College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China.
PLoS One. 2013 Sep 3;8(9):e74588. doi: 10.1371/journal.pone.0074588. eCollection 2013.
Phytophthora capsici is a soilborne plant pathogen capable of infecting a wide range of plants, including many solanaceous crops. However, genetic resistance and fungicides often fail to manage P. capsici due to limited knowledge on the molecular biology and basis of P. capsici pathogenicity. To begin to rectify this situation, Illumina RNA-Seq was used to perform massively parallel sequencing of three cDNA samples derived from P. capsici mycelia (MY), zoospores (ZO) and germinating cysts with germ tubes (GC). Over 11 million reads were generated for each cDNA library analyzed. After read mapping to the gene models of P. capsici reference genome, 13,901, 14,633 and 14,695 putative genes were identified from the reads of the MY, ZO and GC libraries, respectively. Comparative analysis between two of samples showed major differences between the expressed gene content of MY, ZO and GC stages. A large number of genes associated with specific stages and pathogenicity were identified, including 98 predicted effector genes. The transcriptional levels of 19 effector genes during the developmental and host infection stages of P. capsici were validated by RT-PCR. Ectopic expression in Nicotiana benthamiana showed that P. capsici RXLR and Crinkler effectors can suppress host cell death triggered by diverse elicitors including P. capsici elicitin and NLP effectors. This study provides a first look at the transcriptome and effector arsenal of P. capsici during the important pre-infection stages.
辣椒疫霉是一种土传植物病原菌，能够感染包括许多茄科作物在内的广泛植物。然而，由于对辣椒疫霉分子生物学和致病性基础的了解有限，遗传抗性和杀菌剂常常无法有效控制辣椒疫霉。为了开始纠正这种情况，我们使用 Illumina RNA-Seq 对来自辣椒疫霉菌丝体（MY）、游动孢子（ZO）和萌发胞具发芽管（GC）的三个 cDNA 样本进行大规模平行测序。每个 cDNA 文库分析都生成了超过 1100 万个读数。在将读数映射到辣椒疫霉参考基因组的基因模型后，分别从 MY、ZO 和 GC 文库的读数中鉴定出 13901、14633 和 14695 个推定基因。对两个样本之间的比较分析表明，MY、ZO 和 GC 阶段的表达基因含量存在主要差异。鉴定出大量与特定阶段和致病性相关的基因，包括 98 个预测的效应子基因。通过 RT-PCR 验证了 19 个效应子基因在辣椒疫霉发育和宿主感染阶段的转录水平。在本氏烟中的异位表达表明，辣椒疫霉 RXLR 和 Crinkler 效应子可以抑制由多种诱导剂触发的宿主细胞死亡，包括辣椒疫霉激发素和 NLP 效应子。本研究首次观察了辣椒疫霉在重要的感染前阶段的转录组和效应子武器库。
