{"title":"Aberrant light sensing and motility in the green alga <i>Chlamydomonas priscuii</i> from the ice-covered Antarctic Lake Bonney.","authors":"Mackenzie Poirier, Pomona Osmers, Kieran Wilkins, Rachael M Morgan-Kiss, Marina Cvetkovska","doi":"10.1080/15592324.2023.2184588","DOIUrl":null,"url":null,"abstract":"<p><p>The Antarctic green alga <i>Chlamydomonas priscuii</i> is an obligate psychrophile and an emerging model for photosynthetic adaptation to extreme conditions. Endemic to the ice-covered Lake Bonney, this alga thrives at highly unusual light conditions characterized by very low light irradiance (<15 μmol m<sup>-2</sup> s<sup>-1</sup>), a narrow wavelength spectrum enriched in blue light, and an extreme photoperiod. Genome sequencing of <i>C. priscuii</i> exposed an unusually large genome, with hundreds of highly similar gene duplicates and expanded gene families, some of which could be aiding its survival in extreme conditions. In contrast to the described expansion in the genetic repertoire in <i>C. priscuii</i>, here we suggest that the gene family encoding for photoreceptors is reduced when compared to related green algae. This alga also possesses a very small eyespot and exhibits an aberrant phototactic response, compared to the model <i>Chlamydomonas reinhardtii</i>. We also investigated the genome and behavior of the closely related psychrophilic alga <i>Chlamydomonas</i> sp. ICE-MDV, that is found throughout the photic zone of Lake Bonney and is naturally exposed to higher light levels. Our analyses revealed a photoreceptor gene family and a robust phototactic response similar to those in the model <i>Chlamydomonas reinhardtii</i>. These results suggest that the aberrant phototactic response in <i>C. priscuii</i> is a result of life under extreme shading rather than a common feature of all psychrophilic algae. We discuss the implications of these results on the evolution and survival of shade adapted polar algae.</p>","PeriodicalId":320,"journal":{"name":"Food Hydrocolloids","volume":"69 1","pages":"2184588"},"PeriodicalIF":11.0000,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10012900/pdf/","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Food Hydrocolloids","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1080/15592324.2023.2184588","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/3/8 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
引用次数: 1
Abstract
The Antarctic green alga Chlamydomonas priscuii is an obligate psychrophile and an emerging model for photosynthetic adaptation to extreme conditions. Endemic to the ice-covered Lake Bonney, this alga thrives at highly unusual light conditions characterized by very low light irradiance (<15 μmol m-2 s-1), a narrow wavelength spectrum enriched in blue light, and an extreme photoperiod. Genome sequencing of C. priscuii exposed an unusually large genome, with hundreds of highly similar gene duplicates and expanded gene families, some of which could be aiding its survival in extreme conditions. In contrast to the described expansion in the genetic repertoire in C. priscuii, here we suggest that the gene family encoding for photoreceptors is reduced when compared to related green algae. This alga also possesses a very small eyespot and exhibits an aberrant phototactic response, compared to the model Chlamydomonas reinhardtii. We also investigated the genome and behavior of the closely related psychrophilic alga Chlamydomonas sp. ICE-MDV, that is found throughout the photic zone of Lake Bonney and is naturally exposed to higher light levels. Our analyses revealed a photoreceptor gene family and a robust phototactic response similar to those in the model Chlamydomonas reinhardtii. These results suggest that the aberrant phototactic response in C. priscuii is a result of life under extreme shading rather than a common feature of all psychrophilic algae. We discuss the implications of these results on the evolution and survival of shade adapted polar algae.
期刊介绍:
Food Hydrocolloids publishes original and innovative research focused on the characterization, functional properties, and applications of hydrocolloid materials used in food products. These hydrocolloids, defined as polysaccharides and proteins of commercial importance, are added to control aspects such as texture, stability, rheology, and sensory properties. The research's primary emphasis should be on the hydrocolloids themselves, with thorough descriptions of their source, nature, and physicochemical characteristics. Manuscripts are expected to clearly outline specific aims and objectives, include a fundamental discussion of research findings at the molecular level, and address the significance of the results. Studies on hydrocolloids in complex formulations should concentrate on their overall properties and mechanisms of action, while simple formulation development studies may not be considered for publication.
The main areas of interest are:
-Chemical and physicochemical characterisation
Thermal properties including glass transitions and conformational changes-
Rheological properties including viscosity, viscoelastic properties and gelation behaviour-
The influence on organoleptic properties-
Interfacial properties including stabilisation of dispersions, emulsions and foams-
Film forming properties with application to edible films and active packaging-
Encapsulation and controlled release of active compounds-
The influence on health including their role as dietary fibre-
Manipulation of hydrocolloid structure and functionality through chemical, biochemical and physical processes-
New hydrocolloids and hydrocolloid sources of commercial potential.
The Journal also publishes Review articles that provide an overview of the latest developments in topics of specific interest to researchers in this field of activity.