大气增温对杉木幼树叶片及细根生理特征的影响

Effects of atmospheric warming on physiological characteristics of leaves and fine roots of Cunninghamia lanceolata saplings

为揭示亚热带森林对未来全球变暖的生理响应特征,本研究以杉木为研究对象,利用开顶式增温方式模拟气候变暖,研究其对叶片和细根丙二醛含量、活性氧代谢、渗透调节物质含量以及抗氧化酶活性的影响。研究结果显示:(1)增温显著增加杉木叶片和细根的丙二醛含量,且叶片丙二醛含量显著高于细根,说明增温加剧了杉木叶片和细根氧化损伤,且叶片氧化损伤程度高于细根;(2)增温后,杉木叶片脯氨酸和可溶性蛋白含量降低,细根脯氨酸和可溶性蛋白含量则增加;(3)增温显著提高了杉木叶片过氧化物酶活性,对杉木细根抗氧化酶活性无显著影响;(4)增温后,杉木叶片和细根活性氧含量未发生显著变化,杉木叶片活性氧含量显著高于细根。综合分析表明,尽管增温增加了杉木叶片和细根的氧化损伤,但杉木可以通过提高抗氧化保护酶活性(叶片)和积累较多的渗透调节物质(细根)来维持体内活性氧代谢平衡。可见,杉木地上和地下部分器官间的相互合作与协调使杉木能有效地适应高温环境。

In order to reveal the response of physiological characteristics of subtropical forests to global warming in the future,the Cunninghamia lanceolata(C.lanceolata)was taken as the research object,the open-top heating method was used to simulate climate warming to study the contents of malondialdehyde(MDA),active oxygen metabolism,and penetration in leaves and fine roots.The results showed that(1)warming significantly increased the contents of MDA in the leaves and fine roots.Also the content of MDA in leaves was higher than that of fine roots,These indicated that oxidative stress enhanced the oxidative damage of leaves and fine roots,and the degree of oxidative damage of leaves was higher than fine roots;(2)warming increased the contents of proline and soluble protein in fine roots,but decreased the contents of proline and soluble protein in leaves;(3)warming increased the peroxidase activity of the leaves significantly,but had no significant effect on the antioxidant enzyme activity of the fine roots;(4)the active oxygen contents of leaves and fine roots had no significant change after warming,but the active oxygen content of leaves was obviously higher than that of fine roots.Comprehensive analysis showed that although warming increased the oxidative damage of leaves and fine roots,C.lanceolata saplings could maintain their own active oxygen metabolism balance by increasing the antioxidant enzymes activity in leaves and accumulating more osmotic adjustment substances in fine roots.It can be seen that the cooperation and coordination between the aboveground and belowground organs were helpful for C.lanceolata saplings to adapt to the high temperature environment effectively.