Modification of starch metabolism in transgenic Arabidopsis thaliana increases plant biomass and triples oilseed production.
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.
Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada.
Fushan
F
Liu
Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada.
Qianru
Q
Zhao
Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada.
Noel
N
Mano
Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada.
Zaheer
Z
Ahmed
Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada.
Felix
F
Nitschke
Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX, USA.
Yinqqi
Y
Cai
Department of Biological Sciences, Center for Plant Lipid Research, University of North Texas, Denton, TX, USA.
Kent D
KD
Chapman
Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada.
Martin
M
Steup
Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada.
Ian J
IJ
Tetlow
Department of Molecular and Cellular Biology, Summerlee Science Complex, University of Guelph, Guelph, ON, Canada.
Michael J
MJ
Emes
D015061:1,4-alpha-Glucan Branching Enzyme / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D018533:Biomass; D002736:Chloroplasts / Q000201:enzymology; D056625:Endosperm / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D010641:Phenotype; D018515:Plant Leaves / Q000378:metabolism; D010938:Plant Oils / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000254:growth & development* / Q000378:metabolism; D013213:Starch / Q000378:metabolism*; D014170:Transformation, Genetic; D019076:Transgenes; D003313:Zea mays / Q000378:metabolism
D010938:Plant Oils; D012333:RNA, Messenger; D013213:Starch; D015061:1,4-alpha-Glucan Branching Enzyme
amylopectin; biomass; seed oil; starch; starch branching enzymes