大豆异黄酮合成关键酶基因对蚜虫取食的防御响应分析

以蚜虫差异抗性的大豆品种PI567598B(高抗)、绥农30(抗)、东农51(中抗)和Williams 82(感)为试验材料,分别于接种大豆蚜虫0,7,14和21 d时采集大豆叶片,利用q PCR对异黄酮合成关键酶基因苯丙氨酸解氨酶(PAL)、黄烷酮-3-3羟化酶(F3H)、大豆异黄酮合成基因1(ISF1)和大豆异黄酮合成基因2(ISF2)的表达量进行分析。结果表明:蚜虫取食前高抗品种PI567598B中PAL、F3H、ISF1和ISF2基因的相对表达量均高于感虫品种Williams 82;蚜虫取食后,抗蚜品种PI567598B和绥农30中PAL基因在蚜虫取食14 d时显著上调,在21 d时达到最大,F3H基因7 d时表达量最高,然后降低;IFS2表达量于蚜虫取食7 d后显著上调,在21 d时达到最大;中抗品种东农51中PAL、IFS2和F3H基因表达量在7 d时增加,但不显著;而感蚜品种Williams 82蚜虫取食后PAL和IFS2表达量增加但不显著,且相对表达量显著低于抗蚜品种,F3H基因表达量不增反降;抗感大豆品种蚜虫取食后IFS1基因表达均诱导不显著。研究表明,感蚜大豆品种蚜虫取食前后异黄酮合成关键酶基因表达量都比较低,而抗虫品种异黄酮合成关键酶基因表达量高,且防御响应持续时间长,符合其抗性差异。

The Analysis of Key Gene of Soybean Isoflavone Synthesis Response to Aphid Feeding Defense

In order to elucidate isoflavone mechanisms of the response to aphid in the soybean plants,different-resistant soybean varieties PI567598B (high),Suinong 30 (medium),Dongnong 51 (low) and Williams 82 (flu),were inoculated by soybean aphid for 0,7,14 and 21 days.Using qPCR,the expression patterns of key enzyme genes were analyzed in response to aphid feeding defense,including Phenylalanine ammonia lyase (PAL),Flavanone hydroxylase-3-3 (F3H),Isoflavone synthase gene 1 (ISF1) and Isoflavone synthase gene 2 (ISF2).The results showed leaves from PI567598B had higher PAL,F3H,ISF1 and ISF2 expression than Williams 82 without aphid attack.The PAL gene in PI567598B and Suinong 30 was increased significantly after inoculated 14 d and reached highest level at 21 d.The F3H gene was increased rapidly at 7 d and then showed a decreasing trend;the IFS2 gene was increased rapidly and the highest in 24 h.The PAL,IFS2 and F3H genes in Dongnong 51 were not induced significantly after inoculated 7 d.The PAL and IFS2 genes in Williams 82 were not induced significantly and lower than other three lines even after being damaged by aphid,while gene expression of F3H decreased after inoculation.The expression of IFS1 gene was not induced in four lines after inoculation.These result showed that the expression level of isoflavone key enzyme gene were higher and longer in resistant varieties than that in susceptible soybean varieties,which was consistent with its resistance differences.