Institute of Biology, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin, Germany.
Max Planck Institute of Molecular Plant Physiology, Department Secondary Metabolism, Potsdam, Germany.
Plant Cell Environ. 2019 Mar;42(3):1019-1032. doi: 10.1111/pce.13447. Epub 2018 Nov 19.
Plants can improve their antiherbivore defence by taking insect egg deposition as cue of impending feeding damage. Previous studies showed that Pieris brassicae larvae feeding upon egg-deposited Brassicaceae perform worse and gain less weight than larvae on egg-free plants. We investigated how P. brassicae oviposition on Arabidopsis thaliana affects the plant's molecular and chemical responses to larvae. A transcriptome comparison of feeding-damaged leaves without and with prior oviposition revealed about 200 differently expressed genes, including enhanced expression of PR5, which is involved in salicylic acid (SA)-signalling. SA levels were induced by larval feeding to a slightly greater extent in egg-deposited than egg-free plants. The adverse effect of egg-deposited wild-type (WT) plants on larval weight was absent in an egg-deposited PR5-deficient mutant or other mutants impaired in SA-mediated signalling, that is, sid2/ics1, ald1, and pad4. In contrast, the adverse effect of egg-deposited WT plants on larvae was retained in egg-deposited npr1 and wrky70 mutants impaired further downstream in SA-signalling. Oviposition induced accumulation of flavonols in WT plants with and without feeding damage, but not in the PR5-deficient mutant. We demonstrated that egg-mediated improvement of A. thaliana's antiherbivore defence involves SA-signalling in an NPR1-independent manner and is associated with accumulation of flavonols.
植物可以通过将昆虫产卵作为即将发生的取食损伤的线索来提高其抗食草动物防御能力。以前的研究表明，菜粉蝶幼虫在产卵的十字花科植物上取食的表现不如在无卵植物上的幼虫，并且体重增加也较少。我们研究了菜粉蝶在拟南芥上产卵如何影响植物对幼虫的分子和化学反应。对未受损和受损叶片的转录组比较表明，大约有 200 个基因表达不同，包括与水杨酸（SA）信号转导有关的 PR5 的表达增强。与无卵植物相比，卵沉积植物中 SA 水平因幼虫取食而被诱导的程度略高。在 PR5 缺陷突变体或其他 SA 介导的信号转导受损的突变体（即 sid2/ics1、ald1 和 pad4）中，卵沉积野生型（WT）植物对幼虫体重的不利影响不存在。相比之下，在 SA 信号转导进一步下游的 npr1 和 wrky70 突变体中，WT 植物的卵沉积对幼虫的不利影响仍然存在。卵沉积诱导 WT 植物在有或无取食损伤的情况下积累类黄酮，但在 PR5 缺陷突变体中则没有。我们证明，卵介导的拟南芥抗食草动物防御能力的提高涉及 NPR1 非依赖的 SA 信号转导，并与类黄酮的积累有关。
