摘要
联合固氮粪产碱菌结合于水稻根表时能增强水稻根部还原力和稻根超氧化物歧化酶（ＳＯＤ）活性。实验室和田间试验证明粪产碱菌能提高水稻幼苗对高、低温不良环境的抗逆性。经浸种处理的水稻幼苗植株内多元酚含量增加了１２．５％。粪产以菌对接种水稻多元酚抽提物有强烈的趋化性，而该抽提物对粪产碱菌的固氮活性有明显的刺激作用。多元酚抽提物经双向纸层析和薄层层析表明接种诱导了至少一个特征组分含量提高。采用粪产减菌野生型Ａ１５０１（ｎｉｆ＋）和固氮缺陷型Ａ１５０６（Ｎｉｆ－）浸种能改变宿主水稻内源激素水平，提高内根际的ＩＡＡ和Ｚ的含量，促进植株及根系的生长发育，使其侧根和根毛数目明显增多。在根际联合体系形成过程中，多元酚或激素可能充当植物与细菌间相互作用的一类特异信号分子。
Inoculation of rice plant with associative diazotroph A.faecalis A1501(wild type) enhanced redox ability of rice roots,stimulated superoxide dismutase(SOD) activity,and increased resistance of rice seedlings against high or low temperature in laboratory and field experiments.Inoculation might also decrease polyphenol oxidase and increased the content of polyphenolics in rice seedlings.Extracts of polyphenolies from inoculated rice roots could stimulate N2-fixing activity and chemotaxis of A.faecalis.StrainA1501(nif+) and mutant A1506(Nif-) changed the level of phytohormone,increased the content of IAA and Z in the endorhizosphere, and promoted the growth of rice plants.The number of lateral roots and root hairs of inoculated rice plants were much higher than that of the control.It is suggested that polyphenolics and phytohormones might play the role of special siganl molecules in the interaction between host plant and microbe.
关键词
水稻
根
粪产碱菌
多元酚
内源激素
rice rhizoplane,Alcaligenes faecalis,superoxide dismutase(SOD),polyphenolics,phytohomone
