Cloning and Functional Analysis of GarTHA Gene from Gossypium aridum

Abstract

Salinity stress is one of the most important factors that impede the growth and development of various crops.Some Gossypium wild species with tolerance to high salinity are valuable germplasm resource for studying salt tolerance mechanism in Gossypium and improving salinity resistance in upland cotton.In the previous study,we obtained a differential expression fragment by comparing differential expression transcript under stress treatment in diploid G.aridum species using cDNA-AFLP technique.In this study,using the partial cDNA sequences as queries,the Gossypium EST database was screened and the corresponding cDNA sequence containing a complete ORF was assembled.As a result,a novel gene,encoding G.aridum threonine aldolase,was cloned.The gene was designated as GarTHA(G.aridum THA;GenBank accession number:KC167360).The ORF of GarTHA was 822 bp encoding 273 amino acid residues with a predicted molecular weight of 82.57 kD and a predicted isoelectric point of 4.89.The GarTHA showed the highest similarity of 84.6% with poplar PtTHA.To characterize its putative function,we transformed the ORF of GarTHA gene driven by rd29A promoter into Arabidopsis.The growth of transgenic plants was observed under salinity stress.The seed germination rate and root length of transgenic Arabidopsis were significantly higher than those of the wild type plants under salt stress.The results showed that GarTHA gene could improve salt resistance in plants.