To study the combined effects of ocean acidification (OA) and warming on the growth and photosynthetic performance of the economically important marine macroalga Gracilariopsis lemaneiformis, thalli were grown under ambient low CO₂ (390 μatm, LC) and elevated high CO₂ (1000 μatm, HC) conditions with culture temperatures of 20 °C and 24 °C. Based on the evaluation of growth and photosynthetic responses to light and dissolved inorganic carbon (DIC), HC decreased the growth rate and phycoerythrin (PE) and phycocyanin (PC) levels but increased contents of UV-absorbing compounds (UVACs) in G. lemaneiformis at 20 °C, and high temperature counteracted these effects. Photosynthetic responses such as chlorophyll fluorescence parameters (maximum relative electron transport rate, rETR_max; light use efficiency, α; saturation light intensity, I_k; maximum quantum yield, F_V/F_M; effective quantum yield, Y(II) and non-photochemical quenching, NPQ) were not different among the treatments. However, increased oxygen evolution (P_n) and dark respiration (R_d) rates were observed at 20 °C in the HC treatment. No significant effects of HC on apparent carboxylation efficiency (ACE), maximum oxygen evolution rate (V_max) and DIC affinity for oxygen evolution (K_1/2DIC) were found, and HC synergy with high temperature increased K_1/2DIC. A lower C/N ratio with decreased tissue carbon but increased nitrogen was observed under HC and high-temperature treatment. Our results indicate that high temperature may counteract the negative effects of OA on the growth and pigment characteristics of G. lemaneiformis and improve food quality, as evidenced by enhanced N per biomass.

为了研究海洋酸化（OA）和温热的生长和经济上重要的海洋大藻光合性能的综合作用Gracilariopsis菜，菌体周围低的CO下生长₂（390μatm，LC）和升高高的CO ₂（1000μatm ，HC）条件，培养温度为20°C和24°C。根据对光和溶解的无机碳（DIC）的生长和光合作用的评估，HC降低了Lemaneiformis的生长速率和藻红蛋白（PE）和藻蓝蛋白（PC）水平，但增加了紫外线吸收化合物（UVAC）的含量。在20°C时，高温会抵消这些影响。光合作用响应，例如叶绿素荧光参数（最大相对电子传输速率，rETR _max；光利用效率，α；饱和光强度，I _k；最大量子产率，F _V / F _M；有效量子产率，Y（II）和非-光化学淬灭，NPQ）之间没有区别。但是，在HC处理中，在20°C时观察到增加的氧气释放（P _n）和暗呼吸（R _d）速率。HC对表观羧化效率（ACE），最大氧_释放速率（V _max）和DIC对氧_释放的亲和力（K _{1 / 2DIC}）无明显影响）被发现，并且HC与高温的协同作用增加了K _{1 / 2DIC}。在HC和高温处理下，观察到较低的C / N比，组织碳减少，但氮增加。我们的结果表明，高温可能抵消了OA对Lemaneiformis的生长和色素特性的不利影响，并改善了食品质量，这可以通过提高每个生物量的氮来证明。