《植物生理学报》 2010, 46(6): 549-554

NO 参与玉米幼苗对盐胁迫的应答

侯丽霞, 车永梅, 赵方贵, 唐静, 刘新*

青岛农业大学生命科学学院, 山东青岛266109

通信作者：刘新；E-mail: liuxin6080@yahoo.com.cn；Tel: 0532-88030 224

摘　要：

以玉米幼苗为材料, 研究盐胁迫下其內源 NO 含量、NR 和 NOS 活性的变化; NOS 专一性抑制剂 L-NAME 和 NR 非 专一性抑制剂 NaN3 对玉米幼苗內源 NO 含量的影响; 利用激光共聚焦显微技术观测盐胁迫下玉米幼苗根部 NO 含量的变 化及其分布特点。结果表明, 盐胁迫下玉米幼苗根尖和叶片中NO 含量有猝发现象, NOS 活性也随之显著提高, NR 活性则 显著降低; L-NAME 或 NaN3 均可降低盐胁迫所引起的玉米幼苗 NO 水平的增加, L-NAME 对 NO 含量的影响比 NaN3 更显 著。推测, NO 参与玉米幼苗对盐胁迫的应答, NOS 途径是盐胁迫下玉米幼苗內源 NO 合成的主要途径。

关键词：玉米幼苗; 盐胁迫; 一氧化氮; 一氧化氮合酶

收稿：2010-03-25   修定：2010-04-12

资助：山东省教育厅基金(J04C13)和国家自然科学基金(30970228)。

NO Involved in the Response of Maize Seedlings to Salt Stress

HOU Li-Xia, CHE Yong-Mei, ZHAO Fang-Gui, TANG Jing, LIU Xin*

School of Life Sciences, Qingdao Agricultural University, Qingdao, Shandong 266109, China

Corresponding author: LIU Xin; E-mail: liuxin6080@yahoo.com.cn; Tel: 0532-88030 224

Abstract:

The changes of endogenous nitric oxide (NO) content, nitrate reductase (NR) and nitric oxide synthase (NOS) activity, effects of NOS inhibitor N_ω-nitro-L-arginine methyl ester (L-NAME) and NR inhibitor NaN₃ on NO content in maize seedlings under salt stress were studied. The results showed that NO content and NOS activity in root tip and leaf of maize seedlings increased under salt stress, but NR activity decreased. After treated with L-NAME and NaCl together, NO content in maize seedlings decreased significantly, yet NO content decreased a little after treated with NaN₃ and NaCl. In order to prove salt stress-induced NO synthesis in root, the distribution of NO in root of maize seedlings was researched by confocal laser scanning microscope. NO is mainly distributed in root epidermis and hairs. The content of NO treated with L-NAME decreased more significantly than that treated with NaN₃. These results suggested that salt stress could promote the synthesis of NO in maize seedlings by stimulating the NOS pathway, and NO participated in salt signal transduction in maize seedlings.

Key words: maize seedlings; salt stress; nitric oxide; nitric oxide synthase