料中成功表达。OmR40c1可能参与种子萌发。174mmol/L盐胁迫下,野生型种子的发芽率下调一半左右,转OmR40c1基因水稻种子发芽未受影响;转OmR40c1水稻苗期的株高是未经盐处理转基因水稻株高的一半左右;而野生型的株高是未经盐处理野生型水稻株高的1/6左右。盐胁迫下,水稻叶片、根长等都受到不同程度的影响。盐胁迫下,转OmR40c1基因水稻植株内的Na^+浓度是野生型的1.38倍;K^+浓度是野生型的1.25倍。综上,OmR40c1一定程度提高了水稻的耐盐性,且苗期的耐盐性高于成株期。

Salt stress is a major environmental factor limiting rice growth and productivity in saline soil.Planting tolerant line is still the most effective way in response to salt stress.OsR40c1 is an abscisic acid（ABA）and salt stressinduced gene.However,the function of OmR40c1 is poorly studied.Here,we cloned a gene from Oryza meyeriana which shared the same CDS with OmR40c1 but differed in 5′3′ UTR.Subcellular location analysis showed that OmR40c1 was located in cytoplasmic membrane and nuclear.OmR40c1 overexpressing transgenic rice was obtained by using the Agrobacterium-mediated gene transfer system.OmR40c1 might involve in seed germination.The germination rate of OmR40c1 transgenic rice was slightly affected by salt stress,while wild type decreased about 50% compared with their mocks.The seedlings of wild type hardly grown on the 1/2MS medium with salt（174mmol/L NaCl）,the height of 10-day OmR40c1 transgenic rice seedling decreased more than a half.Green leaves and root of OmR40c1 and wild type rice were both seriously affected by salt stress.The concentration of Na~＋ in OmR40c1 was about 1.38 times higher than that in wild type,together with a slight rise in the K~＋ concentration and the results suggest that OmR40c1 may act as a salt tolerance gene in enhancing rice salt tolerance especially at the adult stage.