《植物生理学报》 2009, 45(8): 781-784

一氧化氮对玉米幼苗体内脯氨酸积累及其代谢途径的影响

杨双龙^1,2,3, 龚明^2,3,*

1 中国农业大学水利与土木工程学院, 北京100083; 2 云南师范大学生命科学学院, 昆明650092; 3 教育部生物能源持续开发利用工程研究中心, 昆明650092

通信作者：龚明；E-mail: gongming63@163.com；Tel: 0871-5516516

摘　要：

NO 供体硝普钠(SNP)可显著提高玉米幼苗体内脯氨酸含量和脯氨酸合成途径中关键酶鸟氨酸转氨酶(OAT)的活性, 而降低降解途径中关键酶脯氨酸脱氢酶(ProDH)的活性, 作为NO 淬灭剂的c-PTIO, 其作用则相反。但不论是SNP或c-PTIO 对玉米幼苗中Δ1-吡咯啉-5-羧酸合成酶(P5CS)活性的影响均不显著。表明NO 诱导的脯氨酸积累可能是NO 激活了脯氨酸 合成中的鸟氨酸途径、同时抑制了脯氨酸降解途径的综合结果。

关键词：一氧化氮; 玉米幼苗; 脯氨酸; 代谢途径

收稿：2009-04-29   修定：2009-06-17

资助：国家自然科学基金(30660013)。

Effects of Nitric Oxide on Proline Accumulation and Metabolic Pathways in Maize (Zea mays L.) Seedlings

YANG Shuang-Long^1,2,3, GONG Ming^2,3,*

¹College of Water Conservancy & Civil Engineering, China Agricultural University, Beijing 100083, China; ²College of Life Sciences, Yunnan Normal University, Kunming 650092, China; ³Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming 650092, China

Corresponding author: GONG Ming; E-mail: gongming63@163.com; Tel: 0871-5516516

Abstract:

Treatment with the NO donor sodium nitroprusside (SNP) could lead to a significant accumulation of proline, a rapid increase of the activity of the key enzyme ornithine-δ-aminotransferase (OAT) of proline biosynthesis, and a decrease of the activity of the key enzyme proline dehydrogenase (ProDH) of proline degradation in maize (Zea mays) seedlings. Whereas treatment with the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) exhibited contrary results to the SNP treatment. In addition, both SNP and c-PTIO treatments had little effect on Δ¹-pyrroline-5-carboxylate synthetase (P5CS) activity. These results showed that the NO-induced proline accumulation in the maize seedlings might be a combined result of the activation of ornithine pathways of proline biosynthesis and inhibition of proline degradation pathway.

Key words: nitric oxide; maize seedlings; proline; metabolic pathways