Molecular cloning and expression of 3-ketoacyl-CoA synthase (3KeCs) gene in mulberry (Morus alba L.) under abiotic stresses

A cDNA sequence coding 3-ketoacyl-CoA synthase (3KeCs) gene (GeneBank accession number XM_010114628.1) was cloned from leaves of mulberry (Morus alba L.) based on mulberry expressed sequence tags (ESTs). Sequence analysis showed that its open reading frame (ORF) is 1413 bp encoding a protein of 470 amino acids with a predicted molecular weight and an isoelectric point (pI) of 53.42 kDa and 8.60 respectively. The 3-ketoacyl-CoA synthase had FAE1 (Type III polyketide synthase-like protein) domain with three active binding sites and belonged to condensing enzymes superfamily. A homologous analysis showed that 3KeCs gene was highly conserved in Morus alba and had high levels of similarity with other species like Morus Notabilis, Glycine max and Ipomoea nil. Phylogenetic analysis based 3-ketoacyl synthase gene from various species showed that Morus alba was closely related to Morus notabilis, Cucumis sativus, Juglans regia, Sesamum indicum and Ipomoea nil. The quantitative PCR analysis showed that the transcriptional level of 3KeCs mRNA had a significant change under drought, cold and salt stress conditions. The changes in the mRNA transcriptional levels of 3-ketoacyl-CoA gene in mulberry (Morus alba L.) show that the gene is responsive to abiotic stress conditions.