[Cloning and characterization of an aldehyde dehydrogenase gene GmALDH3-1 from soybean]

To research the mechanism of soybean reproductive development, we identified a number of flower development related genes in soybean by microarray hybridization. A gene predominately expressed in soybean flowers was chosen for further analysis. Through bioinformatic and RT-PCR approaches, the full-length gene was cloned from soybean flowers. The results of BLAST searching indicated that this gene encoded for an aldehyde dehydrogenase and was named as GmALDH3-1. GmALDH3-1 contains a complete open reading frame of 1485 bp in length, which encodes for a peptide of 494 amino acids. The product encoded by GmALDH3-1 shows 83% similarity and 68% identity with Populus tomentosa PtALDH3, respectively, and 39% and 59% with human ALDH3B. Phylogenetic analysis shows that GmALDH3-1 and other ALDH3 subfamily members are grouped into the same branch and GmALDH3-1 is close to PtALDH3 and Arabidopsis AtALDH3F1. Real-time RT-PCR analysis demonstrated that the highest expression level of GmALDH3-1 occurred in flowers, but the expression of this gene was almost undetectable in leaves and roots. We further analyzed GmALDH3-1 expression during the course of seed development based on publicly available microarray data and found that GmALDH3-1 was highly expressed in the seed endothelium, epidermis, outer integument, and hilum.