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1.
Int J Mol Sci ; 23(17)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-36076949

RESUMO

Light is one of the most important environmental cues that affects plant development and regulates its behavior. Light stress directly inhibits physiological responses and plant tissue development and even induces mortality in plants. Korean pine (Pinus koraiensis) is an evergreen conifer species widely planted in northeast China that has important economic and ecological value. However, the effects of light stress on the growth and development of Korean pine are still unclear. In this study, the effects of different shading conditions on physiological indices, molecular mechanisms and metabolites of Korean pine were explored. The results showed that auxin, gibberellin and abscisic acid were significantly increased under all shading conditions compared with the control. The contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid also increased as the shading degree increased. Moreover, a total of 8556, 3751 and 6990 differentially expressed genes (DEGs) were found between the control and HS (heavy shade), control and LS (light shade), LS vs. HS, respectively. Notably, most DEGs were assigned to pathways of phytohormone signaling, photosynthesis, carotenoid and flavonoid biosynthesis under light stress. The transcription factors MYB-related, AP2-ERF and bHLH specifically increased expression during light stress. A total of 911 metabolites were identified, and 243 differentially accumulated metabolites (DAMs) were detected, among which flavonoid biosynthesis (naringenin chalcone, dihydrokaempferol and kaempferol) metabolites were significantly different under light stress. These results will provide a theoretical basis for the response of P. koraiensis to different light stresses.


Assuntos
Pinus , Carotenoides/metabolismo , Clorofila A/metabolismo , Flavonoides/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Pinus/metabolismo , Transcriptoma
2.
Molecules ; 27(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36080426

RESUMO

Pinus species are important in traditional medicine throughout their ranges, and pine essential oils are of interest in aromatherapy and as topical treatments. In this work, the leaf (needle) essential oils of Pinus ponderosa var. ponderosa and Pinus contorta subsp. contorta from Oregon and Pinus flexilis growing in Idaho, have been obtained by hydrodistillation and analyzed by gas chromatographic techniques. The leaf essential oil of P. ponderosa was dominated by ß-pinene (21.5-55.3%), methyl chavicol (8.5-41.5%), α-pinene (3.6-9.6%), δ-3-carene (3.6-6.2%), and α-terpineol (1.4-5.3%). The major components of P. contorta essential oil were ß-phellandrene (23.8%), terpinen-4-ol (11.0%). The essential oil of P. flexilis was dominated by α-pinene (37.1%), ß-pinene (21.9%), bornyl acetate (12.8%), and camphene (8.5%). Chiral gas chromatography revealed the enantiomeric ratios of α-pinene and limonene to be variable, but (-)-ß-pinene predominated in Pinus essential oils.


Assuntos
Aromaterapia , Óleos Voláteis , Pinus , Limoneno , Óleos Voláteis/química , Pinus/química , Terpenos
3.
Environ Monit Assess ; 194(10): 755, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36083387

RESUMO

Mercury (Hg) concentrations in soils and Hg releases from soils during wildfires are not well characterised in Portugal, even though wildfire activity continues to increase around the Mediterranean. This study focused on the low to moderate severity wildfire in Pombal (Portugal) in 2019, which consumed 12.5 ha of maritime pine (Pinus pinaster Ait.). We evaluated Hg concentrations in soil profiles and Hg pools in organic horizons to assess the fire-induced Hg emissions. Moreover, impacts of the fire on forest floor properties were estimated. Four soil profiles were sampled, two at the burned area and two at a nearby unburned area. The soil profiles displayed a typical Hg distribution, with higher Hg concentrations (156 µg kg-1) in the organic horizons with a sharp decrease in the mineral layers. The bond between organic matter and Hg was evident along the profiles, with a strong correlation between TOC and Hg. Ratios of Hg/TOC in the surface layers of the soil were similar in all profiles. The mean organic Hg pool at the studied site was calculated at 10.6 g ha-1. The fire did not seem to affect the topsoil properties based on visual indicators and the lack of statistical differences (p > 0.05) among measured fire-sensitive chemical soil properties (pH, CEC, TOC, TS) between the topsoils of the burned and unburned areas. If we consider a hypothetical complete combustion of the organic layer (743 Mg) and unaffected topsoil, we estimated a release of 133 g of Hg from the burned area. The study emphasised the importance of the forest floor for Hg retention and its crucial role in Hg emissions during wildfires in a country increasingly affected by climate change.


Assuntos
Mercúrio , Pinus , Poluentes do Solo , Incêndios Florestais , Monitoramento Ambiental , Florestas , Mercúrio/análise , Portugal , Solo , Poluentes do Solo/análise
4.
Radiat Prot Dosimetry ; 198(13-15): 1131-1136, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36083725

RESUMO

Since the Fukushima Dai-ichi Nuclear Power Plant (FDNNP) accident in 2011, 134Cs had been detected in atmospheric deposition samples collected in Rokkasho and Aomori in Japan, located ~400-km north of the FDNNP, during March 2011-May 2015. To study the distribution of radiocesium (134, 137Cs) in a Japanese black pine tree forest, we measured the activity concentration of 134, 137Cs in whole black pine trees, including roots collected during 2017-19 along with soil samples in 2015 and 2017-19. The results show that most of the deposited 134Cs was retained in the forest floor in 2015, with depth distribution different from that of the weapon testing fallout. Proportions of the weapon fallout 137Cs in trunks, branches, needles and roots were 44, 17, 13 and 26%, respectively, indicating that >50% of 137Cs in above-ground part existed in the trunks. The total inventories of 134Cs and 137Cs in the forest were estimated to be 8.9 and 2.5·103 Bq m-2, respectively, and ~4.8% of 137Cs inventory was originated from the accident. Inventory of 134Cs in the forest-including the black pine trees-was 1.6 times larger than cumulative deposition outside of the forest due to the canopy effect.


Assuntos
Acidente Nuclear de Fukushima , Pinus , Monitoramento de Radiação , Poluentes Radioativos do Solo , Radioisótopos de Césio/análise , Florestas , Japão , Monitoramento de Radiação/métodos , Poluentes Radioativos do Solo/análise
5.
Biomed Pharmacother ; 153: 113501, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36076511

RESUMO

Pinus koraiensis leaf (PKL) extract exerts antihyperlipidemic, antidiabetic, and anticancer effects; however, its anti-fatigue properties have not been elucidated to date. In this study, the anti-fatigue properties of PKL were evaluated by assessing the endurance of mice by a weight-loaded forced swimming (WLFS) and rotarod (RR) tests. Subsequently, various behavioral, biochemical, and physiological parameters were measured. Treatment with PKL decreased hepatic and muscular glycogen levels in mice subjected to WLFS and RR test compared to those in acute exercise-treated (AET) mice. Additionally, plasma levels of stress-related biochemical factors (lactate, lactate dehydrogenase, aminotransferase, aspartate aminotransferase, and blood urea nitrogen) decreased significantly (P < 0.05), whereas the levels of superoxide dismutase and glutathione peroxidase increased. Furthermore, PKL potentially improved mental fatigue by decreasing corticosterone and increasing serotonin levels. PKL increased the expression of phosphorylated cyclic adenosine-3',5'-monophosphate response element-binding protein and brain-derived neurotrophic factor in the hippocampus. Collectively, the anti-fatigue effects of PKL could be explained by its antioxidant activity, mediating effects on glycogen synthesis, and control over stress. In conclusion, the findings of the present study suggest that PKL is a potential nutraceutical for improving exercise performance and alleviating fatigue.


Assuntos
Pinus , Animais , Modelos Animais de Doenças , Glicogênio/metabolismo , Camundongos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Superóxido Dismutase/metabolismo , Natação
6.
BMC Plant Biol ; 22(1): 424, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050649

RESUMO

BACKGROUND: Pinus massoniana Lamb. is the timber species with the widest distribution and the largest afforestation area in China, providing a large amount of timber, turpentine and ecological products. Seasonal drought caused by climate warming severely constrains the quality and growth of P. massoniana forests. WRKY transcription factors play an important role in plant responses to abiotic stress. In this study, the molecular mechanisms by which P. massoniana responds to drought stress were analysed based on the P. massoniana WRKY (PmWRKY) family of genes. RESULTS: Forty-three PmWRKYs are divided into three major families, 7 sub-families, and the conserved motifs are essentially the same. Among these 43 PmWRKYs express under drought stress but with different expression patterns in response to stress. PmWRKYs respond to drought stress induced by exogenous hormones of SA, ABA, and MeJA. The expression of PmWRKY6, PmWRKY10, and PmWRKY30 up-regulate in different families and tissues under drought stress, while PmWRKY22 down-regulate. Transgenetic tobaccos of PmWRKY31 are with lower malondialdehyde (MDA) content and higher proline (Pro) content than wild type (WT) tobaccos. In transgenic tobaccos of PmWRKY31, expression levels of related genes significantly improve, and drought tolerance enhance. CONCLUSIONS: This study analysed the molecular biological characteristics of PmWRKYs and investigated the expression patterns and functions of PmWRKYs in response to drought stress in P. massoniana. The results of this study provide a basis for in-depth research of the molecular functions of PmWRKYs in response to drought stress.


Assuntos
Secas , Pinus , Regulação da Expressão Gênica de Plantas , Pinus/genética , Pinus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Tabaco/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2305-2313, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131644

RESUMO

We examined the characteristics of understory plant diversity and physicochemical properties and analyzed the correlation between understory plant diversity and soil factors across four Pinus tabuliformis artificial water conservation forests (P. tabuliformis × Larix gmelinii plantation, P. tabuliformis × Quercus mongolica plantation, P. tabuliformis × Armeniaca sibirica plantation, and P. tabuliformis plantation) in Fengning County, upstream of Miyun reservoir. The results showed that the composition and structure of understory community of the four forests were significantly different. The understory community in the P. tabuliformis × A. sibirica plantation was the richest in species composition, with Spiraea salicifolia, Ostryopsis davidiana, and Carex lanceolata as the main dominant species. In terms of species richness, Simpson index, Shannon diversity index, and Pielou index, plant diversity in the P. tabuliformis × A. sibirica plantation was the highest. Species diversity in the shrub layer and the herb layer was the highest in the P. tabuliformis × Q. mongolica plantation and the P. tabuliformis × Q. mongolica plantation, respectively. All physical and chemical indicators except total phosphorus differed significantly among the four forests. Soil physical and chemical properties of the P. tabuliformis × A. sibirica plantation were the best overall, and that in the P. tabuliformis × Q. mongolica plantation was the worst. Soil capillary porosity, pH, and organic matter were the main factors affecting species diversity in the shrub layer, while soil pH and capillary moisture capacity were the main factors affecting plant species diversity in the herb layer. The construction of P. tabuliformis × A. sibirica plantation was more conducive to increasing the diversity of understory plants and promoting soil improvement. Soil pH, organic matter, capillary porosity, and capillary moisture capacity were the dominant soil factors affecting the diversity of understory plants in the study area.


Assuntos
Conservação dos Recursos Hídricos , Pinus , China , Florestas , Fósforo , Plantas , Solo/química
8.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2314-2320, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131645

RESUMO

We investigated the responses of leaf and individual traits, growth, and fluorescence characteristics of seedlings of two dominant species of broad-leaved Korean pine forest in Changbai Mountain, i.e., Pinus koraiensis and Quercus mongolica, to five spectrum-attenuation treatments. Results showed that the architecture and growth of P. koraiensis and Q. mongolica seedlings were mainly regulated by ultraviolet B (UV-B) radiation and blue light. The attenuation of blue light significantly decreased leaf area ratio and relative growth rate of two species. The attenuation of UV-B radiation significantly increased leaf area ratio and relative growth rate of P. koraiensis seedlings by 41.8% and 47.7%, respectively, and significantly decreased plant height, total leaf area, and biomass accumulation of Q. mongolica seedlings. Furthermore, the attenuation of UV-B radiation significantly decreased the fluorescence regulation ability of two tree seedlings, with lower magnitude of P. koraiensis than Q. mongolica. The non-regulatory quantum yield (ΦNO) of P. koraiensis increased by 31.6%, and the ΦNPQ/ΦNO ratio, an indicator for photosynthetic fluorescence regulation ability, decreased by 37.5%. These results suggested that those two species might have evolved adaptation strategies to changes in canopy spectral compositions of their respective habitats. Q. mongolica seedlings tended to improve light capture ability through rapid morphological responses, while P. koraiensis seedlings preferred to increase carbon assimilation efficiency by adjusting fluorescence characteristics.


Assuntos
Pinus , Quercus , Carbono , China , Fluorescência , Quercus/fisiologia , Plântula , Árvores
9.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2321-2330, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131646

RESUMO

Crown width is a critical variable in reflecting the individual tree growth status and in developing forest growth and yield models. With the crown width base model as reference, we developed the crown width quantile regression models for different quantiles (0.50, 0.90, 0.93, 0.95, 0.96, 0.99) based on the data of 2763 Korean pines in 66 permanent plots from the 10-55 years old plantations in Dabiangou forest farm, mountainous areas of eastern Liaoning Province. We used the reparameterization method by introducing the single tree competition index (Rd) and used the dummy variable method by introducing stand density and forest layer variables. We then selected optimal quantile of maximum crown width in the stand by comparing our model developed routine to the traditional methods. The final crown width linear mixed effect quantile regression model was developed based on the optimal quantile at the plot level. The influence of each variable on crown width was analyzed to reflect the difference of crown width among individual trees in the stand. The models with different stand densities and forest layers had significant difference based on F statistical test: the Ra2 of the model increased by 0.0104, the root mean square error decreased by 0.0115 and the mean square error reduction was 7.4%, after the variables of forest layer, forest density, and competition being incorporated into the basic model. The developed quantile regression model performed better than that of the ordinary least square method in simulating the maximum crown width of a single tree in the forest stand. The selected best quantile of the quantile regression model for the upper forest layer and lower forest layer was 0.96 and 0.93, respectively. The linear quantile regression model with the mixed effect was superior to the traditional quantile regression model in Akaike, Bayesion and HQ information criterion and other evaluation para-meters, the standard error for the parameters of estimates was significantly reduced, and the introduced mixed effect well explained differences among different plots. For the upper forest layer and lower forest layer, the maximum crown width decreased with increasing stand density, increased with increasing relative diameters. The influence of stand density on the crown width of the lower forest layer was greater than that of the upper forest layer. The crown width would increase first and then decrease with the increases of DBH when the stand density was large enough. The mixed effect of the quantile regression model developed here could significantly improve the fitting stability of the model. The sustainable development of Korean pine plantation in the mountainous area of eastern Liaoning Pro-vince should be realized by adjusting stand density and moderate tending and thinning in the future.


Assuntos
Florestas , Pinus , China , Modelos Lineares , República da Coreia , Árvores
10.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2347-2355, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131649

RESUMO

We established 340-year chronologies of total ring width, early wood width, and late wood width with tree-ring samples of Pinus taiwanensis at high altitude collected from the western Tianmu Mountain in northern Zhejiang Province. According to the criterion that subsample signal strength (SSS) should be larger than 0.8, the reliable period was from 1810 to 2019. Through the correlation analysis between chronologies and climatic factors, we examined the responses of tree ring growth to climate. The results showed that radial growth of P. taiwanensis was more sensitive to temperature than to precipitation. Comprehensively considering the correlation analysis results for the raw and first-order difference series, early wood width was significantly correlated with the early growing season mean and maximum temperatures of the prior year, while late wood width with prior May and current September mean and maximum temperatures. The correlation pattern of total ring width was similar to that of early wood width, although at a low level. The optimal correlation was between early wood width and prior April-July mean temperature. Based on this relationship, April-July mean temperature of the Tianmu Mountain, East China was reconstructed for the period of 1809-2018 with an explained variance of 61.5%. Both the raw and first-order difference series passed the split sample calibration-verification test. The warm periods were 1809-1833 and 1965-2018, with a cold period in 1834-1964. Temperature had risen rapidly since the 1960s. From the standpoint of low frequency, it reached an unprecedented level since the 1980s over the past 210 years. Spatial correlation analysis showed that the reconstructed temperature series could represent temperature variations of East China, which had a good agreement with a reconstructed regional temperature series from East China. Our results showed that P. taiwanensis had a great potential for paleoclimate reconstruction in East China.


Assuntos
Pinus , Árvores , China , Clima , Temperatura
11.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2397-2404, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131655

RESUMO

Soil fungi are important components of belowground biodiversity and play important roles in soil carbon and nutrient cycling. We investigated fungal communities in the top soil (0-10 cm) of 22 Pinus massoniana forests in the Three Gorges Reservoir Region using high-throughput sequencing technique. We found that Ascomycota and Basidiomycota were the dominant fungi phyla, and Eurotiales, Russulales, and Tremellales were the most abundant fungi orders. The dominant functional groups in P. massoniana forests were saprophytic fungi, ectomycorrhizal fungi, and ericoid mycorrhizal fungi. Results of redundancy analysis showed that environmental variables but not spatial variables were the main drivers of soil fungal community structure across the 22 P. massoniana forests, which suggested that habitat filtering rather than dispersal limitation shaped soil fungal community structure. Aboveground biomass, soil conductivity, available phosphorus, soil bulk density, carbon to nitrogen ratio, nitrate concentration, and proportion of slit were the main factors explaining the variation in soil fungal community structure. It should be noted that the key factors influencing different fungal functional groups differed across forests.


Assuntos
Basidiomycota , Micobioma , Micorrizas , Pinus , Carbono , Florestas , Fungos , Nitratos , Nitrogênio , Fósforo , Solo/química , Microbiologia do Solo
12.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2405-2412, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131656

RESUMO

Forest is the main component of terrestrial ecosystems that harbors about 40% of the existing species on the earth. As a vital component of biodiversity, phyllosphere microbes in the canopy play a critical and unique role in maintaining plant health, improving host resistance, and influencing global biogeochemical cycle. However, the studies on the community structure of phyllosphere fungi in natural forests are scarce as compared to that on rhizosphere microbes. Consequently, we know litter about how phyllosphere fungi associates with leaf traits. In this study, we analyzed fungal community composition of canopy leaves of six dominant tree species (i.e., Pinus koraiensis, Tilia amurensis, Quercus mongolica, Acer mono, Fraxinus mandshurica, and Ulmus japonica), in a broad-leaved Korean pine forest of Changbai Mountain Nature Reserve in Jilin Province, using high-throughput sequencing. We compared the differences of phyllosphere fungal community structure and functional groups of different dominant tree species. Moreover, 14 key leaf functional traits of their host trees were measured to investigate the relationships between fungal community composition and leaf functional traits. We found that the dominant phyla and class of phyllosphere fungi were Ascomycota and Basidiomycota, and Dothideomycetes and Taphrinomycetes, respectively. Results of LEfSe analysis indicated that all the tree species except Ulmus japonica had significant biomarkers, such as the Eurotiomycetes of Pinus koraiensis and the Ascomycetes of Quercus mongolica. The main functional groups of phyllosphere fungi were pathotroph. The results of redundancy and envfit analysis showed that functional traits related to plant nutrient acquisition as well as resistance to diseases and pests were the main factors influencing the community structure of phyllosphere fungi.


Assuntos
Pinus , Quercus , China , Ecossistema , Florestas , Fungos , República da Coreia , Árvores
13.
Ying Yong Sheng Tai Xue Bao ; 33(9): 2530-2538, 2022 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-36131670

RESUMO

Pine wilt disease has caused huge losses in ecological and economic values in China, especially in the southern parts. Analyzing the spatial distribution of pine wilt disease and quantifying the impact of environmental factors on its occurrence were of great significance for its prevention and control. In this study, we examined the spatial pattern of pine wilt disease occurrence and its response to environmental variables in Nankang District, Ganzhou, Jiangxi Province, using kernel-smoothing density, Ripley's K function, and point process model. The results showed that the occurrence of pine wilt disease in the study region was not randomly distributed, but was obviously clustered at some areas. Terrain, vegetation, and human activity were the main factors affecting the heterogeneous distribution of pine wilt disease. Spatial point pattern analysis showed that altitude, slope, distance to the nearest road, road density, distance to nearest settlement, canopy closure, and vegetation type had significant effects on the occurrence of pine wilt disease. In addition to strengthening the control of disease transmission caused by human activities, we should also consider the effects of terrain and vegetation types for early warning and monitoring in forest disease management.


Assuntos
Pinus , China/epidemiologia , Humanos , Análise Espacial
14.
Am Nat ; 200(4): E141-E159, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36150196

RESUMO

AbstractPopulation response functions based on climatic and phenotypic data from common gardens have long been the gold standard for predicting quantitative trait variation in new environments. However, prediction accuracy might be enhanced by incorporating genomic information that captures the neutral and adaptive processes behind intrapopulation genetic variation. We used five clonal common gardens containing 34 provenances (523 genotypes) of maritime pine (Pinus pinaster Aiton) to determine whether models combining climatic and genomic data capture the underlying drivers of height growth variation and thus improve predictions at large geographical scales. The plastic component explained most of the height growth variation, probably resulting from population responses to multiple environmental factors. The genetic component stemmed mainly from climate adaptation and the distinct demographic and selective histories of the different maritime pine gene pools. Models combining climate of origin and gene pool of the provenances as well as height-associated positive-effect alleles (PEAs) captured most of the genetic component of height growth and better predicted new provenances compared with the climate-based population response functions. Regionally selected PEAs were better predictors than globally selected PEAs, showing high predictive ability in some environments even when included alone in the models. These results are therefore promising for the future use of genome-based prediction of quantitative traits.


Assuntos
Pinus , Árvores , Florestas , Genômica , Pinus/genética , Plásticos , Árvores/genética
15.
Genes (Basel) ; 13(9)2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36140811

RESUMO

CCCH-type zinc finger proteins play an important role in multiple biotic and abiotic stresses. More and more reports about CCCH functions in plant development and stress responses have appeared over the past few years, focusing especially on tandem CCCH zinc finger proteins (TZFs). However, this has not been reported in Pinaceae. In this study, we identified 46 CCCH proteins, including 6 plant TZF members in Pinus massoniana, and performed bioinformatic analysis. According to RT-PCR analysis, we revealed the expression patterns of five RR-TZF genes under different abiotic stresses and hormone treatments. Meanwhile, tissue-specific expression analysis suggested that all genes were mainly expressed in needles. Additionally, RR-TZF genes showed transcriptional activation activity in yeast. The results in this study will be beneficial in improving the stress resistance of P. massoniana and facilitating further studies on the biological and molecular functions of CCCH zinc finger proteins.


Assuntos
Regulação da Expressão Gênica de Plantas , Pinus , Hormônios , Pinus/genética , Pinus/metabolismo , Proteínas de Plantas/metabolismo , Transcriptoma , Dedos de Zinco/genética
16.
Int J Mol Sci ; 23(18)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36142347

RESUMO

Peptidases are very important to parasites, which have central roles in parasite biology and pathogenesis. In this study, by comparative genome analysis, genome-wide peptidase diversities among plant-parasitic nematodes are estimated. We find that genes encoding cysteine peptidases in family C13 (legumain) are significantly abundant in pine wood nematodes Bursaphelenchus genomes, compared to those in other plant-parasitic nematodes. By phylogenetic analysis, a clade of B. xylophilus-specific legumain is identified. RT-qPCR detection shows that these genes are highly expressed at early stage during the nematode infection process. Utilizing transgene technology, cDNAs of three species-specific legumain were introduced into the Arabidopsis γvpe mutant. Functional complementation assay shows that these B. xylophilus legumains can fully complement the activity of Arabidopsis γVPE to mediate plant cell death triggered by the fungal toxin FB1. Secretory activities of these legumains are experimentally validated. By comparative transcriptome analysis, genes involved in plant cell death mediated by legumains are identified, which enrich in GO terms related to ubiquitin protein transferase activity in category molecular function, and response to stimuli in category biological process. Our results suggest that B. xylophilu-specific legumains have potential as effectors to be involved in nematode-plant interaction and can be related to host cell death.


Assuntos
Arabidopsis , Micotoxinas , Parasitos , Pinus , Rabditídios , Tylenchida , Animais , Arabidopsis/genética , Cisteína/genética , Cisteína Endopeptidases , Peptídeo Hidrolases/genética , Filogenia , Pinus/parasitologia , Doenças das Plantas/parasitologia , Plantas/parasitologia , Transferases/genética , Tylenchida/genética , Ubiquitinas/genética , Virulência , Xylophilus
17.
PLoS One ; 17(9): e0273741, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36067163

RESUMO

Retention of logging residue as dead wood could be a method to simultaneously increase biodiversity and predation rates of pest insects, in managed forests. Managed forests are generally low in diversity, and dead wood has been demonstrated to increase species diversity. Moreover, managed forests are predicted to suffer from higher frequency of insect outbreaks in the future, particularly in the northern hemisphere. In this study, we explore the effect of dead wood removal and addition in managed pine forest stands in Sweden on arthropod diversity and abundance and predation rates. We performed a controlled field experiment, focusing on logging residue type of dead wood. We used pitfall traps and sticky traps to measure arthropod diversity and abundance and plasticine larvae to assess predation rates. We specifically targeted generalist arthropods (i.e. non-wood living species), and predation rate on tree-dwelling larvae (corresponding to defoliating outbreak pests). We found no effect of dead wood addition on arthropod abundance or diversity, neither did we find an effect on predation rate. Despite the lack of effects in our study, we argue that dead wood can be an important component for both biodiversity of generalist arthropod and for pest control, but the effect may depend on both the specific arthropod group targeted and the specific life stage of the pest insect as well as on inherent components of the dead wood, such as age.


Assuntos
Artrópodes , Pinus , Animais , Biodiversidade , Ecossistema , Florestas , Herbivoria , Insetos , Larva , Comportamento Predatório , Árvores
18.
Proc Biol Sci ; 289(1982): 20221034, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36069017

RESUMO

While droughts, intensified by climate change, have been affecting forests worldwide, pest epidemics are a major source of uncertainty for assessing drought impacts on forest trees. Thus far, little information has documented the adaptability and evolvability of traits related to drought and pests simultaneously. We conducted common-garden experiments to investigate how several phenotypic traits (i.e. height growth, drought avoidance based on water-use efficiency inferred from δ13C and pest resistance based on defence traits) interact in five mature lodgepole pine populations established in four progeny trials in western Canada. The relevance of interpopulation variation in climate sensitivity highlighted that seed-source warm populations had greater adaptive capability than cold populations. In test sites, warming generated taller trees with higher δ13C and increased the evolutionary potential of height growth and δ13C across populations. We found, however, no pronounced gradient in defences and their evolutionary potential along populations or test sites. Response to selection was weak in defences across test sites, but high for height growth particularly at warm test sites. Response to the selection of δ13C varied depending on its selective strength relative to height growth. We conclude that warming could promote the adaptability and evolvability of growth response and drought avoidance with a limited evolutionary influence from pest (biotic) pressures.


Assuntos
Secas , Pinus , Mudança Climática , Florestas , Pinus/genética , Árvores/fisiologia
19.
Pestic Biochem Physiol ; 187: 105180, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127042

RESUMO

Bark beetles rely on detoxifying enzymes to resist the defensive terpenoids of the host tree. Insect cytochrome P450 (CYPs) plays a key role in the detoxification of pesticides and plant allelochemicals. CYP6 family is unique to Insecta, and its biochemical function is basically related to the metabolism of exogenous substances. In this study, we sequenced and characterized the full-length cDNAs of two CYP6 genes from Chinese white pine beetle, Dendroctonus armandi. Spatiotemporal expression profiling revealed that the expression of CYP6CR2 and CYP6DE5 was higher in larval and adult stages of D. armandi than that in other developmental stages, and that two genes predominantly expressed in brain, midgut, fat body, Malpighian tubules or hemolymph. The expression of CYP6CR2 and CYP6DE5 was significantly induced after feeding on the phloem of Pinus armandii and exposure to six stimuli [(±)- α -pinene, (-)-α-pinene, (-)-ß-pinene, (+)-3-carene, (±)-limonene and turpentine]. Importantly, silencing CYP6CR2 and CYP6DE5 separately could increase the sensitivity, led to a significant reduction of the activity of P450, resulting a significant increase in adult mortality after treatment with terpenoids. The comprehensive results of this study showed that in the process of host selection and colonization, the functions of CYPs were mainly to hydrolyze the chemical defense of the host and degrade odor molecules. These findings may help to develop new treatments to control this important pest.


Assuntos
Besouros , Praguicidas , Pinus , Animais , Monoterpenos Bicíclicos , China , Besouros/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Família 6 do Citocromo P450/metabolismo , Limoneno , Monoterpenos/metabolismo , Monoterpenos/farmacologia , Praguicidas/metabolismo , Feromônios/metabolismo , Terpenos , Terebintina/metabolismo
20.
PLoS One ; 17(9): e0274086, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36054240

RESUMO

Monochamus alternatus is a major forest pest that spreads pine wilt disease in pine trees as a vector of pine wilt nematodes. Chemical insecticides used as fumigants to control overwintering M. alternatus in forests are highly toxic to the environment, so we investigated entomopathogenic fungus Beauveria bassiana ERL836 as an eco-friendly and alternative material to control overwintering M. alternatus. In this work, we evaluated the insecticidal activity of B. bassiana ERL836 against M. alternatus adults, the possibility of fungal colonization on pine tree bark, and finally the control efficacy of fungal pre-treatment on pine tree logs against emerging M. alternatus adults in semi-field and field conditions. M. alternatus adults were killed on the pine tree logs pre-treated with the B. bassiana ERL836. White conidia were observed not only on the surface of the dead adults but also on the pine tree logs, suggesting that the adults were killed by the fungus on the pine. A formulated ERL836 powder treatment on larvae-infested pine logs showed high insecticidal activity against adults, similar to that with the fungal powder suspension treatment, but we demonstrated that using the fungal powder was simpler than using the suspension in field conditions. Even in the field condition, the fungal powder treatment showed high insecticidal activity against M. alternatus adults, which we attribute to its ability to maintain fungal activity for a long time in field conditions by covering the pine tree logs with a film during overwintering. We confirmed that the risk that fungus-infected M. alternatus adults would spread the fungus to other non-target forest insects was low. Thus, even a high-concentration treatment in a specific area is unlikely to transmit the fungus outside that area, so it can be safely used to control this pine wilt nematode vector in forest ecosystems.


Assuntos
Beauveria , Besouros , Nematoides , Pinus , Animais , Besouros/microbiologia , Ecossistema , Pós
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