抗烟草黑胫病基因NtR1A-10的克隆及其响应病原侵染的分子机制

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中图分类号：S572 文献标识码：A 文章编号：1000-4440（2025）09-1696-08

Abstract：To elucidate the disease resistance defense mechanism of the tobacco black shank resistance gene NtRIA10，based on the sequenceof Rpi-amr3 gene from Solanum americanum，this study cloned the NtR1A- IO gene from the tobacco variety664-0lresistantto tobacco black shankandconducted bioinformaticsand expresion pattrnanalysesonit. Theresults showed that the relative molecular weight of the NtR1A-1O proteinwas 4.01×104 ，containinga leucine-rich re

peat（LRR）domain. It was classified asan unstable hydrophilicprotein，andtherewereatotal of37 phosphorylatable amino acid sites in its amino acid sequence.The relative expression level of NtR1A- IO in the stemswas extremelysignificantly higherthan thatinthe rootsand leaves （ P<0.01 ）.Using the susceptible variety

Honghuadajinyuan as the geneticbackground，overexpression linesof NtRIA-1O（OE2，OE5，OE13，OE2O）wereconstructed，andtheirdiseaseresistancewasevaluatedbyinoculatingwithPhytophthoranicotianae.FourtendaysafterinoculationwithPhytophthoranicotianae，thediseaseincidenceanddiseaseindexoftheinoculatedOE2andOE5lines wereboth extremely significantly lower than those of the wild-type Honghuadajinyuan （ P<0.01 ），and the relative expression levels of NtPRI and NtNPR in the inoculated OE5 line were extremely significantly higher than those in the wild type （ P<0.01 ）， indicating thatthesynthesisofsalicylicacidwasactivated intheNtRIA- IO overexpression lines.The relative expression level of NtPAL inthe inoculated OE5 line was extremely significantly higher than that in the wild type （ P<0.01 ），while the relative expression levels of NtEPS1，NtEDS5，and NtICS in the inoculated OE5 line were extremely significantly lower than those in the wild type（ P<0.01 ），indicatingthatafter infectionwithPhytophthoranicotianae，NtR1A- IO may regulate the phenylalanine ammonia-lyase（ PAL ）pathway to promote the biosynthesis of salicylic acid（SA）in Nicotiana tabacum， therebyactivating theresponseofdownstreamgeneNtPRlinthesalicylicacidsignaling pathway，andenhancingtheresistance of Nicotiana tabacum to tobacco black shank.This study reveals the molecular mechanism of NtR1A- IO against tobacco black shank，providing a theoreticalbasis for the breeding of highly disease-resistant new tobacco varieties.

Key words： Nicotiana tabacum；black shank；resistance gene NtRIA-1O；phenylalanine ammonia-lyase pathway

烟草黑胫病是由烟草疫霉（Phytophthoranicoti-anae）引起的一种毁灭性土传病害[，该病害喜高温高湿，每年造成的经济损失高达 1.23×108 元，严重时可导致烟草绝收[2]。（剩余10306字）