{"title":"Possible Roles of Near-infrared Light on the Photosynthesis in Synechocystis sp. PCC6803 under Solar Simulating Artificial Light","authors":"Kota Oshita, Takuya Suzuki, T. Kawano","doi":"10.2525/ECB.56.17","DOIUrl":null,"url":null,"abstract":"Solar simulating light (SSL) has been widely used for evaluating the performance of photovoltaic cells and algal photosynthesis. Green plants and algae utilize chlorophylls, thus, the chlorophyll-targeting light components mostly contribute to photosynthesis. In contrast, near infrared (NIR) light hardly energizes photosynthesis. Since SSL spectrum covers a wide range of light from ultraviolet to NIR, we examined the roles of NIR components in SSL during photosynthetic O 2 evolution in Synechocystis (sp. PCC6803), by selectively and step-wisely eliminating the NIR using several NIR-cut filters. Here, the effects of intact SSL spectrum and the NIR-cut filtered SSL spectra (lacking NIR light greater than 690, 710, 750, or 810 nm) were examined. We observed that the 750 nm shortpass filter lowered the maximal photosynthetic velocity ( P max ), and concomitantly, the Michaelis constant-like value for light intensity ( K j ), whereas no significant change was observed with the 810 nm shortpass filter. We concluded that the 750 (cid:1) 810 nm band may contain the photosynthesis-stimulating NIR component acting differently from the known phenomenon (Emerson effect). In contrast, Synechocystis unexpectedly regained the photosynthetic performance by eliminating all range of NIR ( (cid:6) 710 nm), suggesting that 710 (cid:1) 750 nm far-red band corresponding to the absorption band for bacterial phytochrome is possibly inhibitory to photosynthesis.","PeriodicalId":11762,"journal":{"name":"Environmental Control in Biology","volume":"5 1","pages":"17-21"},"PeriodicalIF":0.0000,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Control in Biology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2525/ECB.56.17","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Agricultural and Biological Sciences","Score":null,"Total":0}
引用次数: 3
Abstract
Solar simulating light (SSL) has been widely used for evaluating the performance of photovoltaic cells and algal photosynthesis. Green plants and algae utilize chlorophylls, thus, the chlorophyll-targeting light components mostly contribute to photosynthesis. In contrast, near infrared (NIR) light hardly energizes photosynthesis. Since SSL spectrum covers a wide range of light from ultraviolet to NIR, we examined the roles of NIR components in SSL during photosynthetic O 2 evolution in Synechocystis (sp. PCC6803), by selectively and step-wisely eliminating the NIR using several NIR-cut filters. Here, the effects of intact SSL spectrum and the NIR-cut filtered SSL spectra (lacking NIR light greater than 690, 710, 750, or 810 nm) were examined. We observed that the 750 nm shortpass filter lowered the maximal photosynthetic velocity ( P max ), and concomitantly, the Michaelis constant-like value for light intensity ( K j ), whereas no significant change was observed with the 810 nm shortpass filter. We concluded that the 750 (cid:1) 810 nm band may contain the photosynthesis-stimulating NIR component acting differently from the known phenomenon (Emerson effect). In contrast, Synechocystis unexpectedly regained the photosynthetic performance by eliminating all range of NIR ( (cid:6) 710 nm), suggesting that 710 (cid:1) 750 nm far-red band corresponding to the absorption band for bacterial phytochrome is possibly inhibitory to photosynthesis.