Indagini preliminari sull'effetto della radiazione UV-B sull'espressione di alcuni geni coinvolti nella biosintesi di monoterpeni in Mentha xpiperita L

Due to the depletion of the ozone layer in the Earth's atmosphere, the amount of ultraviolet-B radiation (280-320 nm) reaching the Earth's surface is increasing. Ultraviolet radiation causes a very large number of physiological and biochemical changes in photosynthetic organisms. Photosynthesis is often reduced and the production of plant secondary metabolites increased. Secondary plant products play a fundamental role in chemical defence and interaction with the environment. One of the most important species producing secondary metabolites is Mentha x piperita L. (peppermint), a member of the Lamiaceae family. Peppermint oil composition is particularly affected by environmental factors, including light. In this work the expression of some key genes involved in monoterpene biosynthesis in response to UV-B radiation in peppermint plants was analyzed. For these purposes, total RNA isolated from peppermint leaves collected at different times after treatment was used for semi-quantitative RT-PCR experiments. These preliminary results gave a first indication of an effect of UV-B radiation on the expression of genes involved in monoterpene biosynthesis. In particular, (+)-pulegone reductase and (+)-menthofuran synthase transcription was upregulated by UV-B treatment, whereas (-)-limonene hydroxylase transcription was downregulated.