Effects of elevated CO2 and temperature on Gynostemma pentaphyllum physiology and bioactive compounds.

Abstract Recently, an important topic of research has been how climate change is seriously threatening the sustainability of agricultural production. However, there is surprisingly little experimental data regarding how elevated temperature and CO 2 will affect the growth of medicinal plants and production of bioactive compounds. Here, we comprehensively analyzed the effects of elevated CO 2 and temperature on the photosynthetic process, biomass, total sugars, antioxidant compounds, antioxidant capacity, and bioactive compounds of Gynostemma pentaphyllum . Two different CO 2 concentrations [360 and 720 μmol mol −1 ] were imposed on plants grown at two different temperature regimes of 23/18 and 28/23 °C (day/night) for 60 days. Results show that elevated CO 2 and temperature significantly increase the biomass, particularly in proportion to inflorescence total dry weight. The chlorophyll content in leaves increased under the elevated temperature and CO 2 . Further, electron transport rate (ETR), photochemical quenching (qP), actual photochemical quantum yield (Yield), instantaneous photosynthetic rate (Photo), transpiration rate (Trmmol) and stomatal conductance (Cond) also increased to different degrees under elevated CO 2 and temperature. Moreover, elevated CO 2 increased the level of total sugars and gypenoside A, but decreased the total antioxidant capacity and main antioxidant compounds in different organs of G. pentaphyllum. Accumulation of total phenolics and flavonoids also decreased in leaves, stems, and inflorescences under elevated CO 2 and temperature. Overall, our data indicate that the predicted increase in atmospheric temperature and CO 2 could improve the biomass of G. pentaphyllum , but they would reduce its health-promoting properties.