【摘要】 为探索燕麦主要耐盐基因AsSOS1(Na+/H+逆向转运蛋白)的功能，本研究以耐盐品种青永久195为供试材料，在种子实生苗沙培3周后克隆AsSOS1基因，对其蛋白序列进行同源比对并分析理化性质，预测蛋白的跨膜结构和亲/疏水性以及二级和三级结构，用qRT-PCR分析100 mmol/L NaCl胁迫下AsSOS1基因在燕麦根、茎、叶中的表达。结果表明，AsSOS1的开放阅读框长度为3411 bp，编码1137个氨基酸；AsSOS1蛋白分子量为126.088 KDa，等电点6.62，属于酸性蛋白，稳定系数45.14，疏水性蛋白；AsSOS1蛋白二级结构中包含48.20%的α-螺旋和33.77%的无规则卷曲，三级结构与二级结构预测结果一致，以α-螺旋为主；跨膜结构域预测结果显示，AsSOS1蛋白中包含胞外结构域、跨膜螺旋结构域和胞内结构域，其中氨基酸序列11～424是Na~+/H~+逆向转运蛋白的保守序列，预测该区域与植物耐盐性相关；进化分析发现，其与硬直黑麦草的亲缘关系最近，相似度高达96%。正常生长条件下，AsSOS1基因在燕麦根、茎、叶中均有表达；在100 mmol/L NaCl胁迫下，AsSOS1基因在茎和根中的表达量分别增加了171.4%和54.1%，说明AsSOS1受盐胁迫诱导，在燕麦耐盐过程中起重要作用。更多还原

【Abstract】 In order to explore the function of the main salt tolerance gene AsSOS1(Na~+/H~+ antiporter protein) in oat(Avena sativa), the salt-tolerant variety Qingyongjiu 195 was used as the test material, and AsSOS1 gene was cloned after three weeks of seedling cultivation. The protein sequence was homologous aligned and analyzed for physicochemical properties, predicted for protein transmembrane structure and hydrophilicity/hydrophobicity, secondary and tertiary structures. The expression of AsSOS1 gene in oat roots, stems and leaves of oat under 100 mmol/L NaCl stress was analyzed by qRT-PCR. The results indicated that the length of open reading frame of AsSOS1 gene was 3411 bp, encoding 1137 amino acids.AsSOS1 protein had a molecular weight of 126. 088 KDa and an isoelectric point of 6. 62. It was an acid protein with a stability coefficient of 45. 14 and hydrophobic protein. The secondary structure of AsSOS1protein contained 48. 20% α-helix and 33. 77% random coil, and the tertiary structure was consistent with the predicted secondary structure, mainly α-helix. The results of transmembrane domain prediction showed that AsSOS1 protein may had extracellular domain, transmembrane helical domain and intracellular domain, among which, amino acid sequence 11-424 were conserved sequence of Na~+/H~+ antiporter, indicating this region was predicted to be related to plant salt tolerance. Evolutionary analysis found that it was most closely related to Lulium rigidum, with a similarity of up to 96%. Under normal growth conditions, AsSOS1 gene was expressed in oat roots, stems and leaves. Under 100 mmol/L NaCl stress, the expression of AsSOS1 in stem and root increased by 171. 4% and 54. 1%, respectively. The results indicate that AsSOS1 is induced by salt stress and plays an important role in salt tolerance of oat.更多还原