《植物生理学报》 2017, 53(3): 470-476

NaCl胁迫对银杏幼树渗透调节物质及脯氨酸代谢的影响

孙聪聪, 赵海燕, 郑彩霞^*

北京林业大学生物科学与技术学院, 北京100083

通信作者：郑彩霞；E-mail: zhengcx@bjfu.edu.cn

摘　要：

以盆栽的三年生银杏幼树为材料, 研究NaCl胁迫后银杏叶片渗透调节物质含量及脯氨酸代谢关键酶活性变化规律, 以探索银杏幼树耐盐机制。结果表明, NaCl处理显著影响幼树的生长; 0.4% NaCl处理的银杏幼树叶片可溶性蛋白含量最高; 可溶性糖含量随盐浓度的升高和盐胁迫时间的延长呈先升后降趋势; 脯氨酸含量在盐胁迫后期显著增加, 对银杏耐盐能力起主导作用; 在NaCl胁迫下, Δ₁-吡咯啉-5-羧酸合成酶(P5CS)、鸟氨酸-δ-氨基转移酶(δ-OAT)和脯氨酸脱氢酶(ProDH)协同作用促进了脯氨酸含量的积累。在此过程中, 脯氨酸合成前期以谷氨酸(Glu)途径为主, 后期以鸟氨酸(Orn)途径为主。由上可知银杏可通过积累可溶性蛋白、可溶性糖、脯氨酸进行渗透调节以抵御NaCl胁迫。

关键词：银杏; NaCl胁迫; 渗透调节; 脯氨酸代谢

收稿：2017-02-17   修定：2017-03-01

资助：国家自然科学基金(31170563)。

Effects of NaCl stress on osmolyte and proline metabolism in Ginkgo biloba seedling

SUN Cong-Cong, ZHAO Hai-Yan, ZHENG Cai-Xia^*

College of Biological Science and Technology, Beijing Forest University, Beijing 100083, China

Corresponding author: ZHENG Cai-Xia; E-mail: zhengcx@bjfu.edu.cn

Abstract:

The aim of this study is to investigate the changes of osmolyte content and proline metabolism enzyme activity in three-year-old ginkgo seedling under salt stress, and investigate the salt stress response mechanism. The results showed that the salt stress significantly affected the growth of plants. The soluble protein content of 0.4% NaCl treatment was the highest in ginkgo. The soluble sugar content increased and then decreased with the increase of NaCl concentration and salt stress time. The proline content increased significantly at the late stage of salt stress, and played a leading role in salt tolerance. Under the stress of NaCl, the synergistic effect of P5CS, δ-OAT and ProDH promoted the accumulation of proline. During this period, glutmate pathway, a main synthesis pathway of proline in ginkgo seedling, was replaced by ornithine pathway with the increase of salt treatment time. In conclusion, soluble protein, soluble sugar and proline were mainly accumulated and used for osmotic adjustment in ginkgo under NaCl stress.

Key words: Ginkgo biloba L.; NaCl stress; osmotic adjustment; proline metabolism