Abstract:

【Objective】 The purpose of this study is to reveal the dynamic changes in the expression of wheat resistance genes under the treatment of Streptomyces sp. HU2014 and to explore the possible mechanism by which this strain induces disease resistance in the host. 【Methods】 In this paper, the cell-free fermentation filtrate of this strain was used to irrigate the roots of three wheat varieties Aikang 58 (AK58), Bainong 307 (BN307), and Zhoumai 22 (ZM22). After irrigation, leaves were collected at 2 h, 6 h, 12 h, 24 h, 48 h, and 96 h, and the changes in the expression of related resistance genes were detected by real-time fluorescent quantitative PCR technology. 【Results】 The fermentation filtrate of this strain could induce the expression of 4 defense response genes, 1 salicylic acid pathway gene, and 1 jasmonic acid pathway gene. Among them, the transcript of TaPR1 gene accumulated at highest levels at 6 h in AK58, 24 h in BN307, and 48 h in ZM22 respectively. The expression of TaPR2 gene reached the highest level at 6 hours in AK58, 12 h in BN307, and 24 h in ZM22 respectively. The transcript of TaPR3 gene reached its peak at 2 h in AK58, 6 h in BN307, and 2 h in ZM22 respectively. TaPR5 gene reached its peak at 72 h in AK58, 96 h in BN307, and 12 h in ZM22 respectively. The PAL gene showed the highest fold change at 48 h in AK58, 24 h in BN307, and 24 h in ZM22 respectively. The expression of LOX gene reached its peak at 6 h in AK58, BN307, and ZM22 respectively. 【Conclusion】 The results indicate that the TaPR1 gene is down-regulated in AK58 and ZM22, and the TaPR3 gene is down-regulated in AK58 and BN307. The highest expression levels of TaPR2, TaPR3, TaPR5, PAL, and LOX in ZM22 are higher than those in AK58 and BN307, while the highest expression level of TaPR1 in BN307 is higher than that in AK58 and ZM22. Streptomyces sp. HU2014 can induce systemic acquired resistance and systemic resistance in wheat.

Key words: streptomyces; wheat; disease resistance related genes; biological control; inducing resistance

摘要：

【目的】研究链霉菌HU2014处理对小麦抗性基因表达的动态规律,探讨该菌株诱导寄主植物产生抗病性的可能机制。【方法】采用链霉菌HU2014无细胞发酵滤液对矮抗58(AK58)、百农307(BN307)和周麦22(ZM22)等3个小麦品种进行灌根处理,分别于灌根后2、6、12、24、48和96 h采集叶片,利用实时荧光定量PCR技术检测小麦叶片中相关抗性基因表达量的变化。【结果】 HU2014菌株无细胞发酵液能够诱导4个防卫反应基因、1个水杨酸途径基因和1个茉莉酸途径基因的表达。其中TaPR1基因在处理AK58品种6 h后,BN307品种24 h后和ZM22样品48 h后表达量最大;TaPR2基因的表达在处理AK58的6 h后,BN307的12 h后和ZM22的24 h后达到最大水平;TaPR3基因表达量在AK58的2 h后,BN307的6 h后和ZM22的2 h后达到峰值;TaPR5基因在AK58的72 h后、BN307的96 h后和ZM22的12 h后达到峰值;PAL基因在AK58的48 h后、BN307的24 h后和ZM22的24 h后显示出最高的倍数变化;LOX基因表达在AK58、BN307和ZM22的6 h后达到峰值。【结论】TaPR1基因在AK58和ZM22中下调,TaPR3基因在AK58和BN307中下调。ZM22中TaPR2、TaPR3、TaPR5、PAL和LOX的最高表达水平高于AK58和BN307,而BN307中TaPR1的最高表达水平高于AK58和ZM22。链霉菌HU2014可以诱导小麦系统性获得抗性和诱导性系统抗性。

关键词: 链霉菌, 小麦, 抗病相关基因, 生物防治, 诱导抗病性