共查询到20条相似文献,搜索用时 31 毫秒
1.
Bryan Pfister George Oyler Michael Betenbaugh Gang Bao 《Molecular & cellular biomechanics : MCB》2004,1(4):233-244
The Bcl-2 family of proteins has recently been implicated as a possible player in the complex cascade of neural cell death due to traumatic brain injuries. However, it is unclear if the Bcl-2 pathways are activated in mechanically injured neurons. Here we report the effects of BclXL and Bax over-expression on stretch-induced neural cell death using an in vitro uniaxial stretch model of traumatic axonal injury. Specifically, YFP, YFP-tagged Bax and YFP-tagged BclXL proteins were expressed in differentiated NG108-15 cells and stretch-injury assays were carried out at different strain and strain rate combinations. As a control, insults known to act within the Bcl-2 pathways were used to study cell viability and to compare with the results of cell death due to mechanical stretching. Surprisingly, under the stretch-injury conditions in this study, BclXL did not provide protection against cell death. Further, translocation of Bax could not be identified after stretch-injury. The implications of these findings to cell death pathways in traumatic brain injury are discussed. 相似文献
2.
Sunil Kumar Suryawanshi Usha Chouhan Jyoti Kant Choudhari 《Molecular & cellular biomechanics : MCB》2022,19(4):191-208
Cancer is the second biggest cause of death globally, and the use of therapeutic peptides to specifically target and destroy cancer cells has gotten much interest. Cancer peptides or vaccinations are utilized to treat cancer nowadays, apart from chemotherapy, which has significant discomfort, side effects and costly. It is time demanding to identify and predict potential anticancer peptides using computational biology approaches. Thus, 3-D molecular modeling is being used to find possible ACP candidates. In this research, Curcuma longa has predicted peptide sequences were docked on breast cancer receptors and used a molecular docking technique to assess the anticipated peptides’ binding affinities to MHC molecules. A similar approach was utilized to simulate the interactions of the chosen peptide with the TCR. Additionally, the Pep10 LIRQHVASNIGIAKSKIREPIV was examined, and our findings indicated interaction with MHC classes I and II. However, the maximum binding energy was obtained with TCR at 695.61, giving strength through eight hydrogen bonds. Similarly, the Pep20, GAIIGNRKIKLQPHIIIRID, the projected, has the most significant overall binding energy with MHC classes I and II but a lower global E total value with TCR, namely −600.97 kj/Mol, and also four hydrogen bonds. This research could lead to the development of novel anticancer drugs based on the anticancer activity of the Curcuma longa medicinal plant. 相似文献
3.
Chinese hickory (Carya cathayensis Sarg.) is a popular nut tree in China, but there is little information about the
influences of fertilization on soil CO2 efflux and soil microbial biomass. This study evaluated the short-term
effects of different fertilizer applications on soil CO2 efflux and soil microbial biomass in Chinese hickory stands.
Four fertilizer treatments were established: control (CK, no fertilizer), inorganic fertilizer (IF), organic fertilizer
(OF), and equal parts organic and inorganic N fertilizers (OIF). A field experiment was conducted to measure
soil CO2 effluxes using closed chamber and gas chromatography techniques. Regardless of the fertilization practices, soil CO2 effluxes of all the treatments showed a similar temporal pattern, with the highest value in summer
and the lowest in winter. The mean annual soil CO2 efflux in the IF treatment was significantly higher than that in
the CK, OIF, and OF treatments. There was no significant difference in soil CO2 efflux between the OIF, OF, and
CK treatments. Soil CO2 effluxes were significantly affected by soil temperature. Soil dissolved organic carbon
(DOC) was positively correlated with soil CO2 efflux only in the CK treatment. Regression analysis, including soil
temperature, moisture, and DOC, showed that soil temperature was the primary factor influencing soil CO2
effluxes. Both OF and OIF treatments increased concentrations of soil microbial biomass carbon (MBC) and
microbial biomass nitrogen (MBN), but decreased the ratio of MBC:MBN. These results reveal that applying
organic fertilizer, either alone or combined with inorganic fertilizer, may be the optimal strategy for mitigating
soil CO2 emission and improving soil quality in Chinese hickory stands. 相似文献
4.
5.
Abdelmajid Krouma 《Phyton》2023,92(7):2133-2150
Iron is an essential element for plants as well as all living organisms, functioning in various physiological and
biochemical processes such as photosynthesis, respiration, DNA synthesis, and N2 fixation. In the soil, Fe bioavailability is extremely low, especially under aerobic conditions and at high pH ranges. In contrast, plants with
nodules on their roots that fix atmospheric nitrogen need much more iron. To highlight the physiological traits
underlying the tolerance of N2-fixing common bean to iron deficiency, two genotypes were hydroponically cultivated in a greenhouse: Coco nain (CN) and Coco blanc (CB). Plants were inoculated with an efficient strain of
Rhizobium tropici, CIAT899, and received a nutrient solution added with 0 µM Fe (severe Fe deficiency, SFeD),
5 µM Fe (moderate Fe deficiency, MFeD) or 45 µM Fe (control, C). Several physiological parameters related to
photosynthesis and symbiotic nitrogen fixation were then analyzed. Iron deficiency significantly reduced whole
plant and nodule growth, chlorophyll biosynthesis, photosynthesis, leghemoglobin (LgHb), nitrogenase (N2ase)
activity, nitrogen, and Fe nutrition, with some genotypic differences. As compared to CB, CN maintained better
Fe allocation to shoots and nodules, allowing it to preserve the integrity of its photosynthetic and symbiotic apparatus, thus maintaining the key functional traits of the plant metabolism (chlorophyll biosynthesis and photosynthesis in shoots, leghemoglobin accumulation, and nitrogenase activity in root nodules). Plant growth
depends on photosynthesis, which needs to be supplied with sufficient iron and nitrogen. Fe deficiency stress
index (FeD-SI) and Fe use efficiency (FeUE) are two physiological traits of tolerance that discriminated the
studied genotypes. 相似文献
6.
Abdulkhaliq Alshoaibi 《Phyton》2022,91(1):45-55
Pearl millet (Pennisetum spicatum (L.) Körn.) and maize (Zea mays L.) are C4 grass species grown for feeding humans and animals in Almadinah Almunawwarah, which is in the western part of Saudi Arabia. During the winter, the mean temperature, which drops to 14°C, represents a major problem for the growth of these species in this region. Therefore, the objectives of this research were to investigate the growth response and the photosynthetic performance of P. spicatum and Z. mays under a low temperature stress. The treatments involved daytime and nighttime temperatures of 14/12°C (low temperature) and 24/22°C (optimum temperature). The results indicated that low temperature significantly reduced all growth and physiological parameters, including seed germination, leaf expansion, leaf area, shoot length and root length of the two species compared to those of the control. Additionally, the low temperature significantly decreased the light-saturated assimilation rate (Asat), quantum yield (ϕ), saturated rate of carbon dioxide uptake (Amax) and efficiency of carboxylation on both species compared to those of the control. Moreover, the values of Fv/Fm and the chlorophyll contents of both species were significantly reduced by low temperature compared to those of the control. It can be concluded that both species had little tolerance to low temperatures. 相似文献
7.
Cinnamomum japonicum Sieb. is an excellent roadside tree and medicinal tree species with considerable ornamental and economic value. In this study,
we successfully developed a large-scale micropropagation protocol for C. japonicum for the first time. Sterilized shoots were excised and used as explants for
shoot induction on several basal media, supplemented with different concentrations
of plant growth regulators (PGRs), such as Thidiazuron (TDZ), N6
-Benzyladenine
(6-benzylaminopurine) (BA), α-naphthaleneacetic acid (NAA) and Gibberellic acid
(GA3). After comparison, the most efficient medium for shoot regeneration
was 1/2 Murashige and Skoog (MS) medium containing 0.5 mg L–1 BA,
0.05 mg L–1 NAA and 0.2 mg L–1 GA3, which resulted in an average number of
induced shoots per explant and shoot length of 5.2 and 1.62 cm at 28 d, respectively. Then, elongated adventitious shoots were transferred to induce roots.
86.7% of shoots was able to root on 1/2 MS medium supplemented with 0.5 mg
L–1 NAA and 0.1 mg L–1 BA. The earliest rooting time observed was after 21 d
and the average root length was up to 3.3 cm after 28 d. Our study shows that
C. japonicum can be successfully regenerated through de novo organogenesis,
which lays a foundation for future transformation research on this tree. 相似文献
8.
The lignocellulosic crop Miscanthus spp. has been identified as a good candidate for biomass production. The
responses of Miscanthus sinensis Anderss. to salinity were studied to satisfy the needs for high yields in marginal
areas and to avoid competition with food production. The results indicated that the relative advantages of the
tolerant accession over the sensitive one under saline conditions were associated with restricted Na+ accumulation
in shoots. Seedlings of two accessions (salt-tolerant ‘JM0119’ and salt-sensitive ‘JM0099’) were subjected to 0
(control), 100, 200, and 300 mM NaCl stress to better understand the salt-induced biochemical responses of genes
involved in Na+ accumulation in M. sinensis. The adaptation responses of genes encoding for Na+
/H+ antiporters,
NHX1 and SOS1 to NaCl stress were examined in JM0119 and JM0099.The cDNA sequences of genes examined
were highly conserved among the relatives of M. sinensis based on the sequencing on approximate 600 bp-long
cDNA fragments obtained from degenerate PCR. These salt-induced variations of gene expression investigated by
quantitative real-time PCR provided evidences for insights of the molecular mechanisms of salt tolerance in
M. sinensis. The expression of NHX1 was up-regulated by salt stress in JM0119 shoot and root tissues. However,
it was hardly affected in JM0099 shoot tissue except for a significant increase at the 100 mM salt treatment, and it
was salt-suppressed in the JM0099 root tissue. In the root tissue, the expression of SOS1 was induced by the high
salt treatment in JM0119 but repressed by all salt treatments in JM0099. Thus, the remarkably higher expression
of NHX1 and SOS1 were associated with the resistance to Na+ toxicity by regulation of the Na+ influx, efflux, and
sequestration under different salt conditions. 相似文献
9.
James F Curtin Naiyou Liu Marianela Candolfi Weidong Xiong Hikmat Assi Kader Yagiz Matthew R Edwards Kathrin S Michelsen Kurt M Kroeger Chunyan Liu A. K. M. Ghulam Muhammad Mary C Clark Moshe Arditi Begonya Comin-Anduix Antoni Ribas Pedro R Lowenstein Maria G Castro 《PLoS medicine》2009,6(1)
Background
Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor that carries a 5-y survival rate of 5%. Attempts at eliciting a clinically relevant anti-GBM immune response in brain tumor patients have met with limited success, which is due to brain immune privilege, tumor immune evasion, and a paucity of dendritic cells (DCs) within the central nervous system. Herein we uncovered a novel pathway for the activation of an effective anti-GBM immune response mediated by high-mobility-group box 1 (HMGB1), an alarmin protein released from dying tumor cells, which acts as an endogenous ligand for Toll-like receptor 2 (TLR2) signaling on bone marrow-derived GBM-infiltrating DCs.Methods and Findings
Using a combined immunotherapy/conditional cytotoxic approach that utilizes adenoviral vectors (Ad) expressing Fms-like tyrosine kinase 3 ligand (Flt3L) and thymidine kinase (TK) delivered into the tumor mass, we demonstrated that CD4+ and CD8+ T cells were required for tumor regression and immunological memory. Increased numbers of bone marrow-derived, tumor-infiltrating myeloid DCs (mDCs) were observed in response to the therapy. Infiltration of mDCs into the GBM, clonal expansion of antitumor T cells, and induction of an effective anti-GBM immune response were TLR2 dependent. We then proceeded to identify the endogenous ligand responsible for TLR2 signaling on tumor-infiltrating mDCs. We demonstrated that HMGB1 was released from dying tumor cells, in response to Ad-TK (+ gancyclovir [GCV]) treatment. Increased levels of HMGB1 were also detected in the serum of tumor-bearing Ad-Flt3L/Ad-TK (+GCV)-treated mice. Specific activation of TLR2 signaling was induced by supernatants from Ad-TK (+GCV)-treated GBM cells; this activation was blocked by glycyrrhizin (a specific HMGB1 inhibitor) or with antibodies to HMGB1. HMGB1 was also released from melanoma, small cell lung carcinoma, and glioma cells treated with radiation or temozolomide. Administration of either glycyrrhizin or anti-HMGB1 immunoglobulins to tumor-bearing Ad-Flt3L and Ad-TK treated mice, abolished therapeutic efficacy, highlighting the critical role played by HMGB1-mediated TLR2 signaling to elicit tumor regression. Therapeutic efficacy of Ad-Flt3L and Ad-TK (+GCV) treatment was demonstrated in a second glioma model and in an intracranial melanoma model with concomitant increases in the levels of circulating HMGB1.Conclusions
Our data provide evidence for the molecular and cellular mechanisms that support the rationale for the clinical implementation of antibrain cancer immunotherapies in combination with tumor killing approaches in order to elicit effective antitumor immune responses, and thus, will impact clinical neuro-oncology practice. 相似文献10.
Arctostaphylos pungens HBK is a dominant species with increasing abundance and distribution in chaparral ecosystems as a result of range management and, possibly, changes in climate. The value of this species for carbon (C) sequestration is unknown, and the standard 50% C out of total tree biomass is used as an approximate value. In this study, we aim to determine the C concentration of the primary components of A. pungens. The total C expressed as a percentage of biomass was determined with a Solids TOC Analyzer. We found the C concentration to vary among components. Leaves exhibited the highest C concentration (51.70%). Roots (46.11%), stems (47.30%), fruits (47.89%) and twigs (48.40%) had similar C concentration. These results provided superior estimates of C concentration, and reliable information concerning the potential use of A. pungens in climate-change mitigation programs. 相似文献
11.
12.
Yongjing Xi Zhou Yang Yukun Jin Jing Qu Shuyan Guan Siyan Liu Piwu Wang 《Phyton》2023,92(4):1257-1274
PCR detection, quantitative real-time PCR (q-RTPCR), outdoor insect resistance, and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations (T2, T3, and T4) in transgenic maize germplasms (S3002 and 349) containing the bivalent genes (insect resistance gene Cry1Ab13-1 and disease resistance gene NPR1) and their corresponding wild type. Results indicated that the target genes Cry1Ab13-1 and NPR1 were successfully transferred into both germplasms through tested generations; q-PCR confirmed the expression of Cry1Ab13-1 and NPR1 genes in roots, stems, and leaves of tested maize plants. In addition, S3002 and 349 bivalent gene-transformed lines exhibited resistance to large leaf spots and corn borer in the field evaluation compared to the wild type. Our study confirmed that Cry1Ab13-1 and NPR1 bivalent genes enhanced the resistance against maize borer and large leaf spot disease and can stably inherit. These findings could be exploited for improving other cultivated maize varieties. 相似文献
13.
14.
Oliver Tusevski Marija Todorovska Jasmina Petreska Stanoeva Marina Stefova Sonja Gadzovska Simic 《Phyton》2023,92(3):921-941
Three Hypericum perforatum hairy root lines (HR B, HR F and HR H) along with non-transformed roots were analyzed for phenolic compounds composition and in vitro enzyme inhibitory properties. In silico molecular modeling was performed to predict the interactions of the most representative phenolic compounds in HR clones with enzymes related to depression, neurodegeneration and diabetes. Chromatographic analyses revealed that HR clones represent an efficient source of quinic acid and hydroxybenzoic acids, epicatechin and procyanidin derivatives, quercetin and kaempferol glycosides, as well numerous xanthones. In vitro antidepressant activity of HR extracts through monoamine oxidase A (MAO-A) inhibition was attributed to the production of oxygenated and prenylated xanthones. The neuroprotective potential of HR extracts was related to the accumulation of quercetin 6-C-glucoside, epicatechin, procyanidins and γ-mangostin isomers as potential inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Vanillic acid and prenylated xanthones in HR clones as promising inhibitors of tyrosinase additionally contributed to the neuroprotective activity. Five preeminent xanthones in HR (γ-mangostin, mangiferin, garcinone C, garcinone E and 1,3,7-trihydroxy-6-metoxy-8-prenyl xanthone) along with the flavonol quercetin 6-C-glucoside effectively inhibited α-amylase and α-glucosidase indicating the antidiabetic properties of HR extracts. Transgenic roots of H. perforatum can be exploited for the preparation of novel phytoproducts with multi-biological activities. 相似文献
15.
Sotiropoulou PA Perez SA Voelter V Echner H Missitzis I Tsavaris NB Papamichail M Baxevanis CN 《Cancer immunology, immunotherapy : CII》2003,52(12):771-779
HER-2/neu is an immunogenic protein eliciting both humoral and cellular immune responses in patients with HER-2/neu-positive (+) tumors. Preexisting cytotoxic T lymphocyte (CTL) immunity to HER-2/neu has so far been mainly evaluated in terms of detection of CTL precursor (CTLp) frequencies to the immunogenic HLA-A2–binding nona-peptide 369-377 (HER-2(9369)). In the present study, we examined patients with HER-2/neu+ breast, ovarian, lung, colorectal, and prostate cancers for preexisting CTL immunity to four recently described HER-2/neu–derived and HLA-A2–restricted "cytotoxic" peptides and to a novel one spanning amino acids 777–785 also with HLA-A2–binding motif. We utilized enzyme-linked immunosorbent spot (ELISpot) assay, which allows a quantitative and functional assessment of T cells directed against specific peptides after only brief in vitro incubation. CTL reactivity was determined with an interferon (IFN-) ELISpot assay detecting T cells at the single cell level secreting IFN-. CTLp were defined as peptide-specific precursors per 106 peripheral blood mononuclear cells (PBMCs). Patients' PBMCs with increased CTLp were also tested against autologous tumor targets and peptide-pulsed dendritic cells (DCs) in cytotoxicity assays. We also studied patients with HER-2/neu-negative (-) tumors and healthy individuals. Of the HER-2/neu+ patients examined, 31% had increased CTLp to HER-2(9952), 19% to HER-2(9665), 16% to HER-2(9689), and 12.5% HER-2(9435), whereas only 2 of 32 patients (6%) responded to HER-2(9777). The CTLp recognizing HER-2(9952) were extremely high in two patients with breast cancer, one with lung cancer, and one with prostate cancer. None of the HER-2/neu- patients or healthy donors exhibited increased CTLp to any of these peptides. Besides IFN- production, preexisting CTL immunity to all five HER-2/neu peptides was also shown in cytotoxicity assays where patients' PBMCs with increased CTLp specifically lysed autologous tumor targets and autologous peptide-pulsed DCs. Our results demonstrate for the first time that (1) preexisting immunity to peptides HER-2(9435), HER-2(9952), HER-2(9689), HER-2(9665), and HER-2(9777) is present in patients with HER-2/neu+ tumors of distinct histology, (2) HER-2(9777) is a naturally processed peptide expressed on the surface of HER-2/neu+ tumors, as are the other four peptides, and (3) HER-2/neu+ prostate tumor cells can be recognized and lysed by autologous HER-2 peptide-specific CTL. Our findings broaden the potential application of HER-2/neu-based immunotherapy. 相似文献
16.
Yanhua Li Hualei Huang Youming Shi Shuqin Huang Tao Liu Changming Xiao Xiaoqing Tian Ping Zhao Xiaoyan Dai Taocui Huang Yan Zhou 《Phyton》2023,92(3):815-835
Gibberellin 2-oxidases (GA2ox) are important enzymes that maintain the balance of bioactive GAs in plants. GA2ox genes have been identified and characterized in many plants, but these genes were not investigated in Brassica napus. Here, we identified 31 GA2ox genes in B. napus and 15 of these BnaGA2ox genes were distributed in the A and C subgenomes. Subcellular localization predictions suggested that all BnaGA2ox proteins were localized in the cytoplasm, and gene structure analysis showed that the BnaGA2ox genes contained 2–4 exons. Phylogenetic analysis indicated that BnGA2ox family proteins in monocotyledons and dicotyledons can be divided into four groups, including two C19-GA2ox and two C20-GA2ox clades. Group 4 is a C20-GA2ox Class discovered recently. Most BnaGA2ox genes had a syntenic relationship with AtGA2ox genes. BnaGA2ox genes in the C subgenome had experienced stronger selection pressure than genes in the A subgenome. BnaGA2ox genes were highly expressed in specific tissues such as those involved in growth and development, and most of them were mainly involved in abiotic responses, regulation of phytohormones and growth and development. Our study provided a valuable evolutionary analysis of GA2ox genes in monocotyledons and dicotyledons, as well as an insight into the biological functions of GA2ox family genes in B. napus. 相似文献
17.
Xiaofang Zeng Guangzheng Li Nu’an Liu Yan Li Jianrong Li Xiaozhen Huang Degang Zhao 《Phyton》2022,91(11):2419-2437
Leaf-color mutants play an important role in the study of chlorophyll metabolism, chloroplast development, and
photosynthesis system. In this study, the yellow leaf 1 (yl1) rice mutant was identified from the ethyl methane
sulfonate-treated mutant progeny of Lailong, a glutinous japonica rice landrace cultivated in Guizhou Province,
China. Results showed that yl1 exhibited yellow leaves with decreased chlorophyll content throughout the growth
period. Chloroplast development in the yl1 mutant was disrupted, and the grana lamellae was loosely packed and
disordered. RNA sequencing and real-time quantitative polymerase chain reaction (qRT-PCR) analysis revealed
that the chlorophyll synthesis-related genes OsCHLH, OsCHLM, OsCHLG, PORB, and YGL8, as well as the chloroplast development-related genes FtsZ, OsRpoTp, and RbcL, were down-regulated in the yl1 mutant. Genetic analysis revealed that the yellow leaf phenotype of yl1 was controlled by recessive nuclear gene. By employing the
MutMap method, the mutation responsible for the phenotype was mapped to a 6.17 Mb region between
17.34 and 23.51 Mb on chromosome 3. Two non-synonymous single-nucleotide polymorphisms (SNPs) located
in the gene locus LOC_Os03g31210 and LOC_Os03g36760 were detected in this region. The two SNPs were
further confirmed by PCR and Sanger sequencing. The expression patterns of the two candidate genes indicated
that LOC_Os03g36760 showed greater potential for functional verification. Subcellular protein localization
revealed that the encoded product of LOC_Os03g36760 was localized in the nucleus, cytoplasm, and plasma membrane. These results will be useful for further characterization and cloning of the yl1 gene, and for research on the
molecular mechanisms controlling biogenesis and chloroplast biochemical processes. 相似文献
18.
Adeleh Taghikhani Zuhair Mohammad Hassan Marzieh Ebrahimi Seyyed-Mohammad Moazzeni 《Journal of cellular physiology》2019,234(6):9417-9427
Tumor-derived exosomes (TEX) are known by their immune suppression effects as well as initiation mediators in cancer progression and metastasis. Meanwhile, they are appropriate sources to induce immunity against tumor cells, as consist of tumor specific and associated antigens. The aim of the current study is modifying TEX with microRNA miR-155, miR-142, and let-7i, to enhance their immune stimulation ability and induce potent dendritic cells (DC). For this, exosomes were isolated from mouse mammalian breast cancer cell line; 4T1, and subjected to miR-155, miR-142, and let-7i by electroporation. Immature DCs were generated from mouse bone marrow in the presence of interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF). To mature DCs, lipopolysaccharide (LPS), TEX, and modified TEX were used. The expression level of miRNAs and their target genes (IL-6, IL-17, IL-1b, TGFβ, SOCS1, KLRK1, IFNγ, and TLR4) was determined. TEX were nanovesicles with spheroid morphology which expressed CD81, CD63, and TSG101, as exosome markers, at protein level. MHCII, CD80, and CD40 as maturation markers were assessed by flow cytometry. Overexpression of miRNAs were confirmed in exosomes and mDCs. Up and downregulation of target genes confirmed the gene network in DC maturation. We found that Let-7i could efficiently induce the DC maturation, as well as miR-142 and miR-155 have enhancing effects. These findings reveal that the modified TEX would be a hopeful cell-free vaccine for the cancer treatment. 相似文献
19.
Elizabeth Carrillo-Flores Jonanci Arreola-Rivera Denní Mariana Pazos-Solís Moisés Bocanegra-Mondragón Grisel Fierro-Romero Ma. Elena Mellado-Rojas Elda Beltrán-Peña 《Phyton》2022,91(11):2383-2401
The potential of Plant Growth Promoting Rhizobacteria (PGPR) has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield. A. brasilense produces a wide variety of molecules, including the natural auxin indole-3-acetic acid (IAA), as well as other phytoregulators. However, several studies have suggested that auxin induces changes in plant development during their interaction with the bacteria. The effects of A. brasilense Sp245 on the development of Arabidopsis thaliana root were investigated to help explain the molecular basis of the interaction. The results obtained showed a decrease in primary root length from the first day and remained so throughout the exposure, accompanied by a stimulation of initiation and maturation of lateral root primordia and an increase of lateral roots. An enhanced auxin response was evident in the vascular tissue and lateral root meristems of inoculated plants. However, after five days of bacterization, the response disappeared in the primary root meristems. The role of polar auxin transport (PAT) in auxins relocation involved the PGP1, AXR4-1, and BEN2 proteins, which apparently mediated A. brasilense-induced root branching of Arabidopsis seedlings. 相似文献
20.
Henry López-López Nancy Ruiz-Lau Rocío Meza-Gordillo Víctor Manuel Ruiz-Valdiviezo Joseph Galthier Robledo-Luchetti Carlos Alberto Lecona-Guzmán Juan José Villalobos-Maldonado Luc Dendooven Joaquín Adolfo Montes-Molina 《Phyton》2023,92(4):1235-1255
The objective of this work was to evaluate the effect of Beauveria bassiana (Bb 1205) on controlling Fusarium oxysporum f. sp. lycopersici (Fol 17108) in tomato plants in greenhouse conditions. Inoculation of Bb 1205 was the most promising among the agronomic variables and expression of the activity of the enzymes β-1,3-glucanases and chitinases. Inoculation of Bb 1205 occurred at a concentration of 1 × 108 conidia·mL−1, which was administered onto the leaves, directly into the soil and via injection. Infection with Fol 17108 occurred with 1 × 106 spores·mL−1, which were added directly to the soil. Spectrophotometry was used for measuring agronomic parameters, namely activity of chitinases and β-1,3-glucanases in foliage and roots. When Bb 1205 was added to the soil, the chlorophyll index and aerial part length showed significant differences. In addition, it was determined that root length, fresh weight of foliage, flower, and fruit count increased 82 days after inoculation (dai). Chitinase activity induced by Bb 1205 in leaves and roots of tomato plants infected with Fol 17108 was observed when injected into the stem at 32 dai (41.8 and 11.6-fold, respectively). Inoculation on the foliage showed a 10-fold increase of β-1,3-glucanases in the roots after 82 dpi. As for leaves, a 3.8-fold increase was found when the stem was inoculated. In the different in vivo applications, Bb 1205 activated its defenses by expressing the chitinase enzymes and β-1,3-glucanase, thus reducing the damage caused by Fol 17108, demonstrating increase plant growth thereafter. 相似文献