Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
BMC Plant Biol ; 24(1): 407, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38755531

RESUMO

BACKGROUND: The goal of this research is to enhance the quality of cucumber seedlings grown in greenhouses by experimenting with various soilless culture mediums (CMs) and the application of pistachio wood vinegar (WV). The experimental setup was designed as a factorial experiment within a randomized complete block design (RCBD), in greenhouse conditions featuring three replications to assess the effects of different culture media (CMs) and concentrations of pistachio wood vinegar (WV) on cucumber seedling growth. Cucumber seeds were planted in three CMs: coco peat-peat moss, coco peat-vermicompost, and date palm compost-vermicompost mixed in a 75:25 volume-to-volume ratio. These were then treated with pistachio WV at concentrations of 0, 0.5, and 1%, applied four times during irrigation following the emergence of the third leaf. RESULTS: The study revealed that treating seedlings with 0.5% WV in the date palm compost-vermicompost CM significantly enhanced various growth parameters. Specifically, it resulted in a 90% increase in shoot fresh mass, a 59% increase in shoot dry mass, an 11% increase in root fresh mass, a 36% increase in root dry mass, a 65% increase in shoot length, a 62% increase in leaf area, a 25% increase in stem diameter, a 41% increase in relative water content (RWC), and a 6% improvement in membrane stability index (MSI), all in comparison to untreated seedlings grown in coco peat-peat moss CM. Furthermore, chlorophyll a, b, total chlorophyll, and carotenoid levels were 2.3, 2.7, 2.6, and 2.7 times higher, respectively, in seedlings treated with 0.5% WV and grown in the date palm compost-vermicompost CM, compared to those treated with the same concentration of WV but grown in coco peat-peat moss CM. Additionally, the Fv/Fm ratio saw a 52% increase. When plant nutrition was enhanced with the date palm compost-vermicompost CM and 1% WV, auxin content rose by 130% compared to seedlings grown in coco peat-peat moss CM and treated with 0.5% WV. CONCLUSIONS: The study demonstrates that using 0.5% WV in conjunction with date palm compost-vermicompost CM significantly betters the quality of cucumber seedlings, outperforming other treatment combinations.


Assuntos
Cucumis sativus , Plântula , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Cucumis sativus/crescimento & desenvolvimento , Cucumis sativus/fisiologia , Phoeniceae/fisiologia , Phoeniceae/crescimento & desenvolvimento , Ácido Acético/metabolismo , Pistacia/fisiologia , Pistacia/crescimento & desenvolvimento , Compostagem/métodos , Solo/química , Clorofila/metabolismo
2.
Sci Rep ; 10(1): 5585, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32221354

RESUMO

Long non-coding RNAs (lncRNAs) play crucial roles in regulating gene expression in response to plant stresses. Given the importance regulatory roles of lncRNAs, providing methods for predicting the function of these molecules, especially in non-model plants, is strongly demanded by researchers. Here, we constructed a reference sequence for lncRNAs in P. vera (Pistacia vera L.) with 53220 transcripts. In total, we identified 1909 and 2802 salt responsive lncRNAs in Ghazvini, a salt tolerant cultivar, after 6 and 24 h salt treatment, respectively and 1820 lncRNAs in Sarakhs, a salt sensitive cultivar, after 6 h salt treatment. Functional analysis of these lncRNAs by several hybrid methods, revealed that salt responsive NAT-related lncRNAs associated with transcription factors, CERK1, LEA, Laccase genes and several genes involved in the hormone signaling pathways. Moreover, gene ontology (GO) enrichment analysis of salt responsive target genes related to top five selected lncRNAs showed their involvement in the regulation of ATPase, cation transporter, kinase and UDP-glycosyltransferases genes. Quantitative real-time PCR (qRT-PCR) experiment results of lncRNAs, pre-miRNAs and mature miRNAs were in accordance with our RNA-seq analysis. In the present study, a comparative analysis of differentially expressed lncRNAs and microRNA precursors between salt tolerant and sensitive pistachio cultivars provides valuable knowledge on gene expression regulation under salt stress condition.


Assuntos
Pistacia/genética , RNA Longo não Codificante/genética , Tolerância ao Sal/genética , Sequência Conservada/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Estudo de Associação Genômica Ampla , Sequenciamento de Nucleotídeos em Larga Escala , Repetições de Microssatélites/genética , Pistacia/fisiologia , Estresse Salino , Transcriptoma/genética
3.
Physiol Plant ; 168(4): 973-989, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31670837

RESUMO

In this study, 7-month-old UCB-1, Badami, Ghazvini and Kale-Ghouchi pistachio rootstocks were exposed to control, drought, salinity and drought + salinity environments for 60 d. Total chlorophyll and total carotenoid contents decreased in all cultivars under drought, salinity and drought + salinity stresses. Under drought and salinity stresses, alone or in combination, Na+ and Cl- ions increased in all four pistachio rootstocks, while K+ ion decreased only in Ghazvini and Kaleh-Ghouchi cultivars. The enzyme activities of ascorbate peroxidase, polyphenol oxidase, catalase and guaiacol peroxidase increased in all cultivars when subjected to all three stresses with the exception of the ascorbate peroxidase activity in Kale-Ghouchi cultivar during drought stress. Oxidative stress parameters including electrolyte leakage, malondialdehyde, other aldehydes and hydrogen peroxide increased under all three stress conditions in all genotypes. The content of proline, total free amino acids and total soluble carbohydrates were enhanced under drought, salinity and drought + salinity stresses, whereas the protein content decreased in all pistachio rootstocks. In all evaluated traits, except for the K+ ion content and APX activity, the highest impacts was seen for drought + salinity > salinity > drought stresses, respectively. For the first time, we have proven that K+ ion content has a positive correlation with the ascorbate peroxidase, polyphenol oxidase, catalase and guaiacol peroxidase enzymes activities under drought + salinity stress. Finally, based on the bi-plot and cluster analyses, we have selected the UCB-1 > Badami > Ghazvini > Kale-Ghouchi cultivars as the most tolerant pistachio rootstocks under drought + salinity stress, respectively.


Assuntos
Secas , Pistacia/fisiologia , Salinidade , Estresse Fisiológico , Antioxidantes , Ascorbato Peroxidases , Catalase , Pistacia/enzimologia , Potássio , Estresse Salino
4.
Int J Biometeorol ; 62(12): 2245-2255, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30368676

RESUMO

Temperate deciduous trees can only be productive where winters are cold enough to meet their chilling needs. In the Mediterranean region, chill has traditionally been sufficient for many species, but this may change as temperatures increase. We explored the region's present and future suitability for temperate trees by quantifying chill for the Sfax region in central Tunisia, one of the warmest regions where temperate nuts are commercially grown. We assessed climatic risk by calculating historic chill (since 1973) and using a weather generator calibrated with local weather data (1973-2015) to produce 101 years of chill estimates (computed with the Dynamic Model) and 3 past and 72 future scenarios (for 2041-2070 and 2071-2100, using two representative concentration pathways: RCP4.5 and RCP8.5). For almonds and pistachios, we compared available chill during the chilling period with the species' estimated chilling requirements, and we computed the date by which sufficient chill was expected to have accumulated. Our findings indicated severe chill losses for all future scenarios. For all species, the current chill period is no longer expected to be sufficient for meeting chilling requirements in the future. Chill needs may still be fulfilled later in the year, especially for low-chill almonds, but this would result in delayed phenology, with possible adverse effects on productivity. Temperate nut production is thus unlikely to remain viable at this site, highlighting an urgent need to identify locally appropriate adaptation options. This challenge is likely shared by other warm production regions of temperate fruits and nuts around the world.


Assuntos
Mudança Climática , Pistacia/fisiologia , Prunus dulcis/fisiologia , Nozes , Estações do Ano , Tunísia
5.
Protoplasma ; 255(5): 1349-1362, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29527645

RESUMO

Pistachio, one of the important tree nuts, is cultivated in arid and semi-arid regions where salinity is the most common abiotic stress encountered by this tree. However, the mechanisms underlying salinity tolerance in this plant are not well understood. In the present study, five 1-year-old pistachio rootstocks (namely Akbari, Badami, Ghazvini, Kale-Ghouchi, and UCB-1) were treated with four saline water regimes (control, 8, 12, and 16 dS m-1) for 100 days. At high salinity level, all rootstocks showed decreased relative water content (RWC), total chlorophyll content (TCHC), and carotenoids in the leaf, while ascorbic acid (AsA) and total soluble proteins (TSP) were reduced in both leaf and root organs. In addition, the total phenolic compounds (TPC), proline, glycine betaine, total soluble carbohydrate (TSC), and H2O2 content increased under salinity stress in all studied rootstocks. Three different ion exclusion strategies were observed in the studied rootstocks: (i) Na+ exclusion in UCB-1, because most of its Na+ is retained in the roots; (ii) Cl- exclusion in Badami, in which most of its Cl- remained in the roots; and (iii) similar concentrations of Na+ and Cl- were observed in the leaves and roots of Ghazvini, Akbari, and Kale-Ghouchi. Transport capacity (ST value) of K+ over Na+ from the roots to the leaves was more observable in UCB-1 and Ghazvini. Overall, the root system cooperated more effectively in UCB-1 and Badami for retaining and detoxifying an excessive amount of Na+ and Cl-. The results presented here provide important inputs to better understand the salt tolerance mechanism in a tree species for developing more salt-tolerant genotypes. Based on the results obtained here, the studied rootstocks from tolerant to susceptible are arranged as follows: UCB-1 > Badami > Ghazvini > Kale-Ghouchi > Akbari.


Assuntos
Íons/metabolismo , Osmorregulação/fisiologia , Pistacia/metabolismo , Pistacia/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Homeostase/efeitos dos fármacos , Homeostase/fisiologia , Osmorregulação/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Pistacia/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Cloreto de Sódio/farmacologia
6.
Proc Natl Acad Sci U S A ; 115(8): 1825-1830, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29437956

RESUMO

Spatial patterning of periodic dynamics is a dramatic and ubiquitous ecological phenomenon arising in systems ranging from diseases to plants to mammals. The degree to which spatial correlations in cyclic dynamics are the result of endogenous factors related to local dynamics vs. exogenous forcing has been one of the central questions in ecology for nearly a century. With the goal of obtaining a robust explanation for correlations over space and time in dynamics that would apply to many systems, we base our analysis on the Ising model of statistical physics, which provides a fundamental mechanism of spatial patterning. We show, using 5 y of data on over 6,500 trees in a pistachio orchard, that annual nut production, in different years, exhibits both large-scale synchrony and self-similar, power-law decaying correlations consistent with the Ising model near criticality. Our approach demonstrates the possibility that short-range interactions can lead to long-range correlations over space and time of cyclic dynamics even in the presence of large environmental variability. We propose that root grafting could be the common mechanism leading to positive short-range interactions that explains the ubiquity of masting, correlated seed production over space through time, by trees.


Assuntos
Agricultura/métodos , Modelos Biológicos , Pistacia/fisiologia , Raízes de Plantas , Sementes
7.
Plant Biol (Stuttg) ; 20(2): 296-306, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29125662

RESUMO

Under natural conditions, light exposure for Mediterranean shrubs can be highly variable, especially during cloudy days or under a canopy, and can interfere with other environmental factors such as temperature and water availability. With the aim of decoupling the effect of radiation and temperature from water availability, we conducted an experiment where two perennial and three summer semi-deciduous shrub species were subjected to different levels of irradiation. In order to follow plant responses to light exposure, we measured gas exchange, photosystem II photochemical efficiency, photosynthetic pigments and leaf mass area in spring and summer. Results showed that all study species presented a plastic response to different light conditions, and that light-related traits varied in a coordinated manner. Summer semi-deciduous species exhibited a more opportunistic response, with higher photosynthesis rates in full sun, but under shade conditions, the two strategies presented similar assimilation rates. Stomatal conductance did not show such a drastic response as photosynthetsis, being related to changes in WUE. Daily cycles of Fv /Fm revealed a slight photoinhibitory response during summer, mainly in perennial species. In all cases photosynthetic pigments adjusted to the radiation level; leaves had lower chlorophyll content, higher pool of xanthophylls and higher proportion of the de-epoxydaded state of xanthophylls under sun conditions. Lutein content increased in relation to the xanthophyll pool under shade conditions. Our results evidenced that radiation is an important driving factor controlling morphological and physiological status of Mediterranean shrub species, independently of water availability. Summer semi-deciduous species exhibit a set of traits with higher response variability, maximising their photosynthetic assimilation under different sun conditions.


Assuntos
Cistus/fisiologia , Luz , Myrtus/fisiologia , Pistacia/fisiologia , Rosmarinus/fisiologia , Clorofila/análise , Luteína/análise , Região do Mediterrâneo , Complexo de Proteína do Fotossistema II/fisiologia , Folhas de Planta/química , Folhas de Planta/fisiologia , Xantofilas/análise
8.
BMC Genomics ; 18(1): 627, 2017 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-28814265

RESUMO

BACKGROUND: Pistachio (Pistacia vera L.) is one of the most important commercial nut crops worldwide. It is a salt-tolerant and long-lived tree, with the largest cultivation area in Iran. Climate change and subsequent increased soil salt content have adversely affected the pistachio yield in recent years. However, the lack of genomic/global transcriptomic sequences on P. vera impedes comprehensive researches at the molecular level. Hence, whole transcriptome sequencing is required to gain insight into functional genes and pathways in response to salt stress. RESULTS: RNA sequencing of a pooled sample representing 24 different tissues of two pistachio cultivars with contrasting salinity tolerance under control and salt treatment by Illumina Hiseq 2000 platform resulted in 368,953,262 clean 100 bp paired-ends reads (90 Gb). Following creating several assemblies and assessing their quality from multiple perspectives, we found that using the annotation-based metrics together with the length-based parameters allows an improved assessment of the transcriptome assembly quality, compared to the solely use of the length-based parameters. The generated assembly by Trinity was adopted for functional annotation and subsequent analyses. In total, 29,119 contigs annotated against all of five public databases, including NR, UniProt, TAIR10, KOG and InterProScan. Among 279 KEGG pathways supported by our assembly, we further examined the pathways involved in the plant hormone biosynthesis and signaling as well as those to be contributed to secondary metabolite biosynthesis due to their importance under salinity stress. In total, 11,337 SSRs were also identified, which the most abundant being dinucleotide repeats. Besides, 13,097 transcripts as candidate stress-responsive genes were identified. Expression of some of these genes experimentally validated through quantitative real-time PCR (qRT-PCR) that further confirmed the accuracy of the assembly. From this analysis, the contrasting expression pattern of NCED3 and SOS1 genes were observed between salt-sensitive and salt-tolerant cultivars. CONCLUSION: This study, as the first report on the whole transcriptome survey of P. vera, provides important resources and paves the way for functional and comparative genomic studies on this major tree to discover the salinity tolerance-related markers and stress response mechanisms for breeding of new pistachio cultivars with more salinity tolerance.


Assuntos
Perfilação da Expressão Gênica , Genômica , Pistacia/genética , Salinidade , Sequência Conservada , Flavonoides/biossíntese , Marcadores Genéticos/genética , Repetições de Microssatélites/genética , Anotação de Sequência Molecular , Pistacia/metabolismo , Pistacia/fisiologia , Reguladores de Crescimento de Plantas/genética , Estresse Fisiológico/genética , Fatores de Transcrição/genética
9.
Planta ; 245(3): 671-679, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27995314

RESUMO

Main conclusion Cold acclimation is revealed through induced stem respiration during pre-winter frost of native Pistacia integerrima trees in continental semi-arid environments. Semi-arid environments challenge vegetation by simultaneous abiotic stresses. In this study, we examine the combined effects of water stress and frost on the physiology of Pistacia integerrima stems. This species is native to semi-arid environments where drought and frost frequently co-occur. We quantified carbohydrates and proline in P. integerrima stems responding to frost and experiencing water potentials between -0.2 and -1.8 MPa. We report that dehydrated trees (i.e., Ψstem <=-1 MPa) had more soluble sugars and proline than the well-watered trees (-0.2 MPa). The dehydrated trees also froze at lower temperatures and were less damaged by freezing. Interestingly, we observed a significant increase in stem CO2 efflux at near-freezing temperatures that could be linked to frost protection. This novel finding challenges current paradigm of plant respiration-kinetics which predicts, according to Arrhenius equation, lower respiration rates during frost. Our results support the notion that drought and frost are analogous stresses that can independently activate corresponding physiological processes in trees and amplify protection. This inevitable stress response 'collaboration' may be the key to understanding how non-dormant perennial plants survive the highly variable weather patterns of early winters in semi-arid environments.


Assuntos
Aclimatação/fisiologia , Clima Desértico , Secas , Congelamento , Pistacia/fisiologia , Árvores/fisiologia , Carboidratos/análise , Respiração Celular , Caules de Planta/fisiologia , Prolina/análise , Solubilidade
10.
J Environ Radioact ; 174: 71-77, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27577696

RESUMO

The activity levels of naturally occurring radionuclides Polonium-210 and lead-210 in different subjects including plant species have direct or indirect impact on human beings. High levels of ionising radiation cause oxidative stress and the interaction between antioxidative defense and radionuclides is not well established in plant systems. In this study, we aimed to understand the impact of oxidative stress caused by 210Po and 210Pb in two Mediterranean plants; Quercus coccifera and Pistacia lentiscus. We analysed the constitutive and seasonal levels of 210Po, 210Pb, lipid peroxidation levels, superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in the field-collected samples. The highest activity concentrations of 210Po and 210Pb were detected in both plants in summer and Q. coccifera had higher levels than that of P. lentiscus. SOD and APX activity trends were different between oak and mastic; as compared to P. lentiscus, Q. coccifera efficiently used the two major components of antioxidative defense. Lipid peroxidation levels were low in both plants in all seasons except that of spring which were in good agreement with high antioxidant enzyme activities. In conclusion, we found that high 210Po and 210Pb activity concentrations in oak and mastic did not interfere with their growth and life cycles. The ability of both plants for survival and adaptation to Mediterranean environmental constraints provided an additional advantage for coping radionuclide induced oxidative stress as well.


Assuntos
Radioisótopos de Chumbo/toxicidade , Pistacia/fisiologia , Polônio/análise , Quercus/fisiologia , Catalase/metabolismo , Clorofila/metabolismo , Radioisótopos de Chumbo/análise , Peroxidação de Lipídeos/efeitos da radiação , Estresse Oxidativo , Pistacia/efeitos da radiação , Folhas de Planta/metabolismo , Polônio/toxicidade , Quercus/efeitos da radiação , Superóxido Dismutase/metabolismo
11.
Nat Prod Res ; 31(7): 765-772, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27712103

RESUMO

The metabolic profiling of pistachio (Pistacia vera) aqueous extracts from two different cultivars, namely 'Bianca' and 'Gloria', was monitored over the months from May to September employing high field NMR spectroscopy. A large number of water-soluble metabolites were assigned by means of 1D and 2D NMR experiments. The change in the metabolic profiles monitored over time allowed the pistachio development to be investigated. Specific temporal trends of amino acids, sugars, organic acids and other metabolites were observed and analysed by multivariate Partial Least Squares (PLS) analysis. Statistical analysis showed that while in the period from May to September there were few differences between the two cultivars, the ripening rate was different.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Metaboloma/fisiologia , Pistacia/fisiologia , Aminoácidos/análise , Metabolismo dos Carboidratos , Carboidratos/análise , Metabolômica/métodos , Monitorização Fisiológica/métodos , Pistacia/química
12.
J Exp Bot ; 65(4): 1039-49, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24378602

RESUMO

Sex-related differences in the response of dioecious plants to abiotic stress have been poorly studied to date. This work explored to what extent sex may affect plant stress responses in Pistacia lentiscus L. (Anacardiaceae), a tree well adapted to Mediterranean climatic conditions. It was hypothesized that a greater reproductive effort in females may increase oxidative stress in leaves, particularly when plants are exposed to abiotic stress. Measurements of oxidative stress markers throughout the year revealed increased lipid peroxidation in females, but only during the winter. Enhanced lipid peroxidation in females was associated with reduced photoprotection, as indicated by reduced tocopherol levels and nonphotochemical quenching (NPQ) of chlorophyll fluorescence. Enhanced lipid peroxidation in females was also observed at predawn, which was associated with increased lipoxygenase activity and reduced cytokinin levels. An analysis of the differences between reproductive (R) and nonreproductive (NR) shoots showed an enhanced photoprotective capacity in R shoots compared to NR shoots in females. This capacity was characterized by an increased NPQ and a better antioxidant protection (increased carotenoid and tocopherol levels per unit of chlorophyll) in R compared to NR shoots. It is concluded that (i) females exhibit higher lipid peroxidation in leaves than males, but only during the winter (when sex-related differences in reproductive effort are the highest), (ii) this is associated with a lower photoprotective capacity at midday, as well as enhanced lipoxygenase activity and reduced cytokinin levels at predawn, and (iii) photoprotection capacity is higher in R relative to NR shoots in females.


Assuntos
Pistacia/fisiologia , Pistacia/efeitos da radiação , Antioxidantes/metabolismo , Clorofila/metabolismo , Ritmo Circadiano , Citocininas/metabolismo , Frutas/fisiologia , Frutas/efeitos da radiação , Luz , Peroxidação de Lipídeos/fisiologia , Lipoxigenase/metabolismo , Especificidade de Órgãos , Estresse Oxidativo , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Raízes de Plantas/fisiologia , Raízes de Plantas/efeitos da radiação , Brotos de Planta/fisiologia , Brotos de Planta/efeitos da radiação , Reprodução , Estações do Ano , Árvores , alfa-Tocoferol/metabolismo
13.
BMC Evol Biol ; 13: 193, 2013 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-24020365

RESUMO

BACKGROUND: Plants have evolved an astonishing array of survival strategies. To defend against insects, for example, damaged plants emit volatile organic compounds that attract the herbivore's natural enemies. So far, plant volatile responses have been studied extensively in conjunction with leaf chewing and sap sucking insects, yet little is known about the relationship between plant volatiles and gall-inducers, the most sophisticated herbivores. Here we describe a new role for volatiles as gall-insects were found to benefit from this plant defence. RESULTS: Chemical analyses of galls triggered by the gregarious aphid Slavum wertheimae on wild pistachio trees showed that these structures contained and emitted considerably higher quantities of plant terpenes than neighbouring leaves and fruits. Behavioural assays using goats as a generalist herbivore confirmed that the accumulated terpenes acted as olfactory signals and feeding deterrents, thus enabling the gall-inducers to escape from inadvertent predation by mammals. CONCLUSIONS: Increased emission of plant volatiles in response to insect activity is commonly looked upon as a "cry for help" by the plant to attract the insect's natural enemies. In contrast, we show that such volatiles can serve as a first line of insect defences that extends the 'extended phenotype' represented by galls, beyond physical boundaries. Our data support the Enemy hypothesis insofar that high levels of gall secondary metabolites confer protection against natural enemies.


Assuntos
Afídeos , Pistacia/química , Pistacia/fisiologia , Compostos Orgânicos Voláteis/metabolismo , Animais , Cabras , Herbivoria , Folhas de Planta
14.
Tree Physiol ; 33(2): 211-20, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23329334

RESUMO

Drought stress can induce closure of stomata, thus leading to photoinhibition. The effects of prolonged severe drought under natural growing conditions on photosystem I (PSI), photosystem II (PSII) and cyclic electron flow (CEF) in drought-tolerant tree species are unclear. In spring 2010, southwestern China confronted severe drought that lasted several months. Using three dominant evergreen species, Cleistanthus sumatranus (Miq.) Muell. Arg. (Euphorbiaceae), Celtis philippensis Bl. (Ulmaceae) and Pistacia weinmannifolia J. Poisson ex Franch. (Anacardiaceae) that are native to a tropical limestone forest, we investigated the influence of this stress on PSI and PSII activities as well as light energy distribution in the PSII and P700 redox state. By the end of the drought period, predawn leaf water potential (Ψ(pd)) largely declined in each species, especially in C. sumatranus. Photosystem I activity strongly decreased in the three species, especially in C. sumatranus which showed a decrease of 65%. The maximum quantum yield of PSII after dark adaptation remained stable in P. weinmannifolia and C. philippensis but significantly decreased in C. sumatranus. Light response curves indicated that both linear electron flow and non-photochemical quenching were severely inhibited in C. sumatranus along with disappearance of CEF, resulting in deleterious excess light energy in PSII. We conclude that PSI is more sensitive than PSII to prolonged severe drought in these three drought-tolerant species, and CEF is essential for photoprotection in them.


Assuntos
Adaptação Fisiológica/fisiologia , Magnoliopsida/fisiologia , Complexo de Proteína do Fotossistema I/fisiologia , Complexo de Proteína do Fotossistema II/fisiologia , Água/fisiologia , Carbonato de Cálcio , Clorofila/metabolismo , Escuridão , Secas , Transporte de Elétrons , Luz , Magnoliopsida/efeitos da radiação , Oxirredução , Fotossíntese/fisiologia , Fotossíntese/efeitos da radiação , Complexo de Proteína do Fotossistema I/efeitos da radiação , Complexo de Proteína do Fotossistema II/efeitos da radiação , Pistacia/fisiologia , Pistacia/efeitos da radiação , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Transpiração Vegetal/fisiologia , Estações do Ano , Estresse Fisiológico/fisiologia , Árvores , Ulmaceae/fisiologia , Ulmaceae/efeitos da radiação
15.
Ying Yong Sheng Tai Xue Bao ; 24(9): 2479-84, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24417104

RESUMO

By using fast chlorophyll fluorescence induction dynamics analysis technique (JIP-test), this paper studied the photosynthesis characteristics and fast chlorophyll fluorescence induction dynamics of 1-year old Pistacia chinensis seedlings under the stress of NaCl at the concentrations 0% (CK), 0.15%, 0.3%, 0.45%, and 0.6%. With the increasing concentration of NaCl, the contents of Chl a, Chl b, and Chl (a+b) in the seedlings leaves decreased, the Chl a/b ratio decreased after an initial increase, and the carotenoid content increased. The net photosynthetic rate (P(n)) and stomatal conductance (g(s)) decreased gradually with increasing NaCl concentration. The decrease of P(n) was mainly attributed to the stomatal limitation when the NaCl concentration was lower than 0.3%, and to the non-stomatal limitation when the NaCl concentration was higher than 0.3%. The trapped energy flux per RC (TR0/CS0), electron transport flux per RC (ET0/CS0), density of RCs (RC/CS0), and yield or flux ratio (psi(0) or phi(E0)) decreased, but the absorption flux per CS (ABS/CS0) and the K phase (W(k)) and J phase (V) in the O-J-I-P chlorophyll fluorescence induction curves increased distinctly, indicating that NaCl stress damaged the leaf oxygen-evolving complex (OEC), donor sides, and PS II reaction centers. When the NaCl concentration reached 0.3%, the maximum photochemical efficiency (F(v)/F(m)) and performance index (PI(ABS)) decreased 17.7% and 36.6%, respectively, as compared with the control.


Assuntos
Clorofila/fisiologia , Fotossíntese/efeitos dos fármacos , Pistacia/fisiologia , Cloreto de Sódio/farmacologia , Estresse Fisiológico , Fluorescência , Folhas de Planta/fisiologia
16.
J Integr Plant Biol ; 54(8): 584-94, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22765357

RESUMO

Leaf senescence is a complex phenomenon occurring in all plant species, but it is still poorly understood in plants grown in Mediterranean field conditions and well-adapted to harsh climatic conditions. To better understand the physiological processes underlying leaf senescence in mastic trees (Pistacia lentiscus L.), we evaluated leaf growth, water and N content, photosystem II (PSII) photochemistry, lipid peroxidation and levels of photosynthetic pigments, antioxidants, abscisic acid, and salicylic acid and jasmonic acid during the complete leaf lifespan, from early expansion to late senescence in relation to natural climatic conditions in the field. While mature leaves suffered from water and N deficit during late spring and summer, both young (emerging) and old (senescing) leaves were most sensitive to photo-oxidative stress, as indicated by reductions in the F(v)/F(m) ratio and enhanced lipid peroxidation during late autumn and winter. Reductions in the F(v)/F(m) ratio were associated with low α-tocopherol (vitamin E) levels, while very old, senescing leaves additionally showed severe anthocyanin losses. We have concluded that both young (emerging) and old (senescing) leaves suffer oxidative stress in mastic trees, which may be linked in part to suboptimal temperatures during late autumn and winter as well as to low vitamin E levels.


Assuntos
Estresse Oxidativo , Pistacia/fisiologia , Folhas de Planta/fisiologia , Árvores/fisiologia , Antocianinas/metabolismo , Clima , Complexo de Proteína do Fotossistema II/metabolismo , Reguladores de Crescimento de Plantas/metabolismo
17.
Oecologia ; 170(4): 899-908, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22717626

RESUMO

Plants respond to low nutrient availability by modifying root morphology and root system topology. Root responses to nitrogen (N) and phosphorus (P) limitation may affect plant capacity to withstand water stress. But studies on the effect of nutrient availability on plant ability to uptake and transport water are scarce. In this study, we assess the effect of nitrogen and phosphorus limitation on root morphology and root system topology in Pistacia lentiscus L seedlings, a common Mediterranean shrub, and relate these changes to hydraulic conductivity of the whole root system. Nitrogen and phosphorus deprivation had no effect on root biomass, but root systems were more branched in nutrient limited seedlings. Total root length was higher in seedlings subjected to phosphorus deprivation. Root hydraulic conductance decreased in nutrient-deprived seedlings, and was related to the number of root junctions but not to other architectural traits. Our study shows that changes in nutrient availability affect seedling water use by modifying root architecture. Changes in nutrient availability should be taken into account when evaluating seedling response to drought.


Assuntos
Pistacia/fisiologia , Raízes de Plantas/fisiologia , Adaptação Fisiológica , Secas , Nitrogênio/metabolismo , Fósforo/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Plântula/fisiologia
18.
ScientificWorldJournal ; 2012: 971903, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22645486

RESUMO

A field survey was carried out to record plant species climbed by Ephedra alte in certain parts of Jordan during 2008-2010. Forty species of shrubs, ornamental, fruit, and forest trees belonging to 24 plant families suffered from the climbing habit of E. alte. Growth of host plants was adversely affected by E. alte growth that extended over their vegetation. In addition to its possible competition for water and nutrients, the extensive growth it forms over host species prevents photosynthesis, smothers growth and makes plants die underneath the extensive cover. However, E. alte did not climb all plant species, indicating a host preference range. Damaged fruit trees included Amygdalus communis, Citrus aurantifolia, Ficus carica, Olea europaea, Opuntia ficus-indica, and Punica granatum. Forestry species that were adversely affected included Acacia cyanophylla, Ceratonia siliqua, Crataegus azarolus, Cupressus sempervirens, Pinus halepensis, Pistacia atlantica, Pistacia palaestina, Quercus coccifera, Quercus infectoria, Retama raetam, Rhamnus palaestina, Rhus tripartita, and Zizyphus spina-christi. Woody ornamentals attacked were Ailanthus altissima, Hedera helix, Jasminum fruticans, Jasminum grandiflorum, Nerium oleander, and Pyracantha coccinea. Results indicated that E. alte is a strong competitive for light and can completely smother plants supporting its growth. A. communis, F. carica, R. palaestina, and C. azarolus were most frequently attacked.


Assuntos
Ephedra/fisiologia , Frutas/fisiologia , Plantas Daninhas/fisiologia , Ecologia , Meio Ambiente , Agricultura Florestal , Espécies Introduzidas , Jordânia , Fotossíntese , Pinus/fisiologia , Pistacia/fisiologia , Quercus/fisiologia , Especificidade da Espécie , Fatores de Tempo , Árvores
19.
J Plant Physiol ; 169(7): 704-9, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22418429

RESUMO

The influence of Glomus etunicatum colonization on plant growth and drought tolerance of 3-month-old Pistacia vera seedlings in potted culture was studied in two different water treatments. The arbuscular mycorrhiza (AM) inoculation and plant growth (including plant shoot and root weight, leaf area, and total chlorophyll) were higher for well-watered than for water-stressed plants. The growth of AM-treated seedlings was higher than non-AM-treatment regardless of water status. P, K, Zn and Cu contents in AM-treated shoots were greater than those in non-AM shoots under well-watered conditions and drought stress. N and Ca content were higher under drought stress, while AM symbiosis did not affect the Mg content. The contents of soluble sugars, proteins, flavonoid and proline were higher in mycorrhizal than non-mycorrhizal-treated plants under the whole water regime. AM colonization increased the activities of peroxidase enzyme in treatments, but did not affect the catalase activity in shoots and roots under well-watered conditions and drought stress. We conclude that AM colonization improved the drought tolerance of P. vera seedlings by increasing the accumulation of osmotic adjustment compounds, nutritional and antioxidant enzyme activity. It appears that AM formation enhanced the drought tolerance of pistachio plants, which increased host biomass and plant growth.


Assuntos
Antioxidantes/metabolismo , Glomeromycota/fisiologia , Micorrizas/fisiologia , Pistacia/fisiologia , Água/fisiologia , Biomassa , Clorofila/metabolismo , Secas , Osmose , Pistacia/crescimento & desenvolvimento , Pistacia/microbiologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/fisiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Plântula/fisiologia , Estresse Fisiológico , Simbiose
20.
Nutr Rev ; 70(4): 234-40, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22458696

RESUMO

The pistachio is a nutrient-dense nut with a heart-healthy fatty-acid profile as well as protein, dietary fiber, potassium, magnesium, vitamin K, γ-tocopherol, and a number of phytochemicals. The pistachio's unique green and purple kernel color is a result of its lutein and anthocyanin content. Among nuts, pistachios contain the highest levels of potassium, γ-tocopherol, vitamin K, phytosterols, and xanthophyll carotenoids. Five published randomized cardiovascular trials have shown that pistachios promote heart-healthy blood lipid profiles. Exploratory clinical studies suggest that pistachios help maintain healthy antioxidant and anti-inflammatory activity, glycemic control, and endothelial function. When consumed in moderation, pistachios may help control body weight because of their satiety and satiation effects and their reduced net metabolizable energy content. One study with subjects in a weight-loss program demonstrated lower body mass index and triglyceride levels in individuals who consumed pistachios compared with those who consumed an isocaloric pretzel snack. Emerging research suggests that the addition of pistachios to high-glycemic meals may lower the overall postprandial glycemic response. This review examines the nutrients and phytochemicals in pistachios as well as the potential health effects of these nuts.


Assuntos
Pistacia/química , Antioxidantes/administração & dosagem , Antioxidantes/metabolismo , Glicemia/metabolismo , Peso Corporal , Doenças Cardiovasculares/prevenção & controle , Humanos , Valor Nutritivo , Fitosteróis/administração & dosagem , Fitosteróis/metabolismo , Pistacia/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...