摘要
NPR1(non-expressor of pathogenesis-related gene 1)基因在拟南芥系统获得抗性中起着关键作用,可调控拟南芥植株广谱抗性的发生。本文报道了从心叶烟中克隆NPR1同源基因(NgNPR1)及其表达特性的研究结果。NgNPR1cDNA全长2 253 bp,编码588个氨基酸。将NgNPR1基因组全长与cDNA序列进行比对发现,NgNPR1基因组DNA含有4个外显子和3个内含子。Southern杂交分析表明,在心叶烟基因组中NgNPR1为单拷贝基因。采用绿色荧光蛋白在洋葱表皮瞬时表达的试验,证明了NgNPR1蛋白在水杨酸诱导时会从细胞质转运到细胞核中。Northern杂交分析发现,NgNPR1基因可以被与植物抗病相关的信号分子如水杨酸、茉莉酸甲酯、过氧化氢和乙烯所诱导。进一步研究发现,植物病原物如赤星病菌、青枯病菌和烟草花叶病毒对心叶烟植株的侵染也会使NgNPR1表达量增加。这些结果表明,NgNPR1基因在心叶烟植株抵御病原物侵染过程中可能起着重要作用。
NPR1 （ non-expressor of pathogenesis-related gene 1 ） gene is a key regulator of systemic acquired resistance, which confers broad-spectrum resistance in Arabidopsis. This study reports the isolation of a NPR1 ortholog gene （ designated as NgNPRI ） from Nicotiana glutinosa. The full-length cDNA of NgNPR1 was 2 253 bp encoding 588 amino acids. Analysis of exon/intron structure of the NgNPR1 gene showed that NgN- PR1 consisted of four exons and three introns. Southern blot analysis revealed that NgNPR1 was a single-copy gene in N. glutinosa. Transient expression analysis using NgNPR1-GFP （green fluorescent protein） fusion gene in onion epidermal cells revealed that the NgNPR1 protein was localized in the cytoplasm and moved into the nucleus after salicylic acid （SA） treatment. Northern blot analysis indicated that NgNPR1 was induced by signal molecules for plant defense responses, such as SA, methyl jasmonate （MeJA）, H202 and ethylene （ET）. Transcription level of NgNPR1 was also up-regulated after inoculations with Alternaria alternata, Pseudomonas syringae pv. tabaci, and Tobacco mosaic virus （TMV） respectively. These results suggest that the NgNPR1 may play an important role in response to pathogen infection in N. glutinosa plant.
出处
《植物病理学报》
CAS
CSCD
北大核心
2009年第5期482-490,共9页
Acta Phytopathologica Sinica
基金
National Natural Science Foundation of China(3037092830571215)
