An Insect Counteradaptation against Host Plant Defenses Evolved through Concerted Neofunctionalization. (1st February 2019)

• Record Type: Journal Article
• Authors: Heidel-Fischer, Hanna M; Kirsch, Roy; Reichelt, Michael; Ahn, Seung-Joon; Wielsch, Natalie; Baxter, Simon W; Heckel, David G; Vogel, Heiko; Kroymann, Juergen
• Editors: Purugganan, Michael
• Is Part Of: Molecular biology and evolution. Volume 36:Number 5(2019)
• Page Start: 930
• Page End: 941
• Publication Date: 2019-02-01
• Subjects: chemical ecology -- molecular evolution -- plant–insect interactions -- insect counteradaptation -- Plutella xylostella -- glucosinolate–myrosinase complex -- glucosinolate sulfatase -- coevolutionary arms race -- neofunctionalization -- escape from adaptive conflict -- concerted neofunctionalization; Molecular biology -- Periodicals; Molecular evolution -- Periodicals; Evolution, Molecular -- Periodicals; Molecular Biology -- Periodicals; 572.8
• DOI: 10.1093/molbev/msz019
• Languages: English
• ISSNs: 0737-4038

Abstract

Abstract: Antagonistic chemical interactions between herbivorous insects and their host plants are often thought to coevolve in a stepwise process, with an evolutionary innovation on one side being countered by a corresponding advance on the other. Glucosinolate sulfatase (GSS) enzyme activity is essential for the Diamondback moth, Plutella xylostella, to overcome a highly diversified secondary metabolite-based host defense system in the Brassicales. GSS genes are located in an ancient cluster of arylsulfataselike genes, but the exact roles of gene copies and their evolutionary trajectories are unknown. Here, we combine a functional investigation of duplicated insect arylsulfatases with an analysis of associated nucleotide substitution patterns. We show that the Diamondback moth genome encodes three GSSs with distinct substrate spectra and distinct expression patterns in response to glucosinolates. Contrary to our expectations, early functional diversification of gene copies was not indicative of a coevolutionary arms race between host and herbivore. Instead, both copies of a duplicated arylsulfatase gene evolved concertedly in the context of an insect host shift to acquire novel detoxifying functions under positive selection, a pattern of duplicate gene retention that we call "concerted neofunctionalization."