scholarly journals Shared expression of Crassulacean acid metabolism (CAM) genes predates the origin of CAM in the genus Yucca

2018 ◽  
Author(s):  
Karolina Heyduk ◽  
Jeremy N. Ray ◽  
Saaravanaraj Ayyampalayam ◽  
Nida Moledina ◽  
Anne Borland ◽  
...  

Highlight:Although large differences in metabolism exist between C3 and CAM species, we find that many CAM genes have shared expression patterns regardless of photosynthetic pathway, suggesting ancestral propensity for CAM.Abstract:Crassulacean acid metabolism (CAM) is a carbon-concentrating mechanism that has evolved numerous times across flowering plants and is thought to be an adaptation to water limited environments. CAM has been investigated from physiological and biochemical perspectives, but little is known about how plants evolve from C3 to CAM at the genetic or metabolic level. Here we take a comparative approach in analyzing time-course data of C3, CAM, and C3+CAM intermediate Yucca (Asparagaceae) species. RNA samples were collected over a 24-hour period from both well-watered and drought-stressed plants and were clustered based on time-dependent expression patterns. Metabolomic data reveals differences in carbohydrate metabolism and antioxidant response between the CAM and C3 species, suggesting changes to metabolic pathways are important for CAM evolution and function. However, all three species share expression profiles of canonical CAM pathway genes, regardless of photosynthetic pathway. Despite differences in transcript and metabolite profiles between the C3 and CAM species, shared time-structured expression of CAM genes in both CAM and C3Yucca species suggests ancestral expression patterns required for CAM may have predated its origin in Yucca.

2019 ◽  
Vol 70 (22) ◽  
pp. 6597-6609 ◽  
Author(s):  
Karolina Heyduk ◽  
Jeremy N Ray ◽  
Saaravanaraj Ayyampalayam ◽  
Nida Moledina ◽  
Anne Borland ◽  
...  

Although large differences in metabolism exist between C3 and CAM species, we find that many CAM genes have similar expression patterns regardless of photosynthetic pathway, suggesting ancestral propensity for CAM.


2018 ◽  
Vol 45 (7) ◽  
pp. 681 ◽  
Author(s):  
Jamie Males

Crassulacean acid metabolism (CAM) is a celebrated example of convergent evolution in plant ecophysiology. However, many unanswered questions surround the relationships among CAM, anatomy and morphology during evolutionary transitions in photosynthetic pathway. An excellent group in which to explore these issues is the Bromeliaceae, a diverse monocot family from the Neotropics in which CAM has evolved multiple times. Progress in the resolution of phylogenetic relationships among the bromeliads is opening new and exciting opportunities to investigate how evolutionary changes in leaf structure has tracked, or perhaps preceded, photosynthetic innovation. This paper presents an analysis of variation in leaf anatomical parameters across 163 C3 and CAM bromeliad species, demonstrating a clear divergence in the fundamental aspects of leaf structure in association with the photosynthetic pathway. Most strikingly, the mean volume of chlorenchyma cells of CAM species is 22 times higher than that of C3 species. In two bromeliad subfamilies (Pitcairnioideae and Tillandsioideae), independent transitions from C3 to CAM are associated with increased cell succulence, whereas evolutionary trends in tissue thickness and leaf air space content differ between CAM origins. Overall, leaf anatomy is clearly and strongly coupled with the photosynthetic pathway in the Bromeliaceae, where the independent origins of CAM have involved significant anatomical restructuring.


HortScience ◽  
2006 ◽  
Vol 41 (6) ◽  
pp. 1373-1376 ◽  
Author(s):  
Sang Deok Lee ◽  
Soon Jae Kim ◽  
Seung Il Jung ◽  
Ki-Cheol Son ◽  
Stanley J. Kays

CO2 assimilation rate of Crassula hybrid `Himaturi', a succulent ornamental species with the crassulacean acid metabolism (CAM) photosynthetic pathway, was affected by light intensity (50, 100, 300 μmol·m–2·s–1), photoperiod (16/8, 8/16 h day/night), and temperature (30/25, 25/20 °C day/night). Maximum assimilation of CO2 occurred at 300 μmol·m–2·s–1 of diurnal irradiance, 16/8 h day/night photoperiod, and a day/night temperature of 30/25 °C. Diurnal CO2 assimilation patterns of nine succulent ornamental CAM species were evaluated (300 μmol·m–2 s–1, 35/25 °C day/night and a 16/8-h day/night photoperiod) for CO2 fixation. Of the nine ornamentals, Crassula `Himaturi' had the highest and Echeveria derembergii the lowest maximum CO2 absorption rate (13.0 vs 2.4 μmol kg–1·s–1), total nighttime (179.3 vs 13.4 mmol·kg–1), and 24 h total (200.6 vs 19.0 mmol·kg–1) absorption. Based on the CO2 assimilation patterns, the nine ornamentals were separated into two groups: 1) full CAM (Faucaria tigrina, Gasteria gracilis var. minima, Haworthia cymbiformis, and Haworthia fasciata); and 2) weakly CAM (Adromischus clarifolius, Crassula hybrids `Moonglow' and `Himaturi', E. derembergii, and Haworthia retusa).


2021 ◽  
Vol 8 ◽  
Author(s):  
Kai-Lu Zhang ◽  
Jian-Li Zhou ◽  
Jing-Fang Yang ◽  
Yu-Zhen Zhao ◽  
Debatosh Das ◽  
...  

As a pivotal regulator of 5’ splice site recognition, U1 small nuclear ribonucleoprotein (U1 snRNP)-specific protein C (U1C) regulates pre-mRNA splicing by interacting with other components of the U1 snRNP complex. Previous studies have shown that U1 snRNP and its components are linked to a variety of diseases, including cancer. However, the phylogenetic relationships and expression profiles of U1C have not been studied systematically. To this end, we identified a total of 110 animal U1C genes and compared them to homologues from yeast and plants. Bioinformatics analysis shows that the structure and function of U1C proteins is relatively conserved and is found in multiple copies in a few members of the U1C gene family. Furthermore, the expression patterns reveal that U1Cs have potential roles in cancer progression and human development. In summary, our study presents a comprehensive overview of the animal U1C gene family, which can provide fundamental data and potential cues for further research in deciphering the molecular function of this splicing regulator.


2019 ◽  
Vol 70 (22) ◽  
pp. 6611-6619
Author(s):  
Ming-He Li ◽  
Ding-Kun Liu ◽  
Guo-Qiang Zhang ◽  
Hua Deng ◽  
Xiong-De Tu ◽  
...  

Abstract Members of the Orchidaceae, one of the largest families of flowering plants, evolved the crassulacean acid metabolism (CAM) photosynthesis strategy. It is thought that CAM triggers adaptive radiation into new niche spaces, yet very little is known about its origin and diversification on different continents. Here, we assess the prevalence of CAM in Dendrobium, which is one of the largest genera of flowering plants and found in a wide range of environments, from the high altitudes of the Himalayas to relatively arid habitats in Australia. Based on phylogenetic time trees, we estimated that CAM, as determined by δ 13C values less negative than –20.0‰, evolved independently at least eight times in Dendrobium. The oldest lineage appeared in the Asian clade during the middle Miocene, indicating the origin of CAM was associated with a pronounced climatic cooling that followed a period of aridity. Divergence of the four CAM lineages in the Asian clade appeared to be earlier than divergence of those in the Australasian clade. However, CAM species in the Asian clade are much less diverse (25.6%) than those in the Australasian clade (57.9%). These findings shed new light on CAM evolutionary history and the aridity levels of the paleoclimate on different continents.


2005 ◽  
Vol 32 (5) ◽  
pp. 451 ◽  
Author(s):  
Shin Kore-eda ◽  
Chiyuki Noake ◽  
Masahisa Ohishi ◽  
Jun-ichi Ohnishi ◽  
John C. Cushman

Metabolite transport across multiple organellar compartments is essential for the operation of crassulacean acid metabolism (CAM). To investigate potential circadian regulation of inter-organellar metabolite transport processes, we have identified eight full-length cDNAs encoding an organellar triose phosphate / Pi translocator (McTPT1), a phosphoenolpyruvate / Pi translocator (McPPT1), two glucose-6-phosphate / Pi translocators (McGPT1, 2), two plastidic Pi translocator-like proteins (McPTL1, 2), two adenylate transporters (McANT1, 2), a dicarboxylate transporter (McDCT2), and a partial cDNA encoding a second dicarboxylate transporter (McDCT1) in the model CAM plant, Mesembryanthemum crystallinum L. We next investigated day / night changes in steady-state transcript abundance of each of these transporters in plants performing either C3 photosynthesis or CAM induced by salinity or water-deficit stress. We observed that the expression of both isogenes of the glucose-6-phosphate / Pi translocator (McGPT1, 2) was enhanced by CAM induction, with McGPT2 transcripts exhibiting much more pronounced diurnal changes in transcript abundance than McGPT1. Transcripts for McTPT1, McPPT1, and McDCT1 also exhibited more pronounced diurnal changes in abundance in the CAM mode relative to the C3 mode. McGPT2 and McDCT1 transcripts exhibited sustained oscillations for at least 3 d under constant light and temperature conditions suggesting their expression is under circadian clock control. McTPT1 and McGPT2 transcripts were preferentially expressed in leaf tissues in either C3 or CAM modes. The leaf-specific and / or circadian controlled gene expression patterns are consistent with McTPT1, McGPT2 and McDCT1 playing CAM-specific metabolite transport roles.


2006 ◽  
Vol 188 (16) ◽  
pp. 5821-5830 ◽  
Author(s):  
Tie Koide ◽  
Ricardo Z. N. Vêncio ◽  
Suely L. Gomes

ABSTRACT Xylella fastidiosa is a phytopathogenic bacterium that is responsible for diseases in many economically important crops. Although different strains have been studied, little is known about X. fastidiosa stress responses. One of the better characterized stress responses in bacteria is the heat shock response, which induces the expression of specific genes to prevent protein misfolding and aggregation and to promote degradation of the irreversibly denatured polypeptides. To investigate X. fastidiosa genes involved in the heat shock response, we performed a whole-genome microarray analysis in a time course experiment. Globally, 261 genes were induced (9.7%) and 222 genes were repressed (8.3%). The expression profiles of the differentially expressed genes were grouped, and their expression patterns were validated by quantitative reverse transcription-PCR experiments. We determined the transcription start sites of six heat shock-inducible genes and analyzed their promoter regions, which allowed us to propose a putative consensus for σ32 promoters in Xylella and to suggest additional genes as putative members of this regulon. Besides the induction of classical heat shock protein genes, we observed the up-regulation of virulence-associated genes such as vapD and of genes for hemagglutinins, hemolysin, and xylan-degrading enzymes, which may indicate the importance of heat stress to bacterial pathogenesis. In addition, we observed the repression of genes related to fimbriae, aerobic respiration, and protein biosynthesis and the induction of genes related to the extracytoplasmic stress response and some phage-related genes, revealing the complex network of genes that work together in response to heat shock.


2018 ◽  
Vol 105 (3) ◽  
pp. 587-601 ◽  
Author(s):  
Karolina Heyduk ◽  
Jeremy N. Ray ◽  
Saravanaraj Ayyampalayam ◽  
James Leebens-Mack

1997 ◽  
Vol 24 (6) ◽  
pp. 777 ◽  
Author(s):  
Kate Maxwell ◽  
Susanne von Caemmerer ◽  
John R. Evans

Leaf internal conductance to CO2 (gi) from substomatal cavity to the carboxylation sites of Rubisco was measured in the leaf succulent CAM species, Kalanchoe daigremontiana Hamet et Perr. Measurements were made during Rubisco-mediated atmospheric C3 carboxylation in phase IV photosynthesis. Using simultaneous gas exchange and chlorophyll fluorescence techniques, internal conductance was calculated to be 0.05 mol m-2 s-1 bar-1 , when measured at both saturating and limiting light. This is one of the lowest recorded values for gi as compared to a range of C3 species with comparable Rubisco content and indicates a large diffusion limitation to atmospheric CO2 fixation through the C3 pathway in K. daigremontiana. In ambient air, CO2 partial pressure at the carboxylation sites of Rubisco was 109 µbar. Internal diffusion is limited by a thick leaf consisting of densely packed, succulent mesophyll with a small portion of airspace. We speculate that a low internal conductance to CO2 diffusion results from the compromise between a succulent mesophyll required for C4 acid storage and access for CO2 diffusion to both PEPC in the cytoplasm and Rubisco in the chloroplasts. Restricted diffusion of CO2 within the leaf makes CO2 assimilation less efficient during the transient phases of crassulacean acid metabolism.


2021 ◽  
Author(s):  
Ingrid Jakobsen ◽  
Max Sundkvist ◽  
Niclas Björn ◽  
Henrik Gréen ◽  
Kourosh Lotfi

Abstract Background: Elucidation of the genetic mechanisms underlying treatment response to standard induction chemotherapy in AML patients is warranted, in order to aid in risk-adapted treatment decisions as novel treatments are emerging. In this pilot study, we explored the treatment-induced expression patterns in a small cohort of AML patients by analyzing differential gene expression (DGE) over the first two days of induction chemotherapy.Methods: Blood samples were collected from ten AML patients at baseline (before treatment initiation) and during the first two days of treatment (Day 1; approximately 24 h, and Day 2; approximately 48 h after treatment initiation, respectively) and RNA was extracted for subsequent RNA sequencing. DGE between time points were assessed by pairwise analysis using the R package edgeR version 3.18.1 in all patients as well as in relation to treatment response (complete remission, CR, vs non-complete remission, nCR). Ingenuity Pathway Analysis (Qiagen) software was used for pathway analysis and visualization.Results: After initial data quality control, two patients was excluded from further analysis, resulting in a final cohort of eight patients with data from all three timepoints. DGE analysis demonstrated activation of pathways with genes directly or indirectly associated with NF-κB signaling. Significant activation of the NF-κB pathway was seen in 50% of the patients two days after treatment start, while iNOS pathway effects could be identified already after one day. nCR patients displayed activation of pathways associated with cell cycle progression, oncogenesis and anti-apoptotic behavior, including the STAT3 pathway and Salvage pathways of pyrimidine ribonucleotides. Notably, a significant induction of cytidine deaminase, an enzyme responsible for the deamination of Ara-C, could be observed between baseline and Day 2 in the nCR patients but not in patients achieving CR.Conclusions: In conclusion, we show that time-course analysis of gene expression represents a feasible approach to identify relevant pathways affected by standard induction chemotherapy in AML patients. This poses as a potential method for elucidating new drug targets and biomarkers for categorizing disease aggressiveness and evaluating treatment response. However, more studies on larger cohorts are warranted to elucidate the transcriptional basis for drug response.


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