scholarly journals Evaluation of the Spatiotemporal Dynamics of Oxytetracycline and Its Control Effect Against Citrus Huanglongbing via Trunk Injection

2016 ◽  
Vol 106 (12) ◽  
pp. 1495-1503 ◽  
Author(s):  
Jiahuai Hu ◽  
Nian Wang
Keyword(s):  
Root System ◽  
Early Stage ◽  
Spatiotemporal Dynamics ◽  
Bacterial Disease ◽  
In Planta ◽  
Control Effect ◽  
Chromatography Method ◽  
Effective Measure ◽  
Citrus Huanglongbing ◽  
Trunk Injection

Citrus huanglongbing (HLB) or greening is a devastating bacterial disease that has destroyed millions of trees and is associated with phloem-residing ‘Candidatus Liberibacter asiaticus’ (Las) in Florida. In this study, we evaluated the spatiotemporal dynamics of oxytetracycline in planta and its control effect against HLB via trunk injection. Las-infected ‘Hamlin’ sweet orange trees on ‘Swingle’ citrumelo rootstock at the early stage of decline were treated with oxytetracycline hydrochloride (OTC) using trunk injection with varying number of injection ports. Spatiotemporal distribution of OTC and dynamics of Las populations were monitored by high-performance liquid chromatography method and qPCR assay, respectively. Uniform distribution of OTC throughout tree canopies and root system was achieved 2 days postinjection. High levels of OTC (>850 µg/kg) were maintained in leaf and root for at least 1 month and moderate OTC (>500 µg/kg) persisted for more than 9 months. Reduction of Las populations in root system and leaves of OTC-treated trees were over 95% and 99% (i.e., 1.76 and 2.19 log reduction) between 2 and 28 days postinjection. Conditions of trees receiving OTC treatment were improved, fruit yield was increased, and juice acidity was lowered than water-injected control even though their differences were not statistically significant during the test period. Our study demonstrated that trunk injection of OTC could be used as an effective measure for integrated management of citrus HLB.

scholarly journals Chemical Compounds Effective Against the Citrus Huanglongbing Bacterium ‘Candidatus Liberibacter asiaticus’ In Planta

2011 ◽  
Vol 101 (9) ◽  
pp. 1097-1103 ◽  
Author(s):  
Muqing Zhang ◽  
Charles A. Powell ◽  
Lijuan Zhou ◽  
Zhenli He ◽  
Ed Stover ◽  
...  
Keyword(s):  
Test System ◽  
Candidatus Liberibacter Asiaticus ◽  
In Planta ◽  
Citrus Industry ◽  
Effective Level ◽  
Candidatus Liberibacter ◽  
Citrus Huanglongbing ◽  
Liberibacter Asiaticus ◽  
Trunk Injection ◽  
Therapeutic Compounds

Citrus Huanglongbing (HLB) is one of the most destructive diseases of citrus worldwide and is threatening the survival of the Floridian citrus industry. Currently, there is no established cure for this century-old and emerging disease. As a possible control strategy for citrus HLB, therapeutic compounds were screened using a propagation test system with ‘Candidatus Liberibacter asiaticus’-infected periwinkle and citrus plants. The results demonstrated that the combination of penicillin and streptomycin (PS) was effective in eliminating or suppressing the ‘Ca. L. asiaticus’ bacterium and provided a therapeutically effective level of control for a much longer period of time than when administering either antibiotic separately. When treated with the PS, ‘Ca. L. asiaticus’-infected periwinkle cuttings achieved 70% of regeneration rates versus <50% by other treatments. The ‘Ca. L. asiaticus’ bacterial titers in the infected periwinkle plants, as measured by quantitative real-time polymerase chain reaction, decreased significantly following root soaking or foliar spraying with PS. Application of the PS via trunk injection or root soaking also eliminated or suppressed the ‘Ca. L. asiaticus’ bacterium in the HLB-affected citrus plants. This may provide a useful tool for the management of citrus HLB and other Liberibacter-associated diseases.

scholarly journals Effect of Adjuvants on Oxytetracycline Uptake upon Foliar Application in Citrus

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 677
Author(s):  
Nabil Killiny ◽  
Faraj Hijaz ◽  
Pedro Gonzalez-Blanco ◽  
Shelley E. Jones ◽  
Myrtho O. Pierre ◽  
...  
Keyword(s):  
Foliar Application ◽  
Foliar Spray ◽  
Bacterial Pathogen ◽  
Water Addition ◽  
Candidatus Liberibacter ◽  
Citrus Huanglongbing ◽  
Liberibacter Asiaticus ◽  
Trunk Injection ◽  
Citrus Leaves ◽  
Target Effects

Recently in Florida, foliar treatments using products with the antibiotics oxytetracycline and streptomycin have been approved for the treatment of citrus Huanglongbing (HLB), which is caused by the putative bacterial pathogen ‘Candidatus Liberibacter asiaticus’. Herein, we assessed the levels of oxytetracycline and ‘Ca. L. asiaticus’ titers in citrus trees upon foliar applications with and without a variety of commercial penetrant adjuvants and upon trunk injection. The level of oxytetracycline in citrus leaves was measured using an oxytetracycline ELISA kit and ‘Ca. L. asiaticus’ titer was measured using quantitative PCR. Low levels of oxytetracycline were taken up by citrus leaves after foliar sprays of oxytetracycline in water. Addition of various adjuvants to the oxytetracycline solution showed minimal effects on its uptake by citrus leaves. The level of oxytetracycline in leaves from trunk-injected trees was higher than those treated with all foliar applications. The titer of ‘Ca. L. asiaticus’ in the midrib of leaves from trees receiving oxytetracycline by foliar application was not affected after four days and thirty days of application, whereas the titer was significantly reduced in oxytetracycline-injected trees thirty days after treatment. Investigation of citrus leaves using microscopy showed that they are covered by a thick lipidized cuticle. Perforation of citrus leaf cuticle with a laser significantly increased the uptake of oxytetracycline, decreasing the titer of ‘Ca. L. asiaticus’ in citrus leaves upon foliar application. Taken together, our findings indicate that trunk injection is more efficient than foliar spray even after the use of adjuvants. Our conclusion could help in setting useful recommendations for the application of oxytetracycline in citrus to improve tree health, minimize the amount of applied antibiotic, reduce environmental exposure, and limit off-target effects.

scholarly journals Characterization of the early response of Arabidopsis thaliana to Dickeya dadantii infection using expression profiling

2018 ◽  
Author(s):  
Frédérique Van Gijsegem ◽  
Frédérique Bitton ◽  
Anne-Laure Laborie ◽  
Yvan Kraepiel ◽  
Jacques Pédron
Keyword(s):  
Arabidopsis Thaliana ◽  
Early Stage ◽  
Plant Defence ◽  
Plant Responses ◽  
Type I ◽  
In Planta ◽  
Secretion Systems ◽  
Dickeya Dadantii ◽  
A Genome

AbstractTo draw a global view of plant responses to interactions with the phytopathogenic enterobacterale Dickeya dadantii, a causal agent of soft rot diseases on many plant species, we analysed the early Arabidopsis responses to D. dadantii infection. We performed a genome-wide analysis of the Arabidopsis thaliana transcriptome during D. dadantii infection and conducted a genetic study of identified responses.A limited set of genes related to plant defence or interactions with the environment were induced at an early stage of infection, with an over-representation of genes involved in both the metabolism of indole glucosinolates (IGs) and the jasmonate (JA) defence pathway. Bacterial type I and type II secretion systems are required to trigger the induction of IG and JA-related genes while the type III secretion system appears to partially inhibit these defence pathways. Using Arabidopsis mutants impaired in JA biosynthesis or perception, we showed that induction of some IG metabolism genes was COI1-dependent but, surprisingly, JA-independent. Moreover, characterisation of D. dadantii disease progression in Arabidopsis mutants impaired in JA or IG pathways showed that JA triggers an efficient plant defence response that does not involve IGs.The induction of the IG pathway by bacterial pathogens has been reported several times in vitro. This study shows for the first time, that this induction does indeed occur in planta, but also that this line of defence is ineffective against D. dadantii infection, in contrast to its role to counteract herbivorous or fungal pathogen attacks.

The Role of Dissolved CH4 in Soil Solution in the CH4 Emission from Water-Saving Irrigated Rice Fields

2011 ◽  
Vol 148-149 ◽  
pp. 977-982
Author(s):  
Dao Xi Li
Keyword(s):  
Soil Solution ◽  
Early Stage ◽  
Dominant Role ◽  
Water Layer ◽  
Water Saving ◽  
Rice Fields ◽  
Chromatography Method ◽  
Soil Layers ◽  
Soil Solutions

To examine how the dissolved CH4 in soil solution would affect the CH4 emission from rice field, fluxes of CH4 emission were measured by using a manually closed static chamber-gas chromatography method, and the dissolved CH4 in soil solution was obtained through shaking soil solutions, which were extracted from different paddy soil layers by a soil solution sampler with suction and pressure. The results show that the CH4 fluxes from rice fields and the concentration of dissolved CH4 in soil solution are both reduced significantly under the water-saving irrigation as compared to the traditional flooded irrigation. Under the water-saving irrigation, naturally receding water-layer during the early stage leads to an earlier peak of CH4 flux, but dramatically reduces the concentration of dissolved CH4 in soil solution. The maximum concentration is shifted to about 20-cm depth soil layers, and the relationship between CH4 emissions and dissolved CH4 in soil solution can be estimated using an exponential function of dissolved CH4 in soil solution at the depth of about 20 cm (R2＝0.89, p4 in soil solution plays a more dominant role in CH4 emission under the water-saving irrigation than that under continuously flooded irrigation.

scholarly journals Dissecting the co-transcriptome landscape of plants and microbiota members

2021 ◽  
Author(s):  
Tatsuya Nobori ◽  
Yu Cao ◽  
Frederickson Entila ◽  
Eik Dahms ◽  
Yayoi Tsuda ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Early Stage ◽  
Building Blocks ◽  
Niche Separation ◽  
In Planta ◽  
Bacterial Strains ◽  
Transcriptional Responses ◽  
Associated Bacteria ◽  
Plant Microbiota ◽  
And Function

AbstractInteractions between plants and each neighboring microbial species are fundamental building blocks that collectively determine the structure and function of the plant microbiota, but the molecular basis of such interactions is poorly characterized. Here, we monocolonized Arabidopsis leaves with nine plant-associated bacteria from all major phyla of the plant microbiota and profiled co-transcriptomes of plants and bacteria. These strains elicited quantitatively different plant transcriptional responses including typical pattern-triggered immunity responses. Genes of non-pathogenic bacteria involved in general metabolism and energy production were commonly suppressed in planta in contrast to a virulent pathogen. Various nutrient acquisition pathways that are frequently encoded in the genomes of plant-associated bacteria were induced in planta in a strain-specific manner, shedding light on bacterial adaptation to the plant environment and identifying a potential driving force of niche separation. Integrative analyses of plant and bacterial transcriptomes suggested that the transcriptional reprogramming of plants is largely uncoupled from that of bacteria at an early stage of interactions. This study provides insights into how plants discriminate among bacterial strains and sets the foundation for in-depth mechanistic dissection of plant-microbiota interactions.

scholarly journals Cocktail Therapy of Fosthiazate and Cupric-Ammoniun Complex for Citrus Huanglongbing

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingwei Duan ◽  
Xue Li ◽  
Junzhe Zhang ◽  
Baoping Cheng ◽  
Shuhan Liu ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Starch Accumulation ◽  
Bacterial Disease ◽  
Tree Roots ◽  
Tylenchulus Semipenetrans ◽  
Transmission Electron ◽  
Citrus Root ◽  
Citrus Huanglongbing ◽  
Liberibacter Asiaticus

Huanglongbing (HLB) is a destructive citrus bacterial disease caused by Candidatus Liberibacter asiaticus (Ca.Las) and cannot be cured by current pesticides. Root lesion and Tylenchulus semipenetrans juveniles were observed in HLB-affected citrus tree roots. We hypothesize that root treatment with fosthiazate (FOS) and Cupric-Ammonium Complex (CAC) will improve the root growth and inhibit HLB. CAC is a broad spectrum fungicide and can promote growth of crops. FOS kills Tylenchulus semipenetrans and protects roots from damage by harmful bacteria such as Ca.Las. After 90 days of combination treatment of FOS and CAC through root drenches, the citrus grew new roots and its leaves changed their color to green. The inhibition rate of Ca.Las reached more than 90%. During treatment process, the chlorophyll content and the root vitality increased 396 and 151%, respectively, and starch accumulation decreased by 88%. Transmission electron microscopy (TEM) and plant tissue dyeing experiments showed that more irregular swollen starch granules existed in the chloroplast thylakoid system of the HLB-infected leaves. This is due to the blocking of their secretory tissue by starch. TEM and flow cytometry experiments in vitro showed the synergistic effects of FOS and CAC. A transcriptome analysis revealed that the treatment induced the differential expression of the genes which involved 103 metabolic pathways. These results suggested that the cocktail treatment of FOS and CAC may effectively kill various pathogens including Ca.Las on citrus root and thus effectively control HLB.

scholarly journals The causes of the lack of self-tolerance of winter rye, grown on light sandy soils. 2. Influences of phytotoxins and soil microflora.

1978 ◽  
Vol 26 (3) ◽  
pp. 250-266
Author(s):  
K. Scholte ◽  
L.J.P. Kupers
Keyword(s):  
Root System ◽  
Early Stage ◽  
Sandy Soils ◽  
Soil Microflora ◽  
Circumstantial Evidence ◽  
Winter Rye ◽  
Soil Sterilization ◽  
Self Tolerance

As a result of an investigation into the causes of self-intolerance of rye (i.e. of rye following rye) it could be proved that a number of obvious well-known pathological agents such as nematodes, foot rots and phytotoxins cannot be accepted as important causes. Circumstantial evidence was produced strongly suggesting that the composition of the soil microflora (to a certain extent itself the result of growing this crop in the previous yr) is the main cause. Soil sterilization eliminates self-intolerance. One symptom of self-intolerance is the rapid degeneration of the root system at an early stage of growth. Application of larger rates of N postpones the onset of this phenomenon. The effect of N is indirect. A larger continued uptake of N furthers the potential for compensation of the plant. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals RNA-seq data of Ganoderma boninense at axenic culture condition and under in planta pathogen-oil palm (Elaeis guineensis Jacq.) interaction

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Mui Yun Wong ◽  
Nisha T. Govender ◽  
Chia Sui Ong
Keyword(s):  
Oil Palm ◽  
Molecular Mechanisms ◽  
Elaeis Guineensis ◽  
Early Stage ◽  
Axenic Culture ◽  
Economic Losses ◽  
Post Inoculation ◽  
Ganoderma Boninense ◽  
In Planta ◽  
Rot Disease

Abstract Objective Basal stem rot disease causes severe economic losses to oil palm production in South-east Asia and little is known on the pathogenicity of the pathogen, the basidiomyceteous Ganoderma boninense. Our data presented here aims to identify both the house-keeping and pathogenicity genes of G. boninense using Illumina sequencing reads. Description The hemibiotroph G. boninense establishes via root contact during early stage of colonization and subsequently kills the host tissue as the disease progresses. Information on the pathogenicity factors/genes that causes BSR remain poorly understood. In addition, the molecular expressions corresponding to G. boninense growth and pathogenicity are not reported. Here, six transcriptome datasets of G. boninense from two contrasting conditions (three biological replicates per condition) are presented. The first datasets, collected from a 7-day-old axenic condition provide an insight onto genes responsible for sustenance, growth and development of G. boninense while datasets of the infecting G. boninense collected from oil palm-G. boninense pathosystem (in planta condition) at 1 month post-inoculation offer a comprehensive avenue to understand G. boninense pathogenesis and infection especially in regard to molecular mechanisms and pathways. Raw sequences deposited in Sequence Read Archive (SRA) are available at NCBI SRA portal with PRJNA514399, bioproject ID.

scholarly journals A Cerato-Platanin Family Protein FocCP1 Is Essential for the Penetration and Virulence of Fusarium oxysporum f. sp. cubense Tropical Race 4

2019 ◽  
Vol 20 (15) ◽  
pp. 3785 ◽  
Author(s):  
Siwen Liu ◽  
Bo Wu ◽  
Jing Yang ◽  
Fangcheng Bi ◽  
Tao Dong ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Virulence Factor ◽  
Molecular Mechanisms ◽  
Early Stage ◽  
Transcript Level ◽  
In Planta ◽  
Knock Out ◽  
Penetration Ability ◽  
Fusarium Wilt Of Banana ◽  
Race 4

Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) is well-known as the causal agent of Fusarium wilt of banana and is one of the most destructive phytopathogens for banana plants. The molecular mechanisms underlying Foc TR4 virulence remain elusive. Here, we demonstrate that a cerato-platanin (CP) protein, FocCP1, functions as a virulence factor that is required by Foc TR4 for penetration and full virulence. The FocCP1 gene was expressed in every condition studied, showing a high transcript level in planta at the early stage of infection. Infiltration of the recombinant FocCP1 protein induced significant cell death and upregulated defence-related gene expression. FocCP1 knock-out strains showed a significant decrease in aerial growth rather than aqueous growth, which is reminiscent of hydrophobins. Furthermore, deletion of FocCP1 significantly reduced virulence and dramatically reduced infective growth in banana roots, likely resulting from a defective penetration ability. Taken together, the results of this study provide novel insight into the function of the recently identified FocCP1 as a virulence factor in Foc TR4.

scholarly journals Control Allocation Design of Reaction Control System for Reusable Launch Vehicle

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Rongjun Mu ◽  
Xin Zhang
Keyword(s):  
Control System ◽  
Attitude Control ◽  
Control Method ◽  
Early Stage ◽  
Launch Vehicle ◽  
Programming Algorithm ◽  
Control Allocation ◽  
Control Effect ◽  
Reusable Launch Vehicle ◽  
Reaction Control System

During the early stage of reusable launch vehicle (RLV) reentry flight, reaction control system (RCS) is the major attitude control device. RCS, which is much different from the atmospheric steer’s control, requires a well designed control allocation system to fit the attitude control in high altitude. In this paper, an indexed control method was proposed for RCS preallocation, a 0-1 integer programming algorithm was designed for RCS allocation controller, and then this RCS scheme’s effect was analyzed. Based on the specified flight mission simulation, the results show that the control system is satisfied. Moreover, several comparisons between the attitude control effect and RCS relevant parameters were studied.

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