Effects of irradiance and nitrate on photosynthesis in the seagrass Cymodocea nodosa

IF 0.5 4区生物学 Q4 MARINE & FRESHWATER BIOLOGY Ciencias Marinas Pub Date : 2023-05-26 DOI:10.7773/cm.y2023.3300

A. Cabello‐Pasini, J. Sandoval-Gil, R. Muñiz-Salazar, Víctor Macías-Carranza, F. Figueroa

{"title":"Effects of irradiance and nitrate on photosynthesis in the seagrass Cymodocea nodosa","authors":"A. Cabello‐Pasini, J. Sandoval-Gil, R. Muñiz-Salazar, Víctor Macías-Carranza, F. Figueroa","doi":"10.7773/cm.y2023.3300","DOIUrl":null,"url":null,"abstract":"The effects of temperature, irradiance, and other environmental variables on photosynthesis in seagrasses are well understood. However, little information is available regarding the effects of the nitrate concentration in seawater on the photosynthetic characteristics of marine vegetation. Thus, the aim of this study was to determine the effect of the nitrate concentration in seawater on the effective quantum yield of the seagrass Cymodocea nodosa. Cymodocea nodosa shoots were incubated under different irradiance levels and with different nitrate concentrations. In contrast, a decrease in transmittance and an exponential increase in the absorptance of the shoots were observed as a function of increasing nitrate levels. Furthermore, the effective quantum yield of photosystem II (ΦPSII) in C. nodosa shoots increased exponentially as the nitrate concentration in the media increased. The ΦPSII values in the shoots decreased as irradiance increased and reached minimum values at solar noon or 2 h afterward. However, the decrease of ΦPSII values was 4-fold greater in shoots incubated under full solar radiation (100% natural incident irradiance, Eo) compared to those of shoots incubated with 20% Eo. The ΦPSII values decreased to almost zero in shoots pre-incubated with no nitrate (0 μM NO3–), whereas ΦPSII values in shoots pre incubated with 25 and 100 μM NO3– decreased by approximately 25% of their initial values. Collectively, these results indicate that nitrogen levels in seawater regulate the effective quantum yield values of C. nodosa, which suggests that the photosynthetic characteristics of this seagrass might be regulated by fluctuating nitrate levels in the water column such as those that are observed in upwelling regions.","PeriodicalId":50702,"journal":{"name":"Ciencias Marinas","volume":"1 1","pages":""},"PeriodicalIF":0.5000,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ciencias Marinas","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.7773/cm.y2023.3300","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MARINE & FRESHWATER BIOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

The effects of temperature, irradiance, and other environmental variables on photosynthesis in seagrasses are well understood. However, little information is available regarding the effects of the nitrate concentration in seawater on the photosynthetic characteristics of marine vegetation. Thus, the aim of this study was to determine the effect of the nitrate concentration in seawater on the effective quantum yield of the seagrass Cymodocea nodosa. Cymodocea nodosa shoots were incubated under different irradiance levels and with different nitrate concentrations. In contrast, a decrease in transmittance and an exponential increase in the absorptance of the shoots were observed as a function of increasing nitrate levels. Furthermore, the effective quantum yield of photosystem II (ΦPSII) in C. nodosa shoots increased exponentially as the nitrate concentration in the media increased. The ΦPSII values in the shoots decreased as irradiance increased and reached minimum values at solar noon or 2 h afterward. However, the decrease of ΦPSII values was 4-fold greater in shoots incubated under full solar radiation (100% natural incident irradiance, Eo) compared to those of shoots incubated with 20% Eo. The ΦPSII values decreased to almost zero in shoots pre-incubated with no nitrate (0 μM NO3–), whereas ΦPSII values in shoots pre incubated with 25 and 100 μM NO3– decreased by approximately 25% of their initial values. Collectively, these results indicate that nitrogen levels in seawater regulate the effective quantum yield values of C. nodosa, which suggests that the photosynthetic characteristics of this seagrass might be regulated by fluctuating nitrate levels in the water column such as those that are observed in upwelling regions.

查看原文

微信好友朋友圈 QQ好友复制链接

本刊更多论文

光照和硝酸盐对海草Cymodocea nodosa光合作用的影响

温度、辐照度和其他环境变量对海草光合作用的影响已经很清楚。然而，关于海水中硝酸盐浓度对海洋植被光合特性的影响，目前所知甚少。因此，本研究的目的是确定海水中硝酸盐浓度对Cymodocea nodosa海草有效量子产率的影响。在不同的光照水平和不同的硝酸盐浓度下，对杉树芽进行了培养。相反，随着硝酸盐水平的增加，枝条的透光率降低，吸收率呈指数增长。此外，随着培养基中硝酸盐浓度的增加，C. nodosa芽部光系统II (ΦPSII)的有效量子产率呈指数增长。枝条中ΦPSII值随着辐照度的增加而降低，在正午或之后2 h达到最小值。然而，在完全太阳辐射(100%自然入射辐照度，Eo)下孵育的芽与在20%自然入射辐照度下孵育的芽相比，ΦPSII值的下降幅度大4倍。在无硝酸盐(0 μM NO3 -)预孵育的芽中，ΦPSII值下降到几乎为零，而在25 μM NO3 -和100 μM NO3 -预孵育的芽中，ΦPSII值下降了约25%。综上所述，这些结果表明，海水中的氮水平调节着nodosa的有效量子产量值，这表明这种海草的光合特性可能受到水体中硝酸盐水平波动的调节，例如在上升流地区观察到的硝酸盐水平波动。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文去求助

来源期刊

Ciencias Marinas 生物-海洋与淡水生物学

CiteScore

1.10

自引率

0.00%

发文量

审稿时长

>12 weeks

期刊介绍： A bilingual open-access publication, Ciencias Marinas (CM) is an international peer-reviewed journal that contains original research findings in all areas of marine science. It is published quarterly by the Autonomous University of Baja California, Mexico, and all its contents are publicly available on our journal website. Though a limited number of copies are still printed, the journal is mainly distributed in its electronic format. CM was conceived in 1973 as part of an academic project aimed to entice local researchers to publicly disclose their findings by adopting the culture of peer-review publishing. This academic project evolved into an international journal after accepting papers from researchers in the United States and, eventually, other parts of the world. Because of the diversity in authorship, CM issues were initially published in either Spanish or English, and occasionally in both languages. It was not until 1984 when CM included both language versions of all its contents, and it then became the fully bilingual journal it still is today. At CM we believe our inclusive format allows us not only to address a wider range of submissions from international authors but also to make published findings available to a wider international audience. So whether you are looking for information on the redfish in Icelandic waters or the physical and biological properties of the Gulf of California, feel free to peruse CM contents. You may find them to provide source material for your research.