• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Marine ecology progress series >Photoinactivation, repair and the motility-physiology trade-off in microphytobenthos
【24h】

Photoinactivation, repair and the motility-physiology trade-off in microphytobenthos

机译：微底栖动物的光灭活，修复和运动-生理平衡

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Microphytobenthos (MPB) inhabiting intertidal flats of estuaries form highly productive diatom-dominated biofilms. The capacity to sustain such high photosynthetic activity under conditions prone to cause photoinhibition is thought to be enabled by efficient photoprotective mechanisms, the main ones being the xanthophyll cycle (XC) and vertical migration (VM). This study compared the photoprotective capacity of 2 MPB communities inhabiting contrasting sedimentary habitats and relying on distinct light responses: epipelic communities, colonizing muddy sediments and using motility (VM) to regulate light exposure; and epipsammic communities, inhabiting sandier sediments and relying solely on physiological photoprotection (XC). The efficiency of physiological photoprotection of the 2 communities was compared regarding Photo system II (PSII) photoinactivation caused by light stress. Lincomycin was used to distinguish photo inactivation from counteracting repair. Rate constants of PSII photoinactivation (k(PI)) and repair (k(REC)) were determined on cell suspensions, based on the light and time dependence of maximum quantum yield of PSII, F-v/F-m, as measured using multi-actinic imaging fluorometry. The results show that motile species, in comparison to epipsammic ones, are inherently more susceptible to photoinactivation (higher k(PI)), less dependent on the XC for preventing photodamage (smaller increase of k(PI) induced by nigericin) and more efficient regarding repair capacity (higher k(REC)). The distinct strategies exhibited by epipelic and epipsammic communities to cope with light stress support the hypothesized trade-off between photoprotective motility and photophysiology. Motile forms have a diminished physiological capacity for preventing photodamage and compensate using VM and a better repair capacity. Non-motile epipsammic forms rely mostly on physiological mechanisms to optimize photoprotection capacity.
机译：居住在河口潮间带的微型底栖动物（MPB）形成了高产的以硅藻为主的生物膜。人们认为，在易于引起光抑制的条件下维持如此高的光合活性的能力是通过有效的光保护机制实现的，主要的机制是叶黄素循环（XC）和垂直迁移（VM）。这项研究比较了两个MPB社区的光保护能力，这些MPB社区生活在形成对比的沉积生境中，并且依赖于不同的光响应：上生群落，殖民泥泞的沉积物并利用运动性（VM）调节光照；和流行病群落，栖息于沙质沉积物中，仅依靠生理性光保护（XC）。比较了由光胁迫引起的光系统II（PSII）光灭活的两个社区的生理光保护效率。林可霉素用于区分光灭活和抵消修复作用。 PSII光失活（k（PI））和修复（k（REC））的速率常数在细胞悬液中确定，这是基于PSII最大量子产率Fv / Fm的光和时间依赖性，如使用多光化成像法测得的荧光法。结果表明，与流行病物种相比，活动物种固有地更容易受到光灭活的影响（较高的k（PI）），较少依赖XC来防止光损伤（由尼日灵诱导的k（PI）的增加较小）并且更有效关于修复能力（更高的k（REC））。上肢和癫痫群落为应对光胁迫而表现出的独特策略支持了在光保护性运动与光生理之间的假设权衡。运动形式降低了防止光损伤和使用VM进行补偿的生理能力，并具有更好的修复能力。非运动性癫痫形式主要依靠生理机制来优化光保护能力。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号