Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708PB, The Netherlands.
Plant J. 2018 Feb;93(4):686-702. doi: 10.1111/tpj.13811. Epub 2018 Jan 29.
Parallel adaptations enabling the use of plant cells as the primary food source have occurred multiple times in distinct nematode clades. The hallmark of all extant obligate and facultative plant-feeding nematodes is the presence of an oral stylet, which is required for penetration of plant cell walls, delivery of pharyngeal gland secretions into host cells and selective uptake of plant assimilates. Plant parasites from different clades, and even within a single clade, display a large diversity in feeding behaviours ranging from short feeding cycles on single cells to prolonged feeding on highly sophisticated host cell complexes. Despite these differences, feeding of nematodes frequently (but certainly not always) induces common responses in host cells (e.g. endopolyploidization and cellular hypertrophy). It is thought that these host cell responses are brought about by the interplay of effectors and other biological active compounds in stylet secretions of feeding nematodes, but this has only been studied for the most advanced sedentary plant parasites. In fact, these responses are thought to be fundamental for prolonged feeding of sedentary plant parasites on host cells. However, as we discuss in this review, some of these common plant responses to independent lineages of plant parasitic nematodes might also be generic reactions to cell stress and as such their onset may not require specific inputs from plant parasitic nematodes. Sedentary plant parasitic nematodes may utilize effectors and their ability to synthesize other biologically active compounds to tailor these common responses for prolonged feeding on host cells.
在不同的线虫类群中，已经多次发生了使植物细胞成为主要食物来源的平行适应。所有现存的专性和兼性植物食性线虫的标志是存在口腔刺，这是穿透植物细胞壁、将咽腺分泌物输送到宿主细胞和选择性吸收植物同化产物所必需的。来自不同类群的植物寄生虫，甚至在单个类群内，表现出在摄食行为上的巨大多样性，从对单个细胞的短周期摄食到对高度复杂的宿主细胞复合物的长期摄食。尽管存在这些差异，但线虫的摄食通常（但肯定不是总是）会引起宿主细胞的共同反应（例如，核内多倍体化和细胞肥大）。人们认为，这些宿主细胞的反应是由摄食线虫的刺突分泌物中的效应子和其他生物活性化合物的相互作用引起的，但这仅在最先进的定居性植物寄生虫中进行了研究。事实上，人们认为这些反应对于定居性植物寄生虫在宿主细胞上的长期摄食是基本的。然而，正如我们在这篇综述中讨论的那样，这些对独立的植物寄生线虫谱系的共同植物反应中的一些可能也是对细胞应激的一般反应，因此它们的发生可能不需要植物寄生线虫的特定输入。定居性植物寄生线虫可能利用效应子及其合成其他生物活性化合物的能力，为在宿主细胞上的长期摄食定制这些共同反应。
