摘要： 探讨水杨酸(SA)对低钾胁迫下番茄幼苗生理指标及基因表达的影响,为研究SA和低钾胁迫之间的关系奠定重要的理论基础。研究喷施不同浓度(0.10,0.25,0.50,1.00 mmol/L)的SA对低钾胁迫下番茄幼苗氧化酶活性及基因表达的影响。结果表明,在低钾处理下喷施0.25 mmol/L的SA,番茄幼苗中Chl、Pro的含量、CAT、APX、POD、SOD的活性与对照组相比明显增加,MDA含量则明显降低。同时采用荧光定量PCR对幼苗叶片中的APX、CAT、POD与SOD基因表达模式进行分析,发现这4个基因的表达量在处理48,96 h后明显增加。推测在低钾胁迫下喷施0.25 mmol/L SA能促进APX、CAT、POD与SOD基因的表达,进而降低活性氧ROS的积累,增强番茄幼苗对低钾胁迫的抗性。

关键词: 水杨酸, 番茄, 钾, 抗氧化酶, 基因

Abstract: The effect of SA on physiological indexes and gene expression were studied in tomato seedlings under low potassium stress in order to provide an important theoretical basis for the relationship between SA and low potassium stress. In this study,the different concentrations of salicylic acid (SA) (0.10,0.25,0.50,1.00 mmol/L) affect antioxidant enzyme activities and gene expression in tomato seedlings under low-potassium stress were investigated.The results showed that the chlorophyll (Chl) and proline (Pro) contents,as well as catalase (CAT),ascorbate peroxidase (APX),peroxidase (POD) and superoxide dismutase (SOD) activities,were significantly increased,and malondialdehyde (MDA) concentration decreased under 0.25 mmol/L SA treatment compared with that in the control.Meanwhile,the gene expression levels of APX,CAT,POD,and SOD in tomato leaves were analyzed through quantitative Real-time PCR.Four gene expression levels of antioxidant enzymes were considerably increased after 48,96 h treatment.These results suggested that SA promoted the gene expression levels of APX,CAT,POD,and SOD to alleviate the damage of low potassium stress,and decreased the accumulation of ROS and enhanced resistance in tomato seedlings under low-potassium stress.

Key words: Salicylic acid, Tomato, Potassium, Antioxidant enzyme, Gene

中图分类号: 

• Q78