Mesophyll-Specific Circadian Dynamics of CAM Induction in the Ice Plant Unveiled by Single-Cell Transcriptomics

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 8, 2024

ABSTRACT Crassulacean acid metabolism (CAM) is an evolutionary modification of the C 3 photosynthetic carbon dioxide fixation pathway used by approximately 7% terrestrial plants to live in drought-prone environments. Facultative CAM species, such as Mesembryanthemum crystallinum (common ice plant), possess unique ability switch from photosynthesis response high-salinity and water-deficit stress. Here we characterized environmentally-triggered transition plant using single nucleus RNA sequencing (snRNA-seq) identify its putative regulators, supported a novel high-quality assembled annotated genome. Analysis snRNA-seq datasets leaves transitioning between collected at dawn dusk revealed substantial transcriptional changes mesophyll cells onset induction. Notably, our findings sub-cell types engaged either or dusk. Cell trajectory inference analysis reconstructed both 24-hour cycles, enabling direct comparison gene expression profiles these pathways. This comparative study uncovered divergent patterns key circadian clock genes cell trajectories, pointing connection regulation

Language: Английский

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Response of an obligate CAM plant to competition and increased watering intervals

Physiologia Plantarum, Journal Year: 2025, Volume and Issue: 177(1)

Published: Jan. 1, 2025

Abstract Climate change has exacerbated precipitation variability, profoundly impacting vegetation dynamics and community structures in arid ecosystems. There remains a notable knowledge gap regarding the ecological effects of altered on crassulacean acid metabolism (CAM) plants their interactions with other photosynthetic types. This study investigated response typical obligate CAM plant Orostachys fimbriata to extended watering intervals (WI4‐WI8) various competitive patterns (M 1 ‐M 4 ) C 3 grass Melilotus officinalis Setaria viridis through greenhouse experiments. The results showed that: (1) In species mixtures, had slightly reduced total biomass (TB) compared monocultures, yet maintained competitiveness by increasing root‐to‐shoot (R:S) ratio, stabilizing height, sustaining rates. (2) As increased, adapted further elevating R:S reducing decreasing aboveground biomass. However, CO 2 assimilation rate, above‐ below‐ground were significantly suppressed, particularly when coexisting plants. More extreme regime caused 47.6% decrease TB M , while grasses declined 53.2% 37.8%, respectively. (3) Given predicted extension drought intensification individual rainfall events under future climate conditions, pressure from high tolerance resource acquisition advantages may limit expansion potential drylands. enhances understanding adaptive mechanisms competing variable environments, providing scientific bases for predicting ecosystem dynamics.

Language: Английский

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Predicting photosynthetic pathway from anatomy using machine learning

New Phytologist, Journal Year: 2024, Volume and Issue: 242(3), P. 1029 - 1042

Published: Jan. 4, 2024

Summary Plants with Crassulacean acid metabolism (CAM) have long been associated a specialized anatomy, including succulence and thick photosynthetic tissues. Firm, quantitative boundaries between non‐CAM CAM plants yet to be established – if they indeed exist. Using novel computer vision software measure we combined new measurements published data across flowering plants. We then used machine learning phylogenetic comparative methods investigate relationships anatomy. found significant differences in tissue anatomy differing phenotypes. Machine learning‐based classification was over 95% accurate differentiating from had 70% recall of distinct Phylogenetic least squares regression threshold analyses revealed that evolution significantly correlated increased mesophyll cell size, thicker leaves, decreased intercellular airspace. Our findings suggest may aid the discovery species evolutionary trajectory strong, obligate requires continual anatomical specialization.

Language: Английский

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Atmospheric CO2 decline and the timing of CAM plant evolution

Annals of Botany, Journal Year: 2023, Volume and Issue: 132(4), P. 753 - 770

Published: Aug. 29, 2023

Abstract Background and Aims CAM photosynthesis is hypothesized to have evolved in atmospheres of low CO2 concentration recent geological time because its ability concentrate around Rubisco boost water use efficiency relative C3 photosynthesis. We assess this hypothesis by compiling estimates when clades arose using phylogenetic chronograms for 73 clades. further consider evidence how atmospheric affects Results Where origins can be inferred, strong estimated appeared the past 30 million years 46 48 examined clades, after had declined from high (near 800 ppm) lower (<450 values. In turn, 21 25 containing species (but where are less certain) also years. these probably younger than clade origin. found repeated weak evolution during higher conditions before ago, possible Crassulaceae Cretaceous period prior decline. Most CAM-specific 15 years, a similar pattern observed C4 Conclusions The indicates repeatedly reduced Weaker pre-date and, Crassulaceae, may arisen water-limited microsites under relatively CO2. Experimental extant demonstrates that elevated reduces importance nocturnal fixation increasing contribution daily carbon gain. Thus, advantage would CO2, such appears likely restricted more extreme environments

Language: Английский

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Reconciling continuous and discrete models of C4 and CAM evolution

Annals of Botany, Journal Year: 2023, Volume and Issue: 132(4), P. 717 - 725

Published: Sept. 7, 2023

Abstract Background A current argument in the CAM biology literature has focused on nature of evolutionary trajectory: whether there is a smooth continuum phenotypes between plants with C3 and photosynthesis or are discrete steps phenotypic change such as been modelled for evolution C4 photosynthesis. further implication that would increase evolvability CAM, whereas changes make transition from to more difficult. Scope In this essay, I attempt reconcile these two viewpoints, because think many ways false dichotomy constraining progress understanding how both evolved. reality, space connecting species strong CAM/C4 variably expressed quantitative traits yet also contains certain combinations we able identify discrete, recognizable phenotypes. sense, mechanics origination no different those photosynthesis, nor any other complex trait assemblage. Conclusions To progress, must embrace concept phases evolution, their delineation will force us articulate what aspects variation significant. There some gaps limiting our ability build complete model: first rudimentary biochemical cycle becomes established, second ‘accessory’ C3+CAM recruited into primary metabolism. The connections phenotype looking potentially found behaviour when undergoing physiological stress – that, strangely enough, remains essentially unexplored context.

Language: Английский

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Response of an obligate CAM plant to altered precipitation and competition

Plant and Soil, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 13, 2025

Language: Английский

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Cistanthe longiscapa exhibits ecophysiological and molecular adaptations to the arid environments of the Atacama Desert

PLANT PHYSIOLOGY, Journal Year: 2025, Volume and Issue: 197(4)

Published: March 28, 2025

Abstract Understanding how plants survive extreme conditions is essential to breeding resilient crops. Cistanthe longiscapa, which flourishes in the Atacama Desert, provides a rare glimpse into plant resilience. To uncover genetic basis of its stress tolerance, we investigated ecophysiological and transcriptomic responses C. longiscapa from 3 sites with low but different precipitation levels. Ecophysiological analyses were performed on samples collected field at dusk dawn, are crucial stages crassulacean acid metabolism (CAM), water-efficient type photosynthesis. Additional analysis allowed us evaluate CAM intensity identify changes molecular signature these plants. Our results show that displays considerable trait response variation across sites, including variations markers such as nocturnal accumulation, isotopic carbon ratio, succulence, among others. Analysis gene expression patterns revealed differences exhibiting varying intensities photosynthesis identified key signatures associated their ecological strategies. Additionally, genes related responses, plastid activities, circadian rhythm contrasting levels between strong weak plants, this profile shared other under stress. findings demonstrate valuable resource for identifying involved transition intensities. This may lead discovery enhance tolerance stressful environments.

Language: Английский

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Regulation of Crassulacean acid metabolism at the protein level in Kalanchoë laxiflora

PLANT PHYSIOLOGY, Journal Year: 2025, Volume and Issue: 197(4)

Published: March 28, 2025

Abstract Crassulacean acid metabolism (CAM) is an adaptation to environments where water availability seasonal or extremely low. It serves ensure plant survival and/or maintain productivity in these adverse environments. CAM has repeatedly evolved many lineages, although it requires a large and complex set of enzymes, transporters, regulatory processes control metabolite flux pools. To test the potential levels at which regulated, we analyzed Kalanchoë laxiflora compared with genomes transcriptomes other plants across wide phylogenetic range. We show that CAM-associated transcripts proteins did not exhibit binary on/off pattern abundance between day night K. laxiflora. Instead, displayed shared amino changes among C3 plants, especially starch metabolism. Phosphoproteomics identified differential phosphorylation night. Taken together, our results demonstrate photosynthesis regulated both transcript protein levels.

Language: Английский

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The diverse diaspora of CAM: a pole-to-pole sketch

Annals of Botany, Journal Year: 2023, Volume and Issue: 132(4), P. 597 - 625

Published: June 10, 2023

Crassulacean acid metabolism (CAM) photosynthesis is a successful adaptation that has evolved often in angiosperms, gymnosperms, ferns and lycophytes. Present ~5 % of vascular plants, the CAM diaspora includes all continents apart from Antarctica. Species with inhabit most landscapes colonized by Arctic Circle to Tierra del Fuego, below sea level 4800 m a.s.l., rainforests deserts. They have terrestrial, epiphytic, lithophytic, palustrine aquatic systems, developing perennial, annual or geophyte strategies can be structurally arborescent, shrub, forb, cladode, epiphyte, vine leafless photosynthetic roots. enhance survival conserving water, trapping carbon, reducing carbon loss and/or via photoprotection.

Language: Английский

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Potential expansion of plants with crassulacean acid metabolism in the Anthropocene

BioScience, Journal Year: 2024, Volume and Issue: 74(7), P. 478 - 487

Published: May 22, 2024

Abstract An overlooked phenomenon is a potential increase in the distribution and abundance of plants with highly water-usage-efficient crassulacean acid metabolism (CAM). In present article, we critically analyze recent research to investigate what extent why CAM may have recently expanded their range under global change. We discuss ecophysiological evolutionary mechanisms linked succulence drivers underlying expansion, including drought, warming, atmospheric carbon dioxide enrichment. further map biogeographic pattern expansion show that some (e.g., Cylindropuntia, Opuntia, Agave) are expanding encroaching within dryland landscapes worldwide. Our results collectively highlight plants, trend could be sustained increasing aridity climate recommend evaluated data-model integrated framework better understand predict ecological socioeconomic consequences during Anthropocene.

Language: Английский

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