State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China.
Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin, 300387, China.
Ecotoxicol Environ Saf. 2020 Apr 1;192:110313. doi: 10.1016/j.ecoenv.2020.110313. Epub 2020 Feb 15.
Cyanobacteria always massively grow and even occur blooms in summer, with releasing amount of β-cyclocitral. To uncover the effects of summer high irradiance and temperature on cyanobacterial growth and β-cyclocitral emission, the cell growth, reactive oxygen species (ROS) levels, photosynthetic pigment content, chlorophyll fluorescence and β-cyclocitral emission were investigated in Microcystis aeruginosa under high light and temperature. Compared to the control under 50 μmol m·s, the cell growth was promoted under 100 μmol m·s, but inhibited under 500 and 1000 μmol m·s. The inhibition was also detected under high temperature at 30 and 35 °C in contrast to the control at 25 °C. Under high light and high temperature, M. aeruginosa increased ROS levels and reduced photosynthetic pigment content and photosystem II (PSII) efficiency, which resulted in the inhibition on cell growth. With increasing the light intensity and temperature, O levels gradually increased, while β-carotene content gradually decreased by quenching O, with increasing β-cyclocitral emission. In summer, high irradiance and temperature not benefited the growth of cyanobacteria, but the emission of β-cyclocitral derived from β-carotene quenching O may offset the disadvantages by poisoning other algae.
蓝藻在夏季总是大量生长，甚至出现水华，并释放大量β-环柠檬醛。为了揭示夏季高光强和高温对蓝藻生长和β-环柠檬醛排放的影响，在高光强和高温下研究了铜绿微囊藻中细胞生长、活性氧（ROS）水平、光合色素含量、叶绿素荧光和β-环柠檬醛排放的变化。与 50 μmol·m·s 下的对照相比，在 100 μmol·m·s 下细胞生长得到促进，但在 500 和 1000 μmol·m·s 下受到抑制。与 25°C 的对照相比，在 30 和 35°C 下高温也检测到了抑制作用。在高光强和高温下，铜绿微囊藻增加了 ROS 水平，降低了光合色素含量和光系统 II（PSII）效率，从而抑制了细胞生长。随着光强和温度的增加，O 水平逐渐升高，而β-胡萝卜素含量通过淬灭 O 逐渐降低，导致β-环柠檬醛排放增加。在夏季，高光强和高温不利于蓝藻的生长，但由β-胡萝卜素淬灭 O 产生的β-环柠檬醛的排放可能通过毒害其他藻类来抵消这些不利影响。
