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1.
Sci Rep ; 12(1): 3992, 2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35273205

RESUMO

Bio-impedance non-invasive measurement techniques usage is rapidly increasing in the agriculture industry. These measured impedance variations reflect tacit biochemical and biophysical changes of living and non-living tissues. Bio-impedance circuit modeling is an effective solution used in biology and medicine to fit the measured impedance. This paper proposes two new fractional-order bio-impedance plant stem models. These new models are compared with three commonly used bio-impedance fractional-order circuit models in plant modeling (Cole, Double Cole, and Fractional-order Double-shell). The two proposed models represent the characterization of the biological cellular morphology of the plant stem. Experiments are conducted on two samples of three different medical plant species from the family Lamiaceae, and each sample is measured at two inter-electrode spacing distances. Bio-impedance measurements are done using an electrochemical station (SP150) in the range of 100 Hz to 100 kHz. All employed models are compared by fitting the measured data to verify the efficiency of the proposed models in modeling the plant stem tissue. The proposed models give the best results in all inter-electrode spacing distances. Four different metaheuristic optimization algorithms are used in the fitting process to extract all models parameter and find the best optimization algorithm in the bio-impedance problems.


Assuntos
Algoritmos , Biofísica , Impedância Elétrica , Eletrodos , Caules de Planta
2.
Nat Plants ; 8(4): 346-355, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35347264

RESUMO

Gene duplications are a hallmark of plant genome evolution and a foundation for genetic interactions that shape phenotypic diversity1-5. Compensation is a major form of paralogue interaction6-8 but how compensation relationships change as allelic variation accumulates is unknown. Here we leveraged genomics and genome editing across the Solanaceae family to capture the evolution of compensating paralogues. Mutations in the stem cell regulator CLV3 cause floral organs to overproliferate in many plants9-11. In tomato, this phenotype is partially suppressed by transcriptional upregulation of a closely related paralogue12. Tobacco lost this paralogue, resulting in no compensation and extreme clv3 phenotypes. Strikingly, the paralogues of petunia and groundcherry nearly completely suppress clv3, indicating a potent ancestral state of compensation. Cross-species transgenic complementation analyses show that this potent compensation partially degenerated in tomato due to a single amino acid change in the paralogue and cis-regulatory variation that limits its transcriptional upregulation. Our findings show how genetic interactions are remodelled following duplications and suggest that dynamic paralogue evolution is widespread over short time scales and impacts phenotypic variation from natural and engineered mutations.


Assuntos
Lycopersicon esculentum , Sinais Direcionadores de Proteínas , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Meristema/metabolismo , Peptídeos/metabolismo , Caules de Planta/genética , Caules de Planta/metabolismo
3.
Gene ; 823: 146384, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35248661

RESUMO

UV-B radiation is a typical environmental stressor that can promote phytochemical accumulation in plants. Taxus species are highly appreciated due to the existence of bioactive taxoids (especially paclitaxel) and flavonoids. However, the effect of UV-B radiation on taxoid and flavonoid biosynthesis in Taxus cuspidata Sieb. et Zucc. is largely unknown. In the present work, the accumulation of taxoids and flavonoids in T. cuspidata plantlets was significantly induced by 12 and 24 h of UV-B radiation (3 W/m2), and a large number of significantly differentially expressed genes were obtained via transcriptomic analysis. The significant up-regulation of antioxidant enzyme- and flavonoid biosynthesis-related genes (phenylalanine ammonia lyase 1, chalcone synthase 2, flavonol synthase 1, and flavonoid 3', 5'-hydroxylase 2), suggested that UV-B might cause the oxidative stress thus promoting flavonoid accumulation in T. cuspidata. Moreover, the expression of some genes related to jasmonate metabolism and taxoid biosynthesis (taxadiene synthase, baccatin III-3-amino 3-phenylpropanoyltransferase 1, taxadiene-5α-hydroxylase, and ethylene response factors 15) was significantly activated, which indicated that UV-B might initiate jasmonate signaling pathway that contributed to taxoid enhancement in T. cuspidata. Additionally, the identification of some up-regulated genes involved in lignin biosynthesis pathway indicated that the lignification process in T. cuspidata might be stimulated for defense against UV-B radiation. Overall, our findings provided a better understanding of some potential key genes associated with flavonoid and taxoid biosynthesis in T. cuspidata exposed to UV-B radiation.


Assuntos
Vias Biossintéticas , Flavonoides/biossíntese , Perfilação da Expressão Gênica/métodos , Caules de Planta/crescimento & desenvolvimento , Taxoides/metabolismo , Taxus/genética , Cromatografia Líquida de Alta Pressão , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Estresse Oxidativo , Proteínas de Plantas/genética , Caules de Planta/metabolismo , Caules de Planta/efeitos da radiação , RNA-Seq , Espectrometria de Massas em Tandem , Taxus/crescimento & desenvolvimento , Taxus/metabolismo , Taxus/efeitos da radiação , Raios Ultravioleta/efeitos adversos
5.
Mar Drugs ; 20(3)2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-35323487

RESUMO

Catharanthus roseus (L.) G. Don is a plant belonging to the genus Catharanthus of the Apocynaceae family. It contains more than one hundred alkaloids, of which some exhibit significant pharmacological activities. Chitooligosaccharides are the only basic aminooligosaccharides with positively charged cations in nature, which can regulate plant growth and antioxidant properties. In this study, the leaves of Catharanthus roseus were sprayed with chitooligosaccharides of different molecular weights (1 kDa, 2 kDa, 3 kDa) and different concentrations (0.01 µg/mL, 0.1 µg/mL, 1 µg/mL and 10 µg/mL). The fresh weights of its root, stem and leaf were all improved after chitooligosaccharides treatments. More importantly, the chitooligosaccharides elicitor strongly stimulated the accumulation of vindoline and catharanthine in the leaves, especially with the treatment of 0.1 µg/mL 3 kDa chitooligosaccharides, the contents of them were increased by 60.68% and 141.54%, respectively. Furthermore, as the defensive responses, antioxidant enzymes activities (catalase, glutathione reductase, ascorbate peroxidase, peroxidase and superoxide dismutase) were enhanced under chitooligosaccharides treatments. To further elucidate the underlying mechanism, qRT-PCR was used to investigate the genes expression levels of secologanin synthase (SLS), strictosidine synthase (STR), strictosidine glucosidase (SGD), tabersonine 16-hydroxylase (T16H), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT), peroxidase 1 (PRX1) and octadecanoid-responsive Catharanthus AP2-domain protein 3 (ORCA3). All the genes were significantly up-regulated after chitooligosaccharides treatments, and the transcription abundance of ORCA3, SLS, STR, DAT and PRX1 reached a maximal level with 0.1 µg/mL 3 kDa chitooligosaccharides treatment. All these results suggest that spraying Catharanthus roseus leaves with chitooligosaccharides, especially 0.1 µg/mL of 3 kDa chitooligosaccharides, may effectively improve the pharmaceutical value of Catharanthus roseus.


Assuntos
Catharanthus/efeitos dos fármacos , Quitosana/farmacologia , Oligossacarídeos/farmacologia , Reguladores de Crescimento de Plantas/farmacologia , Antioxidantes/metabolismo , Catharanthus/genética , Catharanthus/crescimento & desenvolvimento , Catharanthus/metabolismo , Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oxirredutases/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Caules de Planta/efeitos dos fármacos , Caules de Planta/crescimento & desenvolvimento , Vimblastina/análogos & derivados , Vimblastina/metabolismo , Alcaloides de Vinca/metabolismo
6.
J Agric Food Chem ; 70(10): 3136-3141, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35232018

RESUMO

Maize stalks support leaves and reproductive structures and functionally support water and nutrient transport; besides, their anatomical and biochemical characteristics have been described as a plant defense against stress, also impacting economically important applications. In this study, we evaluated agronomical and stem description traits in a subset of maize inbred lines that showed variability for cell wall composition in the internodes. Overall, a great proportion of lignin subunit G and a low concentration of p-coumaric acid and lignin subunit S are beneficial for greater rind puncture resistance and taller plants, with a greater biomass yield. Also, the greater the proportions of subunit H, the longer the internode. Finally, the lower the total hemicellulose content, the greater the rind puncture resistance. Our results confirmed the effect of the cell wall on agronomic and stalk traits, which would be useful in applied breeding programs focused on biomass yield improvement.


Assuntos
Parede Celular , Melhoramento Vegetal , Biomassa , Parede Celular/química , Lignina/metabolismo , Caules de Planta/metabolismo , Zea mays/química
7.
Gene ; 821: 146276, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35176432

RESUMO

BACKGROUND: A total of 74,936 SNPs were employed to carry out population structure and genome-wide association studies and post-GWAS for hairiness character of the fifty-six samples including thirty-six Actinidia chinensis var. deliciosa, eighteen A. chinensis var. chinensis, and two A. polygama in the light of morphological observations. RESULTS: The percentage of heterozygous sites of A. chinensis var. deliciosa is higher than that of A. chinensis var. chinensis, which could be one of the reasons for A. chinensis var. deliciosa high disease resistance. Fifty-six samples were divided into two subgroups, in which the genetic distance, ranged from 0.17 to 0.99, according to their genetic divergence. Analysis of molecular variance shows that the frequency of genetic variations within the population is 83.53% and 16.47% between populations. Fst between the two populations is 0.14, and Nm is 1.60. Set at α ≤ 0.05, a total of 327 SNPs and 260 haplotypes were related to the hairiness character. A total of 246 proteins were annotated using GO and KEGG analyses, which indicated the membrane-related genes and stress-resistant metabolic pathways are related to the hairiness character of leaves, stems, and peels of kiwifruit. Protein interaction analysis showed that DNA-directed RNA polymerase was an important node protein that interacted with many proteins. CONCLUSIONS: The genetic basic in the fifty-six genotypes was rich. The results of clustering and morphological observations are not completely consistent, indicating the hairiness character play an important role in the classification of kiwifruit, in which two A. polygama were clustered together with those of A. chinensis var. chinensis. Phylogeny and haplotype analysis showed that the evolution of A. chinensis var. chinensis is later than that of A. chinensis var. deliciosa in A. chinesis. The loss of hairiness character on leaves, stems and peels of A. chinensis var. chinensis compare with A. chinensis var. deliciosa, which is also the result of its poor resistance.


Assuntos
Actinidia/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Análise de Sequência de DNA/métodos , Estudo de Associação Genômica Ampla , Haplótipos , Metagenômica , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/genética , Caules de Planta/genética
8.
Artigo em Inglês | MEDLINE | ID: mdl-35130136

RESUMO

A Gram-stain-negative, facultatively anaerobic, motile by gliding, rod-shaped, oxidase- and catalase-positive bacterial strain, designated BB8T, was isolated from the stems of a Korean soybean cultivar (Glycine max L. cv. Gwangan). The strain produced a yellow pigment on tryptic soy agar. Growth of strain BB8T occurred at pH 5.0-8.0 (optimum, pH 7.0), at 10-35 °C (optimum, 25-30 °C) and in the presence of 0-1 % (w/v) NaCl (optimum, 0.5%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain BB8T formed a lineage within the genus Flavobacterium and was most closely related to Flavobacterium artemisiae SYP-B1015T (96.9 % 16S rRNA gene sequence similarity) and Flavobacterium ustbae T13T (96.8%). The complete genome sequence of strain BB8T was 5 513 159 bp long with a G+C content of 34.1 mol%. The major fatty acids (>10 %) of strain BB8T were iso-C15 : 0 (21 %), summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c, 20.3%) and iso-C16 : 0 3-OH (13.7%). The predominant polar lipids were phosphatidylethanolamine and unidentified aminolipids, and the major respiratory quinone was menaquinone-6. Based on these phenotypic, genotypic and chemotaxonomic characteristics, strain BB8T is considered to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium endoglycinae sp. nov. is proposed. The type strain is BB8T (=KCTC 82167T=CCTCC AB 2020070T).


Assuntos
Flavobacterium , Filogenia , Soja , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacterium/classificação , Flavobacterium/isolamento & purificação , Fosfolipídeos/química , Caules de Planta/microbiologia , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Soja/microbiologia , Vitamina K 2/análogos & derivados , Vitamina K 2/química
9.
Int J Mol Sci ; 23(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35163510

RESUMO

In order to separate transformed cells from non-transformed cells, antibiotic selectable marker genes are usually utilized in genetic transformation. After obtaining transgenic plants, it is often necessary to remove the marker gene from the plant genome in order to avoid regulatory issues. However, many marker-free systems are time-consuming and labor-intensive. Homology-directed repair (HDR) is a process of homologous recombination using homologous arms for efficient and precise repair of DNA double-strand breaks (DSBs). The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 (Cas9) system is a powerful genome editing tool that can efficiently cause DSBs. Here, we isolated a rice promoter (Pssi) of a gene that highly expressed in stem, shoot tip and inflorescence, and established a high-efficiency sequence-excision strategy by using this Pssi to drive CRISPR/Cas9-mediated HDR for marker free (PssiCHMF). In our study, PssiCHMF-induced marker gene deletion was detected in 73.3% of T0 plants and 83.2% of T1 plants. A high proportion (55.6%) of homozygous marker-excised plants were obtained in T1 progeny. The recombinant GUS reporter-aided analysis and its sequencing of the recombinant products showed precise deletion and repair mediated by the PssiCHMF method. In conclusion, our CRISPR/Cas9-mediated HDR auto-excision method provides a time-saving and efficient strategy for removing the marker genes from transgenic plants.


Assuntos
Edição de Genes/métodos , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Regiões Promotoras Genéticas , Sistemas CRISPR-Cas , Embaralhamento de DNA , Flores/genética , Flores/crescimento & desenvolvimento , Recombinação Homóloga , Oryza/genética , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Caules de Planta/genética , Caules de Planta/crescimento & desenvolvimento
10.
Molecules ; 27(3)2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-35164380

RESUMO

Two undescribed ether derivatives of sesquiterpenes, 1-ethoxycaryolane-1, 9ß-diol (1) and 2-ethoxyclovane-2ß, 9α-diol (3), and one new monoterpene glycoside, p-menthane-1α,2α,8-triol-4-O-ß-D-glucoside (5), were obtained, together with eight known compounds from the stems and leaves of I. simonsii. Their structures were elucidated by spectroscopic methods. Compounds 1-11 were evaluated for their potency against Staphylococcus aureus and clinical methicillin-resistant S. aureus (MRSA). Among them, compound 3 was weakly active against S. aureus (MIC = 128 µg/mL), and compounds 6 and 7 exhibited good antibacterial activity against S. aureus and MRSA (MICs = 2-8 µg/mL). A primary mechanism study revealed that compounds 6 and 7 could kill bacteria by destroying bacterial cell membranes. Moreover, compounds 6 and 7 were not susceptible to drug resistance development.


Assuntos
Antibacterianos/análise , Illicium/química , Monoterpenos/análise , Sesquiterpenos/análise , Antibacterianos/farmacologia , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Monoterpenos/farmacologia , Folhas de Planta/química , Caules de Planta/química , Sesquiterpenos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico
11.
Fitoterapia ; 157: 105133, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35114336

RESUMO

Six diterpenoids including three ent-kauranes (1-2, 4) and three cleistanthanes (3, 5-6) were isolated from the roots and stems of Phyllanthus acidus (L.) Skeels. Of them, (16S)-ent-16,17,18-tri-hydroxy-19-nor-kaur-4-en-3-one (1), phyllanthone A (2), and 6-hydroxycleistanthol (3) are new compounds, while the ent-kaurane diterpenoids were reported from the titled plant for the first time. Their structures were elucidated on the basis of the extensive spectroscopic analyses. Compounds 2 and 4-6 displayed cytotoxic potential with IC50 values ranging from 1.96 to 29.15 µM. They also showed moderate anti-inflammatory activities (IC50 = 6.30-12.05 µM). Particularly, the new ent-kaurane 2 displayed cytotoxic potential against HL-60 (IC50 = 2.00 µM) and MCF-7 (IC50 = 3.55 µM) cells, and anti-inflammatory activity (IC50 = 6.47 µM).


Assuntos
Diterpenos do Tipo Caurano/toxicidade , Diterpenos/toxicidade , Phyllanthus/química , Extratos Vegetais/toxicidade , Alcaloides/química , Alcaloides/isolamento & purificação , Alcaloides/toxicidade , Linhagem Celular Tumoral , Diterpenos/química , Diterpenos do Tipo Caurano/química , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Extratos Vegetais/síntese química , Raízes de Plantas/química , Caules de Planta/química
12.
Gene ; 822: 146329, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35181500

RESUMO

Chitinases, the chitin-degrading enzymes, have been shown to play important role in defense against the chitin-containing fungal pathogens. In this study, we identified 48 chitinase-coding genes from the woody model plant Populus trichocarpa. Based on phylogenetic analysis, the Populus chitinases were classified into seven groups. Different gene structures and protein domain architectures were found among the seven Populus chitinase groups. Selection pressure analysis indicated that all the seven groups are under purifying selection. Phylogenetic analysis combined with chromosome location analysis showed that Populus chitinase gene family mainly expanded through tandem duplication. The Populus chitinase gene family underwent marked expression divergence and is inducibly expressed in response to treatments, such as chitosan, chitin, salicylic acid and methyl jasmonate. Protein enzymatic activity analysis showed that Populus chitinases had activity towards both chitin and chitosan. By integrating sequence characteristic, phylogenetic, selection pressure, gene expression and protein activity analysis, this study shed light on the evolution and function of chitinase family in poplar.


Assuntos
Quitinases/genética , Quitinases/metabolismo , Mapeamento Cromossômico/métodos , Populus/enzimologia , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Família Multigênica , Filogenia , Folhas de Planta/enzimologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Caules de Planta/enzimologia , Caules de Planta/genética , Populus/genética , Seleção Genética
13.
Molecules ; 27(4)2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35209099

RESUMO

Natural compounds have been recognized as valuable sources for anticancer drug development. In this work, different parts from Momordica cochinchinensis Spreng were selected to perform cytotoxic screening against human prostate cancer (PC-3) cells. Chromatographic separation and purification were performed for the main constituents of the most effective extract. The content of the fatty acids was determined by Gas Chromatography-Flame Ionization Detector (GC-FID). Chemical structural elucidation was performed by spectroscopic means. For the mechanism of the apoptotic induction of the most effective extract, the characteristics were evaluated by Hoechst 33342 staining, sub-G1 peak analysis, JC-1 staining, and Western blotting. As a result, extracts from different parts of M. cochinchinensis significantly inhibited cancer cell viability. The most effective stem extract induced apoptosis in PC-3 cells by causing nuclear fragmentation, increasing the sub-G1 peak, and changing the mitochondrial membrane potential. Additionally, the stem extract increased the pro-apoptotic (caspase-3 and Noxa) mediators while decreasing the anti-apoptotic (Bcl-xL and Mcl-1) mediators. The main constituents of the stem extract are α-spinasterol and ligballinol, as well as some fatty acids. Our results demonstrated that the stem extract of M. cochinchinensis has cytotoxic and apoptotic effects in PC-3 cells. These results provide basic knowledge for developing antiproliferative agents for prostate cancer in the future.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Momordica/química , Extratos Vegetais/farmacologia , Caules de Planta/química , Antineoplásicos Fitogênicos/química , Apoptose/genética , Biomarcadores Tumorais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Modelos Moleculares , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Relação Estrutura-Atividade
14.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983847

RESUMO

Symplasmicly connected cells called sieve elements form a network of tubes in the phloem of vascular plants. Sieve elements have essential functions as they provide routes for photoassimilate distribution, the exchange of developmental signals, and the coordination of defense responses. Nonetheless, they are the least understood main type of plant cells. They are extremely sensitive, possess a reduced endomembrane system without Golgi apparatus, and lack nuclei and translation machineries, so that transcriptomics and similar techniques cannot be applied. Moreover, the analysis of phloem exudates as a proxy for sieve element composition is marred by methodological problems. We developed a simple protocol for the isolation of sieve elements from leaves and stems of Nicotiana tabacum at sufficient amounts for large-scale proteome analysis. By quantifying the enrichment of individual proteins in purified sieve element relative to bulk phloem preparations, proteins of increased likelyhood to function specifically in sieve elements were identified. To evaluate the validity of this approach, yellow fluorescent protein constructs of genes encoding three of the candidate proteins were expressed in plants. Tagged proteins occurred exclusively in sieve elements. Two of them, a putative cytochrome b561/ferric reductase and a reticulon-like protein, appeared restricted to segments of the endoplasmic reticulum (ER) that were inaccessible to green fluorescent protein dissolved in the ER lumen, suggesting a previously unknown differentiation of the endomembrane system in sieve elements. Evidently, our list of promising candidate proteins ( SI Appendix, Table S1) provides a valuable exploratory tool for sieve element biology.


Assuntos
Retículo Endoplasmático/metabolismo , Células Vegetais/metabolismo , Folhas de Planta/metabolismo , Caules de Planta/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Proteômica , Tabaco/metabolismo , Retículo Endoplasmático/genética , Folhas de Planta/citologia , Folhas de Planta/genética , Caules de Planta/citologia , Caules de Planta/genética , Plantas Geneticamente Modificadas/citologia , Plantas Geneticamente Modificadas/genética , Tabaco/citologia , Tabaco/genética
15.
Plant Physiol ; 189(1): 204-214, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35099552

RESUMO

The hydraulic vulnerability segmentation (HVS) hypothesis implies the existence of differences in embolism resistance between plant organs along the xylem pathway and has been suggested as an adaptation allowing the differential preservation of more resource-rich tissues during drought stress. Compound leaves in trees are considered a low-cost means of increasing leaf area and may thus be expected to show evidence of strong HVS, given the tendency of compound-leaved tree species to shed their leaf units during drought. However, the existence and role of HVS in compound-leaved tree species during drought remain uncertain. We used an optical visualization technique to estimate embolism occurrence in stems, petioles, and leaflets of shoots in two compound-leaved tree species, Manchurian ash (Fraxinus mandshurica) and Manchurian walnut (Juglans mandshurica). We found higher (less negative) water potentials corresponding to 50% loss of conductivity (P50) in leaflets and petioles than in stems in both species. Overall, we observed a consistent pattern of stem > petiole > leaflet in terms of xylem resistance to embolism and hydraulic safety margins (i.e. the difference between mid-day water potential and P50). The coordinated variation in embolism vulnerability between organs suggests that during drought conditions, trees benefit from early embolism and subsequent shedding of more expendable organs such as leaflets and petioles, as this provides a degree of protection to the integrity of the hydraulic system of the more carbon costly stems. Our results highlight the importance of HVS as an adaptive mechanism of compound-leaved trees to withstand drought stress.


Assuntos
Embolia , Juglans , Secas , Folhas de Planta , Caules de Planta , Árvores , Água , Xilema
16.
BMC Plant Biol ; 22(1): 49, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35073838

RESUMO

BACKGROUND: The stalk rind is one of the important factors affecting maize stalk strength that is closely related to stalk lodging. However, the mechanism of rind development in maize is still largely unknown. RESULTS: In this study, we analyzed the mechanical, anatomical, and biochemical properties of the third basal internode in one maize non-stiff-stalk (NSS) line and two stiff-stalk (SS) lines. Compared with the NSS line, the two SS lines had a significantly higher rind penetrometer resistance, thicker rind, and higher dry matter, hemicellulose, cellulose, and lignin weights per unit length. RNA-seq analysis was used to compare transcriptomes of the third basal internode of the two SS lines and the NSS line at the ninth leaf and tasseling stages. Gene Ontology (GO) enrichment analysis revealed that genes involved in hydrolase activity (hydrolyzing O-glycosyl compounds) and cytoskeleton organization were significantly up-regulated in the two SS lines at the ninth leaf stage and that microtubule process-related genes were significantly up-regulated in the two SS lines at the tasseling stage. Moreover, the two SS lines had enhanced expression of cell wall metabolism-related genes at the tasseling stage. CONCLUSIONS: The synthesis of cell wall polysaccharides and the cytoskeleton might play important roles in internode development. Our results can be applied for screening lodging-resistant inbred lines and breeding lodging-resistant cultivars in maize.


Assuntos
Perfilação da Expressão Gênica , Caules de Planta/crescimento & desenvolvimento , Transcriptoma , Zea mays/crescimento & desenvolvimento , Fenômenos Biomecânicos , Caules de Planta/química , Caules de Planta/genética , Caules de Planta/fisiologia , Zea mays/química , Zea mays/genética , Zea mays/fisiologia
17.
Microbiol Spectr ; 10(1): e0223021, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35019779

RESUMO

The Loess Plateau is located in the arid and semi-arid regions in northern China. The ecosystem is particularly sensitive to natural and anthropogenic disturbances. Fungi can produce extracellular enzymes, decompose a variety of organic matter, and regulate carbon and nutrient balance. We studied the changes of soil fungal community compositions in response to straw, inorganic fertilizer, and compost in a typical farmland in the Loess Plateau. Our results demonstrated that the addition of straw significantly reduces the Shannon index of the fungal community, in addition, the participation of straw significantly affects the composition of the fungal community. Functional prediction based on FUNGuild showed that straw significantly reduced the relative abundance of saprotrophs, pathotrophs, symbiotrophs, lichenized, ectomycorrhizal, and plant pathogens. Although fertilization practices destroyed the co-occurrence pattern among the fungal species, the addition of straw alleviated this affect. No significant effect of straw, compost, and inorganic fertilizers on the co-occurrence pattern among species in the soil fungal community was observed. Compared with compost and inorganic fertilizer, the addition of straw shaped the community composition by changing the relative abundance of fungal functional taxa. Thus, in the fragile Loess Plateau environment, over-fertilizing or non-order-fertilizing may destroy the co-occurrence pattern of the fungal communities and Loess Plateau ecosystem. IMPORTANCE Determining the response of soil fungi in sensitive ecosystems to external environmental disturbances is an important, yet little-known, topic in microbial ecology. In this study, we evaluated the impact of traditional fertilization management practices on the composition, co-occurrence pattern, and functional groups of fungal communities in loessial soil. Our results show that in the fragile Loess Plateau environment, fertilizer management changed the composition of the fungal community and disrupted the co-occurrence pattern between fungi. The application of straw alleviates the destroying of the co-occurrence pattern. The current research emphasizes the necessity of rational fertilization of farmland in loessial soil.


Assuntos
Fertilizantes/análise , Fungos/isolamento & purificação , Micobioma , China , Compostagem , Ecossistema , Fungos/classificação , Fungos/genética , Fungos/metabolismo , Caules de Planta/metabolismo , Caules de Planta/microbiologia , Solo/química , Microbiologia do Solo
19.
J Nat Prod ; 85(1): 70-82, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35040315

RESUMO

The cumulative effects of cell damage result in aging, which gradually decreases human function in various aspects and leads to multiple age-related chronic diseases. To overcome the adverse effects of aging, silent mating type information regulation 2 homologue (SIRT1) activators are promising bioactive compounds that mimic calorie restriction to improve quality of life and prevent aging. In this study, 11 new flavonostilbenes (1-11) and three known compounds (12-14) were purified from stems of Rhamnoneuron balansae. The structures of the new compounds were determined using extensive data from spectroscopic methods, including NMR and HRESIMS. Their absolute configurations were deduced by ECD calculations with coupling constant analysis. All of the isolated new compounds (1-11) were evaluated for their effects on SIRT1 deacetylase activity, the NAD+/NADH ratio, and the AMP-activated protein kinase activation level in cell-based assays. The results showed that rhamnoneuronal D (1) exhibits promising biological activity in several in vitro models related to SIRT1 and suggest it is a potential natural-product-based antiaging agent.


Assuntos
Caules de Planta/química , Sirtuína 1/efeitos dos fármacos , Estilbenos/isolamento & purificação , Adenilato Quinase/metabolismo , Animais , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Ativação Enzimática , Humanos , NAD/metabolismo , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Estilbenos/farmacologia , Thymelaeaceae/química
20.
J Nat Prod ; 85(1): 127-135, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35040320

RESUMO

Eight new cadinane sesquiterpenoids (1-8), along with two known compounds (9 and 10), were isolated from infected stems of the semi-mangrove plant, Hibiscus tiliaceus. The structures of compounds 1-8 were elucidated through the analysis of their 1D and 2D NMR and MS data, and their absolute configurations were determined by comparing their experimental and calculated ECD spectra and by single-crystal X-ray diffraction. The two confused known compounds (9 and 10) were resolved using single-crystal X-ray crystallography. Compounds 1-3 have novel norsesquiterpene carbon skeletons arising from a ring contraction rearrangement. All obtained isolates were evaluated against the HepG2 and Huh7 cell lines, and compounds 1b, 2b, 4, 6, and 8 showed cytotoxic activity toward both cell lines, with IC50 values ranging from 3.5 to 6.8 µM.


Assuntos
Hibiscus/química , Caules de Planta/química , Sesquiterpenos Policíclicos/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Sesquiterpenos Policíclicos/química , Sesquiterpenos Policíclicos/isolamento & purificação , Análise Espectral/métodos
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