Whiteman Noah K, Groen Simon C, Chevasco Daniela, Bear Ashley, Beckwith Noor, Gregory T Ryan, Denoux Carine, Mammarella Nicole, Ausubel Frederick M, Pierce Naomi E
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02478, USA.
Mol Ecol. 2011 Mar;20(5):995-1014. doi: 10.1111/j.1365-294X.2010.04901.x. Epub 2010 Nov 13.
Experimental infections of Arabidopsis thaliana (Arabidopsis) with genomically characterized plant pathogens such as Pseudomonas syringae have facilitated the dissection of canonical eukaryotic defence pathways and parasite virulence factors. Plants are also attacked by herbivorous insects, and the development of an ecologically relevant genetic model herbivore that feeds on Arabidopsis will enable the parallel dissection of host defence and reciprocal resistance pathways such as those involved in xenobiotic metabolism. An ideal candidate is Scaptomyza flava, a drosophilid fly whose leafmining larvae are true herbivores that can be found in nature feeding on Arabidopsis and other crucifers. Here, we describe the life cycle of S. flava on Arabidopsis and use multiple approaches to characterize the response of Arabidopsis to S. flava attack. Oviposition choice tests and growth performance assays on different Arabidopsis ecotypes, defence-related mutants, and hormone and chitin-treated plants revealed significant differences in host preference and variation in larval performance across Arabidopsis accessions. The jasmonate and glucosinolate pathways in Arabidopsis are important in mediating quantitative resistance against S. flava, and priming with jasmonate or chitin resulted in increased resistance. Expression of xenobiotic detoxification genes was reduced in S. flava larvae reared on Arabidopsis jasmonate signalling mutants and increased in plants pretreated with chitin. These results and future research directions are discussed in the context of developing a genetic model system to analyse insect-plant interactions.
用基因组特征明确的植物病原体（如丁香假单胞菌）对拟南芥进行实验性感染，有助于剖析典型的真核生物防御途径和寄生虫毒力因子。植物也会受到食草昆虫的攻击，开发一种以拟南芥为食的具有生态相关性的遗传模型食草动物，将能够并行剖析宿主防御和相互抗性途径，如那些参与异源生物代谢的途径。一个理想的候选者是黄潜叶蝇，一种果蝇，其潜叶幼虫是真正的食草动物，在自然界中可以发现它们以拟南芥和其他十字花科植物为食。在这里，我们描述了黄潜叶蝇在拟南芥上的生命周期，并使用多种方法来表征拟南芥对黄潜叶蝇攻击的反应。对不同拟南芥生态型、防御相关突变体以及激素和几丁质处理植物进行的产卵选择测试和生长性能测定，揭示了宿主偏好的显著差异以及不同拟南芥种质间幼虫性能的变化。拟南芥中的茉莉酸和芥子油苷途径在介导对黄潜叶蝇的定量抗性中很重要，用茉莉酸或几丁质引发会导致抗性增加。在拟南芥茉莉酸信号突变体上饲养的黄潜叶蝇幼虫中，异源生物解毒基因的表达降低，而在经几丁质预处理的植物中表达增加。在开发用于分析昆虫 - 植物相互作用的遗传模型系统的背景下，讨论了这些结果和未来的研究方向。
