盐胁迫下外源NO对苜蓿幼苗生长及氮代谢的影响

应用生态学报 ›› 2012, Vol. 23 ›› Issue (11): 3003-3008.

盐胁迫下外源NO对苜蓿幼苗生长及氮代谢的影响

周万海^1，2，3,师尚礼^1，2，3**,寇江涛^1，2，3

(¹甘肃农业大学草业学院, 兰州 730070; ²草业生态系统教育部重点实验室/甘肃省草业工程实验室, 兰州 730070; ³中-美草地畜牧业可持续研究中心, 兰州 730070)

出版日期:2012-11-18 发布日期:2012-11-18

Effects of exogenous nitric oxide on the growth and nitrogen metabolism of alfalfa seedlings under salt stress.

ZHOU Wan-hai^1，2，3, SHI Shang-li^1，2，3, KOU Jiang-tao^1，2，3

(¹College of Pratacultural Science, Gansu Agricultural University, Lanzhou 730070, China; ²Ministry of Education Key Laboratory of Ecosystem/Gansu Province Laboratory of Pratacultural Engineering， Lanzhou 730070， China； ³Sino-US Center for Grazingland Ecosystem Sustainability, Lanzhou 730070, China)

Online:2012-11-18 Published:2012-11-18

摘要/Abstract

摘要： 为探寻增强苜蓿耐盐能力的调控途径,以甘农4号苜蓿品种为材料,采用NO供体硝普钠、NO清除剂c-PTIO及硝普钠类似物亚铁氰化钠处理苜蓿幼苗,研究盐胁迫下外源NO对苜蓿幼苗生长、光合特征、氮同化酶活性和氮代谢物含量的影响.结果表明: 外源NO能明显缓解盐胁迫对苜蓿幼苗生长及光合作用的抑制,单株干质量、叶绿素含量、净光合速率、蒸腾速率和可溶性蛋白含量增加;外源NO能增强硝酸还原酶、谷氨酰胺合成酶和谷氨酸合酶活性,抑制蛋白水解酶和谷氨酸脱氢酶活性, 降低叶片中游离氨基酸含量,提高硝态氮含量,加快铵的同化.NO供体SNP的类似物亚铁氰化钠对盐胁迫下苜蓿幼苗生长及氮代谢无调控作用;施用NO清除剂c-PTIO加剧了盐胁迫对苜蓿幼苗生长和氮代谢的抑制,添加外源NO能缓解c-PTIO的抑制效应.盐胁迫下,外源NO和内源NO均参与了苜蓿幼苗氮代谢的调控.

Abstract: In order to explore the regulation approaches for improving the salt-tolerance of alfalfa, the seedlings of Medicago sativa L. cv. Gannong No. 4 were taken to study their growth and nitrogen metabolism under salt stress as affected by NO-donor SNP, NO-scavenger c-PTIO, and sodium ferrocyanide (a SNP analogue with NO not released). Exogenous NO could obviously alleviate the inhibition effects of salt stress on the seedling growth and photosynthesis via increasing plant dry matter and leaf chlorophyll content, net photosynthesis rate, transpiration rate, and soluble protein content. Exogenous NO enhanced the activities of leaf nitrate reductase, glutamine synthetase, and glutamateoxoglutarate aminotransferase, restrained the activities of protease and glutamate dehydrogenase, decreased the free amino acid content, and improved the nitrate content and ammonium assimilation under salt stress. Applying sodium ferrocyanide did not show any alleviation effect on the seedling growth and nitrogen metabolism under salt stress. As a NO-scavenger, c-PTIO inhibited the growth and nitrogen metabolism under salt stress, but the inhibition effect could be mitigated by supplementing SNP. It was suggested that exogenous and endogenous NO were involved in the regulation of alfalfa nitrogen metabolism under salt stress.

周万海1，2，3,师尚礼1，2，3**,寇江涛1，2，3. 盐胁迫下外源NO对苜蓿幼苗生长及氮代谢的影响[J]. 应用生态学报, 2012, 23(11): 3003-3008.

ZHOU Wan-hai1，2，3, SHI Shang-li1，2，3, KOU Jiang-tao1，2，3. Effects of exogenous nitric oxide on the growth and nitrogen metabolism of alfalfa seedlings under salt stress.[J]. Chinese Journal of Applied Ecology, 2012, 23(11): 3003-3008.