水稻脯氨酸代谢关键酶对水分胁迫的响应

摘要

Using rice seedlings at two - leaf stage as tested materials, the free proline content and activities of enzymes involved in proline metabolism were studied under water stress induced by 15 ％ PEG. The results showed that the proline content increased obviously under stress, reached the maximum after 24 h and then decreased. The activities of Δ1-pyrroline-5-carboxylate synthetase (P5CS) and ornithine-δ-aminotransferase (δ-OAT), the key enzymes of proline accumulation, increased significantly and then declined; while the activity of proline dehydrogenase (ProDH), a key enzyme of proline degradation, declined significantly and then increased.%以二叶期水稻幼苗为试验材料,研究其在15%PEG6000模拟的水分胁迫下脯氨酸积累及代谢关键酶活性变化,结果表明:叶片和根系中脯氨酸含量在胁迫后快速积累,胁迫24 h达到最大值,随后逐渐降低;控制脯氨酸合成的关键酶吡咯啉-5-羧酸合成酶(P5CS)和鸟氨酸转氨酶(δ-OAT)活性都呈现先升后降的变化趋势,而控制脯氨酸降解的关键酶脯氨酸脱氢酶(ProDH)活性呈现先降后升的变化趋势.