Rai Krishan Mohan, Balasubramanian Vimal Kumar, Welker Cassie Marie, Pang Mingxiong, Hii Mei Mei, Mendu Venugopal
Department of Plant & Soil Science, Texas Tech University, 2802, 15th street, Lubbock, TX, 79409, USA.
Current address Sarawak Biodiversity Centre, KM20, Jalan Borneo Heights, Semengoh, Locked Bag No. 3032, Kuching, Sarawak, 93990, Malaysia.
BMC Plant Biol. 2015 Aug 1;15:187. doi: 10.1186/s12870-015-0576-4.
The plant cell wall serves as a primary barrier against pathogen invasion. The success of a plant pathogen largely depends on its ability to overcome this barrier. During the infection process, plant parasitic nematodes secrete cell wall degrading enzymes (CWDEs) apart from piercing with their stylet, a sharp and hard mouthpart used for successful infection. CWDEs typically consist of cellulases, hemicellulases, and pectinases, which help the nematode to infect and establish the feeding structure or form a cyst. The study of nematode cell wall degrading enzymes not only enhance our understanding of the interaction between nematodes and their host, but also provides information on a novel source of enzymes for their potential use in biomass based biofuel/bioproduct industries. Although there is comprehensive information available on genome wide analysis of CWDEs for bacteria, fungi, termites and plants, but no comprehensive information available for plant pathogenic nematodes. Herein we have performed a genome wide analysis of CWDEs from the genome sequenced phyto pathogenic nematode species and developed a comprehensive publicly available database.
In the present study, we have performed a genome wide analysis for the presence of CWDEs from five plant parasitic nematode species with fully sequenced genomes covering three genera viz. Bursaphelenchus, Glorodera and Meloidogyne. Using the Hidden Markov Models (HMM) conserved domain profiles of the respective gene families, we have identified 530 genes encoding CWDEs that are distributed among 24 gene families of glycoside hydrolases (412) and polysaccharide lyases (118). Furthermore, expression profiles of these genes were analyzed across the life cycle of a potato cyst nematode. Most genes were found to have moderate to high expression from early to late infectious stages, while some clusters were invasion stage specific, indicating the role of these enzymes in the nematode's infection and establishment process. Additionally, we have also developed a Nematode's Plant Cell Wall Degrading Enzyme (NCWDE) database as a platform to provide a comprehensive outcome of the present study.
Our study provides collective information about different families of CWDEs from five different sequenced plant pathogenic nematode species. The outcomes of this study will help in developing better strategies to curtail the nematode infection, as well as help in identification of novel cell wall degrading enzymes for biofuel/bioproduct industries.
植物细胞壁是抵御病原体入侵的主要屏障。植物病原体的成功很大程度上取决于其克服这一屏障的能力。在感染过程中，植物寄生线虫除了用其口针（一种用于成功感染的尖锐坚硬口器）穿刺外，还会分泌细胞壁降解酶（CWDEs）。CWDEs通常由纤维素酶、半纤维素酶和果胶酶组成，它们有助于线虫感染并建立取食结构或形成孢囊。对线虫细胞壁降解酶的研究不仅能增进我们对线虫与其宿主之间相互作用的理解，还能提供有关酶的新来源的信息，这些酶有可能用于基于生物质的生物燃料/生物产品行业。尽管有关于细菌、真菌、白蚁和植物中CWDEs的全基因组分析的全面信息，但对于植物病原线虫却没有全面的信息。在此，我们对已进行基因组测序的植物病原线虫物种的CWDEs进行了全基因组分析，并开发了一个全面的公开数据库。
在本研究中，我们对来自五个植物寄生线虫物种的CWDEs进行了全基因组分析，这些物种的基因组已完全测序，涵盖三个属，即松材线虫属、球孢囊线虫属和根结线虫属。利用各个基因家族的隐马尔可夫模型（HMM）保守结构域图谱，我们鉴定出530个编码CWDEs的基因，它们分布在糖苷水解酶（412个）和多糖裂解酶（118个）的24个基因家族中。此外，还分析了这些基因在马铃薯孢囊线虫生命周期中的表达谱。大多数基因在感染早期到晚期表现出中度到高度表达，而一些基因簇是入侵阶段特异性的，这表明这些酶在线虫感染和建立过程中的作用。此外，我们还开发了线虫植物细胞壁降解酶（NCWDE）数据库，作为提供本研究全面结果的平台。
我们的研究提供了来自五个不同测序的植物病原线虫物种的不同CWDEs家族的综合信息。本研究的结果将有助于制定更好的策略来减少线虫感染，并有助于识别用于生物燃料/生物产品行业的新型细胞壁降解酶。
