Abstract
Plant fructose-1,6-bisphosphate aldolase (FBA) is an essential enzyme for glycolysis and Calvin cycle, and FBAs are classfied into cytosolic- and plastidic-type. Three plastidic FBA isozymes were discovered on the Arabidopsis genome, which are designed as FBA1 (At2g01140), FBA2 (At2g21330) and FBA3 (At4g38970). Based on amino acid sequences from various plants, those isozymes can be classified into FBA1 and FBA2/3 group. We previously reported that the Arabidopsis FBA1 was identified as a glutathionylated protein and that it played a central role in a glutathione-dependent regulation of photosynthesis. In this study, we newly made transgenic Arabidopsis plants overexpressing each plastidic FBA isozyme in order to elucidate their enzymatic properties. We obtained transformants that accumulated plastidic FBA proteins more than three times of wild type level, so that FBA activity was relevantly enhanced. Native-PAGE analysis using an extract from the leaf showed that overexpression of each FBA isozyme had an effect on the characteristic of FBA tetramer. Based on the result, we will discuss the characteristic and significance of the plastidic FBA isozymes.
