细菌性角斑病菌诱导黄瓜叶片水杨酸的积累

对黄瓜(Cucumis sativa L.)幼苗第一片真叶接种细菌性角斑病菌(Pseudomonas syringae pv.lachy-mans)后,利用TLC和HPLC方法分离测定了不同时间内游离态和结合态水杨酸(SA)的含量。结果表明,接种显著提高了第一片真叶游离态SA含量,增加了30％～197％,结合态SA的含量变化与游离态相似,提高了79％～240％,但是接种后第三天游离态SA和结合态SA含量都下降。接种还诱导了非接种第二片真叶中SA的积累:游离态SA含量在接种初期增加了29％～46％,接种后第三天达到峰值,第五天回复到正常水平,结合态SA含量在接种初期没有变化,接种后第四至六天也显著增加,提高了62％～107％。

PSEUDOMONAS SYRINGAE PV. LACHYMANS INDUCED ACCUMULATION OF SALICYLIC ACID IN CUCUMBER LEAVES

The contents of free salicylic acid (SA) and conjugated SA were determined by using TLC and HPLC at different time after inoculation with Pseudomonas syringae pv. lachymans in the first true leaf of cucumber ( Cucianis sativa L.) plant. A 30%~197% increase in free SA content in the inoculated leaves was observed. The change of conjugated SA was similar to that of free SA. There occurred a decrease not only in free SA but also in conjugated SA three days after inoculation. The systemic appearance of free SA in the uninoculated leaves was also found two days after inoculation. The content of free SA in the uninoculated leaves increased by 29% to 46% at the initial stage of inoculation; it reached its peak in three days but it stopped increasing five days after inoculation. The content of the conjugated salicylate in the uninoculated leaves significantly increased by 62% to 107%,while the increase in conjugated salicylate began five days after inoculation. The authors' findings suggested that inoculation with P. syringae pv. lachymans in the first true leaf of cucumber plant could improve the systemic acquired resistance by enhancing SA level in the uninoculated leaves.