硝酸镍诱导水稻白叶枯病抗性与防卫反应酶活性的变化

用1．0和2．0mmol／L的硝酸镍处理水稻幼苗2d后，再用稻白叶枯细菌(Xanthomonns oryzae pw.oryzae)挑战接种，14d后调查病情，发现病斑长分别比对照下降了42．1％和48．0％，说明硝酸镍能诱导水稻幼苗对白叶枯病的抗性。生理指标测定及同工酶电泳结果表明，两种浓度的硝酸镍处理均能明显提高叶片中POD、PPO和PAL活性以及木质素含量，大部分POD同工酶带和4条PPO同工酶带增强，提示硝酸镍对水稻抗白叶枯病的诱导效应可能与POD、PPO和PAL活性以及木质素含量升高有关。

Resistance of Rice to Bacterial Leaf Blight Induced by Nickel Nitrate and Changes of Activity of Some Defensive Response Enzymes

Rice seedlings were inoculated to the third leaf with Xanthomonas oryzae pv. oryzae two days after treating with 1.0 and 2.0 mmol/L nickel nitrate solution. The lesion length of the leaf in the two treatments was shorter by 42.1% and 48.0%, respectively, than that in the CK after 2 weeks, which indicated that nickel nitrate had induced resistance to bacterial leaf blight in rice seedlings. Determination of some physiological indices showed that the activity of peroxidase (POD), polyphenol oxidase(PPO) and phenylalanine amminia-lyase (PAL) and the content of lignin were all promoted or increased significantly in the leaves of rice seedlings after the treatment of nickel nitrate. Meanwhile, most of isozyme bands of POD and 4 isozyme bands of PPO were strengthened compared with those of the CK. Therefore, it is suggested that increase in the activity of POD, PPO and PAL and the content of lignin in leaves after treatment may involve in the resistance to bacterial leaf blight induced by nickel nitrate in rice seedlings.