牛蒡低聚果糖诱导烟草对烟草花叶病毒的抗性

Induced Resistance to TMV in Tobacco Seedlings with Burdock Fructooligosaccharide

在室内条件下,研究了牛蒡低聚果糖对烟草花叶病毒抗性的影响及其影响机制。结果表明,在牛蒡低聚果糖处理叶(第三叶)中,接种烟草花叶病毒24h时对照处理叶片中该病毒含量大约是牛蒡低聚果糖处理叶片中的2.6倍,相对防效达61%;在未处理叶(第四叶)中,接种烟草花叶病毒24h时对照处理叶片可检测到TMV-CP的表达,而牛蒡低聚果糖处理叶则检测不到TMV-CP的表达。通过对抗病相关基因的检测发现,牛蒡低聚果糖处理和接种烟草花叶病毒都可诱导抗病相关基因(包括PR-1a、PR-2、PR-3、PI-1、PI-2和PAL)在烟草局部叶和系统叶中大量表达。这些结果表明,牛蒡低聚果糖可诱导烟草对烟草花叶病毒产生抗性,其作用机制可能在于诱导了抗病相关基因在植株体内的表达,增强了植株的系统抗性。

In this study,the effects of burdock fructooligosaccharide（BFO） on the control of TMV in tobacco seedlings and the underlying mechanism were investigated in laboratory.The results indicated that in BFO treated leaves（the third leaf）,the level of TMV-CP transcripts in distilled water（DW） treated leaves was about 2.6-fold higher than that in the BFO treated leaves 24 h after inoculation with TMV,the relative control effect reached to 61%.In untreated leaves（the fourth leaf）,the transcripts of TMV-CP could be detected in DW treated leaves 24 h after inoculation with TMV,but could not be detected in BFO treated leaves.In addition,the results indicated that both treatment with BFO and inoculation with TMV could induce accumulation of transcripts of defense related protein genes,including PR-1a,PR-2,PR-3,PI-1,PI-2 and PAL in both treated and untreated tobacco leaves.These results suggest that BFO could induce resistance to TMV in tobacco leaves.The mechanism might be attributed to the expression of defense related genes which increased the systemic resistance in tobacco seedlings.