The evolution of functional complexity within the β-amylase gene family in land plants

BMC Evolutionary Biology

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[1] 0000 0001 2156 2780, grid.5801.c, Department of Biology, ETH Zürich, Universitätstr. 2, CH-8092, Zurich, Switzerland;0000 0004 1937 0650, grid.7400.3, Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland;0000 0004 1937 0650, grid.7400.3, Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland;Present address: ETH Zürich, Institute of Integrative Biology, Universitätstrasse 16, 8092, Zürich, Switzerland;0000 0004 1937 0650, grid.7400.3, Department of Plant and Microbial Biology, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland;grid.420132.6, Present address: John Innes Centre, Norwich Research Park, NR4 7UH, Norwich, UK;0000 0004 1937 0650, grid.7400.3, Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, CH-8008, Zürich, Switzerland;

关键词: Green plants;    Phylogenetic analysis;    β-Amylase;    Gene duplication;    Functional diversification;    Starch;   

DOI  :  10.1186/s12862-019-1395-2

来源: publisher

【 摘 要 】

Backgroundβ-Amylases (BAMs) are a multigene family of glucan hydrolytic enzymes playing a key role not only for plant biology but also for many industrial applications, such as the malting process in the brewing and distilling industries. BAMs have been extensively studied in Arabidopsis thaliana where they show a surprising level of complexity in terms of specialization within the different isoforms as well as regulatory functions played by at least three catalytically inactive members. Despite the importance of BAMs and the fact that multiple BAM proteins are also present in other angiosperms, little is known about their phylogenetic history or functional relationship.ResultsHere, we examined 961 β-amylase sequences from 136 different algae and land plant species, including 66 sequenced genomes and many transcriptomes. The extraordinary number and the diversity of organisms examined allowed us to reconstruct the main patterns of β-amylase evolution in land plants. We identified eight distinct clades in angiosperms, which results from extensive gene duplications and sub- or neo-functionalization. We discovered a novel clade of BAM, absent in Arabidopsis, which we called BAM10. BAM10 emerged before the radiation of seed plants and has the feature of an inactive enzyme. Furthermore, we report that BAM4 – an important protein regulating Arabidopsis starch metabolism – is absent in many relevant starch-accumulating crop species, suggesting that starch degradation may be differently regulated between species.ConclusionsBAM proteins originated sometime more than 400 million years ago and expanded together with the differentiation of plants into organisms of increasing complexity. Our phylogenetic analyses provide essential insights for future functional studies of this important class of storage glucan hydrolases and regulatory proteins.

【 授权许可】

CC BY