《植物生理学报》 2015, 51(3): 377-384

AtPIN2基因通过影响根尖抗氧化能力参与拟南芥耐铝响应

曹华苹, 吴道铭, 沈宏*

华南农业大学资源环境学院, 广州510642

通信作者：沈宏；E-mail: hshen@scau.edu.cn；Tel: 020-28980056

摘　要：

PIN2是根尖生长素运输的重要蛋白, PIN2基因的差异表达是否影响植物耐铝性并不清楚。本文以不同AtPIN2表达水平的拟南芥为材料, 研究了AtPIN2差异表达对拟南芥耐铝性的影响。结果表明, 铝处理明显增强拟南芥根尖0~5 mm区域AtPIN2基因的转录表达, 与对照相比, 其表达量增加了80%。铝能诱导PIN2蛋白在根尖细胞膜水平方向累积, 并且呈束状分布。通过分析不同AtPIN2表达材料的耐铝性, 发现在铝处理条件下, PIN2缺失突变体(pin2-ko)的根系伸长速率显著小于PIN2超表达(PIN2-OX)和野生型材料(Col); 并且, pin2-ko累积较多的活性氧; pin2-ko的SOD、CAT和APX活性以及GSH含量均显著低于PIN2-OX。上述结果表明, AtPIN2表达差异影响拟南芥耐铝性, 敲除AtPIN2导致其对铝毒更敏感, 其机理可能是AtPIN2通过影响根尖抗氧化能力参与拟南芥耐铝响应。

关键词：铝胁迫; 拟南芥; AtPIN2; 抗氧化能力

收稿：2014-12-04   修定：2015-01-30

资助：国家自然科学基金项目(31172026和31372125)。

AtPIN2 Is Involved in Aluminum Tolerance by Affecting Antioxidant Capacity in the Roots of Arabidopsis

CAO Hua-Ping, WU Dao-Ming, SHEN Hong*

College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China

Corresponding author: SHEN Hong; E-mail: hshen@scau.edu.cn; Tel: 020-28980056

Abstract:

PIN2 is an important auxin efflux protein. It remains unclear whether differential expression of At- PIN2 influences aluminum tolerance of Arabidopsis thaliana. In this study, the relationship between differential expression of AtPIN2 and aluminum tolerance was examined using Arabidopsis PIN2 overexpression line (PIN2-OX), PIN2 knock-out line (pin2-ko), and Columbia wild type (Col) as materials. Al treatment enhanced the expression of AtPIN2 in 0–5 mm root tips of Arabidopsis seedlings obviously, and its expression was increased by 80% in comparison to the control. Al could induce the accumulation of PIN2 protein in the plasma membrane horizontal direction, and PIN2 protein showed a cluster distribution. Exposure to Al stress, a more serious root inhibition was observed in pin2-ko than in PIN2-OX and Col. PIN2-OX had a lower content of H₂O₂ and O₂ ¯• than pin2-ko. Exposure to Al stress, SOD, CAT and APX activities and GSH content of pin2-ko were lower than PIN2-OX. These results suggested that different expression of AtPIN2 influenced Al tolerance of Arabidopsis seedling, pin2-ko was more sensitive to Al, and this might be AtPIN2 involved in aluminum tolerance by affecting antioxidant capacity.

Key words: aluminum stress; Arabidopsis thaliana; AtPIN2; antioxidant capacity