Isolation and characterization of Ras-related GTP-binding protein (Ran) from Lepidium latifolium L. reveals its potential role in regulating abiotic stress tolerance

Abstract

Lepidium latifolium L., a weed distributed in the Ladakh region of Himalayan range, belongs to Brassicaceae family and reported to withstand low temperature stress <−20 °C. RACE primers were designed from EST encoding Ras-related GTP-binding like protein (FG618354) from L. latifolium and full-length LlaRan (GU014818) was obtained. Its cDNA sequence consisted of 672 bp long open-reading frame, 5′ UTR of 95 bp and 3′ UTR of 115 bp, respectively. The predicted Lepidium RAN protein encodes a 223 aa protein of 25.59 kDa and pI 6.08. In silico characterization of LlaRan suggested that it has a universal RAN domain across species and likely to follow similar functions. Transcript accumulation studies in response to cold stress suggested that it is an early downregulated gene but a late upregulated gene. Quantitative analysis using real-time PCR revealed differential regulation of the transcript not only under cold stress but also under the effect of stress regulators like jasmonic acid, salicylic acid, calcium, abscisic acid and ethylene which suggests a possible crosstalk between different pathways where LlaRan may have an important role to play. Thus, LlaRan is a candidate gene for engineering plants against abiotic stresses after its further functional validation in model plants.