cDNA Cloning and Investigating Gene Expression, Physicochemical Characteristics and Functional Structures of β-galactosidase Enzymes of Tomato Fruit (Lycopersicum esculentum cv. Falcato)

β-galactosidases participate in many processes related to plant development and are introduced as the key enzymes in the ripening-related softening of fleshy fruits. In this study، six full-length cDNAs encoding β-galactosidase enzymes (called STBG2-7) are cloned from the tomato fruit tissue of Falcato cultivar، and their expression levels and amino acid sequences are investigated. Also، the expression levels and amino acid sequences deduced from these isoforms are compared to their corresponding isoforms in Rutgers cultivar، and differences are studied and discussed. In the follow-up، by alignment of the protein sequences of STBG2-7، two highly-conserved and less-conserved halves are identified in these enzymes، and on the basis of the characteristics of the less-conserved halves and the recent experimental findings، it is suggested that the differential functions of these isoforms are related to these less-conserved halves.