水稻（Oryza sativa L.）是世界主要粮食作物之一，干旱和高盐等非生物胁迫环境严重影响水稻产量，提高水稻水分利用效率的主要途径是提高其抗旱性和耐盐性。克隆和利用水稻抗旱耐盐相关基因，提高水稻的抗逆能力，对我国乃至全世界粮食安全都具有重要意义。本研究报道了水稻maspardin蛋白基因OsMas1的克隆、生物学功能以及分子作用机制。亚细胞定位分析，结果表明 OsMas1蛋白定位于细胞质。逆境胁迫表达分析表明，OsMas1基因受到200 mM甘露醇、20% PEG6000、200 mM NaCl和100 μM ABA诱导表达。构建植物过表达载体和RNAi干扰载体，将该基因导入水稻品种中花11号（WT），通过对转基因水稻材料抗性鉴定，结果表明过表达（OsMas1-OE）植株的耐盐性和抗旱性显著增强，而干扰（OsMas1-RNAi）植株的耐盐性和抗旱性显著降低。对OsMas1-OE、OsMas1-RNAi和WT水稻材料进行芽期和苗期的外源ABA处理，结果发现OsMas1-OE植株对ABA的敏感性明显高于WT植株，而OsMas1-RNAi植株对ABA的敏感性明显低于WT植株。干旱、盐胁迫处理后，OsMas1-OE植株的ABA、脯氨酸、K⁺含量以及超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）和光合活性显著高于OsMas1-RNAi植株和WT植株，而丙二醛（MDA）、过氧化氢（H₂O₂）、超氧阴离子自由基（O^2-）和Na⁺含量显著低于OsMas1-RNAi植株和WT植株。qRT-PCR分析表明，在盐、干旱胁迫下，过表达OsMas1基因显著上调ABA生物合成与信号途径、脯氨酸生物合成途径、活性氧（ROS）清除系统、光合作用和离子转运相关基因的表达，从而显著提高了转基因水稻植株的耐盐性和抗旱性，为水稻水分高效利用和抗逆育种奠定理论基础。

Myo-inositol-1-phosphate synthase (MIPS) is a key rate limiting enzyme in the de novo biosynthesis of myo-inositol in plants. In the present study, the IbMIPS1 gene was introduced into sweetpotato cultivar Xushu 18 and the transgenic plants exhibited significantly enhanced salt tolerance compared with the wild-type (WT). Overexpression of IbMIPS1 up-regulated the salt stress responsive genes, including myo-inositol monophosphatase (MIPP), pyrroline-5-carboxylate synthase (P5CS), pyrroline-5-carboxylate reductase (P5CR), psbA, phosphoribulokinase (PRK), and superoxide dismutase (SOD) genes, under salt stress. Inositol and proline content, SOD and photosynthesis activities were significantly increased, whereas malonaldehyde (MDA) and H2O2 contents were significantly decreased in the transgenic plants. These findings suggest that the IbMIPS1 gene may enhance salt tolerance of sweetpotato by regulating the expression of salt stress responsive genes, increasing the content of inositol and proline and enhancing the activity of photosynthesis.

Trehalose plays an important role in metabolic regulation and abiotic stress tolerance in a variety of organisms. In plants, its biosynthesis is catalyzed by two key enzymes: trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP). In the present study, a TPS gene, named IbTPS, was first isolated from sweetpotato (Ipomoea batatas (L.) Lam.) cv. Lushu 3 by rapid amplification of cDNA ends (RACE). The open reading frame (ORF) contained 2 580 nucleotides encoding 859 amino acids with a molecular weight of 97.433 kDa and an isoelectric point (pI) of 5.7. The deduced amino acid sequence showed high identities with TPS of other plants. Real-time quantitative PCR analysis revealed that the expression level of IbTPS gene was significantly higher in stems of Lushu 3 than in its leaves and roots. Subcellular localization analysis in onion epidermal cells indicated that IbTPS gene was located in the nucleus. Transgenic tobacco (cv. Wisconsin 38) plants over-expressing IbTPS gene exhibited significantly higher salt tolerance compared with the control plant. Trehalose and proline content was found to be significantly more accumulated in transgenic tobacco plants than in the wild-type and several stress tolerance related genes were up-regulated. These results suggest that IbTPS gene may enhance salt tolerance of plants by increasing the amount of treahalose and proline and regulating the expression of stress tolerance related genes.