{"title":"光波长是蓝藻昼夜节律钟环境适应性的一个促成因素。","authors":"Naohiro Kawamoto, Shuji Nakanishi, Ginga Shimakawa","doi":"10.1093/pcp/pcae022","DOIUrl":null,"url":null,"abstract":"<p><p>A circadian clock is an essential system that drives the 24-h expression rhythms for adaptation to day-night cycles. The molecular mechanism of the circadian clock has been extensively studied in cyanobacteria harboring the KaiC-based timing system. Nevertheless, our understanding of the physiological significance of the cyanobacterial circadian clock is still limited. In this study, we cultured wild-type Synechococcus elongatus PCC 7942 and circadian clock mutants in day-night cycles at different light qualities and found that the growth of the circadian clock mutants was specifically impaired during 12-h blue light/12-h dark (BD) cycles for the first time. The arrhythmic mutant kaiCAA was further analyzed by photosynthetic measurements. Compared with the wild type, the mutant exhibited decreases in the chlorophyll content, the ratio of photosystem I to II, net O2 evolution rate and efficiency of photosystem II photochemistry during BD cycles. These results indicate that the circadian clock is necessary for the growth and the maintenance of the optimum function of the photosynthetic apparatus in cyanobacteria under blue photoperiodic conditions.</p>","PeriodicalId":20575,"journal":{"name":"Plant and Cell Physiology","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Light Wavelength as a Contributory Factor of Environmental Fitness in the Cyanobacterial Circadian Clock.\",\"authors\":\"Naohiro Kawamoto, Shuji Nakanishi, Ginga Shimakawa\",\"doi\":\"10.1093/pcp/pcae022\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>A circadian clock is an essential system that drives the 24-h expression rhythms for adaptation to day-night cycles. The molecular mechanism of the circadian clock has been extensively studied in cyanobacteria harboring the KaiC-based timing system. Nevertheless, our understanding of the physiological significance of the cyanobacterial circadian clock is still limited. In this study, we cultured wild-type Synechococcus elongatus PCC 7942 and circadian clock mutants in day-night cycles at different light qualities and found that the growth of the circadian clock mutants was specifically impaired during 12-h blue light/12-h dark (BD) cycles for the first time. The arrhythmic mutant kaiCAA was further analyzed by photosynthetic measurements. Compared with the wild type, the mutant exhibited decreases in the chlorophyll content, the ratio of photosystem I to II, net O2 evolution rate and efficiency of photosystem II photochemistry during BD cycles. These results indicate that the circadian clock is necessary for the growth and the maintenance of the optimum function of the photosynthetic apparatus in cyanobacteria under blue photoperiodic conditions.</p>\",\"PeriodicalId\":20575,\"journal\":{\"name\":\"Plant and Cell Physiology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2024-05-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Plant and Cell Physiology\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1093/pcp/pcae022\",\"RegionNum\":2,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CELL BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant and Cell Physiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/pcp/pcae022","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
摘要
昼夜节律钟是驱动 24 小时表达节律以适应昼夜循环的重要系统。昼夜节律钟的分子机制已在携带基于 KaiC 的定时系统的蓝藻中得到广泛研究。然而,我们对蓝藻昼夜节律钟生理意义的了解仍然有限。在这项研究中,我们在不同光质的昼夜循环中培养了野生型细长鞘藻 PCC 7942 和昼夜节律时钟突变体,并首次发现昼夜节律时钟突变体在 12 小时蓝光/12 小时黑暗循环(BD)中的生长特别受到影响。通过光合测量进一步分析了心律失常突变体 kaiCAA。与野生型相比,突变体在 BD 周期中的叶绿素含量、光系统 I 与 II 的比例、净 O2 进化率、光系统 II 光化学效率均有所下降。这些结果表明,昼夜节律对蓝藻在蓝色光周期条件下的生长和光合装置最佳功能的维持是必要的。
Light Wavelength as a Contributory Factor of Environmental Fitness in the Cyanobacterial Circadian Clock.
A circadian clock is an essential system that drives the 24-h expression rhythms for adaptation to day-night cycles. The molecular mechanism of the circadian clock has been extensively studied in cyanobacteria harboring the KaiC-based timing system. Nevertheless, our understanding of the physiological significance of the cyanobacterial circadian clock is still limited. In this study, we cultured wild-type Synechococcus elongatus PCC 7942 and circadian clock mutants in day-night cycles at different light qualities and found that the growth of the circadian clock mutants was specifically impaired during 12-h blue light/12-h dark (BD) cycles for the first time. The arrhythmic mutant kaiCAA was further analyzed by photosynthetic measurements. Compared with the wild type, the mutant exhibited decreases in the chlorophyll content, the ratio of photosystem I to II, net O2 evolution rate and efficiency of photosystem II photochemistry during BD cycles. These results indicate that the circadian clock is necessary for the growth and the maintenance of the optimum function of the photosynthetic apparatus in cyanobacteria under blue photoperiodic conditions.
期刊介绍:
Plant & Cell Physiology (PCP) was established in 1959 and is the official journal of the Japanese Society of Plant Physiologists (JSPP). The title reflects the journal''s original interest and scope to encompass research not just at the whole-organism level but also at the cellular and subcellular levels.
Amongst the broad range of topics covered by this international journal, readers will find the very best original research on plant physiology, biochemistry, cell biology, molecular genetics, epigenetics, biotechnology, bioinformatics and –omics; as well as how plants respond to and interact with their environment (abiotic and biotic factors), and the biology of photosynthetic microorganisms.