Photosynthetic responses of Pyropia yezoensis f. narawaensis (Bangiales, Rhodophyta) to a thermal and PAR gradient vary with the life-history stage
Photosynthetic responses of Pyropia yezoensis f. narawaensis (Bangiales, Rhodophyta) to a thermal and PAR gradient vary with the life-history stage
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DOI：
10.2216/16-25.1
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发表时间：
2016-08
期刊：
影响因子：
1.6
通讯作者：
Yuki Watanabe;H. Yamada;Takayuki Mine;Y. Kawamura;Gregory N. Nishihara;Ryuta Terada
中科院分区：
文献类型：
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作者：
Yuki Watanabe;H. Yamada;Takayuki Mine;Y. Kawamura;Gregory N. Nishihara;Ryuta Terada
摘要：研究了光合有效辐射（PAR）和温度对条斑Pyropia yezoensis f. narawaensis（佐贺-#5菌株，Bangiales），用脉冲振幅荧光测定法和溶解氧传感器测定微观孢子体和宏观配子体。最大量子产额（Fv/Fm）和总光合作用（GP）的温度响应在两个生活史阶段之间有明显的差异。孢子体Fv/Fm对温度不敏感，尽管模型显示Fv/Fm在16.7°C时最大（0.60）。配子体Fv/Fm对温度敏感，在14.7°C时达到最大值0.55。GP与温度的关系也不同。孢子体GP的最大速率发生在30.7°C，为17.1 μg O2 mgchl-a−1 min−1（15.4-19.4，95%贝叶斯可信区间）;然而，配子体GP的最大速率要高得多（110 μmol O2 mgchl-a−1 min−1），发生在较低的温度（14.4°C）。光合速率对PAR的响应也不同，配子体的初始斜率（α）、饱和PAR（Ek）和最大光合速率（Pmax）均明显高于孢子体。因此，我们假设，在一个异形的生活史，如属Pyropia的物种，生理反应的环境梯度将是不同的。
Abstract: The effect of photosynthetically active radiation (PAR) and temperature on photosynthesis of the cultivated red alga, Pyropia yezoensis f. narawaensis (Saga-#5 Strain, Bangiales), was determined for microscopic sporophytes and macroscopic gametophytes with pulse-amplitude fluorometry and dissolved oxygen sensors. A clear difference in the temperature response of the maximum quantum yield (Fv/Fm) and oxygenic gross photosynthesis (GP) was revealed between the two life-history stages. The sporophyte Fv/Fm was not sensitive to temperature, although the model revealed an Fv/Fm maximum (0.60) at 16.7°C. In contrast, the gametophyte Fv/Fm was clearly sensitive to temperature and attained a maximum mean value of 0.55 at 14.7°C. The relationship between GP and temperature was also different. The maximum rates of GP of the sporophyte occurred at 30.7°C and was 17.1 μg O2 mgchl-a−1 min−1 (15.4–19.4, 95% Bayesian credible interval); however, maximum rates of GP for the gametophyte were much higher (110 μmol O2 mgchl-a−1 min−1) and occurred at a lower temperature (14.4°C). The response of oxygenic net photosynthesis to PAR also varied, and the initial slope (α), the saturation PAR (Ek) and the maximum photosynthetic rate (Pmax) of the gametophyte were much higher than the sporophyte. Therefore, we hypothesised that in species with a heteromorphic life history, such as those in the genus Pyropia, physiological responses to environmental gradients would be dissimilar.