High light might alleviate inhibitory effects of high temperature on growth and physiological parameters of Ulva prolifera. (19th February 2020) - Jiang, Jianan
Abstract: In order to explore the effects of high temperature (HT) and light on the physiological and biochemical aspects of macroalga Ulva prolifera, we cultured this species under two temperatures (20°C: low temperature, LT; 30°C: HT) and two light intensities (80 μmol m −2 s −1 : low light, LL; 400 μmol m −2 s −1 : high light, HL) for 5 days. It was found that (a) compared to 20°C, the chlorophyll a (Chl a ) content was increased at 30°C under LL conditions, the relative growth rate (RGR) was significantly decreased at 30°C; (b) compared to LL treatment, HL significantly increased RGR but significantly decreased Chl a content; (c) LL‐grown U. prolifera at 30°C showed the highest photosynthetic oxygen evolution rate; however, there were no significant effects of temperature and light on the relative electron transport rate; (d) superoxide dismutase activity was significantly decreased by HL, but no significant effects of temperature were observed; and (e) compared to LL, HL significantly increased the soluble sugar content at 20°C, but significantly reduced at 30°C. These results showed that the inhibitory effects of HT can be offset by HL intensity.