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Modification of starch metabolism in transgenic Arabidopsis thaliana increases plant biomass and triples oilseed production |
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| Authors: | Fushan Liu Qianru Zhao Noel Mano Zaheer Ahmed Felix Nitschke Yinqqi Cai Kent D Chapman Martin Steup Ian J Tetlow Michael J Emes |
| Institution: | 1. Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada;2. Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada;3. Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX, USA |
| Abstract: | We have identified a novel means to achieve substantially increased vegetative biomass and oilseed production in the model plant Arabidopsis thaliana. Endogenous isoforms of starch branching enzyme (SBE) were substituted by either one of the endosperm‐expressed maize (Zea mays L.) branching isozymes, ZmSBEI or ZmSBEIIb. Transformants were compared with the starch‐free background and with the wild‐type plants. Each of the maize‐derived SBEs restored starch biosynthesis but both morphology and structure of starch particles were altered. Altered starch metabolism in the transformants is associated with enhanced biomass formation and more‐than‐trebled oilseed production while maintaining seed oil quality. Enhanced oilseed production is primarily due to an increased number of siliques per plant whereas oil content and seed number per silique are essentially unchanged or even modestly decreased. Introduction of cereal starch branching isozymes into oilseed plants represents a potentially useful strategy to increase biomass and oilseed production in related crops and manipulate the structure and properties of leaf starch. |
| Keywords: | starch seed oil biomass amylopectin starch branching enzymes |