National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083, China.
National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083, China.
Int J Biol Macromol. 2019 Jun 1;130:50-57. doi: 10.1016/j.ijbiomac.2019.02.115. Epub 2019 Feb 20.
Expansins play a pivotal role in plant adaptation to environmental stress via cell wall loosening. To evaluate the roles of expansin in response to different environmental stress conditions, the expansin gene PttEXPA8 from Populus tomentosa was transformed into tobacco. Analysis of physiological indices demonstrated the transgenic plants with improved resistance to heat, drought, salt, cold, and cadmium stress but to different extents. In mature plants, PttEXPA8 exerted the greatest effect on heat stress, with a response index value of 137.46%, followed by drought, cadmium, cold, and salt stress with response index values of 101.04%, 70.61%, 69.95%, and 54.68%, respectively. Over-expression of PttEXPA8 resulted in differential responses in physiological indices to the stresses. Soluble sugar content showed the highest response to the stresses, with an average response index value of 29.29%, whereas the absolute response index value for malondialdehyde content, relative electrolyte leakage, chlorophyll content, and superoxide dismutase activity ranged from 11.01% to 19.21%. The present results provide insight into the roles of expansin in stress resistance in Populus.
扩展蛋白通过细胞壁松弛在植物适应环境胁迫中起关键作用。为了评估扩展蛋白在应对不同环境胁迫条件下的作用，将毛白杨的扩展蛋白基因 PttEXPA8 转入烟草。生理指标分析表明，转基因植株对热、干旱、盐、冷和镉胁迫的抗性得到了提高，但程度不同。在成熟植株中，PttEXPA8 对热胁迫的作用最大，响应指数值为 137.46%，其次是干旱、镉、冷和盐胁迫，响应指数值分别为 101.04%、70.61%、69.95%和 54.68%。PttEXPA8 的过表达导致对这些胁迫的生理指标产生差异响应。可溶性糖含量对胁迫的响应最高，平均响应指数值为 29.29%，而丙二醛含量、相对电解质渗透率、叶绿素含量和超氧化物歧化酶活性的绝对响应指数值范围为 11.01%至 19.21%。本研究结果为研究扩展蛋白在杨树抗逆性中的作用提供了新的见解。
