Phytoplasma-Associated Diseases in South America: Thirty Years of Research.

Phytoplasma-associated diseases are mainly insect-transmitted and are present worldwide. Considering that disease detection is a relevant environmental factor that may elucidate the presence of these diseases, a review reporting the geographic distribution of phytoplasma taxa in geographically consistent areas helps manage diseases appropriately and reduce their spreading. This work summarizes the data available about the identification of the phytoplasma associated with several diverse diseases in South America in the last decades.

Paulownia Witches' Broom Disease: A Comprehensive Review.

Phytoplasmas are insect-transmitted bacterial pathogens associated with diseases in a wide range of host plants, resulting in significant economic and ecological losses. Perennial deciduous trees in the genus are widely planted for wood harvesting and ornamental purposes. Paulownia witches' broom (PaWB) disease, associated with a 16SrI-D subgroup phytoplasma, is a destructive disease of paulownia in East Asia.

Multilocus Gene Analyses Indicate as Reservoir Host of Diverse Phytoplasmas Associated with Witches' Broom and Yellowing Symptomatology.

Tamarisk witches' broom, yellowing, and little leaf symptoms were observed during 2018-2023 surveys of rural deserts in central regions of Iran with the highest disease incidence up to 72% in Chah Afzal (Yazd province). A verification of the presence and identity of phytoplasmas associated with these symptoms was then performed. Tamarisk tree branch cuttings obtained from symptomatic plants sprouted up to 90.

Phloem-Localized Insect-Transmitted Bacteria Associated with Plant Diseases.

In the last three decades, an increasing number of plant diseases associated with the presence of phloem-localized insect-transmitted bacteria have been observed around the world, causing serious economic losses [...

Small RNA Profiling of Aster Yellows Phytoplasma-Infected Plants Showing Different Symptoms.

Micropropagated plants infected with ' Phytoplasma asteris' showed virescence symptoms, witches' broom symptoms, or became asymptomatic after their planting in pots. Nine plants were grouped into three categories according to these symptoms, which were then employed for investigation. The phytoplasma concentration, as determined by qPCR, correlated well with the severity of symptoms.

European primary datasets of alien bacteria and viruses.

Bacteria and viruses are a natural component of Earth biodiversity and play an essential role in biochemical and geological cycles. They may also pose problems outside their native range, where they can negatively impact on natural resources, wildlife, and human health. To address these challenges and develop sustainable conservation strategies, a thorough understanding of their invasion related- factors is needed: origin, country and year of introduction, and pathways dynamics.

Plants and Phytoplasmas: When Bacteria Modify Plants.

Plant pathogen presence is very dangerous for agricultural ecosystems and causes huge economic losses. Phytoplasmas are insect-transmitted wall-less bacteria living in plants, only in the phloem tissues and in the emolymph of their insect vectors. They are able to manipulate several metabolic pathways of their hosts, very often without impairing their life.

Revision of the ' Phytoplasma' species description guidelines.

The genus ' Phytoplasma' was proposed to accommodate cell wall-less bacteria that are molecularly and biochemically incompletely characterized, and colonize plant phloem and insect vector tissues. This provisional classification is highly relevant due to its application in epidemiological and ecological studies, mainly aimed at keeping the severe phytoplasma plant diseases under control worldwide. Given the increasing discovery of molecular diversity within the genus '.

Survey for ' Liberibacter' and ' Phytoplasma' in Citrus in Chile.

The considerable economic losses in citrus associated with ' Liberibacter' and ' Phytoplasma' presence have alerted all producing regions of the world. In Chile, none of these bacteria have been reported in citrus species. During the years 2017 and 2019, 258 samples presenting symptoms similar to those associated with the presence of these bacteria were examined.

Molecular Variability and Host Distribution of ' Phytoplasma solani' Strains from Different Geographic Origins.

The knowledge of phytoplasma genetic variability is a tool to study their epidemiology and to implement an effective monitoring and management of their associated diseases. ' Phytoplasma solani' is associated with "bois noir" disease in grapevines, and yellowing and decline symptoms in many plant species, causing serious damages during the epidemic outbreaks. The epidemiology of the diseases associated with this phytoplasma is complex and related to numerous factors, such as interactions of the host plant and insect vectors and spreading through infected plant propagation material.

Containment of Phytoplasma-Associated Plant Diseases by Antibiotics and Other Antimicrobial Molecules.

Phytoplasmas are plant-pathogenic bacteria that infect many important crops and environmentally relevant plant species, causing serious economic and environmental losses worldwide. These bacteria, lacking a cell wall, are sensitive to antibiotics such as tetracyclines that affect protein synthesis mechanisms. Phytoplasma cultivation in axenic media has not been achieved for many strains; thus, the screening of antimicrobials must be performed using mainly materials.

Update and New Epidemiological Aspects about Grapevine Yellows in Chile.

To date, phytoplasmas belonging to six ribosomal subgroups have been detected to infect grapevines in Chile in 36 percent of the sampled plants. A new survey on the presence of grapevine yellows was carried out from 2016 to 2020, and 330 grapevine plants from the most important wine regions of the country were sampled and analyzed by nested PCR/RFLP analyses. Phytoplasmas enclosed in subgroups 16SrIII-J and 16SrVII-A were identified with infection rates of 17% and 2%, respectively.

Plasma activated water triggers plant defence responses.

Nowadays, one of the main challenges is moving towards an eco-sustainable agriculture, able to preserve the food production through a reduced use of pesticides. Current global food sustenance by intensive agriculture is mainly based on economic crop monocultures and drastically reduces the biodiversity, increasing the yield losses due to the presence of biotic and abiotic stresses. A technology based on plasma activated water (PAW), characterized by the presence in liquid of reactive oxygen and nitrogen species, was tested to try to ensure yield stability also enhancing the plant resistance responses and to promote an eco-sustainable management of plant diseases.

A new species of planthopper in the genus Agoo Bahder amp; Bartlett (Hemiptera: Fulgoroidea: Derbidae) from coconut palm (Cocos nucifera L.) in Jamaica.

A new species of the genus Agoo Bahder Bartlett, Agoo beani sp. n. was found associated with coconut (Cocos nucifera L.

Detection of 16SrVI and 16SrIX phytoplasma groups in pot marigold and tickseed plants in northeastern Iran.

Pot marigold and tickseed are ornamental plants with many medicinal and cosmetic uses and for landscape, respectively. During a survey in 2018, phyllody symptoms were observed in high percentages in these plants in some regions of the Razavi Khorasan province (northeastern Iran). Total DNA was extracted from symptomatic and asymptomatic plants and polymerase chain reaction was carried on using universal phytoplasma primer pairs P1/P7 and nested primer pairs R16F2n/R16R2.

A new species of planthopper belonging to the genus Oecleus Stål, 1862 (Hemiptera: Fulgoroidea: Cixiidae) from coconut palm (Cocos nucifera L) in Jamaica.

A new species of cixiid planthopper (Hemiptera: Fulgoroidea) in the genus Oecleus Stål, Oecleus mackaspringi sp. n., is described from Spring Garden, Jamaica.

Identification and transmission of phytoplasmas and their impact on essential oil composition in .

plants showing symptoms of witches' broom, little leaf, and leaf roll were observed in 50% of the plants grown in the deserts of Hormozgan province, Iran. This study was carried out to verify possible phytoplasma association with this disease, insect vector, and modification of the chemical composition of symptomatic . Aerial parts were collected at the full flowering stage from symptomatic and asymptomatic plants and samples were examined for phytoplasma presence by nested-PCR assays.

Global Status of Phytoplasma Diseases in Vegetable Crops.

The presence of phytoplasmas and their associated diseases is an emerging threat to vegetable production which leads to severe yield losses worldwide. Phytoplasmas are phloem-limited pleomorphic bacteria lacking the cell wall, mainly transmitted through leafhoppers but also by plant propagation materials and seeds. Phytoplasma diseases of vegetable crops are characterized by symptoms such as little leaves, phyllody, flower virescence, big buds, and witches' brooms.

Molecular and biological characterization of phytoplasmas from coconut palms affected by the lethal yellowing disease in Africa.

Côte d'Ivoire lethal yellowing (CILY) is a devastating disease associated with phytoplasmas and has recently rapidly spread to several coconut-growing areas in the Country. Phytoplasmas are phloem-restricted bacteria that affect plant species worldwide. These bacteria are transmitted by plant sap-feeding insects, and their cultivation was recently achieved in complex artificial media.

Plasma activated water as resistance inducer against bacterial leaf spot of tomato.

Plant bacterial diseases are routinely managed with scheduled treatments based on heavy metal compounds or on antibiotics; to reduce the negative environmental impact due to the use of such chemical compounds, as pollution or selection of antibiotic resistant pathogens, the integrated control management is required. In the frame of a sustainable agriculture the use of bacterial antagonists, biological agents, plant defence response elicitors or resistant host plant genotypes are the most effective approaches. In this work, cold atmospheric pressure plasma (CAP) was applied to sterile distilled water, inducing the production of a hydrogen peroxide, nitrite and nitrate, and a pH reduction.

Association of a ' Phytoplasma aurantifolia'-related strain with apricot showing European stone fruit yellows symptoms in Iran.

During 2012-2015 surveys in some orchards in Faraghe (Iran), a number of apricot trees showed symptoms resembling those associated with the phytoplasma disease known as European stone fruit yellows that are severe leaf roll, yellowing and die back. The presence of an infectious agent was confirmed by graft transmission experiments in which all the previously symptomless GF-677 (peach × almond) trees showed phytoplasma-type symptoms. The phytoplasma presence was confirmed by nested PCR assays using DNA extracted from samples from both field collected and graft-inoculated trees.

Standard Detection Protocol: PCR and RFLP Analyses Based on 16S rRNA Gene.

Phytoplasma detection and identification is primarily based on PCR followed by restriction fragment length polymorphism analysis. This method detects and differentiates phytoplasmas including those not yet identified. The protocol describes the application of this method for identification of phytoplasmas at 16S rRNA (16Sr) group and 16Sr subgroup levels on amplicons and also in silico on the same sequences.

Characterization of a 16SrII subgroup D phytoplasma strain associated with phyllody in Iran.

plants with phyllody symptoms (CaoP) were observed in Yazd and Ashkezar (Yazd province, Iran) during 2013-2016. Twenty-one symptomatic and four asymptomatic plants were transferred individually to the greenhouse and potted for the biological and molecular characterization of associated phytoplasma. The dodder transmission from symptomatic potted marigold plants, induced virescence, phyllody and witches' broom symptoms in periwinkle.

Draft Whole Genome Sequence Analyses on Pseudomonas syringae pv. actinidiae Hypersensitive Response Negative Strains Detected from Kiwifruit Bleeding Sap Samples.

Kiwifruit bleeding sap samples, collected in Italian and Chilean orchards from symptomatic and asymptomatic plants, were evaluated for the presence of Pseudomonas syringae pv. actinidiae, the causal agent of bacterial canker. The saps were sampled during the spring in both hemispheres, before the bud sprouting, during the optimal time window for the collection of an adequate volume of sample for the early detection of the pathogen, preliminarily by molecular assays, and then through its direct isolation and identification.