《植物生理学报》 2010, 46(10): 1040-1044

草酸氧化酶在水稻胚芽鞘衰老中的作用

张建军, 赖宇雄, 刘娥娥*, 彭新湘

华南农业大学生命科学学院分子植物生理研究室, 广州510642

通信作者：刘娥娥；E-mail: eeliu70@163.com；Tel: 020-85280194

摘　要：

草酸氧化酶(OxO)催化草酸氧化产生 CO2 和H2O2, 其在植物发育及防御过程中可能具有重要作用。本文以水稻品种‘ 湘糯 1 号 ’ (‘Xiangnuo 1’)为材料, 对胚芽鞘中的 OxO 及其生理功能进行了研究。结果表明, 胚芽鞘中的 H2O2 含量在其衰 老时增加; OxO 活性在浸种后96 h 时较低, 之后也迅速增加, 在240 h 达到最高; 而可溶性蛋白、O－• 和草酸含量以及过氧化氢酶(CAT)活性则随着胚芽鞘的衰老迅速降低。由于 H2O2 能够诱导细胞死亡, 推测OxO 可能通过降解草酸产生H2O2 参与 胚芽鞘的衰老。

关键词：草酸氧化酶; 胚芽鞘; 衰老; 水稻

收稿：2010-07-01   修定：2010-09-14

资助：广东省博士启动基金(05300955)和广东省自然科学基金项目(8151064201000060)。

Function of Oxalate Oxidase (OxO) during Coleoptile Senescence in Rice (Oryza sativa L.)

ZHANG Jian-Jun, LAI Yu-Xiong, LIU E-E*, PENG Xin-Xiang

Laboratory of Molecular Plant Physiology, College of Life Sciences, South China Agricultural University, Guangzhou 510642, China

Corresponding author: LIU E-E; E-mail: eeliu70@163.com; Tel: 020-85280194

Abstract:

Oxalate oxidase (OxO; EC1.2.3.4) catalyzes oxidation of oxalate and yields CO₂ and H₂O₂. It may play important roles in plant growth and defense. In this study, OxO activity, oxalate content and H₂O₂ production were detected during senescence of coleoptiles in the rice (Oryza sativa) ‘Xiangnuo 1’ to analysis the possible functions of OxO in senescence of coleoptiles. The results showed that H₂O₂ content was enhanced with the senescence of coleoptiles. OxO activity was very low at 96 h after imbibition, and then increased significantly and with a maximum at 240 h. Conversely, the levels of soluble protein, oxalate, O₂¯ and catalase (CAT) activity in coleoptiles were the highest at 96 h, and then decreased. It suggested that OxO might be involved in the senescence of coleoptiles in rice by catalyzing the oxidation of oxalate.

Key words: oxalate oxidase; coleoptile; senescence; rice