Mbinda Wilton, Ombori Omwoyo, Dixelius Christina, Oduor Richard
Department of Biochemistry and Biotechnology, Pwani University, P.O Box 195-80108, Kilifi, Kenya.
Department of Biochemistry and Biotechnology, Kenyatta University, Nairobi, Kenya.
Mol Biotechnol. 2018 Mar;60(3):203-214. doi: 10.1007/s12033-018-0063-x.
Sweetpotato is a significant crop which is widely cultivated particularly in the developing countries with high and stable yield. However, drought stress is a major limiting factor that antagonistically influences the crop's productivity. Dehydration stress caused by drought causes aggregation of reactive oxygen species (ROS) in plants, and aldose reductases are first-line safeguards against ROS caused by oxidative stress. In the present study, we generated transgenic sweetpotato plants expressing aldose reductase, XvAld1 isolated from Xerophyta viscosa under the control of a stress-inducible promoter via Agrobacterium-mediated transformation. Our results demonstrated that the transgenic sweetpotato lines displayed significant enhanced tolerance to simulated drought stress and enhanced recuperation after rehydration contrasted with wild-type plants. In addition, the transgenic plants exhibited improved photosynthetic efficiency, higher water content and more proline accumulation under dehydration stress conditions compared with wild-type plants. These results demonstrate that exploiting the XvAld1 gene is not only a compelling and attainable way to improve sweetpotato tolerance to drought stresses without causing any phenotypic imperfections but also a promising gene candidate for more extensive crop improvement.
甘薯是一种重要作物，在发展中国家广泛种植，产量高且稳定。然而，干旱胁迫是一个主要限制因素，对该作物的生产力产生不利影响。干旱引起的脱水胁迫会导致植物体内活性氧（ROS）聚集，醛糖还原酶是抵御氧化应激引起的ROS的第一道防线。在本研究中，我们通过农杆菌介导的转化，培育出了在胁迫诱导型启动子控制下表达从粘叶旱生植物中分离的醛糖还原酶XvAld1的转基因甘薯植株。我们的结果表明，与野生型植株相比，转基因甘薯品系对模拟干旱胁迫表现出显著增强的耐受性，复水后恢复能力也有所增强。此外，与野生型植株相比，转基因植株在脱水胁迫条件下表现出更高的光合效率、更高的含水量和更多的脯氨酸积累。这些结果表明，利用XvAld1基因不仅是一种在不引起任何表型缺陷的情况下提高甘薯耐旱性的有吸引力且可行的方法，也是更广泛作物改良的一个有前景的基因候选者。
