Institute for the Conservation and Breeding of the Agricultural Biodiversity, Universitat Politècnica de València (COMAV-UPV), Camino de Vera s/n, 46022, Valencia, Spain.
BMC Genomics. 2012 Nov 8;13:601. doi: 10.1186/1471-2164-13-601.
Monosporascus cannonballus is the main causal agent of melon vine decline disease. Several studies have been carried out mainly focused on the study of the penetration of this pathogen into melon roots, the evaluation of symptoms severity on infected roots, and screening assays for breeding programs. However, a detailed molecular view on the early interaction between M. cannonballus and melon roots in either susceptible or resistant genotypes is lacking. In the present study, we used a melon oligo-based microarray to investigate the gene expression responses of two melon genotypes, Cucumis melo 'Piel de sapo' ('PS') and C. melo 'Pat 81', with contrasting resistance to the disease. This study was carried out at 1 and 3 days after infection (DPI) by M. cannonballus.
Our results indicate a dissimilar behavior of the susceptible vs. the resistant genotypes from 1 to 3 DPI. 'PS' responded with a more rapid infection response than 'Pat 81' at 1 DPI. At 3 DPI the total number of differentially expressed genes identified in 'PS' declined from 451 to 359, while the total number of differentially expressed transcripts in 'Pat 81' increased from 187 to 849. Several deregulated transcripts coded for components of Ca2+ and jasmonic acid (JA) signalling pathways, as well as for other proteins related to defence mechanisms. Transcriptional differences in the activation of the JA-mediated response in 'Pat 81' compared to 'PS' suggested that JA response might be partially responsible for their observed differences in resistance.
As a result of this study we have identified for the first time a set of candidate genes involved in the root response to the infection of the pathogen causing melon vine decline. This information is useful for understanding the disease progression and resistance mechanisms few days after inoculation.
Monosporascus cannonballus 是甜瓜蔓枯病的主要致病因子。已经进行了几项研究，主要集中在研究该病原体穿透甜瓜根系、评估感染根系的症状严重程度以及为育种计划进行筛选试验上。然而，对于 M. cannonballus 与甜瓜根系之间的早期相互作用，缺乏详细的分子视角，无论是在易感基因型还是抗性基因型中都是如此。在本研究中，我们使用甜瓜寡核苷酸芯片来研究两个甜瓜基因型（Cucumis melo 'Piel de sapo'（'PS'）和 C. melo 'Pat 81'）的基因表达反应，这两个基因型对该疾病具有不同的抗性。这项研究是在 M. cannonballus 感染后 1 天和 3 天（DPI）进行的。
我们的结果表明，易感基因型与抗性基因型在 1 天至 3 天之间的表现行为不同。'PS'在 1 DPI 时比 'Pat 81'表现出更快的感染反应。在 3 DPI 时，在 'PS'中鉴定出的差异表达基因总数从 451 个减少到 359 个，而在 'Pat 81'中的差异表达转录物总数从 187 个增加到 849 个。一些下调的转录物编码钙和茉莉酸（JA）信号通路的成分，以及其他与防御机制相关的蛋白质。与 'PS'相比，'Pat 81'中 JA 介导的反应的转录差异表明，JA 反应可能部分解释了它们观察到的抗性差异。
作为这项研究的结果，我们首次鉴定了一组参与根对引起甜瓜蔓枯病的病原体感染的反应的候选基因。这些信息对于在接种后几天内了解疾病进展和抗性机制非常有用。
