Variation in phytochemical characteristics and some relevant gene expression in chromosome doubled Salvia officinalis L.

Polyploidy, as one of the main factors in the speciation and adaptation of plants, can increase the pharmaceutical constituents of medicinal plants. Salvia officinalis L. is a perennial plant from the Lamiaceae family with various medicinal properties. This study aimed to analyze and compare some phytochemical characteristics, such as essential oil and phenolic acid contents and examine the expression of some genes involved in the biosynthesis pathway of phenolic acids in diploid and induced tetraploid plants of S. officinalis by GC-MS and real-time PCR, respectively. The results revealed that S. officinalis essential oil components such as α-pinene, camphene, camphor, borneol, and fenchyl acetate were significantly increased (P < 0.05) in tetraploid plants compared with diploids. Furthermore, tetraploidy increased the level of phenolic acids of gallic, caffeic, rutin, coumaric, rosmarinic, quercetin, cinnamic, apigenin, and chlorogenic acids in S. officinalis. Also, based on RT-PCR results, a higher expression of C4H (Cinnamate 4-Hydroxylase), PAL1 (Phenylalanine ammonia-lyase), 4CL (4-Hydroxycinnamate coenzyme A ligase), TAT (Tyrosine aminotransferase), HPPR (Hydroxyphenylpyruvate reductase), and CYP98A14 (cytochrome P450-dependent monooxygenase) genes involved in their biosynthesis pathway was observed tetraploids compared with diploids. The results confirmed that polyploidy breeding in medicinal plants could be applied to enhance secondary metabolite production.