中国烟草科学2000，Vol.21Issue(4)：1-5,5.
抗赤星病烟草的防卫基因的表达与基因组DNA结构的变化
Defence gene expression and DNA structure mutation in tobacco resistant to brown spot
梁元存 1潘军 1刘爱新 1董汉松 1徐文联2
作者信息
- 1. 山东农业大学 泰安 271018
- 2. 清华大学
- 折叠
摘要
Abstract
AT-toxin produced by a virulent strain TBA28 of tobacco brown spot pathogen Altemaria alternata induced systemic resistance being over 80% of a susceptible cultivar NC89. The resistance induced by the toxin was 20% higher than that by a hypovirulent strain TBA16 of the pathogen. A resistant somaclene NC89-TT had been produced by the process of tissue culture and plant regeneration, in which AT-toxin was used as pressuring factor. NC89-TT was reproduced by seed production. Expressions of 5 defence genes were tested and DNA structural alternations were analyzed. Dot blots of RNAs from NC89 and NC89-TT plants either immunized by the elicitor and AT-toxin or untreated were probed with cDNAs for pathogensis-related (PR) protein PR-1a, chitinase (CHT), phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), and lipoxygenase (LOX). Both PAL and PR-la genes did not constitutively transcript in untreated NC89, and did in the fourth generation plants of NC89-TT. While, CHT gene was inverse. Transcription of PR-la gene was activated by elicitor or AT-toxin, and transcription of PAL gene only by the toxin. The genes of CHS and LOX showed constitutively feeble transcripts in untreated NC89, and were greatly enhanced in their transcript activity in NC89 plants induced by elicitor or AT-toxin. A consistent tendency was found between the transcription activity and product accumulation of the genes indicated by PR-la electrophoresis. Genome DNA structure mutation in different tobaccos was tested by random amplified polymorphic DNA (RAPD) using 5 primers. It was suggested that the sequence rearrangement or nucleotide substitution was responsible for the constitutive expression of the defence genes and such an expression resulted in resistance enhancement.关键词
烟草赤星病 诱导抗性 抗病品系NC89-TT 防卫基因 DNA结构变异Key words
Tobacco brown spot/Induced resistanee/Resistant somaclene NC89-TT/Defence genes/Gene mutation分类
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梁元存,潘军,刘爱新,董汉松,徐文联..抗赤星病烟草的防卫基因的表达与基因组DNA结构的变化[J].中国烟草科学,2000,21(4):1-5,5.
