Kohli Deshika, Chidambaranathan Parameswaran, Prasanth Tej Kumar J, Singh Ashish Kumar, Kumar Anil, Sirohi Anil, Subramaniam K, Srinivasan Ramamurthy, Bharadvaja Navneeta, Jain Pradeep K
ICAR-NRC on Plant Biotechnology,Pusa Campus,New Delhi 110012,India.
Division of Nematology,ICAR-Indian Agricultural Research Institute,Pusa Campus,New Delhi 110012,India.
Parasitology. 2018 Dec;145(14):1896-1906. doi: 10.1017/S0031182018000641. Epub 2018 Apr 25.
GLP-1 (abnormal germline proliferation) is a Notch-like receptor protein that plays an essential role in pharyngeal development. In this study, an orthologue of Caenorhabditis elegans glp-1 was identified in Meloidogyne incognita. A computational analysis revealed that the orthologue contained almost all the domains present in the C. elegans gene: specifically, the LIN-12/Notch repeat, the ankyrin repeat, a transmembrane domain and different ligand-binding motifs were present in orthologue, but the epidermal growth factor-like motif was not observed. An expression analysis showed differential expression of glp-1 throughout the life cycle of M. incognita, with relatively higher expression in the egg stage. To evaluate the silencing efficacy of Mi-glp-1, transgenic Arabidopsis plants carrying double-stranded RNA constructs of glp-1 were generated, and infection of these plants with M. incognita resulted in a 47-50% reduction in the numbers of galls, females and egg masses. Females obtained from the transgenic RNAi lines exhibited 40-60% reductions in the transcript levels of the targeted glp-1 gene compared with females isolated from the control plants. Second-generation juveniles (J2s), which were descendants of the infected females from the transgenic lines, showed aberrant phenotypes. These J2s exhibited a significant decrease in the overall distance from the stylet to the metacorpus region, and this effect was accompanied by disruption around the metacorporeal bulb of the pharynx. The present study suggests a role for this gene in organ (pharynx) development during embryogenesis in M. incognita and its potential use as a target in the management of nematode infestations in plants.
GLP-1（异常生殖系增殖）是一种类Notch受体蛋白，在咽部发育中起重要作用。在本研究中，在南方根结线虫中鉴定出秀丽隐杆线虫glp-1的一个直系同源物。计算分析表明，该直系同源物包含秀丽隐杆线虫基因中几乎所有的结构域：具体而言，直系同源物中存在LIN-12/Notch重复序列、锚蛋白重复序列、一个跨膜结构域和不同的配体结合基序，但未观察到表皮生长因子样基序。表达分析表明，glp-1在南方根结线虫的整个生命周期中存在差异表达，在卵期表达相对较高。为了评估Mi-glp-1的沉默效果，构建了携带glp-1双链RNA构建体的转基因拟南芥植株，用南方根结线虫感染这些植株后，虫瘿、雌虫和卵块数量减少了47%-50%。与从对照植株分离的雌虫相比，从转基因RNAi品系获得的雌虫中靶向glp-1基因的转录水平降低了40%-60%。来自转基因品系受感染雌虫后代的第二代幼虫（J2）表现出异常表型。这些J2从口针到中肠区域的总距离显著缩短，并且这种影响伴随着咽部中肠球周围的破坏。本研究表明该基因在南方根结线虫胚胎发育过程中的器官（咽部）发育中起作用，并且其有可能作为植物线虫防治的一个靶点。
