Stomatal patterning
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Occurrence of stomata on both leaf surfaces (amphistomaty) promotes higher stomatal conductance and photosynthesis while simultaneously increasing exposure to potential disease agents in black cottonwood (Populus trichocarpa). A genome-wide association study (GWAS) with 2.2M single nucleotide polymorphisms generated through whole-genome sequencing found 280 loci associated with variation in adaxial stomatal traits, implicating genes regulating stomatal development and behavior. Strikingly, numerous loci regulating plant growth and response to biotic and abiotic stresses were also identified. The most significant locus was a poplar homologue of SPEECHLESS (PtSPCH1). Individuals possessing PtSPCH1 alleles associated with greater adaxial stomatal density originated primarily from environments with shorter growing seasons (e.g. northern latitudes, high elevations) or with less precipitation. PtSPCH1 was expressed in developing leaves but not developing stem xylem. In developing leaves, RNA sequencing showed patterns of coordinated expression between PtSPCH1 and other GWAS-identified genes. The breadth of our GWAS results suggests that the evolution of amphistomaty is part of a larger, complex response in plants. Suites of genes underpin this response, retrieved through genetic association to adaxial stomata, and show coordinated expression during development. We propose that the occurrence of amphistomaty in P. trichocarpa involves PtSPCH1 and reflects selection for supporting rapid growth over investment in immunity.
- MeSH
- alely MeSH
- celogenomová asociační studie MeSH
- druhová specificita MeSH
- fenotyp MeSH
- genotyp MeSH
- imunita rostlin genetika MeSH
- jednonukleotidový polymorfismus genetika MeSH
- kvantitativní znak dědičný MeSH
- podnebí MeSH
- Populus genetika růst a vývoj imunologie fyziologie MeSH
- průduchy rostlin genetika fyziologie MeSH
- regulace genové exprese u rostlin MeSH
- rostlinné geny MeSH
- rostlinné proteiny genetika metabolismus MeSH
- rozvržení tělního plánu * MeSH
- vývoj rostlin MeSH
- zeměpis MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Stomata modulate the exchange of water and CO2between plant and atmosphere. Although stomatal density is known to affect CO2diffusion into the leaf and thus photosynthetic rate, the effect of stomatal density and patterning on CO2assimilation is not fully understood. We used wild types Col-0 and C24 and stomatal mutants sdd1-1 and tmm1 of Arabidopsis thaliana, differing in stomatal density and pattern, to study the effects of these variations on both stomatal and mesophyll conductance and CO2assimilation rate. Anatomical parameters of stomata, leaf temperature and carbon isotope discrimination were also assessed. Our results indicate that increased stomatal density enhanced stomatal conductance in sdd1-1 plants, with no effect on photosynthesis, due to both unchanged photosynthetic capacity and decreased mesophyll conductance. Clustering (abnormal patterning formed by clusters of two or more stomata) and a highly unequal distribution of stomata between the adaxial and abaxial leaf sides in tmm1 mutants also had no effect on photosynthesis. Except at very high stomatal densities, stomatal conductance and water loss were proportional to stomatal density. Stomatal formation in clusters reduced stomatal dynamics and their operational range as well as the efficiency of CO2transport.
- MeSH
- Arabidopsis genetika metabolismus MeSH
- fotosyntéza genetika fyziologie MeSH
- geneticky modifikované rostliny genetika metabolismus MeSH
- izotopy uhlíku metabolismus MeSH
- oxid uhličitý metabolismus MeSH
- proteiny huseníčku genetika metabolismus MeSH
- průduchy rostlin genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Stomatal ontogenesis, patterning, and function are hallmarks of environmental plant adaptation, especially to conditions limiting plant growth, such as elevated temperatures and reduced water availability. The specification and distribution of a stomatal cell lineage and its terminal differentiation into guard cells require a master regulatory protein phosphorylation cascade involving the YODA mitogen-activated protein kinase kinase kinase. YODA signaling results in the activation of MITOGEN-ACTIVATED PROTEIN KINASEs (MPK3 and MPK6), which regulate transcription factors, including SPEECHLESS (SPCH). Here, we report that acute heat stress affects the phosphorylation and deactivation of SPCH and modulates stomatal density. By using complementary molecular, genetic, biochemical, and cell biology approaches, we provide solid evidence that HEAT SHOCK PROTEINS 90 (HSP90s) play a crucial role in transducing heat-stress response through the YODA cascade. Genetic studies revealed that YODA and HSP90.1 are epistatic, and they likely function linearly in the same developmental pathway regulating stomata formation. HSP90s interact with YODA, affect its cellular polarization, and modulate the phosphorylation of downstream targets, such as MPK6 and SPCH, under both normal and heat-stress conditions. Thus, HSP90-mediated specification and differentiation of the stomatal cell lineage couples stomatal development to environmental cues, providing an adaptive heat stress response mechanism in plants.
- MeSH
- Arabidopsis fyziologie MeSH
- buněčná diferenciace MeSH
- buněčné dělení MeSH
- buněčný rodokmen MeSH
- epigeneze genetická MeSH
- fosforylace MeSH
- kotyledon cytologie MeSH
- MAP kinasy kinas (kinas) genetika metabolismus MeSH
- mitogenem aktivované proteinkinasy kinas metabolismus MeSH
- mitogenem aktivované proteinkinasy metabolismus MeSH
- mutace MeSH
- proteiny huseníčku genetika metabolismus MeSH
- proteiny tepelného šoku HSP90 genetika metabolismus MeSH
- průduchy rostlin cytologie růst a vývoj metabolismus MeSH
- reakce na tepelný šok * MeSH
- regulace genové exprese u rostlin MeSH
- signální transdukce MeSH
- transkripční faktory bHLH metabolismus MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The initiation of stomata, microscopic valves in the epidermis of higher plants that control of gas exchange, requires a co-ordinated sequence of asymmetric and symmetric divisions, which is under tight environmental and developmental control. Arabidopsis leaves grown under elevated photosynthetic photon flux density have a higher density of stomata. STOMAGEN encodes an epidermal patterning factor produced in the mesophyll, and our observations indicated that elevated photosynthetic irradiation stimulates STOMAGEN expression. Our analysis of gain and loss of function of STOMAGEN further detailed its function as a positive regulator of stomatal formation on both sides of the leaf, not only in terms of stomatal density across the leaf surface but also in terms of their stomatal index. STOMAGEN function was rate limiting for the light response of the stomatal lineage in the adaxial epidermis. Mutants in pathways that regulate stomatal spacing in the epidermis and have elevated stomatal density, such as stomatal density and distribution (sdd1) and too many mouth alleles, displayed elevated STOMAGEN expression, suggesting that STOMAGEN is either under the direct control of these pathways or is indirectly affected by stomatal patterning, suggestive of a feedback mechanism. These observations support a model in which changes in levels of light irradiation are perceived in the mesophyll and control the production of stomata in the epidermis by mesophyll-produced STOMAGEN, and whereby, conversely, stomatal patterning, either directly or indirectly, influences STOMAGEN levels.
- MeSH
- Arabidopsis genetika růst a vývoj metabolismus účinky záření MeSH
- fotosyntéza MeSH
- listy rostlin růst a vývoj metabolismus účinky záření MeSH
- proteiny huseníčku genetika metabolismus MeSH
- průduchy rostlin genetika růst a vývoj metabolismus účinky záření MeSH
- regulace genové exprese u rostlin účinky záření MeSH
- signální transdukce MeSH
- světlo MeSH
- vývojová regulace genové exprese účinky záření MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
INTRODUCTION: Oral manifestations of deficiency of iron, vitamin B12 and folic acid are thought to be common. Prevalence of these deficiencies among patients with compatible symptoms is not well known. The goal of this study was to summarize evidence from a dental practice of iron, vitamin B12 and folic acid deficiency in patients presenting with compatible oral manifestations. METHODS: 250 patients who presented with burning mouth syndrome, angular cheilitis, recurrent aphthous stomatitis, papillar atrophy of the tongue dorsum or mucosal erythema were identified. Patients underwent clinical examination, and the blood samples were taken. RESULTS: 250 patients (208 females; 42 males, mean age 44.1 years) with at least one corresponding symptom or sign were identified. The nutritional deficiency of one or more nutrients was found in 119 patients (47.6%). Seven times more females than males were noted to have one type of deficiency (104 females, 15 males). Iron deficiency as defined was diagnosed in 62 patients (24.8%), vitamin B12 or folic acid deficiency in 44 patients (17.6%) and both deficiencies (iron + vitamin B12/folic acid) in 13 patients (5.2%). The only predictive factor was gender and only for iron deficiency. The presence of more than one deficiency was noted in 10 patients (4.9%). CONCLUSION: The most commonly observed deficiency in dental practice over the course of 11 years was an iron deficiency in the female population. Age, diet and reported co-morbidities did not show statistically significant predictable value in recognizing these deficiencies.
- MeSH
- dospělí MeSH
- kyselina listová krev MeSH
- lidé MeSH
- nedostatek kyseliny listové * MeSH
- nedostatek vitaminu B12 * MeSH
- nemoci úst * MeSH
- podvýživa MeSH
- sexuální faktory MeSH
- vitamin B 12 krev MeSH
- vzorové postupy ve stomatologii statistika a číselné údaje MeSH
- železo * MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
The Canary Islands, an archipelago east of Morocco's Atlantic coast, present steep altitudinal gradients covering various climatic zones from hot deserts to subalpine Mediterranean, passing through fog-influenced cloud forests. Unlike the majority of the Canarian flora, Pinus canariensis C. Sm. ex DC. in Buch grow along most of these gradients, allowing the study of plant functioning in contrasting ecosystems. Here we assess the water sources (precipitation, fog) of P. canariensis and its physiological behavior in its different natural environments. We analyzed carbon and oxygen isotope ratios of water and organics from atmosphere, soil and different plant organs and tissues (including 10-year annual time series of tree-ring cellulose) of six sites from 480 to 1990 m above sea level on the Canary Island La Palma. We found a decreasing δ18O trend in source water that was overridden by an increasing δ18O trend in needle water, leaf assimilates and tree-ring cellulose with increasing altitude, suggesting site-specific tree physiological responses to relative humidity. Fog-influenced and fog-free sites showed similar δ13C values, suggesting photosynthetic activity to be limited by stomatal closure and irradiance at certain periods. In addition, we observed an 18O-depletion (fog-free and timberline sites) and 13C-depletion (fog-influenced and fog-free sites) in latewood compared with earlywood caused by seasonal differences in: (i) water uptake (i.e., deeper ground water during summer drought, fog water frequency and interception) and (ii) meteorological conditions (stem radial growth and latewood δ18O correlated with winter precipitation). In addition, we found evidence for foliar water uptake and strong isotopic gradients along the pine needle axis in water and assimilates. These gradients are likely the reason for an unexpected underestimation of pine needle water δ18O when applying standard leaf water δ18O models. Our results indicate that soil water availability and air humidity conditions are the main drivers of the physiological behavior of pine along the Canary Island's altitudinal gradients.
- MeSH
- borovice * MeSH
- ekosystém MeSH
- izotopy kyslíku analýza MeSH
- izotopy uhlíku analýza MeSH
- stromy MeSH
- voda * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Španělsko MeSH
PURPOSE: PFAPA syndrome is a benign, recurrent inflammatory disease of childhood. Tonsillectomy is one of the therapeutic options with a yet unexplained biological mechanism. We tested whether specific lymphocyte subsets recruited from blood to human tonsils participate in PFAPA pathogenesis. METHODS: Paired tonsils/peripheral blood (PB) samples were investigated (a) from children with PFAPA that successfully resolved after tonsillectomy (n=10) (b) from children with obstructive sleep apnoea syndrome as controls (n=10). The lymphocyte profiles were analysed using 8-colour flow cytometry, immunoglobulin (IGH) and T-cell receptor (TCR) gene rearrangements via PCR and next generation sequencing; a TREC/KREC analysis was performed using qPCR. RESULTS: The PFAPA tonsils in the asymptomatic phase had a lower percentage of B-lymphocytes than controls; T-lymphocyte counts were significantly higher in PB. The percentages of cytotoxic CD8pos T-lymphocytes were approximately 2-fold higher in PFAPA tonsils; the transitional B cells and naïve stages of both the CD4pos and CD8pos T-lymphocytes with a low expression of PD-1 molecule and high numbers of TREC were also increased. With the exception of elevated plasmablasts, no other differences were significant in PB. The expression levels of CXCL10, CXCL9 and CCL19 genes were significantly higher in PFAPA tonsils. The IGH/TCR pattern showed no clonal/oligoclonal expansion. DNA from the Epstein-Barr virus, Human Herpervirus-6 or adenovirus was detected in 7 of 10 PFAPA tonsils but also in 7 of 9 controls. CONCLUSIONS: Our findings suggest that the uninhibited, polyclonal response of newly derived lymphocytes participate in the pathogenesis of PFAPA. Because most of the observed changes were restricted to tonsils and were not present in PB, they partly explain the therapeutic success of tonsillectomy in PFAPA syndrome.
- MeSH
- Adenoviridae genetika izolace a purifikace MeSH
- aftózní stomatitida komplikace imunologie chirurgie MeSH
- antigeny CD279 biosyntéza MeSH
- B-lymfocyty imunologie MeSH
- CD8-pozitivní T-lymfocyty imunologie MeSH
- chemokin CCL19 biosyntéza MeSH
- chemokin CXCL10 biosyntéza MeSH
- chemokin CXCL9 biosyntéza MeSH
- dítě MeSH
- faryngitida komplikace imunologie chirurgie MeSH
- horečka neznámého původu komplikace imunologie chirurgie MeSH
- kojenec MeSH
- krční mandle cytologie imunologie chirurgie MeSH
- lidé MeSH
- lidský herpesvirus 6 genetika izolace a purifikace MeSH
- lymfadenitida komplikace imunologie chirurgie MeSH
- obstrukční spánková apnoe imunologie chirurgie MeSH
- počet lymfocytů MeSH
- předškolní dítě MeSH
- receptory antigenů T-buněk genetika MeSH
- T-lymfocyty - podskupiny imunologie MeSH
- tonzilektomie MeSH
- virus Epsteinův-Barrové genetika izolace a purifikace MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cytokinins (CKs) are phytohormones regulating plant growth and development as well as response to the environment. In order to evaluate their function in heat stress (HS) responses, the effect of CK elevation was determined during three types of HS - targeted to shoots, targeted to roots and applied to the whole plant. The early (30min) and longer term (3h) responses were followed at the hormonal, transcriptomic and proteomic levels in Arabidopsis transformants with dexamethasone-inducible expression of the CK biosynthetic gene isopentenyltransferase (ipt) and the corresponding wild-type (Col-0). Combination of hormonal and phenotypic analyses showed transient up-regulation of the CK/abscisic acid ratio, which controls stomatal aperture, to be more pronounced in the transformant. HS responses of the root proteome and Rubisco-immunodepleted leaf proteome were followed using 2-D gel electrophoresis and MALDI-TOF/TOF. More than 100 HS-responsive proteins were detected, most of them being modulated by CK increase. Proteome and transcriptome analyses demonstrated that CKs have longer term positive effects on the stress-related proteins and transcripts, as well as on the photosynthesis-related ones. Transient accumulation of CKs and stimulation of their signal transduction in tissue(s) not exposed to HS indicate that they are involved in plant stress responses.
- MeSH
- alkyltransferasy a aryltransferasy fyziologie MeSH
- Arabidopsis účinky léků metabolismus fyziologie MeSH
- cytokininy fyziologie MeSH
- dexamethason farmakologie MeSH
- kořeny rostlin metabolismus fyziologie MeSH
- kyselina abscisová fyziologie MeSH
- proteomika MeSH
- reakce na tepelný šok fyziologie MeSH
- regulace genové exprese u rostlin fyziologie MeSH
- regulátory růstu rostlin fyziologie MeSH
- signální transdukce účinky léků fyziologie MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- stanovení celkové genové exprese MeSH
- výhonky rostlin metabolismus fyziologie MeSH
- vysoká teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: The southern African Oxalis radiation is extremely morphologically variable. Despite recent progress in the phylogenetics of the genus, there are few morphological synapomorphies supporting DNA-based clades. Leaflet anatomy can provide an understudied and potentially valuable source of information on the evolutionary history and systematics of this lineage. Fifty-nine leaflet anatomical traits of 109 southern African Oxalis species were assessed in search of phylogenetically significant characters that delineate clades. RESULTS: A combination of 6 leaflet anatomical traits (stomatal position, adaxial epidermal cells, abaxial epidermal cells, mesophyll, sheath around vascular tissue, degree of leaflet conduplication) clearly support various clades defined by previous DNA-based phylogenetic work. Other, mostly continuous leaflet anatomical traits were highly variable and showed less phylogenetic pattern. CONCLUSIONS: Major and unexpected findings include the transition from ancestral hypostomatic leaflets to adaxially-located stomata in the vast majority of southern African Oxalis, the loss of semi-swollen AB epidermal cells and the gain of swollen adaxial and abaxial epidermal cells in selected clades, and multiple changes from ancestral bifacial mesophyll to isobilateral or homogenous mesophyll types. The information gathered in this study will aid in the taxonomic revision of this speciose member of the Greater Cape Floristic Region and provide a basis for future hypotheses regarding its radiation.
- MeSH
- biologická evoluce MeSH
- cévní svazky rostlin cytologie MeSH
- duplikace genu MeSH
- fenotyp MeSH
- fylogeneze * MeSH
- kvantitativní znak dědičný MeSH
- listy rostlin anatomie a histologie cytologie genetika MeSH
- mezofylové buňky cytologie MeSH
- Oxalidaceae anatomie a histologie genetika MeSH
- průduchy rostlin cytologie MeSH
- trichomy cytologie MeSH
- Publikační typ
- časopisecké články MeSH