David Ezra

Agricultural Research Organization ARO | aro · Department of Plant Pathology and Weed Research

BACKGROUND Fungal plant diseases cause major crop losses. Phytopathogenic fungi's ability to evolve resistance to fungicides, alongside ongoing prohibition of such agents by the European Commission because of their pronounced adverse effects on human health and the environment, make their control a challenge. Moreover, the development of less peril...

Bioassays are the main tool to decipher bioactivities from natural resources thus their selection and quality are critical for optimal bioprospecting. They are used both in the early stages of compounds isolation/purification/identification, and in later stages to evaluate their safety and efficacy. In this review, we provide a comprehensive overvi...

Persimmon (Diospyros kaki) fruits accumulate vitamins, carotenoids, flavonoids, and antioxidants in their skin tissues, and therefore, considered as highly nutritional. Yet some persimmon varieties suffer from skin disorders including calyx-end cracking, shallow concentric cracks, and cloudy stains. These unfavorable disorders result in reduced fru...

Secondary metabolites—organic compounds that are often bioactive—produced by endophytes, among others, provide a selective advantage by increasing the organism’s survivability. Secondary metabolites mediate the symbiotic relationship between endophytes and their host, potentially providing the host with tolerance to, and protection against biotic a...

During May 2016, a corky textured, "star like" symptom, located at the apex on the far side of the fruit was observed on young persimmon fruitlets (Fig. 1), on several persimmon varieties in plantations located along the Mediterranean Sea coast. The lesions caused cosmetic damage, which disqualified the fruit from marketing and can affect as much a...

The worldwide demand for reduced and restricted use of pesticides in agriculture due to serious environmental effects, health risks and the development of pathogen resistance calls for the discovery of new bioactive compounds. In the medical field, antibiotic‐resistant microorganisms have become a major threat to man, increasing mortality. Endophyt...

The growth and development of mature, fruit bearing, avocado trees in Menashe Heights region of Israel was retarded from the late-2000s. As time passed the trees decayed gradually, leaves dropped off and eventually the trees died. This process usually spanned 2 to 4 years. The objectives of the study were to: (i) map the spatial distribution of sym...

Species distribution models are widely used to estimate the potential geographic distribution of species habitat. They are also used to predict the impact of climate change on species distributions. In this study, we examined the distribution of Mal Secco disease, an infective disease of citrus caused by the fungus Plenodomus tracheiphilus. To mode...

Endophytes are microorganisms that live inside the plant tissue without causing external symptoms. All plants in nature harbor endophytes. Some endophytes produce and secrete biologically active compounds, known as secondary metabolites, which can help the host plant cope with bacterial, fungal, and other pest pathogens. Endophytes are isolated fro...

Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...

Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...

Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...

Coastal countries have traditionally relied on the existing marine resources (e.g., fishing, food, transport, recreation, and tourism) as well as tried to support new economic endeavors (ocean energy, desalination for water supply, and seabed mining). Modern societies and lifestyle resulted in an increased demand for dietary diversity, better healt...

Black mold, caused by Aspergillus niger, is the main fungal disease affecting date fruits. Symptoms develop inside the fruit, at the inner space between the pulp and the seed. This study focuses on the etiology of black mold disease in 'Medjoul' fruit. We followed symptoms appearance naturally and after artificial A. niger inoculation at different...

Metarhizium brunneum is a generalist entomopathogenic fungus known to be virulent against Acari. We investigated Metarhizium brunneum-7 (Mb7) interactions in three systems of phytophagous mites and their respective plant hosts: Volkamer lemon (Citrus volkameriana) and the citrus rust mite Phyllocoptruta oleivora; common bean (Phaseolus vulgaris) an...

Marine organisms produce a vast diversity of metabolites with biological activities useful for humans, e.g., cytotoxic, antioxidant, anti-microbial, insecticidal, herbicidal, anticancer, pro-osteogenic and pro-regenerative, analgesic, anti-inflammatory, anti-coagulant, cholesterol-lowering, nutritional, photoprotective, horticultural or other benef...

Dothideomycetes is the largest class of kingdom Fungi and comprises an incredible diversity of lifestyles, many of which have evolved multiple times. Plant pathogens represent a major ecological niche of the class Dothideomycetes and they are known to infect most major food crops and feedstocks for biomass and biofuel production. Studying the ecolo...

BACKGROUND Sclerotium rolfsii is a soil‐borne phytopathogenic fungus that causes diseases in economically important crops. Eradication of the fungus is hampered by its wide range of hosts, as well as its capacity to form sclerotia. Recently, we have shown that the endophytic fungus Daldinia cf. concentrica emits biologically active volatile organic...

Mal Secco is a severe disease of citrus in which the fungus Plenodomus tracheiphilus (formerly Phoma tracheiphila) penetrates the vascular system of the host. In this study, we characterized the spatial dynamics of the disease in seven lemon orchards. A representative block of trees from each orchard was evaluated monthly during three consecutive y...

Heart rot, caused by Alternaria alternata, is a major pomegranate disease that impacts production worldwide; most fruits in orchards are colonized by A. alternata but, nevertheless, symptoms are apparent on only a small proportion of the colonized fruits. During the years of our previous research it was noticed that within individual orchards, the...

The bionematicidal effect of a synthetic volatile mixture (SVM) of four volatile organic compounds (VOCs) emitted by the endophytic fungus Daldinia cf. concentrica against the devastating plant-parasitic root-knot nematode Meloidogyne javanica has been recently demonstrated in both in vitro and greenhouse experiments. However, the mode of action go...

Comparative phenotype study of L4 larvae of C. elegans exposed to 4-heptanone (0.2 mL, 1.43 mmole), SVM, ivermectin (1 μM) or aldicarb (300 μM). Representative bright-field images of (A) WT C. elegans, (B) the ivermectin-resistant strain DA1316 and (C) the aldicarb-resistant strain CB113. Individual L4 larvae were microscopically observed and image...

Species of Diaporthe are considered important plant pathogens, saprobes, and endophytes on a wide range of plant hosts. Several species are well-known on grapevines, either as agents of pre- or post-harvest infections, including Phomopsis cane and leaf spot, cane bleaching, swelling arm and trunk cankers. In this study we explore the occurrence, di...

Fungal gummosis syndrome of deciduous fruit trees was reported from several countries, including Israel. Symptomatic 5–7 to 10–14-year-old trees exude large amounts of gum on the trunk, limbs, branches, and twigs, accompanied by sunken lesions on the bark. The necrotic area extends to the xylem to form black to brown staining of the tissue. The gen...

Plant-parasitic nematodes form one of the largest sources of biotic stress imposed on plants, and are very difficult to control; among them are the obligate parasites, the sedentary root-knot nematodes (RKNs)–Meloidogyne spp.–which are extremely polyphagous and exploit a very wide range of hosts. Endophytic fungi are organisms that spend most of th...

Endophytic fungi are organisms that spend most of their life cycle within plant tissues without causing any visible damage to the host plant. Many endophytes were found to secrete specialized metabolites and/or emit volatile organic compounds (VOCs), which may be biologically active and assist fungal survival inside the plant as well as benefit the...

Pomegranate (Punica granatum L., Punicaceae) is an ancient plant and fruit, native to central Asia. Since the pomegranate tree is highly adaptive to a wide range of climates and soil conditions, it is grown in many different geographical regions including the Mediterranean basin. Fruit rot also known as "heart rot" or "black heart", is a major pome...

Crown rot decay caused by the gray mold Botrytis cinerea and Penicillium sp. is responsible for severe economic losses during postharvest storage and marketing of pomegranate fruit. In the present study, the efficacy of Switch® and Scholar® (Syngenta Crop Protection Inc., NC, USA) fungicides as pre-and postharvest sprays on development of crown rot...

Pomegranate fruit rot disease, known as “heart rot” or “black heart,” is a major pomegranate disease that impacts production worldwide. Heart rot is characterized by black rot of the fruit core that spreads from the calyx area, whereas the outer peel and the hard rind retain their healthy appearance. Aims of the present study were to identify the p...

All plants in natural ecosystems appear to be symbiotic with endophytes. This includes many economically important agricultural products as well as essential food crops. The endophytes confer fitness benefits to their hosts in various and variable aspects such as growth enhancement and increased reproductive success and confer tolerance to biotic a...

Pitahaya (Hylocereus undatus [Haw.] Britton & Rose) was introduced to Israel in 1994, and is grown throughout the country. In the summer of 2009, fruit with internal black rot was collected from a field in central Israel. Symptomatic tissue from the black rot was placed on potato dextrose agar (PDA) plates amended with 12 μg/ml tetracycline and inc...

Mal secco disease, caused by the pathogenic fungus Phoma tracheiphila, is a devastating disease of susceptible citrus species, especially lemon. To study the molecular interactions between the pathogen and its host, a method for identifying the genes involved in pathogenicity is needed. This work describes the transformation of P. tracheiphila phia...

Gat, T., Liarzi. O., Skovorodnikova, Y.. and Ezra, D. 2012. Characterization of Alternaria alternata causing black spot disease of pomegranate in Israel using a molecular marker. Plant Dis. 96:1513-1518. Black spot disease of pomegranate is a relatively new disease in Israel that is caused by Altemaria alternata. The symptoms include black spots on...

The objective of the research was to isolate from grapevines endophytes with antagonistic activity against phytoplasmas. In order to overcome the inability of grow phytoplasmas in vitro, the antagonistic activities of endophytes isolated from various grapevines on Spiroplasma melliferum, a phylogenetic close and cultivable Mollicute as a model orga...

Powdery mildew, caused by Podosphaera aphanis, is one of the major fungal diseases of cultivated strawberry (Fragaria × ananassa Duchense) world-wide. In the present research were port the efficacy of various control agents in induced resistance in strawberry plants againstPowdery mildew. Inducers tested are Trichoderma harzianum T39, acibenzolar-S...

An unusual Phomopsis sp. was isolated as endophyte of Odontoglossum sp. (Orchidaceae), associated with a cloud forest in Northern Ecuador. This fungus produces a unique mixture of volatile organic compounds (VOCs) including sabinene (a monoterpene with a peppery odor) only previously known from higher plants. In addition, some of the other more abu...

Black spot disease of pomegranate is a new disease caused by Alternaria alternata on pomegranates in Israel. Symptoms can be seen on the leaves and fruits but no damage to the inner edible tissue is found. The causal agent was isolated and Koch Postulates were demonstrated. This is the first report of black spot disease of pomegranate in Israel.

An endophytic fungus of Persea indica was identified, on the basis of its anamorphic stage, as Nodulosporium sp. by SEM. Partial sequence analysis of ITS rDNA revealed the identity of the teleomorphic stage of the fungus as Hypoxylon sp. It produces an impressive spectrum of volatile organic compounds (VOCs), most notably 1,8-cineole, 1-methyl-1,4-...

Muscodor albus strain GBA is a newly isolated endophytic fungus from Ginko biloba (family Ginkoaceae) collected in Newport, RI, USA. The cultural characteristics (color, growth pattern) and mycelial/hyphal characteristics resemble many isolates of Muscodor albus. The ITS rDNA sequence of the strain has at least 98% similarity with other isolates of...

Symbiotic endophytes, unlike plant pathogens, do not usually induce visible host response. This may constraint the researcher's decision whether a plant has been successfully infected by the endophyte. In order to properly study the establishment, development and progress of an endophyte in the host plant and host-endophyte interactions, methods fo...

Lemon (Citrus limon (L.) Burm. f) is the most popular acid citrus fruit because of its appealing color, odor, and flavor. World production of lemons was about 7 to 8 million metric tons in 2007. Major produc-ers and exporters of lemon in the world include Argentina, Spain, Iran, the United States, Italy, Turkey, Egypt, Greece, South Africa, Cyprus,...

Muscodor crispans (isolate B-23) is described as a new species of Muscodor. It is an anamorphic sterilia endophytic fungus residing within the stem tissues of Ananas ananassoides, a wild pineapple in the Bolivian Amazon Basin. This strain is characterized by the production of a pinkish felt-like mycelium on potato dextrose agar (PDA) and other medi...

Catharanthus roseus (L.) is well known for its production of several anticancerous vinca alkaloids such as vincristine, vindesine, vinorelbine, vinblastin, and the recently discovered vinflunine. This plant is a host to a plethora of endophytic fungi. A total 183 endophytic fungi representing 13 fungal taxa were isolated from leaf, stem and root ti...

Muscodor albus is an endophytic fungus, represented by a number of isolates from tropical tree and vine species in several of the world's rainforests, that produces volatile organic compounds (VOCs) with antibiotic activity. A new isolate, E-6, of this organism, with unusual biochemical and biological properties, has been obtained from the branches...

Mal secco disease of citrus caused by Phoma tracheiphila is a devastating disease in the Mediterranean basin. Susceptible citrus species include lemon, citron, lime and others. Trees attacked by the fungus show characteristic symptoms; the smallest twigs die first, followed by the larger branches. Eventually, the whole tree is killed. The symptoms...

Endophytic streptomycetes have been isolated and characterized from several species of Nothofagus and other plants growing in the southern reaches of Patagonia. No endophytic streptomycete was obtained from any plant species studied in Northern Patagonia. However, from Southern Patagonia, biologically active Streptomyces spp. from several plant spe...

Muscodor albus, an endophytic fungus originally isolated from Cinnamomum zeylanicum, produces a mixture of volatile organic compounds (VOCs) in culture and its spectrum of antimicrobial activity is broad. Using the original isolate of M. albus as a selection tool, it has been possible to find other culturally and biochemically unique wild-type isol...

Muscodor albus is an endophytic fungus that produces volatile organic compounds (VOCs) that both inhibit and kill other microorganisms. This fungus is now being used to treat human wastes and disinfest soils of plant disease causing organisms. The development of a method to accurately determine the quantity and quality of volatiles being emitted by...

Coronamycin is a complex of novel peptide antibiotics with activity against pythiaceous fungi and the human fungal pathogen Cryptococcus neoformans. It is also active against the malarial parasite, Plasmodium falciparum, with an IC(50) of 9.0 ng ml(-1). Coronamycin is produced by a verticillate Streptomyces sp. isolated as an endophyte from an epip...

Coronamycin is a complex of novel peptide antibiotics with activity against pythiaceous fungi and the human fungal pathogen Cryptococcus neoformans. It is also active against the malarial parasite, Plasmodium falciparum, with an IC(50) of 9.0 ng ml(-1). Coronamycin is produced by a verticillate Streptomyces sp. isolated as an endophyte from an epip...

SUMMARY Pantoea agglomerans pv. gypsophilae (Pag) causes root and crown gall disease on gypsophila, whereas P. agglomerans pv. betae (Pab) induces the disease on beet as well as gypsophila. Both pathovars harbour a pathogenicity plasmid (pPATH(Pag) or pPATH(Pab)) that determines disease development. We have previously isolated and partially charact...

Muscodor albus, a newly described endophytic fungus, inhibits and kills other fungi and bacteria by emitting volatile organic compounds (VOCs) with antibiotic properties. The composition of the medium used to support the growth of this fungus greatly influences the quality and effectiveness of the volatiles emitted by this organism. A sucrose enric...

An endophytic isolate of Gliocladium sp. was obtained from the Patagonian Eucryphiacean tree—Eucryphia cordifolia, known locally as “ulmo”. The fungus was identified on the basis of its morphology and aspects of its molecular biology. This fungus produces a mixture of volatile organic compounds (VOC's) lethal to such plant pathogenic fungi as Pythi...

Muscodor vitigenus is a recently described endophytic fungus of Paullinia paullinioides, a liana growing in the understorey of the rainforests of the Peruvian Amazon. This fungus produces naphthalene under certain cultural conditions. Naphthalene produced by M. vitigenus was identified by gas chromatography/mass spectrometry. Its chromatographic an...

Muscodor vitigenus, anam. sp. nov., is described as a deuteromycetous (mycelia sterilia) endophytic species of Paullinia paullinioides, a liana, bearing a genetic relatedness to the ascomycetous group Xylaria. No fruiting bodies or spores have been observed. The hyphae (0.71-2.14 μm dia) frequently intertwine to form stalk-like strands (9.1-145.5 μ...

Erwinia herbicola pv. gypsophilae (Ehg) incites galls only on gypsophila whereas E. herbicola pv. betae (Ehb) elicits galls on both beet and gypsophila. hsvG is a positive-acting pathogenicity gene that determines host specificity of both pathovars on gypsophila. By employing the ice nucleation reporter gene inaZ it was found that the transcription...

The host range of the gall-forming bacterium Erwinia herbicola pv. gypsophilae (Ehg) is restricted to gypsophila whereas Erwinia herbicola pv. betae (Ehb) attacks beet as well as gypsophila. Both pathovars contain an indigenous plasmid (pPATH(Ehg or pPATH(Ehb)) that harbors pathogenicity genes, including the hrp gene cluster. A cosmid library of Eh...