Characterisation of an Arabidopsis-Leptosphaeria maculans pathosystem:: resistance partially requires camalexin biosynthesis and is independent of salicylic acid, ethylene and jasmonic acid signalling
Characterisation of an Arabidopsis-Leptosphaeria maculans pathosystem:: resistance partially requires camalexin biosynthesis and is independent of salicylic acid, ethylene and jasmonic acid signalling
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DOI：
10.1046/j.1365-313x.2003.01927.x
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发表时间：
2004-01-01
期刊：
影响因子：
7.2
通讯作者：
Dixelius, C
中科院分区：
文献类型：
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作者：
Bohman, S;Staal, J;Dixelius, C
在168个拟南芥种质中筛选出1个（An-1）表现出明显的病害症状。为了确定L.在拟南芥中筛选L.进行黄斑变性易感（LMS）突变体。分离到11个lms突变体，它们对L.斑点。lms 1与哥伦比亚（Col-0）和Ws-0杂交，两个群体的作图数据显示与2号染色体上的区域的最高连锁。PR-1和PDF1.2的表达水平降低，发现在lms 1相比，野生型植物病原体接种后48小时。与此相反，lms 1突变体显示上调的任一标记基因化学处理后，可能作为一个改变乙烯（ET）反应的影响。为了评估不同防御途径的贡献，表达细菌水杨酸羟化酶（nahG）基因、PR 1（npr 1）-1和植物抗毒素缺陷（pad 4 -1）的非表达子、茉莉酸（JA）信号传导的水杨酸（SA）信号传导植物中涉及的基因型（冠菌素不敏感（coi）1-16，增强的疾病易感性（eds）8-1和茉莉酸抗性（jar）1-1）和ET信号传导（EDS 4 -1、乙烯不敏感（EIN）2、EIN 3 -1和乙烯抗性（ETR）1-1）。所有筛选的基因型都具有与野生型一样的抗性，证明了这些途径在L.抗斑点病当检测涉及细胞死亡反应的突变体时，对拮抗剂1的反应性（ran 1）-1表现出弱的易感表型，而加速细胞死亡（acd）1-20表现出快速的损伤发展。Camalexin对L.在拟南芥中，pad 3 -1和增强的对链格孢属（esa）1的易感性清楚地显示了易感性响应，而野生型水平的camalexin存在于An-1和lms 1中。所提供的数据表明，存在多种防御机制控制L。在拟南芥中发现了斑点藻。
Out of 168 Arabidopsis accessions screened with isolates of Leptosphaeria maculans, one (An-1) showed clear disease symptoms. In order to identify additional components involved in containment of L. maculans in Arabidopsis, a screen for L. maculans-susceptible (lms) mutants was performed. Eleven lms mutants were isolated, which displayed differential susceptibility responses to L. maculans. lms1 was crossed with Columbia (Col-0) and Ws-0, and mapping data for both populations showed the highest linkage to a region on chromosome 2. Reduced levels of PR-1 and PDF1.2 expression were found in lms1 compared to wild-type plants 48 h after pathogen inoculation. In contrast, the lms1 mutant displayed upregulation of either marker gene upon chemical treatment, possibly as an effect of an altered ethylene (ET) response. To assess the contribution of different defence pathways, genotypes implicated in salicylic acid (SA) signalling plants expressing the bacterial salicylate hydroxylase (nahG) gene, non-expressor of PR1 (npr1)-1 and phytoalexin-deficient (pad4-1), jasmonic acid (JA) signalling (coronatine insensitive (coi)1-16, enhanced disease susceptibility (eds)8-1 and jasmonic acid resistant (jar)1-1) and ET signalling (eds4-1, ethylene insensitive (ein)2, ein3-1 and ethylene resistant (etr)1-1) were screened. All the genotypes screened were as resistant as wild-type plants, demonstrating the dispensability of the pathways in L. maculans resistance. When mutants implicated in cell death responses were assayed, responsive to antagonist 1 (ran1)-1 exhibited a weak susceptible phenotype, whereas accelerated cell death (acd)1-20 showed a rapid lesion development. Camalexin is only partially responsible for L. maculans containment in Arabidopsis, as pad3-1 and enhanced susceptibility to Alternaria (esa)1 clearly showed a susceptible response while wild-type levels of camalexin were present in An-1 and lms1. The data presented point to the existence of multiple defence mechanisms controlling the containment of L. maculans in Arabidopsis.