Quantitative and qualitative influence of inoculation methods on in planta growth of rice blast fungus
Quantitative and qualitative influence of inoculation methods on in planta growth of rice blast fungus
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DOI：
10.1094/phyto-96-0346
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发表时间：
2006-04-01
期刊：
影响因子：
3.2
通讯作者：
Valent, B
中科院分区：
文献类型：
--
作者：
Berruyer, R;Poussier, S;Valent, B
早期病害事件的分子分析需要受感染的植物组织，其中病原体大量存在并以田间发现的方式与植物相互作用。在这项研究中，定量聚合酶链反应（Q-PCR）测定，以确定所有的“感染率”的真菌植物细胞在受感染的组织。该试验用于评价四种接种方法（喷雾、喷雾、修剪和鞘）以及整株植物或切除部分的使用。荧光体视显微镜用于跟踪从附着胞到宏观症状的个体病变。在接种后24至96 It（hpi）记录疾病进展和结局，以及Pi-ta介导的抗性的有效性。即使在96 hpi，真菌增殖远远超过可见的植物损害，特别是在静脉。在离体叶片中，发育中的病斑有时被较绿的区域包围。喷雾接种不足以检测96 h前植物中真菌基因的表达。或者，叶鞘测定在34小时内产生含有10至30%真菌DNA的感染组织。一起使用，Q-PCR定量和荧光立体显微镜将有助于早期植物入侵的研究，因为感染密度和真菌的生长阶段是直接观察到的，而不是假设从孵育时间。
Molecular analyses of early disease events require infected plant tissue in which the pathogen is present in high quantities and interacts with the plant in a way found in the field. In this study, a quantitative polymerase chain reaction (Q-PCR) assay was developed to determine all "infection ratio" of fungal to plant cells in infected tissues. This assay was used to evaluate four inoculation methods (spray, mist, clip, and sheath) as well as use of whole plants or excised parts. Fluorescence stereomicroscopy was used to follow individual lesions developing from appressoria to macroscopic symptoms. Disease progression and outcomes were documented front 24 to 96 It postinoculation (hpi), as well as effectiveness of Pi-ta-mediated resistance. Even at 96 hpi, fungus proliferated well ahead of visible plant damage, especially in veins. Developing lesions sometimes were Surrounded by greener areas in detached leaves. Spray inoculation was not sufficient for detecting fungal gene expression in planta before 96 h. Alternatively, a leaf sheath assay produced infected tissues containing 10 to 30% fungal DNA by 34 h. Used together, Q-PCR quantification and fluorescence stereomicroscopy will facilitate studies of early plant invasion because infection density and fungal growth stages are directly observed, not assumed from incubation time.