Open AccessExpression of Zm GA 20ox cDNA alters plant morphology and increases biomass production of switchgrass ( Panicum virgatum L.)
Author(s) -
Do Phat T.,
De Tar Joann R.,
Lee Hyeyoung,
Folta Michelle K.,
Zhang Zhanyuan J.
Publication year - 2016
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12514
Subject(s) - panicum virgatum , biology , panicum , genetically modified crops , biomass (ecology) , agronomy , botany , transgene , gene , bioenergy , microbiology and biotechnology , biofuel , genetics
Summary Switchgrass ( Panicum virgatum L.) is considered a model herbaceous energy crop for the USA , for its adaptation to marginal land, low rainfall and nutrient‐deficient soils; however, its low biomass yield is one of several constraints, and this might be rectified by modulating plant growth regulator levels. In this study, we have determined whether the expression of the Zea mays gibberellin 20‐oxidase ( Zm GA 20ox ) cDNA in switchgrass will improve biomass production. The Zm GA 20ox gene was placed under the control of constitutive Ca MV 35S promoter with a strong TMV omega enhancer, and introduced into switchgrass via Agrobacterium ‐mediated transformation. The transgene integration and expression levels of Zm GA 20ox in T0 plants were analysed using Southern blot and qRT‐ PCR . Under glasshouse conditions, selected transgenic plants exhibited longer leaves, internodes and tillers, which resulted in twofold increased biomass. These phenotypic alterations correlated with the levels of transgene expression and the particular gibberellin content. Expression of Zm GA 20ox also affected the expression of genes coding for key enzymes in lignin biosynthesis. Our results suggest that the employment of ectopic Zm GA 20ox and selection for natural variants with high level expression of endogenous GA 20ox are appropriate approaches to increase biomass production of switchgrass and other monocot biofuel crops.