ArticlePlant physiology2022
Gene co-expression reveals the modularity and integration of C4 and CAM in Portulaca.
Article in Plant physiology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers.
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24 citing papers in PubMed, 38 citations in OpenAlex.
- Open questions on facultative C4-CAM photosynthesis in Portulaca.Journal of experimental botany · 2026Review
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- Screening and Stability Validation of RT-qPCR Reference Genes inInternational journal of molecular sciences · 2026Article
- Why "Where" Matters as Much as "How Much": Single-Cell and Spatial Transcriptomics in Plants.International journal of molecular sciences · 2025Review
- Resilience of Portulaca plants to environmental stresses and the economic potential of their bioactive compounds.Planta · 2025Review
- Regulation of Crassulacean acid metabolism at the protein level in Kalanchoë laxiflora.Plant physiology · 2025Article
- An Effective Somatic-Cell Regeneration and Genetic Transformation Method Mediated byPlants (Basel, Switzerland) · 2024Article
- A chromosome-level genome assembly provides insights into the local adaptation of Tamarix austromongolica in the Yellow River Basin, China.DNA research : an international journal for rapid publication of reports on genes and genomes · 2024Article
- CBMC genomics · 2024Article
- Engineering Crassulacean Acid Metabolism in CCold Spring Harbor perspectives in biology · 2024Review
- Genomics and resequencing ofFrontiers in plant science · 2024Article
- The diverse diaspora of CAM: a pole-to-pole sketch.Annals of botany · 2023Review
- Prospects and perspectives: inferring physiological and regulatory targets for CAM from molecular and modelling approaches.Annals of botany · 2023Review
- Reconciling continuous and discrete models of C4 and CAM evolution.Annals of botany · 2023Article
- The CAM lineages of planet Earth.Annals of botany · 2023Article
- Gene duplications facilitate C4-CAM compatibility in common purslane.Plant physiology · 2023Article
- Defining Mechanisms of CInternational journal of molecular sciences · 2023Review
- Genome sequencing reveals the genetic architecture of heterostyly and domestication history of common buckwheat.Nature plants · 2023Article
- A high-qualityHorticulture research · 2023Article
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Authors and funding
5 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
C4 photosynthesis and Crassulacean acid metabolism (CAM) have been considered as largely independent adaptations despite sharing key biochemical modules. Portulaca is a geographically widespread clade of over 100 annual and perennial angiosperm species that primarily use C4 but facultatively exhibit CAM when drought stressed, a photosynthetic system known as C4 + CAM. It has been hypothesized that C4 + CAM is rare because of pleiotropic constraints, but these have not been deeply explored. We generated a chromosome-level genome assembly of Portulaca amilis and sampled mRNA from P. amilis and Portulaca oleracea during CAM induction. Gene co-expression network analyses identified C4 and CAM gene modules shared and unique to both Portulaca species. A conserved CAM module linked phosphoenolpyruvate carboxylase to starch turnover during the day-night transition and was enriched in circadian clock regulatory motifs in the P. amilis genome. Preservation of this co-expression module regardless of water status suggests that Portulaca constitutively operate a weak CAM cycle that is transcriptionally and posttranscriptionally upregulated during drought. C4 and CAM mostly used mutually exclusive genes for primary carbon fixation, and it is likely that nocturnal CAM malate stores are shuttled into diurnal C4 decarboxylation pathways, but we found evidence that metabolite cycling may occur at low levels. C4 likely evolved in Portulaca through co-option of redundant genes and integration of the diurnal portion of CAM. Thus, the ancestral CAM system did not strongly constrain C4 evolution because photosynthetic gene networks are not co-regulated for both daytime and nighttime functions.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.