N-acetyltransferase gene NATA1 from Vigna angularis confers resistance against Uromyces vignae infection

Abstract

N-acetyltransferases are part of the general control non-repressible 5 (GCN5)-related N-acetyltransferases superfamily (GNATs), which play important roles in plant response to biotic and abiotic stresses. In this study, VaNATA1, the N-acetyltransferase gene from Vigna angularis, was separately obtained from genomic DNA (gDNA) and complementary DNA (cDNA) samples using PCR. The two sequences amplified from gDNA and cDNA were exactly the same and were composed of 552 nucleotides, indicating that there is no intron insert in VaNATA1. Conserved domain prediction and phylogenic analysis revealed that VaNATA1 belongs to the spermine/spermidine N-acetyltransferases (SSAT) family of GNATs. Expression of VaNATA1 was analyzed in varieties with different susceptibility to the rust fungus Uromycesvignae. VaNATA1 was rapidly induced in the rust-resistant cultivar at 12 h post inoculation (hpi), and then was maintained at a high level throughout the whole infection process. In the susceptible cultivar, there were no obvious changes in expression of VaNATA1 in response to U. vignae infection. The expression of VaNATA1 was further analyzed in the susceptible cultivar inoculated with U. vignae after pretreatment with 1-aminocyclopropane-1-coumaric acid (ACC), and the results showed that ACC significantly induced resistance in adzuki bean and increased the expression of VaNATA1 at 12, 48, and 120 hpi. These results suggested that VaNATA1 is a positive regulator of the defense system in V. angularis during response to U. vignae infection.