A mutualistic bacterium rescues a green alga from an antagonist

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(15)

Опубликована: Апрель 3, 2024

Photosynthetic protists, known as microalgae, are key contributors to primary production on Earth. Since early in evolution, they coexist with bacteria nature, and their mode of interaction shapes ecosystems. We have recently shown that the bacterium Pseudomonas protegens acts algicidal microalga Chlamydomonas reinhardtii. It secretes a cyclic lipopeptide polyyne deflagellate, blind, lyse algae [P. Aiyar et al. , Nat. Commun. 8 1756 (2017) V. Hotter Proc. Natl. Acad. Sci. U.S.A. 118 e2107695118 (2021)]. Here, we report about Mycetocola lacteus, which establishes mutualistic relationship C. reinhardtii helper. While M. lacteus enhances algal growth, it receives methionine needed organic sulfur vitamins B 1 3 5 from algae. In tripartite cultures alga antagonistic P. aids surviving bacterial attack. By combining synthetic natural product chemistry high-resolution mass spectrometry an Ca 2+ reporter line, found rescues by cleaving ester bond involved. The resulting linearized seco acid does not trigger cytosolic homeostasis imbalance leads deflagellation. Thus, remain motile, can swim away survive All three involved genera cooccur nature. Remarkably, related species also act antagonistically against or helper cultures.

Язык: Английский

---

Chlamydomonas reinhardtii, Volvox carteri and related green algae accumulate ketocarotenoids not in vegetative cells but in zygospores

The Plant Journal, Год журнала: 2025, Номер 121(3)

Опубликована: Фев. 1, 2025

Zygospores of green alga such as Chlamydomonas reinhardtii, Volvox carteri or Dunaliella salina display a bright orange color indicative carotenoids, yet there have been no reports on their pigment composition. The genomes these algae contain genes for homologs the β-carotene ketolase (BKT) from well-known astaxanthin producer Haematococcus pluvialis, that were assumed to be pseudogenes, because none species has reported accumulate other ketocarotenoids. Here, we show C. reinhardtii and V. synthesize ketocarotenoids specifically in zygospores. Contrary vegetative aplanospores H. major ketocarotenoid zygospores is not but 4-ketolutein. Moreover, maturing are synthesized de novo carotenoids photosynthetic apparatus liberated by massive breakdown thylakoid membranes. In line with this conclusion, incubation at 9°C instead 22°C resulted reduced only low amounts ketocarotenoids, while accumulation storage lipids was less affected. Furthermore, full-length BKT catalyze ketolation both α-carotene lutein carotenogenic bacteria. We also detected putative various known suggesting zygospore-specific common among Chlamydomonadales. Our observation together sheds light physiology largely unexplored algal life stage crucial survival propagation.

Язык: Английский

---

The Chlamydomonas reinhardtii chloroplast envelope protein LCIA transports bicarbonate in planta

Journal of Experimental Botany, Год журнала: 2023, Номер 74(12), С. 3651 - 3666

Опубликована: Март 29, 2023

Abstract LCIA (low CO2-inducible protein A) is a chloroplast envelope associated with the CO2-concentrating mechanism of green alga Chlamydomonas reinhardtii. postulated to be HCO3– channel, but previous studies were unable show that was actively transporting bicarbonate in planta. Therefore, activity investigated more directly two heterologous systems: an Escherichia coli mutant (DCAKO) lacking both native carbonic anhydrases and Arabidopsis (βca5) missing plastid anhydrase βCA5. Neither DCAKO nor βca5 can grow ambient CO2 conditions, as they lack anhydrase-catalyzed production necessary concentration for lipid nucleic acid biosynthesis. Expression restored growth systems which strongly suggests facilitating uptake each system. To our knowledge, this first direct evidence moves across membranes bacteria plants. Furthermore, plant bioassay used study system testing transport planta, experimental breakthrough will valuable future aimed at improving photosynthetic efficiency crop plants using components from algal mechanisms.

Язык: Английский

---

Mastigoneme structure reveals insights into the O-linked glycosylation code of native hydroxyproline-rich helices

Cell, Год журнала: 2024, Номер 187(8), С. 1907 - 1921.e16

Опубликована: Март 28, 2024

Hydroxyproline-rich glycoproteins (HRGPs) are a ubiquitous class of protein in the extracellular matrices and cell walls plants algae, yet little is known their native structures or interactions. Here, we used electron cryomicroscopy (cryo-EM) to determine structure hydroxyproline-rich mastigoneme, an filament isolated from cilia alga Chlamydomonas reinhardtii. The demonstrates that mastigonemes formed two HRGPs (a MST1 wrapped around single copy MST3) both have hyperglycosylated poly(hydroxyproline) helices. Within helices, O-linked glycosylation hydroxyproline residues O-galactosylation interspersed serine create carbohydrate casing. Analysis associated glycans reveals how pattern repetition determines type extent glycosylation. MST3 possesses PKD2-like transmembrane domain forms heteromeric polycystin-like cation channel with PKD2 SIP, explaining tethered ciliary membranes.

Язык: Английский

---

Haematococcus lacustris genome assembly and annotation reveal diploid genetic traits and stress-induced gene expression patterns

Algal Research, Год журнала: 2024, Номер 80, С. 103567 - 103567

Опубликована: Май 31, 2024

The green alga Haematococcus lacustris (formerly pluvialis) is a primary source of astaxanthin, ketocarotenoid with high antioxidant activity and several industrial applications. Here, the highly repetitive genome was reconstructed by exploiting next-generation sequencing integrated Hi-C scaffolding, obtaining 151 Mb assembly in 32 scaffolds at near-chromosome level continuity. Surprisingly, distribution single-nucleotide-polymorphisms identified demonstrates diploid configuration for genome, further validated Sanger heterozygous regions. Functional annotation RNA-seq data enabled identification 13,946 nuclear genes, >5000 genes not previously this species, providing insights into molecular basis metabolic rearrangement stressing conditions such as light and/or nitrogen starvation, where astaxanthin biosynthesis triggered. These constitute rich genetic resource biotechnological manipulation highlighting potential targets to improve carotenoid productivity.

Язык: Английский

---

Protofilament-specific nanopatterns of tubulin post-translational modifications regulate the mechanics of ciliary beating

Current Biology, Год журнала: 2024, Номер unknown

Опубликована: Сен. 1, 2024

Язык: Английский

---

A gap-free genome assembly of Chlamydomonas reinhardtii and detection of translocations induced by CRISPR-mediated mutagenesis

Plant Communications, Год журнала: 2022, Номер 4(2), С. 100493 - 100493

Опубликована: Ноя. 17, 2022

Genomic assemblies of the unicellular green alga Chlamydomonas reinhardtii have provided important resources for researchers. However, assembly errors, large gaps, and unplaced scaffolds as well strain-specific variants currently impede many types analysis. By combining PacBio HiFi Oxford Nanopore long-read technologies, we generated a de novo genome strain CC-5816, derived from crosses strains CC-125 CC-124. Multiple methods evaluating completeness base-pair error rate suggest that final telomere-to-telomere is highly accurate. The CC-5816 enabled previously difficult analyses include characterization 17 centromeres, rDNA arrays on three chromosomes, 56 insertions organellar DNA into nuclear genome. Using sequencing, identified sites cytosine (CpG) methylation, which are enriched at centromeres. We analyzed CRISPR-Cas9 insertional mutants in PF23 gene. Two alleles produced progeny displayed patterns meiotic inviability suggested presence chromosomal aberration. Mapping reads pf23-2 pf23-3 onto showed these two each carry translocation was initiated gene locus chromosome 11 joined with chromosomes 5 or 3, respectively. translocations were verified by demonstrating linkage between loci translocated progeny. pf23 display expected short-cilia phenotype, immunoblotting lacks protein. Our will undoubtedly provide an tool research community.

Язык: Английский

---

Current Nuclear Engineering Strategies in the Green Microalga Chlamydomonas reinhardtii

Life, Год журнала: 2023, Номер 13(7), С. 1566 - 1566

Опубликована: Июль 15, 2023

The green model microalga Chlamydomonas reinhardtii recently emerged as a sustainable production chassis for the efficient biosynthesis of recombinant proteins and high-value metabolites. Its capacity scalable, rapid light-driven growth in minimal salt solutions, its simplicity genetic manipulation “Generally Recognized As Safe” (GRAS) status are key features application industrial biotechnology. Although nuclear transformation has typically resulted limited transgene expression levels, recent developments now allow design powerful innovative bioproduction concepts. In this review, we summarize main obstacles to engineering C. describe all essential aspects sequence adaption vector enable sufficient from genome. Several biotechnological examples successful serve blueprints future establishment cell factory.

Язык: Английский

---

Type II metacaspase mediates light-dependent programmed cell death in Chlamydomonas reinhardtii

PLANT PHYSIOLOGY, Год журнала: 2023, Номер 194(4), С. 2648 - 2662

Опубликована: Ноя. 16, 2023

Abstract Among the crucial processes that preside over destiny of cells from any type organism are those involving their self-destruction. This process is well characterized and conceptually logical to understand in multicellular organisms; however, levels knowledge comprehension its existence still quite enigmatic unicellular organisms. We use Chlamydomonas (Chlamydomonas reinhardtii) lay foundation for understanding mechanisms programmed cell death (PCD) a photosynthetic organism. In this paper, we show while PCD induces proportion cells, it allows survival remaining population. A quantitative proteomic analysis aiming at unveiling proteome allowed us identify key proteins led discovery essential mechanisms. Chlamydomonas, relies on light dependence generate reactive oxygen species induce death. Finally, obtained mutants 2 metacaspase genes showed II execution.

Язык: Английский

---

Challenges and advances towards the rational design of microalgal synthetic promoters in Chlamydomonas reinhardtii

Journal of Experimental Botany, Год журнала: 2023, Номер 74(13), С. 3833 - 3850

Опубликована: Апрель 7, 2023

Microalgae hold enormous potential to provide a safe and sustainable source of high-value compounds, acting as carbon-fixing biofactories that could help mitigate rapidly progressing climate change. Bioengineering microalgal strains will be key optimizing modifying their metabolic outputs, render them competitive with established industrial biotechnology hosts, such bacteria or yeast. To achieve this, precise tuneable control over transgene expression essential, which would require the development rational design synthetic promoters strategy. Among green microalgae, Chlamydomonas reinhardtii represents reference species for bioengineering biology; however, repertoire functional this species, microalgae generally, is limited in comparison other commercial chassis, emphasizing need expand current gene toolbox. Here, we discuss state-of-the-art promoter analyses, highlight areas research required advance C. reinhardtii. In particular, exemplify high-throughput studies performed model systems applicable propose novel approaches interrogating algal promoters. We lastly outline major limitations hindering development, while providing suggestions perspectives how overcome them.

Язык: Английский

---