Anagha Krishnan, Melissa Cano, Devin A Karns, Tyson A Burch, Maria Likhogrud, Moena Aqui, Shaun Bailey, John Verruto, William Lambert, Fedor Kuzminov, Mahva Naghipor, Yingjun Wang, Christopher C Ebmeier, Joseph C Weissman, Matthew C Posewitz
{"title":"Simultaneous CAS9 editing of cp<i>SRP43</i>, <i>LHCA6</i>, and <i>LHCA7</i> in <i>Picochlorum celeri</i> lowers chlorophyll levels and improves biomass productivity.","authors":"Anagha Krishnan, Melissa Cano, Devin A Karns, Tyson A Burch, Maria Likhogrud, Moena Aqui, Shaun Bailey, John Verruto, William Lambert, Fedor Kuzminov, Mahva Naghipor, Yingjun Wang, Christopher C Ebmeier, Joseph C Weissman, Matthew C Posewitz","doi":"10.1002/pld3.530","DOIUrl":null,"url":null,"abstract":"<p><p>High cellular pigment levels in dense microalgal cultures contribute to excess light absorption. To improve photosynthetic yields in the marine microalga <i>Picochlorum celeri</i>, CAS9 gene editing was used to target the molecular chaperone cpSRP43. Depigmented strains (>50% lower chlorophyll) were generated, with proteomics showing attenuated levels of most light harvesting complex (LHC) proteins. Gene editing generated two types of cpSRP43 transformants with distinct lower pigment phenotypes: (i) a transformant (Δ<i>srp43</i>) with both cp<i>SRP43</i> diploid alleles modified to encode non-functional polypeptides and (ii) a transformant (STR30309) with a 3 nt in-frame insertion in one allele at the CAS9 cut site (non-functional second allele), leading to expression of a modified cpSRP43. STR30309 has more chlorophyll than Δ<i>srp43</i> but substantially less than wild type. To further decrease light absorption by photosystem I in STR30309, CAS9 editing was used to stack in disruptions of both LHCA6 and LHCA7 to generate STR30843, which has higher (5-24%) productivities relative to wild type in solar-simulating bioreactors. Maximal productivities required frequent partial harvests throughout the day. For STR30843, exemplary diel bioreactor yields of ~50 g m<sup>-2</sup> day<sup>-1</sup> were attained. Our results demonstrate diel productivity gains in <i>P. celeri</i> by lowering pigment levels.</p>","PeriodicalId":20230,"journal":{"name":"Plant Direct","volume":"7 9","pages":"e530"},"PeriodicalIF":2.3000,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/23/df/PLD3-7-e530.PMC10497401.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant Direct","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1002/pld3.530","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/9/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"PLANT SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
High cellular pigment levels in dense microalgal cultures contribute to excess light absorption. To improve photosynthetic yields in the marine microalga Picochlorum celeri, CAS9 gene editing was used to target the molecular chaperone cpSRP43. Depigmented strains (>50% lower chlorophyll) were generated, with proteomics showing attenuated levels of most light harvesting complex (LHC) proteins. Gene editing generated two types of cpSRP43 transformants with distinct lower pigment phenotypes: (i) a transformant (Δsrp43) with both cpSRP43 diploid alleles modified to encode non-functional polypeptides and (ii) a transformant (STR30309) with a 3 nt in-frame insertion in one allele at the CAS9 cut site (non-functional second allele), leading to expression of a modified cpSRP43. STR30309 has more chlorophyll than Δsrp43 but substantially less than wild type. To further decrease light absorption by photosystem I in STR30309, CAS9 editing was used to stack in disruptions of both LHCA6 and LHCA7 to generate STR30843, which has higher (5-24%) productivities relative to wild type in solar-simulating bioreactors. Maximal productivities required frequent partial harvests throughout the day. For STR30843, exemplary diel bioreactor yields of ~50 g m-2 day-1 were attained. Our results demonstrate diel productivity gains in P. celeri by lowering pigment levels.
期刊介绍:
Plant Direct is a monthly, sound science journal for the plant sciences that gives prompt and equal consideration to papers reporting work dealing with a variety of subjects. Topics include but are not limited to genetics, biochemistry, development, cell biology, biotic stress, abiotic stress, genomics, phenomics, bioinformatics, physiology, molecular biology, and evolution. A collaborative journal launched by the American Society of Plant Biologists, the Society for Experimental Biology and Wiley, Plant Direct publishes papers submitted directly to the journal as well as those referred from a select group of the societies’ journals.