Cloning of Formate dehydrogenase Gene and Effect on the Waterlogging Tolerance of Brassica napus L.

A Formate dehydrogenase (FDH) gene, named BnFDH-1, was cloned from oilseeds (Brassica napus L.) by the Rapid Amplification of cDNA Ends (RACE) method. The Complementary DNA (cDNA) consisted of 1488 bp and had an open reading frame of 1140 bp encoding a polypeptide of 384 amino acids with a molecular weight of 42.3 kD and an isoelectric point of 8.17. BnFDH-1 showed high homology to known FDH genes, especially FDH from Arabidopsis thaliana. Conserved domain search and motif characterization identified BnFDH protein as Rossmann-fold NAD (P) (+)-binding proteins. NetPhos 2.0 search predicted 18 significant phosphorylation sites. To investigate the effect of BnFDH on waterlogging tolerance of B. napus, 12 B. napus cultivars with different waterlogging tolerance were used in the research and waterlogging Tolerance Index (WTI) was calculated by multiplying relative percentage germination and the relative seedling height. BnFDH-1 was cloned from the 12 materials also, but the results indicated all of them had same protein sequence. BnFDH expression level in 12 B. napus cultivates with different waterlogging tolerance after waterlogging treatment was measured. The results indicated expression level of BnFDH in 12 cultivates had significant difference. But correlation analysis proved that BnFDH expression level was uncorrelated with Waterlogging tolerance index (WTI). So it was not the BnFDH BnFDH that was key gene for the waterlogging tolerance of B. napus.