美洲黑杨×毛果杨NDR1基因表达对E4锈菌侵染的响应

Impact of NDR1 gene on the incompatible Populus deltoides × P.trichocarpa infected with Melampsora larici-populina E4

【目的】非小种专化抗病因子1(non-race-specific disease resistance 1,NDR1)可将病原入侵信号传入细胞膜内,继而激活含有CC结构域的CC-NBS-LRR抗性蛋白,介导植物抗性反应。探究杨树NDR1基因功能,克隆获得美洲黑杨×毛果杨(简称杂交杨)的PdtNDR1基因,并对PdtNDR1抗叶锈病基因表达进行研究。【方法】采用接种试验鉴定杂交杨和欧美杨与落叶松-杨栅锈菌E4强致病生理小种。采用PCR技术克隆杂交杨和欧美杨的NDR1基因(PdtNDR1和PndNDR1),并通过生物信息学分析其编码蛋白的结构与功能。采用荧光定量PCR技术分析锈菌接种后7个时间点PdtNDR1和PndNDR1的表达量变化。【结果】接种试验表明欧美杨是E4锈菌的感病品种,与E4锈菌构成亲和型互作关系。杂交杨是低感病品种,与E4锈菌构成非亲和型互作关系。生物信息学分析表明PdtNDR1和PndNDR1属于NHL家族。氨基酸序列分析表明PdtNDR1的N末端13—34位氨基酸和C末端嵌合在细胞膜上,中段氨基酸序列位于细胞外可以接触病原的侵染信号,N末端位于细胞内可将病原侵染信号传递到细胞内。荧光定量PCR技术检验锈菌接种后7个时间点PdtNDR1和PndNDR1对E4锈菌侵染的应激反应差异显著。PdtNDR1基因表达量在E4锈菌接种后持续增强,PndNDR1基因表达量未显著增加。【结论】PdtNDR1基因表达与杂交杨对E4锈菌的感病性正相关,决定杂交杨与锈菌的非亲和关系。

【Objective】The plant host resistance protein CC-NBS-LRR harboring CC domain could be activated to mediate plant resistance reaction after non-race-specific disease resistance 1（NDR1） and introduces pathogenic invasion signals into the cell membrane.To explore the function of NDR1,PdtNDR1 from Populus deltoids × P.trichocarpa was cloned and its expression on rust resistance was studied.【Method】Compatible interactions of P.deltoides × P.trichocarpa and against Melampsora larici-populina E4 were observed by inoculation study.NDR1 genes,PdtNDR1 and PndNDR1 from P.deltoides × P.trichocarpa and P.× earamericama,respectively,were cloned by PCR.Structures and functions of PdtNDR1 and PndNDR1 encoded proteins were studied through bioinformatics analysis.The expressions of PdtNDR1 and PndNDR1 for 7 time points after being inoculated with E4 were analyzed by q PCR.【Result】The inoculation study showed that P.× earame ricama was susceptible to E4,which was compatible to E4.P.deltoides × P.trichocarpa was a low susceptible species,which was incompatible to E4.The bioinformatics analysis indicated that PdtNDR1 and PndNDR1 belonged to NHL（NDR1/HIN1-like） family.Amino acid sequence analysis illustrated that 13-34 amino acids of the N-terminal and the C-terminal of PdtNDR1 located at the plasma membrane,the middle amino acids of PdtNDR1 located outside of the plasma membrane which could contact pathogenic invasion signals and the N-terminal of Pdt-NDR1 located inside of the cell enabling entrances of pathogenic invasion signals.q PCR results showed that PdtNDR1 and PndNDR1 responded to rust infection significantly differently.PdtNDR1 was enhanced continually after the rust infection,while the expression of PndNDR1 was not enhanced obviously.【Conclusion】The expression of PdtNDR1 correlated with the susceptibility of P.deltoids × P.trichocarpa positively and determined its in compatible interaction against rust.