Microbial rhodopsins are increasingly favoured over chlorophyll in High Nutrient Low Chlorophyll waters
Microbial rhodopsins are increasingly favoured over chlorophyll in High Nutrient Low Chlorophyll waters
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DOI：
10.1111/1758-2229.12948
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发表时间：
2021-04-18
影响因子：
3.3
通讯作者：
Gomez-Consarnau, Laura
中科院分区：
文献类型：
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作者：
Hassanzadeh, Babak;Thomson, Blair;Gomez-Consarnau, Laura
微生物视紫红质是一种简单的捕光复合物，与叶绿素光合系统不同，其合成和光养功能不需要铁。在这里，我们报告的环境浓度的视紫红质沿着亚热带锋面带新西兰，亚热带沃茨遇到铁有限的亚班尼特高营养低叶绿素（HNLC）地区。在叶绿素a浓度最低的HNLC沃茨中，视紫红质浓度最高。此外，虽然视紫红质叶绿素a光系统的比例平均为沿着断面20，这一比例增加到超过60在HNLC沃茨。我们进一步表明，微生物视紫红质是丰富的微微浮游生物（0.2-3 μ m），并在较大的（>3 μ m）的尺寸级分的微生物群落含有真核浮游生物和/或颗粒附着原核生物。这些发现表明，视紫红质光养可能是浮游微生物适应光合作用和可能的细胞呼吸受损的资源限制性环境的关键。
Microbial rhodopsins are simple light-harvesting complexes that, unlike chlorophyll photosystems, have no iron requirements for their synthesis and phototrophic functions. Here, we report the environmental concentrations of rhodopsin along the Subtropical Frontal Zone off New Zealand, where Subtropical waters encounter the iron-limited Subantarctic High Nutrient Low Chlorophyll (HNLC) region. Rhodopsin concentrations were highest in HNLC waters where chlorophyll-a concentrations were lowest. Furthermore, while the ratio of rhodopsin to chlorophyll-a photosystems was on average 20 along the transect, this ratio increased to over 60 in HNLC waters. We further show that microbial rhodopsins are abundant in both picoplankton (0.2-3 mu m) and in the larger (>3 mu m) size fractions of the microbial community containing eukaryotic plankton and/or particle-attached prokaryotes. These findings suggest that rhodopsin phototrophy could be critical for microbial plankton to adapt to resource-limiting environments where photosynthesis and possibly cellular respiration are impaired.