Liu Guanze, Li Xuelin, Jin Shuangxia, Liu Xuyan, Zhu Longfu, Nie Yichun, Zhang Xianlong
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, P. R. China ; College of Tobacco Science, Yunnan Agricultural University, Kunming, Yunnan, P. R. China.
Agricultural College, Henan University of Science and Technology, Luoyang, Henan, P. R. China.
PLoS One. 2014 Jan 28;9(1):e86895. doi: 10.1371/journal.pone.0086895. eCollection 2014.
The SNAC1 gene belongs to the stress-related NAC superfamily of transcription factors. It was identified from rice and overexpressed in cotton cultivar YZ1 by Agrobacterium tumefaciens-mediated transformation. SNAC1-overexpressing cotton plants showed more vigorous growth, especially in terms of root development, than the wild-type plants in the presence of 250 mM NaCl under hydroponic growth conditions. The content of proline was enhanced but the MDA content was decreased in the transgenic cotton seedlings under drought and salt treatments compared to the wild-type. Furthermore, SNAC1-overexpressing cotton plants also displayed significantly improved tolerance to both drought and salt stresses in the greenhouse. The performances of the SNAC1-overexpressing lines under drought and salt stress were significantly better than those of the wild-type in terms of the boll number. During the drought and salt treatments, the transpiration rate of transgenic plants significantly decreased in comparison to the wild-type, but the photosynthesis rate maintained the same at the flowering stage in the transgenic plants. These results suggested that overexpression of SNAC1 improve more tolerance to drought and salt in cotton through enhanced root development and reduced transpiration rates.
SNAC1基因属于与胁迫相关的NAC转录因子超家族。它是从水稻中鉴定出来的，并通过根癌农杆菌介导的转化在棉花品种YZ1中过表达。在水培生长条件下，250 mM NaCl存在时，过表达SNAC1的棉花植株比野生型植株生长更旺盛，尤其是在根系发育方面。与野生型相比，干旱和盐处理下转基因棉花幼苗中脯氨酸含量增加，但丙二醛含量降低。此外，过表达SNAC1的棉花植株在温室中对干旱和盐胁迫的耐受性也显著提高。在干旱和盐胁迫下，过表达SNAC1的株系在棉铃数量方面的表现明显优于野生型。在干旱和盐处理期间，与野生型相比，转基因植株蒸腾速率显著降低，但在开花期转基因植株光合速率保持不变。这些结果表明，SNAC1的过表达通过增强根系发育和降低蒸腾速率提高了棉花对干旱和盐的耐受性。
