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1.
Mar Pollut Bull ; 191: 114974, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37116250

RESUMO

Due to ever-increasing global warming, ocean acidification, and inshore eutrophication, the outbreak of golden tides with Sargassum horneri has increased in the Yellow sea, where the biomass carbon enters three main carbon pathways: a. Removal of carbon from seawater by salvage, known as removable carbon; b. Biomass carbon is deposited to the seafloor through POC and RDOC through Biological Carbon Pump and Microbial Carbon Pump; c. Re-entering the carbon cycle through the food chain or re-entering the atmosphere through the action of microbes. Estimating carbon fixation (removable carbon) and storage (particulate organic carbon (POC) and refractory dissolved organic carbon (RDOC)) is vital in studying the global carbon cycle. In this research, it was observed that the C content of S. horneri was high, and the utilization rate of dissolved organic carbon (DOC), RDOC, and POC was also high in the eutrophication environment, where only 2.71 % of algal biomass carbon was converted to RDOC, and only 0.20 % converted to POC. The C + N + P combination has a restart effect on the seasonal accumulation of RDOC in relevant sea areas. It is suggested that the salvage and resource utilization should be strengthened to effectively control the golden tide and reduce the substantial economic losses to realize the win-win situation of carbon sink and environmental restoration.


Assuntos
Carbono , Água do Mar , Matéria Orgânica Dissolvida , Concentração de Íons de Hidrogênio , Biomassa
2.
Food Res Int ; 165: 112559, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36869543

RESUMO

Seaweeds (green algae, red algae and brown algae) are rich in nutrients, and incorporating algae into the human diet can provide important health benefits. However, consumer acceptance of food is closely related to its flavor, and in this respect, volatile compounds are key factors. This article reviews the extraction methods and composition of volatile compounds from Ulva prolifera, Ulva lactuca, Sargassum spp. and economically valuable cultured seaweeds such as Undaria pinnatifida, Laminaria japonica, Neopyropia haitanensis and Neopyropia yezoensis. Research found that the volatile compounds of the above seaweeds were composed mainly of aldehydes, ketones, alcohols, hydrocarbons, esters, acids, sulfur compounds, furans and small amounts of other compounds. Volatile compounds such as benzaldehyde, 2-octenal, octanal, ß-ionone and 8-heptadecene have been identified in several macroalgae. This review argues that more research on the volatile flavor compounds of edible macroalgae is required. Such research could aid new product development or widen applications of these seaweeds in the food or beverage sectors.


Assuntos
Produtos Biológicos , Alga Marinha , Humanos , Alimentos , Bebidas , Ésteres
3.
Mar Pollut Bull ; 188: 114710, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36860024

RESUMO

The green tide event that occurred in the Southern Yellow Sea in 2007 lasted for 16 years, causing serious economic losses and ecological damage to coastal cities. To address this problem, a series of studies were conducted. However, the contribution of micropropagules to green tide outbreaks remains poorly understood, and the relationship between micropropagules and green algae that are settled nearshore or floating at sea also needs to be further explored. The present study focuses on the identification of these micropropagules in the Southern Yellow Sea and uses the Citespace tool to quantitatively analyze current research hotspots, frontier trends, and development trends. In addition, it examines the micropropagules' life cycle and how it directly affects the green algal biomass and clarifies the temporal and spatial distribution of micropropagules in the entire Southern Yellow Sea. The study also discusses unresolved scientific problems and limitations in the current research on algal micropropagules and provides an outlook on future research directions. We expect to further analyze the contribution of micropropagules to green tide outbreaks and provide data to support comprehensive green tide management.


Assuntos
Surtos de Doenças , Biomassa , Cidades
4.
Artigo em Inglês | MEDLINE | ID: mdl-36673828

RESUMO

In the context of ecological priority and green development strategy, accelerating the upgrading of tourism structure and promoting the development of ecotourism is an important guarantee to achieve green and low-carbon economic growth and high-quality development. On the basis of constructing comprehensive evaluation indicators of tourism development (TD) and green development efficiency (GDE), this study analyzed the impulse response relationship between TD and GDE and the impact effect of TD on GDE in the Yangtze River Delta region from 2000-2018. Findings showed that: (1) During the study period, TD generally exhibited a W-shaped fluctuating upward trend and GDE showed a staggered evolution of upward and downward fluctuations, while both regional gaps of TD and GDE continued to decrease. (2) Most cities had made a leap from low to medium, high, and higher levels of tourism development, with tourism development levels decreasing along the Yangtze River basin to the north and south of the delta. The overall green development efficiency was relatively low, showing a spatial pattern of high value in the southern delta and low value in the northwest delta. (3) There was a one-way Granger causality of TD on GDE, and the impact of TD on GDE showed a significant positive cumulative effect. (4) TD exhibited a significant inverted U-shaped impact on GDE. The economic development level and government intervention had a significant positive impact on GDE. The proportion of secondary industry, energy consumption intensity, and foreign direct investment had a significant negative driving effect on GDE. While the impact of environmental regulation on GDE was insignificant positive. This study has great practical significance to alleviate the problems of urban resources and environment, and to realize a green economy and high-quality life.


Assuntos
Condução de Veículo , Desenvolvimento Sustentável , Turismo , Desenvolvimento Econômico , Investimentos em Saúde , Cidades , China , Eficiência
5.
Chemosphere ; 313: 137504, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36513205

RESUMO

In this work, different synthetic methods of polymeric aluminum silicate sulfate (PASS) and their coagulability to oily sewage were comparatively studied. PASS was synthesized by two methods: gravity supercritical method and basic titration method, denoted as PASS-B and PASS-S, respectively. The results show that the PASS prepared by gravity supercritical method has better Alb and stability. By applying two coagulants to oily sewage, it was found that PASS-B exhibited better turbidity and oil removal. It was found that PASS-B still has good coagulation by testing its coagulation after placing the coagulant for 2 months. In acidic test water, PASS-B exhibited stronger deprotonation ability. Finally, the polymerization mechanism and coagulation mechanism of PASS-B were analyzed in combination with Al morphology distribution and coagulation experiments. Gravity supercritical method as a new polymerization method may replace the traditional preparation method of inorganic polymer coagulants in the future, especially in large-scale applications.


Assuntos
Esgotos , Purificação da Água , Sulfatos , Silicatos , Silicatos de Alumínio , Água , Purificação da Água/métodos , Floculação
6.
Environ Sci Pollut Res Int ; 30(6): 14805-14820, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36161566

RESUMO

By constructing the two evaluation systems of urban tourism development (TD) and habitat environment (HE), the dynamic response relationship between the two systems in the Yangtze River Delta urban agglomeration from 2001 to 2020 is explored by using panel vector autoregression (PVAR) model and coupled coordination degree model. The study unearthed four intriguing findings: (1) the level of TD in the study area has been continuously rising from 2001 to 2020, with an initial slow growth rate and then fast. The level of HE is increasing steadily at an average annual rate of 7.05%. There exists a reciprocal response relationship between the two systems, with a strong shock effect in the short term and a synergistic evolution in the long term. (2) The coupling degree between the urban TD and HE has an increasing trend, and the coupling coordination degree of the two systems has an average annual rate of 4.165%, implying the interaction and promotion effect between the two systems is improving. (3) Most of the cities in the Yangtze River Delta gradually realize the evolution from dysfunctional type to coordinated type, but the overall coordination intensity is low. (4) The barrier degrees of TD system indicators show a small annual increasing trend, while the barrier degrees of HE system indicators show a substantial and continuous decreasing trend. In terms of the barrier degree factors, some important factors that restrict the coupled and coordinated development of the two systems are also reported. This research can provide a useful reference for the synergistic improvement of urban tourism economy and habitat environment.


Assuntos
Rios , Turismo , Cidades , Ecossistema , Desenvolvimento Econômico , China
7.
Front Plant Sci ; 13: 1023628, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36561463

RESUMO

Prunus mume (Rosaceae, Prunoideae) serves as an excellent ornamental woody plant with a large-temperature-range cultivation scope. Its flower buds require a certain low temperature to achieve flowering circulation. Thus, it is important to delve into the processes of flower bud differentiation and dormancy, which affected its continuous flowering. These processes are generally considered as regulation by the MADS-box homologs, SHORT VEGETATIVE PHASE (SVP), and DORMANCY-ASSOCIATED MADS-BOX (DAM). However, a precise model on their interdependence and specific function, when acting as a complex in the flower development of P. mume, is needed. Therefore, this study highlighted the integral roles of PmDAMs and PmSVPs in flower organ development and dormancy cycle. The segregation of PmDAMs and PmSVPs in a different cluster suggested distinct functions and neofunctionalization. The expression pattern and yeast two-hybrid assays jointly revealed that eight genes were involved in the floral organ development stages, with PmDAM1 and PmDAM5 specifically related to prolificated flower formation. PmSVP1-2 mingled in the protein complex in bud dormancy stages with PmDAMs. Finally, we proposed the hypothesis that PmSVP1 and PmSVP2 could combine with PmDAM1 to have an effect on flower organogenesis and interact with PmDAM5 and PmDAM6 to regulate flower bud dormancy. These findings could help expand the current molecular mechanism based on MADS-box genes during flower bud development and dormancy.

8.
Materials (Basel) ; 15(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36500110

RESUMO

Submerged arc additive manufacturing (SAAM) is a viable technique for manufacturing large and complex specialized parts used in structural applications. At present, manufacturing high-strength low-alloy steel T-branch pipe through SAAM has not been reported. This paper uses this technology to manufacture low-alloy structural steel parts. The microstructures of the samples were characterized, which revealed that they were mainly composed of polygonal ferrites. The tensile properties in the horizontal and vertical directions of deposits were studied. Results show that the horizontal tensile strength of deposits was quite close to the vertical one, while the elongation rate in the vertical direction was obviously lower than that in the horizontal direction. Fatigue results indicate that the strain fatigue limit of high-strength low-alloy steel samples in vertical direction was 0.24%. The fatigue fractures of fatigue samples of deposits showed multi-source crack initiation characteristics and the crack propagation regions exhibited typical fatigue striations, so the final instantaneous fracture region showed a ductile fracture. Fatigue performance is very important for the safe service of structural parts, but there is a lack of relevant research on this additive manufacturing part. The results of this paper may support the popularization of the SAAM for high-strength low-alloy steel T-branch pipe.

9.
Mitochondrial DNA B Resour ; 7(8): 1489-1491, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35989881

RESUMO

Phalaenopsis malipoensis Z.J. Liu et S.C. Chen, 2005 is a valuable species of Orchidaceae with significant ornamental value. This study reports the first complete chloroplast genome of P.malipoensis was collected integrally and clarified further. The genome was 144,528 bp in length and comprised four regions, including a pair of inverted repeats each 24,710 bp, a large single-copy region of 83,475 bp, and a small single-copy region of 11,633 bp. The whole genome contained 125 genes, including 8 rRNAs, and 39 tRNAs. Phylogenetic analysis indicated that P. malipoensis was closely related to Phalaenopsis lobbii. The analysis of P. malipoensis chloroplast genome will provide significant data for the identification and further improvement of P. malipoensis.

10.
J Genet Genomics ; 49(8): 823-832, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35760352

RESUMO

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker, a devastating disease threatening the Actinidia fruit industry. In a search for non-host resistance genes against Psa, we find that the nucleotide-binding leucine-rich repeat receptor (NLR) protein ZAR1 from both Arabidopsis and Nicotiana benthamiana (Nb) recognizes HopZ5 and triggers cell death. The recognition requires ZED1 in Arabidopsis and JIM2 in Nb plants, which are members of the ZRK pseudokinases and known components of the ZAR1 resistosome. Surprisingly, Arabidopsis ZAR1 and RPM1, another NLR known to recognize HopZ5, confer disease resistance to HopZ5 in a strain-specific manner. Thus, ZAR1, but not RPM1, is solely required for resistance to P. s. maculicola ES4326 (Psm) carrying hopZ5, whereas RPM1 is primarily required for resistance to P. s. tomato DC3000 (Pst) carrying hopZ5. Furthermore, the ZAR1-mediated resistance to Psm hopZ5 in Arabidopsis is insensitive to SOBER1, which encodes a deacetylase known to suppress the RPM1-mediated resistance to Pst hopZ5. In addition, hopZ5 enhances P. syringae virulence in the absence of ZAR1 or RPM1 and that SOBER1 abolishes such virulence function. Together the study suggests that ZAR1 may be used for improving Psa resistance in Actinidia and uncovers previously unknown complexity of effector-triggered immunity and effector-triggered virulence.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Bactérias , Hidrolases de Éster Carboxílico , Proteínas de Transporte , Proteínas NLR , Fosfotransferases , Doenças das Plantas , Pseudomonas syringae
11.
Med Sci Monit ; 28: e935455, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35673773

RESUMO

BACKGROUND We aimed to investigate the impact of microalbuminuria complicated with low estimate glomerular filtration rate (eGFR) on the incidence and prognosis of contrast-induced acute kidney injury (CI-AKI) in patients with coronary artery disease after coronary intervention. MATERIAL AND METHODS A total of 943 patients were enrolled in the study. Based on microalbumin/creatinine (ACR) measurements, the patients were divided into a microalbuminuria cohort (MA; 222 patients) and a normal albuminuria cohort (NA; 721 patients). According to eGFR levels, the cohorts were further subdivided into normal, mild, moderate, and severe renal dysfunction groups. The basic data and indicators of all enrolled patients were collected. The patients were followed up at 30 days, 6 months, 1 year, and 3 years after surgery. RESULTS The overall incidence of CI-AKI in the MA cohort was higher than that in the NA cohort (17.6% vs 8.2%, P.


Assuntos
Injúria Renal Aguda , Albuminúria , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/epidemiologia , Albuminúria/complicações , Meios de Contraste/efeitos adversos , Creatinina , Taxa de Filtração Glomerular , Humanos , Fatores de Risco
12.
Front Public Health ; 10: 863571, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35530733

RESUMO

The equalization of healthcare supply is not only related to the people's need for a better life, but can also provide a strong guarantee for the high-quality and sustainable development of the Yangtze River Delta integration. By using exploratory spatial analysis techniques, this study analyzed the spatio-temporal evolution characteristics and heterogeneous influence effects of the supply level of healthcare service in the Yangtze River Delta from 2007 to 2019. It was found that the supply level of healthcare service in the Yangtze River Delta had improved significantly. The differences in the supply level of healthcare service between cities had tended to narrow without polarization, and the supply level of healthcare service generally showed a high spatial pattern in the south delta and low spatial pattern in the north delta. The higher the supply level of healthcare service was, the weaker the interannual variability was. The supply level of healthcare service in the Yangtze River Delta region presented obvious spatial association and differentiated tendency of local high and low spatial clusters. The relative length and curvature of the supply level of healthcare service in the Yangtze River Delta generally presented a spatial pattern with low values in the northeast and high values in the southwest. Population density and urban-rural income gap generally exhibited negative spatio-temporal impact on the supply level of healthcare service across most cities. On the other hand, urbanization level and per capita disposable income generally had positive spatio-temporal impact on the supply level of healthcare service across most cities. Per capita gross domestic product (GDP) showed an increasingly positive spatio-temporal impact on the supply level of healthcare service across most cities. While per capita fiscal expenditure exhibited significantly negative impact on the supply level of healthcare service across most cities in space.


Assuntos
Rios , Urbanização , Cidades , Atenção à Saúde , Humanos , Análise Espacial
13.
Molecules ; 27(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35566160

RESUMO

Chemicals underlying the floral aroma of dry teas needs multi-dimensional investigations. Green, black, and freeze-dried tea samples were produced from five tea cultivars, and only 'Chunyu2' and 'Jinguanyin' dry teas had floral scents. 'Chunyu2' green tea contained the highest content of total volatiles (134.75 µg/g) among green tea samples, while 'Jinguanyin' black tea contained the highest content of total volatiles (1908.05 µg/g) among black tea samples. The principal component analysis study showed that 'Chunyu2' and 'Jinguanyin' green teas and 'Chunyu2' black tea were characterized by the abundant presence of certain alcohols with floral aroma, while 'Jinguanyin' black tea was discriminated due to the high levels of certain alcohols, esters, and aldehydes. A total of 27 shared volatiles were present in different tea samples, and the contents of 7 floral odorants in dry teas had correlations with those in fresh tea leaves (p < 0.05). Thus, the tea cultivar is crucial to the floral scent of dry tea, and these seven volatiles could be promising breeding indices.


Assuntos
Camellia sinensis , Compostos Orgânicos Voláteis , Álcoois/análise , Camellia sinensis/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Odorantes/análise , Melhoramento Vegetal , Chá/química , Compostos Orgânicos Voláteis/análise
14.
Mar Pollut Bull ; 180: 113772, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35623218

RESUMO

Green tides dominated by Ulva prolifera have be present in the Southern Yellow Sea for 15 consecutive years. They not only damage the marine environment, but also cause economic losses to coastal cities. However, there is still no fully effective approach for preventing green tides. In this article, approaches for the prevention of U. prolifera taken over recent years are reviewed. They can be generally divided into physical, chemical, and biological approaches. Physical approaches have been used to control the overwhelming green macroalgae bloom and inhibit the germination of U. prolifera, including physical salvage approach, refrigeration net technology, improved farming methods and raft technology, and modified clay method. These approaches require significant labor and material resources. Many chemical reagents have been used to eliminate U. prolifera early germination and growth, such as oxidative algaecide, acid treatment, heavy metal compounds, antifouling coating, and alkaloids. Chemical approaches have high efficiency, high economic benefit, and simple operation. Presently, biological control approaches remain in the exploratory stage. The verification of pilot and large-scale experiment results in sea areas is lacking, including the application of large organisms and microorganisms to control U. prolifera, and some of the mechanisms have not been thoroughly studied. This article introduces the three types of approaches, and evaluates the advantages and disadvantages of different methods to facilitate the reduction of the green tide bloom scale in the Southern Yellow Sea.


Assuntos
Alga Marinha , Ulva , China , Eutrofização
15.
Artigo em Inglês | MEDLINE | ID: mdl-35173798

RESUMO

OBJECTIVE: Contrast-induced acute kidney injury (CI-AKI) is a serious side effect of contrast media use. The purpose of this study was to investigate the role and mechanism of tolvaptan (TOL) in CI-AKI. METHODS: 24 Wistar male rats were randomly divided into 4 groups (n = 6). And a rat model of CI-AKI was established. Then, the blood and urine of rats in each group were collected to detect relevant parameters. HE staining was utilized for the observation of the pathological changes of rat kidney tissues, TUNEL assay for the detection of tubular cell apoptosis, biochemical detection for the confirmation of oxidative stress level in kidney tissues, and western blot for the test of the expression of apoptotic proteins and the Nrf2 signaling pathway-related proteins in kidney tissues. RESULTS: TOL could significantly reduce the serum level of urea nitrogen, creatinine, and neutrophil gelatinase-associated lipocalin and decrease serum Cys-C and urine KIM-1 in CI-AKI rats. The result above meant that TOL could improve kidney injury and reduce tubular cell apoptosis in CI-AKI rats. In addition, TOL contributed to a reduction of oxidative stress level by downregulating myeloperoxidase level and increasing the activities of superoxide dismutase and glutathione peroxidase in the kidney tissue of CI-AKI rats. After the pretreatment of TOL, the expression of proapoptotic proteins cleaved-caspase 3 and BAX, as well as mitochondrial fusion proteins DRP1 and MFN2 was downregulated, while the expression of Bcl-2 and PINK1 was upregulated in the kidney tissue of CI-AKI rats. Further, TOL could activate the Nrf2 signaling pathway, and the Nrf2 inhibitor ML385 reversed the effect of TOL on CI-AKI. CONCLUSION: TOL can improve CI-AKI by activating the Nrf2/HO-1 signaling pathway, inhibiting oxidative stress response, and reducing tubular cell apoptosis.


Assuntos
Injúria Renal Aguda , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Animais , Apoptose , Rim/patologia , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Tolvaptan/efeitos adversos
16.
Plant Cell ; 34(5): 1600-1620, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35166827

RESUMO

The nucleotide-binding, leucine-rich receptor (NLR) protein HOPZ-ACTIVATED RESISTANCE 1 (ZAR1), an immune receptor, interacts with HOPZ-ETI-DEFICIENT 1 (ZED1)-related kinases (ZRKs) and AVRPPHB SUSCEPTIBLE 1-like proteins to form a pentameric resistosome, triggering immune responses. Here, we show that ZAR1 emerged through gene duplication and that ZRKs were derived from the cell surface immune receptors wall-associated protein kinases (WAKs) through the loss of the extracellular domain before the split of eudicots and monocots during the Jurassic period. Many angiosperm ZAR1 orthologs, but not ZAR1 paralogs, are capable of oligomerization in the presence of AtZRKs and triggering cell death, suggesting that the functional ZAR1 resistosome might have originated during the early evolution of angiosperms. Surprisingly, inter-specific pairing of ZAR1 and AtZRKs sometimes results in the formation of a resistosome in the absence of pathogen stimulation, suggesting within-species compatibility between ZAR1 and ZRKs as a result of co-evolution. Numerous concerted losses of ZAR1 and ZRKs occurred in angiosperms, further supporting the ancient co-evolution between ZAR1 and ZRKs. Our findings provide insights into the origin of new plant immune surveillance networks.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Transporte/metabolismo , Proteínas NLR/metabolismo , Fosfotransferases/metabolismo , Imunidade Vegetal/fisiologia
17.
Mitochondrial DNA B Resour ; 7(1): 257-258, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35087948

RESUMO

Phalaenopsis stobartiana Reichenbach f. 1877 is mainly distributed in Yunnan province of China and has a high ornamental and breeding value. Here, we reported the chloroplast genome of P. stobartiana. The length of the chloroplast genome was 145,900 bp, encoding 120 genes. The average GC content was 36.8%. Phylogenetic analysis revealed that P. stobartiana and P. wilsonii are closely related. The chloroplast genome could be used for further phylogenetic research, and provide molecular data for future genetic protection and breeding programs.

18.
Stress Biol ; 2(1): 12, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-37676556

RESUMO

Plant innate immunity begins with the recognition of pathogens by plasma membrane localized pattern-recognition receptors (PRRs) and intracellular nucleotide-binding domain leucine-rich repeat containing receptors (NLRs), which lead to pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), respectively. For a long time, PTI and ETI have been regarded as two independent processes although they share multiple components and signal outputs. Increasing evidence shows an intimate link between PTI and ETI. PTI and ETI mutually potentiate each other, and this is essential for robust disease resistance during pathogen infection. An ancient class of NLRs called RNLs, so named because they carry a Resistance to Powdery Mildew 8 (RPW8)-like coiled-coil (CC) domain in the N terminus, has emerged as a key node connecting PTI and ETI. RNLs not only act as helper NLRs that signal downstream of sensor NLRs, they also directly mediate PTI signaling by associating with PRR complexes. Here, we focus on Activated Disease Resistance 1 (ADR1), a subclass of RNLs, and discuss its role and mechanism in plant immunity.

19.
Nature ; 598(7881): 495-499, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34497423

RESUMO

Plants deploy cell-surface and intracellular leucine rich-repeat domain (LRR) immune receptors to detect pathogens1. LRR receptor kinases and LRR receptor proteins at the plasma membrane recognize microorganism-derived molecules to elicit pattern-triggered immunity (PTI), whereas nucleotide-binding LRR proteins detect microbial effectors inside cells to confer effector-triggered immunity (ETI). Although PTI and ETI are initiated in different host cell compartments, they rely on the transcriptional activation of similar sets of genes2, suggesting pathway convergence upstream of nuclear events. Here we report that PTI triggered by the Arabidopsis LRR receptor protein RLP23 requires signalling-competent dimers of the lipase-like proteins EDS1 and PAD4, and of ADR1 family helper nucleotide-binding LRRs, which are all components of ETI. The cell-surface LRR receptor kinase SOBIR1 links RLP23 with EDS1, PAD4 and ADR1 proteins, suggesting the formation of supramolecular complexes containing PTI receptors and transducers at the inner side of the plasma membrane. We detected similar evolutionary patterns in LRR receptor protein and nucleotide-binding LRR genes across Arabidopsis accessions; overall higher levels of variation in LRR receptor proteins than in LRR receptor kinases are consistent with distinct roles of these two receptor families in plant immunity. We propose that the EDS1-PAD4-ADR1 node is a convergence point for defence signalling cascades, activated by both surface-resident and intracellular LRR receptors, in conferring pathogen immunity.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Hidrolases de Éster Carboxílico/metabolismo , Proteínas de Ligação a DNA/metabolismo , Imunidade Vegetal , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Arabidopsis/química , Hidrolases de Éster Carboxílico/química , Proteínas de Ligação a DNA/química , Domínios Proteicos , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Multimerização Proteica , Proteínas Serina-Treonina Quinases/química , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo
20.
Cell ; 184(13): 3528-3541.e12, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-33984278

RESUMO

Nucleotide-binding, leucine-rich repeat receptors (NLRs) are major immune receptors in plants and animals. Upon activation, the Arabidopsis NLR protein ZAR1 forms a pentameric resistosome in vitro and triggers immune responses and cell death in plants. In this study, we employed single-molecule imaging to show that the activated ZAR1 protein can form pentameric complexes in the plasma membrane. The ZAR1 resistosome displayed ion channel activity in Xenopus oocytes in a manner dependent on a conserved acidic residue Glu11 situated in the channel pore. Pre-assembled ZAR1 resistosome was readily incorporated into planar lipid-bilayers and displayed calcium-permeable cation-selective channel activity. Furthermore, we show that activation of ZAR1 in the plant cell led to Glu11-dependent Ca2+ influx, perturbation of subcellular structures, production of reactive oxygen species, and cell death. The results thus support that the ZAR1 resistosome acts as a calcium-permeable cation channel to trigger immunity and cell death.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Arabidopsis/metabolismo , Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Resistência à Doença/imunologia , Imunidade Vegetal , Transdução de Sinais , Animais , Morte Celular , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Ácido Glutâmico/metabolismo , Bicamadas Lipídicas/metabolismo , Oócitos/metabolismo , Células Vegetais/metabolismo , Multimerização Proteica , Protoplastos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Imagem Individual de Molécula , Vacúolos/metabolismo , Xenopus
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