不同基因型颗石藻(Emiliania huxleyi)对海洋酸化及高光耦合的生理响应

Physiological Response of Different Genotypes of Emiliania huxleyi to Ocean Acidification and High Light Coupling

为探究不同基因型的颗石藻(E.huxleyi)PERU41和PERU46在酸化条件下及短期高光下的生理响应,设置两种二氧化碳分压(0.04%、0.1%),强光条件为400μmol·m^(-2)·s^(-1),比较两者生理参数的差异。结果表明,酸化条件下颗石藻的生长率及细胞粒径均下降。高p(CO_(2))条件对PERU41和PERU46的钙化作用影响不同,PERU46的颗粒无机碳(PIC)含量、产率均降低,表明其钙化作用被抑制,相反PERU41的PIC含量产率均上升表明钙化作用被促进。酸化条件导致细胞的饱和光强、表观光合效率及最大电子传递速率均降低,但细胞通过增加光合色素含量提高光捕获能力。在高p(CO_(2))条件及高光胁迫下,细胞非光化学淬灭、有效光化学效率、PSⅡ的修复速率均下降,PSⅡ的损伤速率则上升,但与PERU41相比,钙化较弱的PERU46受高光的胁迫更强。以上结果表明不同基因型的颗石藻对酸化条件的响应不同,酸化条件会加剧高光胁迫。

To investigate the physiological responses of different genotypes of E.huxleyi PERU41 and PERU46 under acidification conditions and short-term high light,two partial pressures of carbon dioxide(400 and 1000 ppmv)and 400μmol·m^(-2)·s^(-1) under high light conditions are set to compare the differences in their physiological parameters.The results show that the growth rate and cell particle size of the algae decrease under acidification conditions.The high p(CO_(2))conditions have different effects on calcification in PERU41 and PERU46,and the PIC content yield of PERU46 reduces,while the PIC content yield of PERU41 increases,indicating that calcification is promoted.The saturation light intensity,apparent photosynthetic efficiency and maximum electron transfer rate of the cells reduce under acidification conditions,but the cells improve the light capture capacity by increasing the photosynthetic pigment content.Under high p(CO_(2))and high light stress,the non-photochemical quenching,effective photochemical efficiency,and repair rate of PSⅡdecrease,while the damage rate of PSⅡincrease but the change is greater in PERU46,which has weaker calcification compared with PERU41.These results suggest that different genotypes of E.huxleyi respond differently to acidification conditions,which exacerbate high light stress.