Heterologous expression and transcript analysis of gibberellin biosynthetic genes of grasses reveals novel functionality in the GA3ox family

BMC Plant Biology

Research Article

Alison K Huttly¹  Ian M Prosser¹  Archana Patil¹  Peter Hedden¹  Barbora Gallova¹  Simon P Vaughan¹  Andrew L Phillips¹  Yi-dan Li²  Stephen Pearce³  Jorge Dubcovsky⁴  Jane A Coghill⁵ 

[1] Department of Plant Biology and Crop Science, Rothamsted Research, AL5 2JQ, Harpenden, UK;Department of Plant Biology and Crop Science, Rothamsted Research, AL5 2JQ, Harpenden, UK;Biotechnology Research Centre, Jilin Academy of Agricultural Sciences, 130033, Changchun, China;Department of Plant Sciences, University of California, 95616, Davis, CA, USA;Department of Plant Sciences, University of California, 95616, Davis, CA, USA;Howard Hughes Medical Institute, 20815, Chevy Chase, MD, USA;University of Bristol Transcriptomics Facility, School of Biological Sciences, BS8 1UG, Bristol, UK;

关键词: Gibberellin;    Wheat;    Biosynthesis;    Signalling;    Gene sequences;    De novo assembly;    Transcriptomics;    Heterologous expression;    GA 1-oxidase;   

DOI  :  10.1186/s12870-015-0520-7

 received in 2015-01-07, accepted in 2015-05-01,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe gibberellin (GA) pathway plays a central role in the regulation of plant development, with the 2-oxoglutarate-dependent dioxygenases (2-ODDs: GA20ox, GA3ox, GA2ox) that catalyse the later steps in the biosynthetic pathway of particularly importance in regulating bioactive GA levels. Although GA has important impacts on crop yield and quality, our understanding of the regulation of GA biosynthesis during wheat and barley development remains limited. In this study we identified or assembled genes encoding the GA 2-ODDs of wheat, barley and Brachypodium distachyon and characterised the wheat genes by heterologous expression and transcript analysis.ResultsThe wheat, barley and Brachypodium genomes each contain orthologous copies of the GA20ox, GA3ox and GA2ox genes identified in rice, with the exception of OsGA3ox1 and OsGA2ox5 which are absent in these species. Some additional paralogs of 2-ODD genes were identified: notably, a novel gene in the wheat B genome related to GA3ox2 was shown to encode a GA 1-oxidase, named as TaGA1ox-B1. This enzyme is likely to be responsible for the abundant 1β-hydroxylated GAs present in developing wheat grains. We also identified a related gene in barley, located in a syntenic position to TaGA1ox-B1, that encodes a GA 3,18-dihydroxylase which similarly accounts for the accumulation of unusual GAs in barley grains. Transcript analysis showed that some paralogs of the different classes of 2-ODD were expressed mainly in a single tissue or at specific developmental stages. In particular, TaGA20ox3, TaGA1ox1, TaGA3ox3 and TaGA2ox7 were predominantly expressed in developing grain. More detailed analysis of grain-specific gene expression showed that while the transcripts of biosynthetic genes were most abundant in the endosperm, genes encoding inactivation and signalling components were more highly expressed in the seed coat and pericarp.ConclusionsThe comprehensive expression and functional characterisation of the multigene families encoding the 2-ODD enzymes of the GA pathway in wheat and barley will provide the basis for a better understanding of GA-regulated development in these species. This analysis revealed the existence of a novel, endosperm-specific GA 1-oxidase in wheat and a related GA 3,18-dihydroxylase enzyme in barley that may play important roles during grain expansion and development.

【 授权许可】

Unknown   
© Pearce et al. 2015. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.