Isolation and characterization of cold responsive NAC gene from Lepidium latifolium.

Cold stress is one of the major limiting factor in crop productivity. Plants growing in colder regions acclimatize to severe conditions owing to the presence of 'cold stress tolerant genes'. Isolation and functional characterization of these genes are important before their exploitation in modern agricultural practices. Here, we have cloned full length NAC gene (1,388 bp) from Lepidium latifolium (LlaNAC). This gene belongs to NAP sub-group which also includes ANAC056 of Arabidopsis thaliana, nearest relative of LlaNAC. Upstream analysis and microarray data analysis of ANAC056 suggested that LlaNAC might also be ABA-regulated. However, quantitative transcript expression analysis revealed that LlaNAC transcript upregulated by cold stress and downregulated in response to varying concentrations of abscisic acid, salicylic acid, calcium chloride and ethylene. There is also a possibility that the gene may be getting regulated by a pathway whose components are still unknown. Any further investigations to understand the mechanism of regulation of LlaNAC gene expression are likely to find immense importance in plant biotechnology and crop improvement.