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1.
Ying Yong Sheng Tai Xue Bao ; 32(12): 4315-4326, 2021 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-34951273

RESUMO

We analyzed the relationship between gross primary productivity (GPP) and environmental factors at Sidaoqiao Superstation of the Ejina Oasis in China's Gobi Desert, by combining eddy flux and meteorological data from 2018 to 2019 and Sentinel-2 remote sensing images from 2017 to 2020. We evaluated the applicability of 12 remote sensing vegetation indices to simulate the growth of Tamarix chinensis and extract key phenological metrics. A seven-parameter double-logistic function (DL-7) + global model function (GMF) was used to fit the growth curves of GPP and vegetation indices. Three key phenological metrics, i.e., the start of the growing season (SOS), the peak of the growing season (POS), and the end of the growing season (EOS), were extracted for each year. Growing season degree days (GDD) and soil water content were the main environmental factors affecting the phenological dynamics of T. chinensis. Compared with 2018, the lower temperatures in 2019 resulted in slower accumulation rate of accumulated temperature before the SOS. T. chinensis required longer heat accumulation to enter growing season, which might cause later SOS in 2019. The hydrothermal conditions between SOS and POS were similar for 2018 and 2019. Howe-ver, the POS in 2019 was 8 days later than that in 2018, because of the late SOS in 2019. Following the POS in 2019, high GDD and low soil water content caused the T. chinensis to suffer from water stress, resulting in a shortened late growing season. The linear regression between the standardized Sentinel-2 vegetation index and the average value of GPP between 10:00 and 14:00 indicated that the enhanced vegetation index of the broadband vegetation index and the chlorophyll red edge index, inverted red edge chlorophyll index, and red-edge normalized difference vegetation index (NDVI705) of the narrowband vegetation index were highly consistent with the GPP of T. chinensis. Remote sensing extraction of SOS and POS of T. chinensis suggested that the Sentinel-2 narrowband vegetation index was more accurate than the broadband vegetation index. The modified chlorophyll absorption in reflectance index provided the most accurate extraction of SOS, while the MERIS terrestrial chlorophyll index provided the most accurate extraction of EOS. Conversely, the Sentinel-2 broadband vegetation index was the most accurate for extracting POS, especially the 2-band enhanced vegetation index and the near-infrared reflectance of vegetation. Overall, NDVI705 was the best index to estimate phenological metrics.


Assuntos
Tamaricaceae , Benchmarking , Dióxido de Carbono , Tecnologia de Sensoriamento Remoto , Estações do Ano
2.
Am J Bot ; 108(8): 1343-1353, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34415569

RESUMO

PREMISE: Plants rely on pools of internal nonstructural carbohydrates (NSCs: soluble sugars plus starch) to support metabolism, growth, and regrowth of tissues damaged from disturbance such as foliage herbivory. However, impacts of foliage herbivory on the quantity and composition of NSC pools in long-lived woody plants are currently unclear. We implemented a controlled defoliation experiment on mature Tamarix spp.-a dominant riparian woody shrub/tree that has evolved with intense herbivory pressure-to test two interrelated hypotheses: (1) Repeated defoliation disproportionately impacts aboveground versus belowground NSC storage. (2) Defoliation disproportionately impacts starch versus soluble sugar storage. METHODS: Hypotheses were tested by transplanting six Tamarix seedlings into each of eight cylinder mesocosms (2 m diameter, 1 m in depth). After 2.5 years, plants in four of the eight mesocosms were mechanically defoliated repeatedly over a single growing season, and all plants were harvested in the following spring. RESULTS: Defoliation had no impact on either above- or belowground soluble sugar pools. However, starch in defoliated plants dropped to 55% and 26% in stems and roots, respectively, relative to control plants, resulting in an over 2-fold higher soluble sugar to starch ratio in defoliated plants. CONCLUSIONS: The results suggest that defoliation occurring over a single growing season does not impact immediate plant functions such as osmoregulation, but depleted starch could limit future fitness, particularly where defoliation occurs over multiple years. These results improve our understanding of how woody plants cope with episodic defoliation caused by foliage herbivory and other disturbances.


Assuntos
Tamaricaceae , Folhas de Planta , Amido , Açúcares , Árvores
3.
Plant Sci ; 310: 110976, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34315592

RESUMO

NAM, ATAF1/2, and CUC2 (NAC) proteins regulate plant responses to salt stress. However, the molecular mechanisms by which NAC proteins regulate salt-induced programmed cell death (PCD) are unclear. We identified 56 NAC genes, 35 of which had complete open reading frames with complete NAM domain, in the R. trigyna transcriptome. Salt stress and methyl jasmonate (MeJA) mediated PCD-induced leaf senescence in R. trigyna seedlings. Salt stress accelerated endogenous JA biosynthesis, upregulating RtNAC100 expression. This promoted salt-induced leaf senescence in R. trigyna by regulating RtRbohE and RtSAG12/20 and enhancing ROS accumulation. Transgenic assays showed that RtNAC100 overexpression aggravated salt-induced PCD in transgenic lines by promoting ROS and Na+ accumulation, ROS-Ca2+ hub activation, and PCD-related gene expression. Therefore, RtNAC100 induces PCD via the MeJA signaling pathway in R. trigyna under salt stress.


Assuntos
Acetatos/farmacologia , Ciclopentanos/farmacologia , Oxilipinas/farmacologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tamaricaceae/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Plantas Geneticamente Modificadas/genética , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Tamaricaceae/efeitos dos fármacos
4.
Artigo em Inglês | MEDLINE | ID: mdl-34323677

RESUMO

An aerobic, Gram-stain-negative, bacterium, designated CLL3-39T was isolated from seashore sediment collected at a Tamarix chinensis forest in the Marine Ecology Special Reserve of Changyi, Shandong Province, PR China. Cells of strain CLL3-39T were olive-shaped and no flagellum was observed. Strain CLL3-39T grew optimally at 33 °C, pH 7.5 and salinity (sea salts) of 40 g l-1. The main fatty acids in the cell membrane of strain CLL3-39T comprised anteiso-C15 : 0 (22.3 %), iso-C15 : 0 (14.0 %), C16 : 0 (9.2 %) and summed feature 8 (contains C18 : 1 ω7c/C18 : 1 ω6c. 26. 7 %). The main polar lipids of CLL3-39T were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylcholine. The respiratory quinone was Q10. The G+C content of the genomic DNA of strain CLL3-39T was 69.6 mol%. The average nucleotide identity between CLL3-39T and Pseudoroseicyclus aestuarii DB-4T was 74.7 % and the in silico DNA-DNA hybridization value was 20.1 %. Phylogenetically, strain CLL3-39T belonged to the genus Pseudoroseicyclus, branching with only one type strain P. aestuarii DB-4T with 96.3 % 16S rRNA gene similarity, followed by Limimaricola cinnabarinus LL-001T (95.2 %). Based on its phenotypic, phylogenetic and chemotaxonomic characteristics, we propose strain CLL3-39T (=MCCC 1A14815T =KCTC 72665T) as a representative of a novel species in the genus Pseudoroseicyclus, for which the name Pseudoroseicyclus tamaricis sp. nov. is proposed.


Assuntos
Tamaricaceae , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Florestas , Hibridização de Ácido Nucleico , Fosfolipídeos , Filogenia , RNA Ribossômico 16S/genética , Rhodobacteraceae , Água do Mar , Análise de Sequência de DNA
5.
Molecules ; 26(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208688

RESUMO

This study aimed to examine the extract of barks of Tamarix aphylla as a corrosion inhibitor. The methodology briefly includes plant sample collection, extraction of the corrosion inhibitor, gravimetric analysis, plotting potentiodynamic polarization plots, electrochemical impedance spectroscopic measurements, optimization of conditions, and preparation of the inhibitor products. The results show that the values of inhibition efficiency (IE%) increased as the concentrations of the inhibitor increased, with a maximum achievable inhibition efficiency of 85.0%. Potentiodynamic polarization (PP) tests revealed that the extract acts as a dual-type inhibitor. The results obtained from electrochemical impedance spectroscopy (EIS) measurements indicate an increase in polarisation resistance, confirming the inhibitive capacity of the tested inhibitor. The adsorption of the inhibitor on the steel surface follows the Langmuir adsorption isotherm model and involves competitive physio-sorption and chemisorption mechanisms. The EIS technique was utilized to investigate the effect of temperature on corrosion inhibition within the 298-328 K temperature range. Results confirm that the inhibition efficiency (IE%) of the inhibitor decreased slightly as the temperature increased. Lastly, the thermodynamic parameters for the inhibitor were calculated.


Assuntos
Aço/química , Tamaricaceae/química , Tamaricaceae/metabolismo , Carbono , Corrosão , Espectroscopia Dielétrica , Casca de Planta/química , Casca de Planta/metabolismo , Extratos Vegetais/química , Propriedades de Superfície , Termodinâmica
6.
Int J Mol Sci ; 22(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068763

RESUMO

Heat shock transcription factors (HSFs) play critical roles in several types of environmental stresses. However, the detailed regulatory mechanisms in response to salt stress are still largely unknown. In this study, we examined the salt-induced transcriptional responses of ThHSFA1-ThWRKY4 in Tamarix hispida and their functions and regulatory mechanisms in salt tolerance. ThHSFA1 protein acts as an upstream regulator that can directly activate ThWRKY4 expression by binding to the heat shock element (HSE) of the ThWRKY4 promoter using yeast one-hybrid (Y1H), chromatin immunoprecipitation (ChIP), and dual-luciferase reporter assays. ThHSFA1 and ThWRKY4 expression was significantly induced by salt stress and abscisic acid (ABA) treatment in the roots and leaves of T. hispida. ThHSFA1 is a nuclear-localized protein with transactivation activity at the C-terminus. Compared to nontransgenic plants, transgenic plants overexpressing ThHSFA1 displayed enhanced salt tolerance and exhibited reduced reactive oxygen species (ROS) levels and increased antioxidant enzyme activity levels under salt stress. Therefore, we further concluded that ThHSFA1 mediated the regulation of ThWRKY4 in response to salt stress in T. hispida.


Assuntos
Proteínas de Arabidopsis/genética , Fatores de Transcrição de Choque Térmico/genética , Estresse Salino/genética , Tamaricaceae/genética , Fatores de Transcrição/genética , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Estresse Salino/efeitos dos fármacos , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Sais/toxicidade , Tamaricaceae/efeitos dos fármacos , Tamaricaceae/crescimento & desenvolvimento
7.
Plant Physiol Biochem ; 165: 1-9, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34029940

RESUMO

Stress associated proteins (SAPs), a class of A20/AN1 zinc finger domain-containing proteins, are involved in a variety of biotic and abiotic stress responses in plants. However, little is known about the SAP gene family and their functions in Tamarix hispida. In this study, we isolated and characterized 11 SAPs from T. hispida. The expression patterns of ThSAPs were analyzed under various stresses (salt and drought) and phytohormone treatment (SA, ABA and MeJA) using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR). Most ThSAPs exhibited transcriptional responses to abiotic stresses and phytohormones. Among these ThSAPs, ThSAP6 was significantly induced by salt stress. Gain-and loss-of-function analyses revealed that ThSAP6 was a positive regulator of salt stress response. Overexpression of ThSAP6 in T. hispida increased antioxidant enzymes activity and proline content and decreased reactive oxygen species (ROS) accumulation and cell membrane damage under salt stress, while the opposite physiological changes were observed in ThSAP6-RNAi (RNA interference) lines. This study provides a comprehensive description of the SAP gene family in T. hispida, and demonstrates that ThSAP6 is a potential candidate for biotechnological approaches to improve salt tolerance in plants.


Assuntos
Tamaricaceae , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Tamaricaceae/genética , Tamaricaceae/metabolismo
8.
J Plant Res ; 134(5): 1121-1138, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34037878

RESUMO

Reaumuria trigyna, a Tamaricaceae archaic recretohalophyte, is an important feral forage plant in the desert steppe of northwestern China. We identified two significantly differentially expressed leucoanthocyanidin dioxygenase genes (RtLDOX/RtLDOX2) and investigated the function and characteristics of RtLDOX2. RtLDOX2 from R. trigyna was rapidly upregulated by salt, drought, and abscisic acid, consistent with the stress-related cis-regulatory elements in the promoter region. Recombinant RtLDOX2 converted dihydrokaempferol to kaempferol in vitro, and was thus interchangeable with flavonol synthase, a dioxygenase in the flavonoid pathway. Transgenic plants overexpressing RtLDOX2 accumulated more anthocyanin and flavonols under abiotic stresses, speculating that RtLDOX2 may act as a multifunctional dioxygenase in the synthesis of anthocyanins and flavonols. Overexpression of RtLDOX2 enhanced the primary root length, biomass accumulation, and chlorophyll content of salt-, drought-, and ultraviolet-B-stressed transgenic Arabidopsis. Antioxidant enzyme activity; proline content; and expression of antioxidant enzyme, proline biosynthesis, and ion-transporter genes were increased in transgenic plants. Therefore, RtLDOX2 confers tolerance to abiotic stress on transgenic Arabidopsis by promoting the accumulation of anthocyanins and flavonols. This in turn increases reactive oxygen species scavenging and activates other stress responses, such as osmotic adjustment and ion transport, and so improves tolerance to abiotic stresses.


Assuntos
Tamaricaceae , Antocianinas , Secas , Flavonoides , Regulação da Expressão Gênica de Plantas , Oxigenases , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal , Estresse Fisiológico , Tamaricaceae/genética , Tamaricaceae/metabolismo
9.
Plant Physiol Biochem ; 163: 27-35, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33812224

RESUMO

NAC (NAM, ATAF1/2 and CUC2) transcription factors play critical roles in plant development and abiotic stress responses, and aquaporins have diverse functions in environmental stress responses. In this study, we described the salt-induced transcriptional responses of ThNAC12 and ThPIP2;5 in Tamarix hispida, and their regulatory mechanisms in response to salt stress. Using yeast one-hybrid (Y1H), chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays, we identified that ThNAC12 directly binds to the NAC recognition sequence (NACRS) of the ThPIP2;5 promoter and then activates the ThPIP2;5 expression. Subcellular localization and transcriptional activation assays demonstrated that ThNAC12 was a nuclear protein with a C-terminal transactivation domain. Compared with the corresponding control plants, transgenic plants overexpressing ThNAC12 exhibited enhanced salt tolerance and displayed increased reactive oxygen species (ROS) scavenging capability and antioxidant enzyme activity levels under salt stress. All results suggested that overexpression of ThNAC12 in plants enhanced salt tolerance through modulation of ROS scavenging via direct regulation of ThPIP2;5 expression in T. hispida.


Assuntos
Tamaricaceae , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal , Estresse Fisiológico , Tamaricaceae/genética , Tamaricaceae/metabolismo
10.
Sci Total Environ ; 772: 145501, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-33571770

RESUMO

Construction of circumlittoral shelter forest is of great significance to maintain ecological security of coastal zones, the safety of people's lives and property in the Yellow River Delta (YRD) in China. Tamarix chinensis-grass patterns have shown obvious advantages in construction of circumlittoral shelter forest and improving the soil quality of coastal saline soil. This study aimed to explore the soil-improving effects of various Tamarix chinensis-grass community patterns and identify the best vegetation pattern for improving the soil quality in the coastal saline-alkali land. Six kinds of Tamarix chinensis-grass community patterns were selected from the saline-alkali soil of the YRD, with bare land as the control. Effects of different Tamarix chinensis-grass patterns on the coastal saline soil were evaluated using statistical methods (e.g. principal component analysis and fuzzy membership function method). The results showed that various Tamarix chinensis-grass community patterns significantly decreased the salt contents and increased the available nutrient contents in the coastal saline-alkali soil. The soil improvement effects showed obvious distinctions among the different Tamarix chinensis-grass patterns. The mixed forest-grass pattern consisting of Tamarix chinensis, Phragmites australis, and other salt-resistant grasses showed the best effects in relation to reducing salt, preventing alkalization and increasing the soil nutrients, which resulted in the lowest salt contents and the highest nutrients. Grass species play a major role in increasing soil nutrient contents, and the density of new Tamarix chinensis forest contributes greatly to the decrease of soil salt. And the more kinds of grass species are, the better improvement effects they will have. Therefore, during the construction of the circumlittoral shelter forest system in the muddy coastal zone of the YRD, it is recommended to prioritize the high density Tamarix chinensis-Phragmites australis (TPA) community pattern, and live together with other kinds of salt-resistant grasses.


Assuntos
Tamaricaceae , China , Humanos , Poaceae , Rios , Solo
11.
Microb Ecol ; 82(3): 652-665, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33598747

RESUMO

Coastal salinity typically alters the soil microbial communities, which subsequently affect the biogeochemical cycle of nutrients in the soil. The seasonal variation of the soil fungal communities in the coastal area, closely associated with plant population, is poorly understood. This study provides an insight into the fungal community's variations from autumn to winter and spring to summer at a well-populated area of salt-tolerant Tamarix chinensis and beach. The richness and diversity of fungal community were higher in the spring season and lower in the winter season, as showed by high throughput sequencing of the 18S rRNA gene. Ascomycota was the predominant phylum reported in all samples across the region, and higher difference was reported at order level across the seasonal variations. The redundancy analysis suggested that the abundance and diversity of fungal communities in different seasons are mainly correlated to total organic carbon and total nitrogen. Additionally, the saprotrophic and pathotrophic fungi decreased while symbiotic fungi increased in the autumn season. This study provides a pattern of seasonal variation in fungal community composition that further broadens our limited understanding of how the density of the salt-tolerant T. chinensis population of the coastal saline soil could respond to their seasonal variations.


Assuntos
Micobioma , Tamaricaceae , Baías , China , Fungos/genética , Estações do Ano , Solo , Microbiologia do Solo
12.
Int J Phytoremediation ; 23(2): 130-138, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32755391

RESUMO

Heavy metal polluted soils can be remediated using plants, a process called phytoremediation. However, high concentrations of heavy metals can negatively affect plant physiology and growth. We experimentally evaluated the effects of cadmium (Cd) on the growth, (i.e. height, shoot and biomass) and physiology (i.e. leaf chlorophyll and relative water contents) of Tamarix usneoides. In a greenhouse experiment, T. usneoides clones were subjected to a once off treatment of 100 mmol/l NaCl with three different Cd concentrations (6, 12, and 18 mg/kg) applied 3 times/week for eight weeks. We predicted that plant health would decrease with an increase in Cd concentration. Results revealed a 35.9% reduction in chlorophyll content between the 18 mg/kg Cd treated plants and the control, suggesting that T. usneoides experienced a reduction in photosynthetic rate, which in turn influenced the growth and relative water content (RWC) of the plant. Although T. usneoides' growth and physiology were significantly decreased at 12 and 18 mg/kg Cd concentrations, the plants tolerated up to 6 mg/kg Cd concentration, a level found in most anthropogenic Cd-contaminated soils. Tamarix usneoides should thus be confirmed as a good phytoremediation candidate once its ability to extract, translocate and concentrate Cd has been determined.


Assuntos
Metais Pesados , Poluentes do Solo , Tamaricaceae , Biodegradação Ambiental , Cádmio/análise , Cádmio/toxicidade , Metais Pesados/análise , Raízes de Plantas/química , Plantas Tolerantes a Sal , Solo , Poluentes do Solo/toxicidade
13.
Chemosphere ; 262: 127977, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182103

RESUMO

Coastal wetlands are ecologically and economically important; however, they are currently faced with fragmentation and loss. Plants are a fundamental element of wetlands and previous researches have focused on wetland plant connectivity; however, these researches have been conducted at the landscape but not species level. Here, given that tidal flats are important areas in coastal wetlands, we investigated the connectivity characteristics of typical plant species and environmental factors in different wetland regions influenced by various tidal conditions to reveal vegetation connectivity and its relationship with environmental factors on a small-patch scale. We found that tides negatively affect plant connectivity because both the Tamarix chinensis and Suaeda salsa have the highest connectivity on river banks, which are not influenced by tides. Of two tidal regions, different tides conditions have different influence on two plant species. T. chinensis had higher connectivity in the supratidal zone, whereas S. salsa had higher connectivity in the intertidal zone. Besides, the soil water content and soil salinity were significantly different in the three regions, but the soil total nitrogen and phosphorous were not. Soil water content and soil salinity were two factors that significantly affected plant connectivity. Specifically, soil water content positively affected the connectivity of T. chinensis and S. salsa, whereas soil salinity negatively affected the connectivity of T. chinensis. Taken together, these results indicate that tidal conditions affect plant connectivity on a small-patch scale. River banks and supratidal zone are beneficial for the recovery and growth of T. chinensis, intertidal zone and river banks are more conducive to the recovery and growth of S. salsa. Based on the above research, this study provides insights that could be applied to vegetation restoration in coastal wetlands.


Assuntos
Chenopodiaceae/crescimento & desenvolvimento , Rios/química , Solo/química , Tamaricaceae/crescimento & desenvolvimento , Ondas de Maré , Áreas Alagadas , China , Nitrogênio/análise , Fósforo/análise , Salinidade
14.
Plant Sci ; 302: 110668, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33288032

RESUMO

MYB transcription factors are important in abiotic stress responses; however, the detailed mechanisms are unclear. Tamarix hispida contains multiple MYB genes. The present study characterized T. hispida MYB8 (ThMYB8) during salt stress using transgenic T. hispida and Arabidopsis assays. ThMYB8 overexpression and ThMYB8 RNAi analysis demonstrated that ThMYB8 enhanced the salt stress tolerance. Transgenic Arabidopsis ectopic expression of ThMYB8 significantly increased root growth, fresh weight, and seed germination rate compared with that of the wild-type under salt stress. Physiological parameters analysis in T. hispida and Arabidopsis showed that ThMYB8 overexpressing plants had the lowest levels of O2, H2O2, cell death, malondialdehyde, and electrolyte leakage. Overexpression of ThMYB8 regulated Na+ and K+ concentrations in plant tissues while maintaining K+/Na+ homeostasis. Analysis using qRT-PCR and ChIP-PCR identified possible downstream ThMYB8-regulated genes. ThMYB8 regulated the expression of ThCYP450-2 (cytochrome p450-2), Thltk (leucine-rich repeat transmembrane protein kinase), and ThTIP (aquaporin TIP) by binding to the MBSI motif ('CAACTG') in their promoters. The results indicated that ThMYB8 enhanced salt stress tolerance in T. hispida by regulating gene expression related to the activation of stress-associated physiological changes, such as enhanced reactive oxygen species scavenging capability, maintaining K+/Na+ homeostasis, and decreasing the malondialdehyde content and lipid peroxidation cell membranes.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/fisiologia , Proteínas Proto-Oncogênicas c-myb/fisiologia , Plantas Tolerantes a Sal/metabolismo , Tamaricaceae/fisiologia , Árabes , Imunoprecipitação da Cromatina , Perfilação da Expressão Gênica , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estresse Salino , Plantas Tolerantes a Sal/genética , Análise de Sequência de DNA , Tamaricaceae/genética , Tamaricaceae/metabolismo , Técnicas do Sistema de Duplo-Híbrido
15.
Sci Total Environ ; 761: 143221, 2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33218805

RESUMO

Groundwater is the major source of water for Tamarix chinensis growth in the Yellow River Delta (YRD) region, and the groundwater depth (GWD) dramatically influences the physiological activities of T. chinensis. The quantitative response of the photosynthetic physiological process of T. chinensis to the GWD in freshwater habitats remains unclear. In this study, the response characteristics of gas exchange parameters in the leaves of three-year-old T. chinensis seedlings were measured and analyzed at a graded series of seven GWDs (0 m, 0.3 m, 0.6 m, 0.9 m, 1.2 m, 1.5 m and 1.8 m). The GWD thresholds corresponding to drastic changes in the photosynthetic efficiency and the GWDs of several levels of photosynthetic productivity and efficiency were also determined. In the freshwater habitats of the YRD, variations in GWD significantly altered the relative soil water content (RSWC) and thus influenced the photosynthetic efficiency of T. chinensis. RSWC at 0 ≤ GWD ≤ 0.9 m and GWD at 1.2 m ≤ GWD ≤ 1.8 m directly influenced the photosynthetic physiology of T. chinensis. When the GWD was 1.2 m, net photosynthetic rate (Pn), apparent quantum efficiency and water use efficiency (WUE) values all peaked. Thus, T. chinensis exhibited a high light and water use efficiency, wide ecological amplitude in terms of light, and high photosynthetic capacity. The optimum GWD for photosynthetic carbon assimilation and WUE in T. chinensis was determined to be 1.2 m. At a deep (≥1.64 m) or shallow (≤0.53 m) GWD, both Pn and WUE in T. chinensis clearly decreased below the corresponding mean values. The main causes for the reduction in Pn in these two GWD ranges (≤0.53 m, ≥1.64 m) were stomatal and nonstomatal limitations, respectively. Additionally, a moderate GWD of 1.09-1.25 m corresponded to the "high-productivity and high-efficiency GWD" range, in which T. chinensis displayed a high photosynthetic yield and WUE. Overall, the photosynthetic capacity of T. chinensis shows characteristics of high tolerance to moderate GWDs from 1.09 m to 1.25 m but intolerance at both shallow (≤0.53 m) and deep (≥1.64 m) GWDs in freshwater habitats.


Assuntos
Água Subterrânea , Tamaricaceae , Ecossistema , Fotossíntese , Folhas de Planta , Solo , Água
16.
Environ Sci Process Impacts ; 23(1): 73-85, 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33325952

RESUMO

We investigated the mechanisms of uranium (U) uptake by Tamarix (salt cedars) growing along the Rio Paguate, which flows throughout the Jackpile mine near Pueblo de Laguna, New Mexico. Tamarix were selected for this study due to the detection of U in the roots and shoots of field collected plants (0.6-58.9 mg kg-1), presenting an average bioconcentration factor greater than 1. Synchrotron-based micro X-ray fluorescence analyses of plant roots collected from the field indicate that the accumulation of U occurs in the cortex of the root. The mechanisms for U accumulation in the roots of Tamarix were further investigated in controlled-laboratory experiments where living roots of field plants were macerated for 24 h or 2 weeks in a solution containing 100 µM U. The U concentration in the solution decreased 36-59% after 24 h, and 49-65% in two weeks. Microscopic and spectroscopic analyses detected U precipitation in the root cell walls near the xylems of the roots, confirming the initial results from the field samples. High-resolution TEM was used to study the U fate inside the root cells, and needle-like U-P nanocrystals, with diameter <7 nm, were found entrapped inside vacuoles in cells. EXAFS shell-by-shell fitting suggest that U is associated with carbon functional groups. The preferable binding of U to the root cell walls may explain the U retention in the roots of Tamarix, followed by U-P crystal precipitation, and pinocytotic active transport and cellular entrapment. This process resulted in a limited translocation of U to the shoots in Tamarix plants. This study contributes to better understanding of the physicochemical mechanisms affecting the U uptake and accumulation by plants growing near contaminated sites.


Assuntos
Nanopartículas , Tamaricaceae , Urânio , New Mexico , Fósforo , Raízes de Plantas/química , Urânio/análise
17.
J Ethnopharmacol ; 269: 113692, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33321187

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Type 2 diabetes mellitus (DM) is a complicated metabolic disorder with no definite treatment. Different species of the genus Tamarix (tamarisk) are used by local people to treat DM. Tamarix stricta Boiss. is an endemic species to Iran with several traditional therapeutic uses in Persian Medicine. This study aimed to assess the antidiabetic activity of T. stricta. MATERIALS AND METHODS: Hydroethanolic extract of the plant was prepared and analyzed by High-performance liquid chromatography (HPLC). The protective effect of the extract was evaluated in streptozotocin (STZ)-induced toxicity and markers of autophagy in pancreatic RIN-5F cells. The effect of intragastric 10 or 20 mg/kg of the extract was compared with negative control (water) or positive control (metformin) treatment during four weeks of administration in high-fat diet + STZ-induced DM in Balb/c mice. RESULTS: Results showed the presence of 8.436 mg of gallic acid in each gram of the extract. A significant cytoprotective effect was observed by T. stricta in STZ-induced toxicity in RIN-5F cells, partially due to the modulation of autophagy. Also, animals treated with the extract showed a significant improvement in glycemic and lipid profiles, liver function, and histopathologic features of pancreas and liver compared with the negative control. CONCLUSION: T. stricta demonstrated beneficial effects in animal model of DM; though, further studies are recommended to confirm the clinical use of this plant in DM.


Assuntos
Autofagia/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Extratos Vegetais/uso terapêutico , Tamaricaceae , Animais , Autofagia/fisiologia , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/metabolismo , Dieta Hiperlipídica/efeitos adversos , Relação Dose-Resposta a Droga , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Ratos , Estreptozocina
18.
Plant Physiol Biochem ; 159: 135-147, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33360237

RESUMO

Reaumuria trigyna, an endangered recretohalophyte, is a small archaic wild shrub endemic to arid and semiarid plateau regions of Inner Mongolia, China. Based on salt-related transcriptomic data, we isolated a GRX family gene, glutaredoxin like protein (RtGRL1), from R. trigyna that is associated with the removal of active oxygen and regulation of redox status. RtGRL1 encodes a plasma membrane and chloroplast-localized protein induced by salt, cold, drought stress, ABA, and H2O2. In Arabidopsis thaliana, ectopically expressed RtGRL1 positively regulated biomass accumulation, chlorophyll content, germination rate, and primary root length under salt and drought stress. Overexpression of RtGRL1 induced expression of genes related to antioxidant enzymes and proline biosynthesis, thus increasing glutathione biosynthesis, glutathione-dependent detoxification of reactive oxygen species (ROS), and proline content under stress. Changes in RtGRL1 expression consistently affected glutathione/oxidizedglutathione and ascorbate/dehydroascorbate ratios and H2O2 concentrations. Furthermore, RtGRL1 promoted several GSH biosynthesis gene transcripts, decreased leaf Na+ content, and maintained lower Na+/K+ ratios in transgenic A. thaliana compared to wild type plants. These results suggest a critical link between RtGRL1 and ROS modulation, and contribute to a better understanding of the mechanisms governing plant responses to drought and salt stress.


Assuntos
Glutationa , Peróxido de Hidrogênio , Proteínas de Plantas , Estresse Fisiológico , Tamaricaceae , Arabidopsis/genética , China , Secas , Regulação da Expressão Gênica de Plantas , Glutarredoxinas/genética , Glutarredoxinas/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico/genética , Tamaricaceae/genética , Tamaricaceae/metabolismo
19.
Physiol Plant ; 172(2): 371-390, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32506430

RESUMO

Coal-mined areas are often associated with hostile environmental conditions where the scarcity of water and key nutrient resources negatively affect plant growth and development. In this study we specifically addressed how different combinations of water (W), nitrogen (N) and phosphorus (P) might affect morpho-physiological and biochemical attributes of a native shrub species, Tamarix chinensis, grown on coal mine spoils. Our results show that under greenhouse conditions the application of moderate-to-high doses of W, N and P considerably improved growth-associated parameters (i.e. plant height, stem diameter, dry weight), as well as gas-exchange parameters, photosynthetic pigment contents and leaf water status of T. chinensis. Under field conditions high W and low N, P doses led to significant increases in plant growth-associated traits, gas-exchange parameters and leaf water status. Plant growth was generally higher under greenhouse conditions mainly because seedlings faced multiple stress when growing under field conditions. Low W-regime, regardless of N-P additions, improved osmotic adjustments in leaf tissues and also boosted the activity of several antioxidant enzymes to reduce the oxidative stress associated with W scarcity under greenhouse conditions. Importantly, our study shows how maximum growth performance of T. chinensis under field conditions was achieved at W, N and P doses of 150 mm year-1 , 80 kg ha-1 and 40 kg ha-1 , respectively. Our findings suggest that achieving optimal rates of W, N and P application is crucial for promoting the ecological restoration of coal-mined areas with T. chinensis under arid environmental conditions.


Assuntos
Fertilizantes , Tamaricaceae , Carvão Mineral , Fotossíntese , Folhas de Planta , Água
20.
Zootaxa ; 4868(2): zootaxa.4868.2.7, 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33311403

RESUMO

Eight unrelated Thysanoptera species are known to be associated with the arid zone plant genus Tamarix [Tamaricaceae]. One new species, Lissothrips hemingi sp.n., is described from Iran based on specimens collected on branches of Tamarix. Liothrips jazykovi Moulton, described from specimens taken on Tamarix, is considered a new synonym of Liothrips reuteri (Bagnall), a widespread species on the foliage of this plant.


Assuntos
Tamaricaceae , Tisanópteros , Animais
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