Abstract
We have demonstrated that, among 27 types of Arabidopsis Nudix hydrolases (AtNUDX1-27), cytosolic AtNUDX11 and mitochondrial AtNUDX15 hydrolyze CoA and its derivatives (Plant Physiol. 2008, 148: 1412-24, Plant J. in press). AtNUDX15 produced not only mitochondrial protein but also predicted peroxisomal isoform by an alternative splicing. Here we studied the physiological role of AtNUDX11 and 15 using T-DNA insertion mutant of the respective gene (KO Atnudx11 and KO Atnudx15). Activities of CoA pyrophosphohydrolase in KO-Atnudx11 and KO-Atnudx15 mutants were reduced to 80.4 and 46.2%, respectively. There was no difference in growth, flowering, and seed development between the wild-type plants and both mutants. The mutants did now show the inhibition of seed germination and seedling growth in the medium without sucrose and the tolerance against salt (125 mM) which were observed commonly in mutants defective a enzyme involved in CoA biosynthesis. These results suggest that AtNUDX11 and 15 are functionally redundant.
