Identification, Isolation and Characterization of GaCyPI Gene in Gossypium arboreum under Cotton Leaf Curl Virus Disease Stress

Abstract

Pakistan is facing the threat of Cotton Leaf Curl Virus (CLCuV) which is transmitted through whitefly to cotton crop. Molecular mechanism of leaf epicuticular wax protects the plants from different pathogens including insect attack and disease transmission. Objective of current study is the isolation and characterization of a wax related gene GaCyPI from Gossypium arboreum under CLCuV infection. A fragment of 475 bp was isolated from the total RNA and 3’ and 5’ RACE-PCR products were arranged by overlapping the extended sequences at both the ends. Deduced protein sequence of GaCyPI showed homology with Cyclophilin cis-trans isomerase gene of Gossypium ramondii and Gossypium barbadanse. Multiple sequence alignment also revealed homology among the coding sequences of same gene. GaCyPI protein comprised of 173 amino acids and ORF finder revealed the 69 bases upstream at 5’ while 350 bp at 3’UTR. InterProScan revealed that it belongs to Cyclophilin-type peptidyl prolyl cis/trans isomerase (PPIase) family. Active sites are visible at specific amino acid positions and 3D structure was stable in Ramachandran plot. Prosa server showed protein residues have average 3D-1D score >= 0.2 and Z-Score was −6.74. Phylogenetic analysis revealed that G. raimondii is the closest species that shares the same sequence. Hence, GaCyPI has strong role in plants’ epicuticular wax and its genetic transformation may protect the cotton from whitefly which transmits CLCuV.