Over-expression of the AtGA2ox8 gene decreases the biomass accumulation and lignification in rapeseed (Brassica napus L.).
Gibberellin 2-oxidase (GA 2-oxidase) plays very important roles in plant growth and development. In this study, the AtGA2ox8 gene, derived from Arabidopsis (Arabidopsis thaliana), was transformed and over-expressed in rapeseed (Brassica napus L.) to assess the role of AtGA2ox8 in biomass accumulation and lignification in plants. The transgenic plants, identified by resistant selection, polymerase chain reaction (PCR) and reverse-transcription PCR (RT-PCR) analyses, and green fluorescence examination, showed growth retardation, flowering delay, and dwarf stature. The fresh weight and dry weight in transgenic lines were about 21% and 29% lower than those in wild type (WT), respectively, and the fresh to dry weight ratios were higher than that of WT. Quantitative measurements demonstrated that the lignin content in transgenic lines decreased by 10%-20%, and histochemical staining results also showed reduced lignification in transgenic lines. Quantitative real-time PCR analysis indicated that the transcript levels of lignin biosynthetic genes in transgenic lines were markedly decreased and were consistent with the reduced lignification. These results suggest that the reduced biomass accumulation and lignification in the AtGA2ox8 over-expression rapeseed might be due to altered lignin biosynthetic gene expression.
Zhao
Xiao-ying
XY
Bioenergy and Biomaterial Research Center, Institute of Life Science and Technology, State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, China.
Zhu
Deng-feng
DF
Zhou
Bo
B
Peng
Wu-sheng
WS
Lin
Jian-zhong
JZ
Huang
Xing-qun
XQ
He
Re-qing
RQ
Zhuo
Yu-hong
YH
Peng
Dan
D
Tang
Dong-ying
DY
Li
Ming-fang
MF
Liu
Xuan-ming
XM
D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D018533:Biomass; D029688:Brassica napus / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D008031:Lignin / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014170:Transformation, Genetic
D029681:Arabidopsis Proteins; D017931:DNA Primers; D018744:DNA, Plant; D011994:Recombinant Proteins; D008031:Lignin; D006899:Mixed Function Oxygenases; C499576:AtGA2ox8 protein, Arabidopsis