School of Biological Sciences, Monash University, Clayton, Victoria, Australia.
Photochem Photobiol. 2020 Jul;96(4):936-940. doi: 10.1111/php.13214. Epub 2020 Apr 10.
Rising global temperatures have been suggested to favor cyanobacteria over eukaryotic algae, but UV-B fluxes are also predicted to remain high and may interact with temperature to affect algal growth. To understand the interactive effects of temperature and UV-B radiation, cultures of Microcystis aeruginosa and Anabaena circinalis were grown at either 25 or 30°C and then exposed to an acute irradiance of UV-B (1.4 W m ). Both species showed differences in growth rates at both temperature regimes. The growth rates of M. aeruginosa (0.41 ± 0.02 day ) and A. circinalis (0.38 ± 0.01 day ) were higher at 25 and 30°C, respectively. Rates of damage (k) and repair (r) were calculated from the kinetics of change in effective quantum yield, F '/F '. Analysis of the estimates of r and k shows that M. aeruginosa exhibited relatively high values for both parameters, compared to A. circinalis, at both growth temperatures. In both species, repair rates were higher at 30°C than at 25°C but in A. circinalis damage was also greater at the higher temperature. In contrast, M. aeruginosa showed a lower damage rate at the higher temperature. For both species, the ratio of r:k was higher at the higher temperature. However, the percent inhibition of effective quantum yield by UV-B was greater in A. circinalis than in M. aeruginosa as the r:k was lower A. circinalis. Therefore, it could be concluded that temperature may influence growth and bloom formation of cyanobacteria and that different species may respond differently to UV-B and temperature interactions.
全球气温上升被认为有利于蓝藻而不是真核藻类，但也预计 UV-B 通量仍将很高，并且可能与温度相互作用影响藻类生长。为了了解温度和 UV-B 辐射的相互作用，将铜绿微囊藻和鱼腥藻的培养物在 25 或 30°C 下生长，然后暴露于急性 UV-B 辐照度（1.4 W m ）下。两种物种在两种温度条件下的生长速率均表现出差异。M. aeruginosa（0.41 ± 0.02 天）和 A. circinalis（0.38 ± 0.01 天）的生长速率分别在 25 和 30°C 下更高。从有效量子产量 F'/F 的变化动力学计算出损伤（k）和修复（r）的速率。r 和 k 的估计分析表明，与 A. circinalis 相比，M. aeruginosa 在两种生长温度下均表现出相对较高的 r 和 k 值。在两种物种中，修复速率在 30°C 下高于 25°C，但在较高温度下 A. circinalis 的损伤也更大。相比之下，M. aeruginosa 在较高温度下显示出较低的损伤率。对于两种物种，r:k 在较高温度下更高。然而，由于 r:k 较低，A. circinalis 中有效量子产量的 UV-B 抑制百分比大于 M. aeruginosa。因此，可以得出结论，温度可能会影响蓝藻的生长和水华形成，并且不同的物种可能对 UV-B 和温度相互作用有不同的反应。
