外源ABA对低温胁迫下小桐子幼苗脯氨酸积累及其代谢途径的影响

邓凤飞*, 杨双龙*, 龚明**
云南师范大学生命科学学院, 生物能源持续开发利用教育部工程研究中心, 云南省生物质能与环境生物技术重点实验室, 昆明650500

通信作者: 龚明;E-mail: gongming6307@163.com;Tel: 0871-65941370

摘 要:

本文以小桐子为材料, 研究了外源脱落酸(ABA)对低温胁迫下小桐子幼苗脯氨酸积累的影响。结果表明, 低温胁迫(5℃)可促进小桐子幼苗体内脯氨酸的积累, 上调脯氨酸合成关键酶Δ1-吡咯琳-5-羧酸合成酶(P5CS)和鸟氨酸转氨酶(OAT)的活性, 上调P5CS基因(JcP5CS)的表达, 及抑制脯氨酸降解酶脯氨酸脱氢酶(ProDH)的活性。用外源ABA处理低温胁迫下的小桐子幼苗, 发现150 μmol•L-1的ABA可显著提高其低温胁迫下的脯氨酸含量, 上调P5CS的活性和JcP5CS的表达水平, 及抑制ProDH的活性。表明外源ABA可通过活化脯氨酸合成的谷氨酸途径和抑制脯氨酸的降解途径来促进低温胁迫下小桐子幼苗脯氨酸的积累。

关键词:小桐子; 低温胁迫; 脱落酸; 脯氨酸; 代谢途径

收稿:2014-11-07   修定:2015-01-21

资助:国家自然科学基金(31260169)、国家自然科学基金(31260064)和云南师范大学研究生科研创新基金。 * 同等贡献。 ** 通讯作者。

Effect of Exogenous Abscisic Acid on Proline Accumulation and Metabolic Pathways in Jatropha curcas Seedlings under Cold Stress

DENG Feng-Fei*, YANG Shuang-Long*, GONG Ming**
Key Laboratory of Biomass Energy and Environmental Biotechnology of Yunnan Province, Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, School of Life Sciences, Yunnan Normal University, Kunming 650500, China

Corresponding author: DENG Feng-Fei; E-mail: gongming6307@163.com; Tel: 0871-65941370

Abstract:

Jatropha curcas seedlings were used as materials to study the effect of exogenous abscisic acid (ABA) on proline accumulation under cold stress. The results showed that cold stress (5 ℃) led to a significant accumulation of proline in J. curcas seedlings. It also induced a rapid increase of activities of the key enzymes Δ1-pyrroline-5-carboxylate synthetase (P5CS) and ornithine aminotransferase (OAT) of proline biosynthesis, and an up-regulation of P5CS gene (JcP5CS) expression, and a decrease of the activity of the key enzyme proline dehydrogenase (ProDH) of proline degradation. Treatment with 150 μmol•L-1 abscisic acid (ABA) could enhance the accumulation of proline in J. curcas seedlings under cold stress. ABA also increased the activity of P5CS, and improved the expression level of JcP5CS. Furthermore, the ABA treatment decreased the activity of ProDH in J. curcas seedlings under cold stress. These results showed that the ABA-induced proline accumulation in the J. curcas seedlings under cold stress might be a combined result of the activation of glutamate pathways of proline biosynthesis and inhibition of proline degradation pathway.

Key words: Jatropha curcas; cold stress; abscisic acid; proline; metabolic pathways

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