Ammopiptanthus mongolicus stress-responsive NAC gene enhances the tolerance of transgenic Arabidopsis thaliana to drought and cold stresses

Abstract Drought and cold are the primary factors limiting plant growth worldwide. The Ammopiptanthus mongolicus NAC11 (AmNAC11) gene encodes a stress-responsive transcription factor. Expression of the AmNAC11 gene was induced by drought, cold and high salinity. The AmNAC11 protein was localized in the nucleus and plays an important role in tolerance to drought, cold and salt stresses. We also found that differential expression of AmNAC11 was induced in the early stages of seed germination and was related to root growth. When the AmNAC11 gene was introduced into Arabidopsis thaliana by an Agrobacterium-mediated method, the transgenic lines expressing AmNAC11 displayed significantly enhanced tolerance to drought and freezing stresses compared to wild-type Arabidopsis thaliana plants. These results indicated that over-expression of the AmNAC11 gene in Arabidopsis could significantly enhance its tolerance to drought and freezing stresses. Our study provides a promising approach to improve the tolerance of crop cultivars to abiotic stresses through genetic engineering.

摘要 干旱与低温是全球范围内限制植物生长的主要胁迫因子。蒙古沙冬青（Ammopiptanthus mongolicus）NAC11（AmNAC11）基因编码一种胁迫响应转录因子。AmNAC11基因的表达可被干旱、低温及高盐胁迫诱导。AmNAC11蛋白定位于细胞核，在植物抵御干旱、低温及盐胁迫过程中发挥重要作用。本研究还发现，AmNAC11的差异表达在种子萌发早期被诱导，且与根系生长密切相关。通过农杆菌介导法将AmNAC11基因导入拟南芥（Arabidopsis thaliana）后，与野生型拟南芥相比，表达AmNAC11的转基因株系对干旱和冻胁迫的耐受性显著提升。上述结果表明，在拟南芥中过表达AmNAC11基因可显著提升其对干旱与冻胁迫的耐受性。本研究为通过基因工程手段改良作物品种的非生物胁迫耐受性提供了极具应用前景的技术途径。