Study on the expression of stress responsive genes in transgenic arabidopsis thaliana Carrying GmNAC20 under dehydration stress

Abstract

Dehydration stress, which is induced by drought, salinity and low temperature conditions, gives rise to various detrimental effects on plant growth and development. The involvement of NAC transcription factors in the regulatory pathways of multiple environmental adversities has been reported in a number of plants. Glycine max NAC20 (GmNAC20) was previously isolated from soybean and characterized as a dehydration-induced gene. This study was performed in an attempt to identify the molecular activities of GmNAC20 in regulation of plant responses to dehydration using the transgenic Arabidopsis thaliana line overexpressing GmNAC20 and quantitative RT-PCR method. In comparison with wild-type plants under dehydration condition, the transgenic line exhibited the differential expression of four stress-responsive genes, copper/zinc superoxide dismutase 1 (CSD1), responsive to aba 18 (RAB18), late embryogenesis abundant 14 (LEA14), and early responsive to dehydration 11 (ERD11), especially the up-regulation of CSD1 and LEA14. The result suggested that overexpression of GmNAC20 led to a change in the transcript levels of some specific stress-responsive genes in response to water loss condition. This study provided clues about the involvement of GmNAC20 in the ability of dehydration tolerance. Therefore, further studies should be carried out to investigate other associated downstream genes of GmNAC20 and ascertain the significance of its functions in plants under abiotic stresses. KEYWORDS Arabidopsis thaliana, dehydration, transgenic plant, NAC transcription factor, GmNAC20, stress-responsive gene, Glycine max