Molecular Cloning and Abiotic Stress Expression Analysis of GTPase Era Gene in Mulberry (Morus alba L.)

Escherichia coli Ras-like protein (Era) forms a special GTPase family, which functions in the regulation of the cell cycle by coupling cell division with the growth rate. A cDNA sequence coding GTPase Era mRNA has been cloned from mulberry in the present report. Sequence analysis revealed that its ORF is 1275 bp in length, encoding 424 amino acid protein. The GTPase Era gene had an era domain that belonged to the FeoB_N superfamily. Phylogenetic analysis of the amino acid sequences encoded by the GTPase gene from different species reveals that Morus alba L. was closely connected to Morus notabilis , Ipomoea nill , Capsicum annuum , S olanum pennellii , Nicotiana sylvestris and Nicotiana tabacum . GTPase Era expression patterns treated under drought, low temperature, and salt stress treatment were investigated using quantitative PCR (RT-qPCR) in real-time. The expression level of mRNA showed a significant change in drought, cold, and salt stress treatment compared to the standard growth environment. The highest expression were observed on the third day for drought stress, on the sixth day for low temperature and the seventh day for the salt stress. These findings provide a more definite knowledge on the molecular basis of signal transduction in mulberry trees during stress responses.