The effects of four stressors, irradiance, temperature, desiccation, and salinity on the photosynthesis of a red alga, Agarophyton vermiculophyllum (Gracilariales) from a native distributional range in Japan
The effects of four stressors, irradiance, temperature, desiccation, and salinity on the photosynthesis of a red alga, Agarophyton vermiculophyllum (Gracilariales) from a native distributional range in Japan
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DOI：
10.1007/s10811-021-02469-1
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发表时间：
2021-05
影响因子：
3.3
通讯作者：
Ryo Kameyama;Gregory N. Nishihara;Chikara Kawagoe;Ryuta Terada
中科院分区：
文献类型：
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作者：
Ryo Kameyama;Gregory N. Nishihara;Chikara Kawagoe;Ryuta Terada
从日本北海道和鹿儿岛红藻的自然分布区出发，研究了光照、温度、干燥和盐度4种胁迫因素对红藻Agarophyton vermiculophyllum(=Gracilaria vermiculophylla，Gracilariales，Rhotophyta)光合作用的影响。8℃、16℃和28℃下的光合作用-辐照度(P-E)曲线表明，两个品系的最大净光合速率(NPmax)和饱和辐照度(Ek)在28℃时最高。在8~40℃、200μ摩尔光子m~(-2)·s~(-1)下测定的总光合作用表明，北海道和鹿儿岛的总光合作用最大值分别出现在25.3℃和28.0℃，这与各栖息地夏季海水温度基本一致。光系统II的有效量子产率(ΔF/Fm‘)的温度响应(4-40℃)与光合作用的温度响应相似，北海道的最适温度为20.0℃，鹿儿岛的最适温度为30.1℃。在干燥实验中，ΔF/Fm‘随绝对含水率的降低而降低，但对于绝对含水率高于20%的样品，ΔF/Fm’在随后的海水中复水1d后恢复到初始水平，表明其对干燥的耐受性较强。该藻类在7天的暴露中对盐度的耐受性范围从20到60PSU，而ΔF/FM‘在3天的暴露中对盐度的耐受性为0PSU。《FA》的改编。从其原产于日本的范围到相对较高的照度，较宽的温度范围，以及较强的渗透(干燥和盐度)耐受性，解释了其潜在的高入侵能力。
We examined the effects of four stressors, irradiance, temperature, desiccation, and salinity on the photosynthesis of a red alga,Agarophyton vermiculophyllum(=Gracilaria vermiculophylla, Gracilariales, Rhodophyta) from its native distributional range in Hokkaido and Kagoshima, Japan. Photosynthesis–irradiance (P–E) curves at 8, 16, and 28°C showed that the maximum net-photosynthetic rates (NPmax) and saturation irradiance (Ek) were highest at 28°C for both strains. Gross-photosynthesis determined at 8–40°C at 200 μmol photons m-2s-1showed that the maximum gross-photosynthetic rate (GPmax) occurred at 25.3°C for Hokkaido and 28.0°C for Kagoshima (), which is almost consistent with the summer-time seawater temperature at each habitat. The temperature responses (4–40°C) of effective quantum yields (ΔF/Fm') of photosystem II during 7-day exposures were similar to that of oxygenic photosynthesis and the optimum temperature () was 20.0°C for Hokkaido and 30.1°C for Kagoshima. In the desiccation experiment, theΔF/Fm' decreased with decreasing absolute water content (AWC); nevertheless, for samples with an AWC above 20%,ΔF/Fm' retuned to initial levels after subsequent 1-day rehydration in seawater, suggesting relatively strong tolerance to desiccation. This alga also showed a broad range of tolerance to salinity ranging from 20 to 60 psu in 7-day exposures, and theΔF/Fm' tolerated 0 psu at 3-day exposure. The adaptations ofA. vermiculophyllumfrom its native range in Japan to relatively high irradiance, a broad range of temperature, and strong osmotic (desiccation and salinity) tolerance explain its potentially high invasive capacity.