Ultrastructural plasticity in the plant-parasitic nematode, Bursaphelenchus xylophilus
Ultrastructural plasticity in the plant-parasitic nematode, Bursaphelenchus xylophilus
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DOI：
10.1038/s41598-020-68503-3
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发表时间：
2020-07-14
影响因子：
4.6
通讯作者：
Shinya, Ryoji
中科院分区：
文献类型：
--
作者：
Ekino, Taisuke;Kirino, Haru;Shinya, Ryoji
表型可塑性是低流动性生物在波动环境中生存的最重要策略之一。表型可塑性在线虫中起着至关重要的作用，因为它们的身体很小，没有翅膀或腿，因此不能自己移动很远。引起松树萎蔫病的致病性线虫Bursaphelenchus xylophilus在其整个生活史中经历了波动的条件；也就是说，在食植物期和食菌期。然而，木芽孢杆菌的功能形态在不同的生命阶段是否会发生变化尚不清楚。我们的研究揭示了两个阶段木芽孢的超微结构的差异。与食菌期相比，植食期的侧翼发育良好，肠道微绒毛萎缩。植食期的超微结构与水生期形态相似，使其能够在恶劣的环境中生存。这表明木杉在活树环境中生存的条件较为恶劣，超微结构的表型可塑性是木杉在活树环境中生存的关键策略。此外，对与木芽孢杆菌密切相关的专性植物寄生物种的超微结构观察显示，木芽孢杆菌可能正在适应以植物细胞为食的过程中。
Phenotypic plasticity is one of the most important strategies used by organisms with low mobility to survive in fluctuating environments. Phenotypic plasticity plays a vital role in nematodes because they have small bodies and lack wings or legs and thus, cannot move far by themselves. Bursaphelenchus xylophilus, the pathogenic nematode species that causes pine wilt disease, experiences fluctuating conditions throughout their life history; i.e., in both the phytophagous and mycetophagous phases. However, whether the functional morphology changes between the life phases of B. xylophilus remains unknown. Our study revealed differences in the ultrastructure of B. xylophilus between the two phases. Well-developed lateral alae and atrophied intestinal microvilli were observed in the phytophagous phase compared with the mycetophagous phase. The ultrastructure in the phytophagous phase was morphologically similar to that at the dauer stage, which enables the larvae to survive in harsh environments. It suggests that the living tree represents a harsh environment for B. xylophilus, and ultrastructural phenotypic plasticity is a key strategy for B. xylophilus to survive in a living tree. In addition, ultrastructural observations of obligate plant-parasitic species closely related to B. xylophilus revealed that B. xylophilus may be in the process of adapting to feed on plant cells.