Iris Yedidia - Academia.edu (original) (raw)

Papers by Iris Yedidia

Plant disease, Jul 13, 2024

Applied and Environmental Microbiology, Mar 1, 1999

Microbial Biotechnology

Soft rot pectobacteria (SRP) are phytopathogens of the genera Pectobacterium and Dickeya that cau... more Soft rot pectobacteria (SRP) are phytopathogens of the genera Pectobacterium and Dickeya that cause soft rots on a wide range of crops and ornamental plants. SRP produce plant cell wall degrading enzymes (PCWDEs), including pectinases. Bdellovibrio and like organisms are bacterial predators that can prey on a variety of Gram‐negative species, including SRP. In this research, a low methoxyl pectin (LMP)‐based immobilization system for B. bacteriovorus is established. It takes advantage that pectin residues induce PCWDE secretion by the pathogens, bringing upon the release of the encapsulated predators. Three commercial LMPs differing in the degree of esterification (DE) and amidation (DA) were tested as potential carriers, by examining their effect on SRP growth, enzymes secretion and substrate breakdown. A clear advantage was observed for pectin 5 CS with the lowest DE and DA content. The degradation of 5 CS pectin‐based carriers was further optimized by reducing cross‐linker and pe...

Microorganisms, Dec 19, 2022

Frontiers in Plant Science

IntroductionThe eons-long co-evolvement of plants and bacteria led to a plethora of interactions ... more IntroductionThe eons-long co-evolvement of plants and bacteria led to a plethora of interactions between the two kingdoms, in which bacterial pathogenicity is counteracted by plant-derived antimicrobial defense molecules. In return, efflux pumps (EP) form part of the resistance mechanism employed by bacteria to permit their survival in this hostile chemical environment. In this work we study the effect of combinations of efflux pump inhibitors (EPIs) and plant-derived phytochemicals on bacterial activity using Pectobacteriun brasiliense 1692 (Pb1692) as a model system.MethodsWe measured the minimal inhibitory concentration (MIC) of two phytochemicals, phloretin (Pht) and naringenin (Nar), and of one common antibiotic ciprofloxacin (Cip), either alone or in combinations with two known inhibitors of the AcrB EP of Escherichia coli, a close homolog of the AcrAB-TolC EP of Pb1692. In addition, we also measured the expression of genes encoding for the EP, under similar conditions.Results...

Frontiers in Plant Science

The effects of phloretin a phytoalexin from apple, was tested on Pectobacterium brasiliense (Pb16... more The effects of phloretin a phytoalexin from apple, was tested on Pectobacterium brasiliense (Pb1692), an emerging soft-rot pathogen of potato. Exposure of Pb1692 to 0.2 mM phloretin a concentration that does not affect growth, or to 0.4 mM a 50% growth inhibiting concentration (50% MIC), reduced motility, biofilm formation, secretion of plant cell wall-degrading enzymes, production of acyl–homoserine lactone (AHL) signaling molecules and infection, phenotypes that are associated with bacterial population density-dependent system known as quorum sensing (QS). To analyze the effect of growth inhibition on QS, the activity of ciprofloxacin, an antibiotic that impairs cell division, was compared to that of phloretin at 50% MIC. Unlike phloretin, the antibiotic hardly affected the tested phenotypes. The use of DH5α, a QS-negative Escherichia coli strain, transformed with an AHL synthase (ExpI) from Pb1692, allowed to validate direct inhibition of AHL production by phloretin, as demonstra...

Microorganisms, 2021

The microbial community inhabiting a plant’s root zone plays a crucial role in plant health and p... more The microbial community inhabiting a plant’s root zone plays a crucial role in plant health and protection. To assess the ability of commercial plant growth-promoting products to enhance the positive effects of this environment, two products containing beneficial soil bacteria and a product containing plant extracts were tested on Zantedeschia aethiopica and Ornithogalum dubium. The products were tested in two different growing media: a soil and a soilless medium. The effects of these products on Pectobacterium brasiliense, the causal agent of soft rot disease, were also evaluated in vitro, and on naturally occurring infections in the greenhouse. The growing medium was found to have the strongest effect on the microbial diversity of the root-associated microbiome, with the next-strongest effect due to plant type. These results demonstrate that either a single bacterial strain or a product will scarcely reach the level that is required to influence soil microbial communities. In addi...

1. On the travel of ribosomes toward and along the cytoplasmic membrane: An essential pathway for... more 1. On the travel of ribosomes toward and along the cytoplasmic membrane: An essential pathway for proper biosynthesis of integral membrane proteins. Cytoplasmic membrane proteins have indispensable functions in cellular physiology, metabolism, structure and communication. In all living cells the biogenesis of these proteins requires the Signal Recognition Particle (SRP) system (Fig. 1A), which mediates there translation on membranebound ribosomes. We are studying central mechanistic and structural aspects of the SRP system in E. coli, in the context of the biosynthetic pathway of membrane proteins. We have demonstrated that the bacterial homologue of the mammalian SRP receptor (FtsY) is essential for targeting ribosomes to the membrane and for expression of membrane proteins. In contrast, in the absence of the SRP itself, ribosome targeting and membrane protein synthesis continue, although their proper assembly is severely impaired. These observations, combined with additional consi...

ACS Chemical Biology, 2020

Plant Diseases Caused by Dickeya and Pectobacterium Species, 2021

Soft rot Pectobacteriaceae (SRP) are ubiquitous on earth as there are records of findings from al... more Soft rot Pectobacteriaceae (SRP) are ubiquitous on earth as there are records of findings from all continents where host plants are grown. This chapter describes information on soft rot diseases on these continents. For some countries, detailed information is provided by local experts on the SRP present, their economic damage, and the management strategies applied for their control. The focus of the chapter is mainly on SRP as causative agents of potato blackleg, although in specific cases details are provided on SRP in other host plants. In Europe, the SRP cause important economic losses mainly on potato, with most species described in the literature being found. In Latin America significant losses are also reported due to potato diseases caused by various Dickeya and Pectobacterium species, while in Australia and Oceania, recent outbreaks of D. dianthicola in potato have resulted in high economic losses. In Asia, however, SRP cause economic losses mainly in vegetable crops other than potato, while in North America SRP cause diseases on a wide range of crops (including potato and ornamental plants) in both field and storage. In Africa SRP are only known to occur in 17 of the 54 African countries but where it is known, potato is the most affected crop.

Food and Chemical Toxicology, 2020

Plant Methods, 2019

Background Despite wheat being a worldwide staple, it is still considered the most difficult to t... more Background Despite wheat being a worldwide staple, it is still considered the most difficult to transform out of the main cereal crops. Therefore, for the wheat research community, a freely available and effective wheat transformation system is still greatly needed. Results We have developed and optimised a reproducible Agrobacterium-mediated transformation system for the spring wheat cv ‘Fielder’ that yields transformation efficiencies of up to 25%. We report on some of the important factors that influence transformation efficiencies. In particular, these include donor plant health, stage of the donor material, pre-treatment by centrifugation, vector type and selection cassette. Transgene copy number data for independent plants regenerated from the same original immature embryo suggests that multiple transgenic events arise from single immature embryos, therefore, actual efficiencies might be even higher than those reported. Conclusion We reported here a high-throughput, highly eff...

Scientific Reports, 2016

Quorum sensing (QS) is a population density-dependent regulatory system in bacteria that couples ... more Quorum sensing (QS) is a population density-dependent regulatory system in bacteria that couples gene expression to cell density through accumulation of diffusible signaling molecules. Pectobacteria are causal agents of soft rot disease in a range of economically important crops. They rely on QS to coordinate their main virulence factor, production of plant cell wall degrading enzymes (PCWDEs). Plants have evolved an array of antimicrobial compounds to anticipate and cope with pathogens, of which essential oils (EOs) are widely recognized. Here, volatile EOs, carvacrol and eugenol, were shown to specifically interfere with QS, the master regulator of virulence in pectobacteria, resulting in strong inhibition of QS genes, biofilm formation and PCWDEs, thereby leading to impaired infection. Accumulation of the signal molecule N-acylhomoserine lactone declined upon treatment with EOs, suggesting direct interaction of EOs with either homoserine lactone synthase (ExpI) or with the regula...

Journal of Biotechnology, 2016

The genus Ornithogalum includes several ornamental species that suffer substantial losses from ba... more The genus Ornithogalum includes several ornamental species that suffer substantial losses from bacterial soft rot caused by Pectobacteria. The absence of effective control measures for use against soft rot bacteria led to the initiation of a project in which a small antimicrobial peptide from an Asian horseshoe crab, tachyplesin (tpnI), was introduced into two commercial cultivars: O. dubium and O. thyrsoides. Disease severity and bacterial colonization were examined in transgenic lines expressing this peptide. Disease resistance was evaluated in six lines of each species by measuring bacterial proliferation in the plant tissue. Three transgenic lines of each species were subjected to further analysis in which the expression level of the transgene was evaluated using RT-PCR and qRT-PCR. The development of disease symptoms and bacterial colonization of the plant tissue were also examined using GFP-expressing strain of P. carotovorum subsp. brasiliense Pcb3. Confocal-microscopy imaging revealed significantly reduced quantities of bacterial cells in the transgenic plant lines that had been challenged with the bacterium. The results clearly demonstrate that tpnI expression reduces bacterial proliferation, colonization and disease symptom (reduced by 95-100%) in the transgenic plant tissues. The quantity of tpnI transcripts, as measured by qRT-PCR, was negatively correlated with the protection afforded to the plants, as measured by the reduced severity of disease symptoms in the tissue.

Ornamental Geophytes, 2012

Globalization of the Flower Bulb Industry August A. De Hertogh, Johan van Scheepen, Marcel Le Nar... more Globalization of the Flower Bulb Industry August A. De Hertogh, Johan van Scheepen, Marcel Le Nard, Hiroshi Okubo, and Rina Kamenetsky Taxonomy and Phylogeny Alan W. Meerow Biodiversity of Geophytes: Phytogeography, Morphology, and Survival Strategies Rina Kamenetsky Botanical and Horticultural Aspects of Major Ornamental Geophytes Hiroshi Okubo and Dariusz Sochacki Introduction and Development of New Ornamental Geophytes Mark P. Bridgen Breeding and Genetics of Ornamental Geophytes Jaap M. van Tuyl, Paul Arens, and Agnieszka Marasek-Ciolakowska Biotechnology for the Modification of Horticultural Traits in Geophytes Kathryn K. Kamo, Frans A. Krens, and Meira Ziv Florogenesis Rina Kamenetsky, Michele Zaccai, and Moshe A. Flaishman Dormancy Hiroshi Okubo Propagation of Ornamental Geophytes: Physiology and Management Systems Anna Bach and Dariusz Sochacki Production Chain, Forcing Physiology, and Flower Production Systems William B. Miller Postharvest: Cut Flowers and Potted Plants Michael S. Reid and Cai-Zhong Jiang Sustainable Production and Integrated Management: Environmental Issues Gary A. Chastagner, Gordon R. Hanks, Margery L. Daughtrey, Iris Yedidia, Timothy W. Miller, and Hanu R. Pappu Geophyte Research and Production in Asia Seiichi Fukai Geophyte Research and Production in Brazil Antonio F. C. Tombolato, Roberta P. Uzzo, Antonio H. Junqueira, Marcia da S. Peetz, and Giulio C. Stancato Geophyte Research and Production in Chile Eduardo A. Olate and Flavia Schiappacasse Geophyte Research and Production in New Zealand Keith A. Funnell, Ed R. Morgan, Glenn E. Clark, and Joo Bee Chuah Geophyte Research and Production in South Africa Graham D. Duncan Geophyte Research and Production in Turkey Ibrahim Baktir Conclusions and Future Research Rina Kamenetsky, Gary A. Chastagner, and Hiroshi Okubo Appendix: Botanical Names Mentioned in This Book Index

From Basic Science to Sustainable Production, 2012

Plant disease, Jul 13, 2024

Applied and Environmental Microbiology, Mar 1, 1999

Microbial Biotechnology

Soft rot pectobacteria (SRP) are phytopathogens of the genera Pectobacterium and Dickeya that cau... more Soft rot pectobacteria (SRP) are phytopathogens of the genera Pectobacterium and Dickeya that cause soft rots on a wide range of crops and ornamental plants. SRP produce plant cell wall degrading enzymes (PCWDEs), including pectinases. Bdellovibrio and like organisms are bacterial predators that can prey on a variety of Gram‐negative species, including SRP. In this research, a low methoxyl pectin (LMP)‐based immobilization system for B. bacteriovorus is established. It takes advantage that pectin residues induce PCWDE secretion by the pathogens, bringing upon the release of the encapsulated predators. Three commercial LMPs differing in the degree of esterification (DE) and amidation (DA) were tested as potential carriers, by examining their effect on SRP growth, enzymes secretion and substrate breakdown. A clear advantage was observed for pectin 5 CS with the lowest DE and DA content. The degradation of 5 CS pectin‐based carriers was further optimized by reducing cross‐linker and pe...

Microorganisms, Dec 19, 2022

Frontiers in Plant Science

IntroductionThe eons-long co-evolvement of plants and bacteria led to a plethora of interactions ... more IntroductionThe eons-long co-evolvement of plants and bacteria led to a plethora of interactions between the two kingdoms, in which bacterial pathogenicity is counteracted by plant-derived antimicrobial defense molecules. In return, efflux pumps (EP) form part of the resistance mechanism employed by bacteria to permit their survival in this hostile chemical environment. In this work we study the effect of combinations of efflux pump inhibitors (EPIs) and plant-derived phytochemicals on bacterial activity using Pectobacteriun brasiliense 1692 (Pb1692) as a model system.MethodsWe measured the minimal inhibitory concentration (MIC) of two phytochemicals, phloretin (Pht) and naringenin (Nar), and of one common antibiotic ciprofloxacin (Cip), either alone or in combinations with two known inhibitors of the AcrB EP of Escherichia coli, a close homolog of the AcrAB-TolC EP of Pb1692. In addition, we also measured the expression of genes encoding for the EP, under similar conditions.Results...

Frontiers in Plant Science

The effects of phloretin a phytoalexin from apple, was tested on Pectobacterium brasiliense (Pb16... more The effects of phloretin a phytoalexin from apple, was tested on Pectobacterium brasiliense (Pb1692), an emerging soft-rot pathogen of potato. Exposure of Pb1692 to 0.2 mM phloretin a concentration that does not affect growth, or to 0.4 mM a 50% growth inhibiting concentration (50% MIC), reduced motility, biofilm formation, secretion of plant cell wall-degrading enzymes, production of acyl–homoserine lactone (AHL) signaling molecules and infection, phenotypes that are associated with bacterial population density-dependent system known as quorum sensing (QS). To analyze the effect of growth inhibition on QS, the activity of ciprofloxacin, an antibiotic that impairs cell division, was compared to that of phloretin at 50% MIC. Unlike phloretin, the antibiotic hardly affected the tested phenotypes. The use of DH5α, a QS-negative Escherichia coli strain, transformed with an AHL synthase (ExpI) from Pb1692, allowed to validate direct inhibition of AHL production by phloretin, as demonstra...

Microorganisms, 2021

The microbial community inhabiting a plant’s root zone plays a crucial role in plant health and p... more The microbial community inhabiting a plant’s root zone plays a crucial role in plant health and protection. To assess the ability of commercial plant growth-promoting products to enhance the positive effects of this environment, two products containing beneficial soil bacteria and a product containing plant extracts were tested on Zantedeschia aethiopica and Ornithogalum dubium. The products were tested in two different growing media: a soil and a soilless medium. The effects of these products on Pectobacterium brasiliense, the causal agent of soft rot disease, were also evaluated in vitro, and on naturally occurring infections in the greenhouse. The growing medium was found to have the strongest effect on the microbial diversity of the root-associated microbiome, with the next-strongest effect due to plant type. These results demonstrate that either a single bacterial strain or a product will scarcely reach the level that is required to influence soil microbial communities. In addi...

1. On the travel of ribosomes toward and along the cytoplasmic membrane: An essential pathway for... more 1. On the travel of ribosomes toward and along the cytoplasmic membrane: An essential pathway for proper biosynthesis of integral membrane proteins. Cytoplasmic membrane proteins have indispensable functions in cellular physiology, metabolism, structure and communication. In all living cells the biogenesis of these proteins requires the Signal Recognition Particle (SRP) system (Fig. 1A), which mediates there translation on membranebound ribosomes. We are studying central mechanistic and structural aspects of the SRP system in E. coli, in the context of the biosynthetic pathway of membrane proteins. We have demonstrated that the bacterial homologue of the mammalian SRP receptor (FtsY) is essential for targeting ribosomes to the membrane and for expression of membrane proteins. In contrast, in the absence of the SRP itself, ribosome targeting and membrane protein synthesis continue, although their proper assembly is severely impaired. These observations, combined with additional consi...

ACS Chemical Biology, 2020

Plant Diseases Caused by Dickeya and Pectobacterium Species, 2021

Soft rot Pectobacteriaceae (SRP) are ubiquitous on earth as there are records of findings from al... more Soft rot Pectobacteriaceae (SRP) are ubiquitous on earth as there are records of findings from all continents where host plants are grown. This chapter describes information on soft rot diseases on these continents. For some countries, detailed information is provided by local experts on the SRP present, their economic damage, and the management strategies applied for their control. The focus of the chapter is mainly on SRP as causative agents of potato blackleg, although in specific cases details are provided on SRP in other host plants. In Europe, the SRP cause important economic losses mainly on potato, with most species described in the literature being found. In Latin America significant losses are also reported due to potato diseases caused by various Dickeya and Pectobacterium species, while in Australia and Oceania, recent outbreaks of D. dianthicola in potato have resulted in high economic losses. In Asia, however, SRP cause economic losses mainly in vegetable crops other than potato, while in North America SRP cause diseases on a wide range of crops (including potato and ornamental plants) in both field and storage. In Africa SRP are only known to occur in 17 of the 54 African countries but where it is known, potato is the most affected crop.

Food and Chemical Toxicology, 2020

Plant Methods, 2019

Background Despite wheat being a worldwide staple, it is still considered the most difficult to t... more Background Despite wheat being a worldwide staple, it is still considered the most difficult to transform out of the main cereal crops. Therefore, for the wheat research community, a freely available and effective wheat transformation system is still greatly needed. Results We have developed and optimised a reproducible Agrobacterium-mediated transformation system for the spring wheat cv ‘Fielder’ that yields transformation efficiencies of up to 25%. We report on some of the important factors that influence transformation efficiencies. In particular, these include donor plant health, stage of the donor material, pre-treatment by centrifugation, vector type and selection cassette. Transgene copy number data for independent plants regenerated from the same original immature embryo suggests that multiple transgenic events arise from single immature embryos, therefore, actual efficiencies might be even higher than those reported. Conclusion We reported here a high-throughput, highly eff...

Scientific Reports, 2016

Quorum sensing (QS) is a population density-dependent regulatory system in bacteria that couples ... more Quorum sensing (QS) is a population density-dependent regulatory system in bacteria that couples gene expression to cell density through accumulation of diffusible signaling molecules. Pectobacteria are causal agents of soft rot disease in a range of economically important crops. They rely on QS to coordinate their main virulence factor, production of plant cell wall degrading enzymes (PCWDEs). Plants have evolved an array of antimicrobial compounds to anticipate and cope with pathogens, of which essential oils (EOs) are widely recognized. Here, volatile EOs, carvacrol and eugenol, were shown to specifically interfere with QS, the master regulator of virulence in pectobacteria, resulting in strong inhibition of QS genes, biofilm formation and PCWDEs, thereby leading to impaired infection. Accumulation of the signal molecule N-acylhomoserine lactone declined upon treatment with EOs, suggesting direct interaction of EOs with either homoserine lactone synthase (ExpI) or with the regula...

Journal of Biotechnology, 2016

The genus Ornithogalum includes several ornamental species that suffer substantial losses from ba... more The genus Ornithogalum includes several ornamental species that suffer substantial losses from bacterial soft rot caused by Pectobacteria. The absence of effective control measures for use against soft rot bacteria led to the initiation of a project in which a small antimicrobial peptide from an Asian horseshoe crab, tachyplesin (tpnI), was introduced into two commercial cultivars: O. dubium and O. thyrsoides. Disease severity and bacterial colonization were examined in transgenic lines expressing this peptide. Disease resistance was evaluated in six lines of each species by measuring bacterial proliferation in the plant tissue. Three transgenic lines of each species were subjected to further analysis in which the expression level of the transgene was evaluated using RT-PCR and qRT-PCR. The development of disease symptoms and bacterial colonization of the plant tissue were also examined using GFP-expressing strain of P. carotovorum subsp. brasiliense Pcb3. Confocal-microscopy imaging revealed significantly reduced quantities of bacterial cells in the transgenic plant lines that had been challenged with the bacterium. The results clearly demonstrate that tpnI expression reduces bacterial proliferation, colonization and disease symptom (reduced by 95-100%) in the transgenic plant tissues. The quantity of tpnI transcripts, as measured by qRT-PCR, was negatively correlated with the protection afforded to the plants, as measured by the reduced severity of disease symptoms in the tissue.

Ornamental Geophytes, 2012

Globalization of the Flower Bulb Industry August A. De Hertogh, Johan van Scheepen, Marcel Le Nar... more Globalization of the Flower Bulb Industry August A. De Hertogh, Johan van Scheepen, Marcel Le Nard, Hiroshi Okubo, and Rina Kamenetsky Taxonomy and Phylogeny Alan W. Meerow Biodiversity of Geophytes: Phytogeography, Morphology, and Survival Strategies Rina Kamenetsky Botanical and Horticultural Aspects of Major Ornamental Geophytes Hiroshi Okubo and Dariusz Sochacki Introduction and Development of New Ornamental Geophytes Mark P. Bridgen Breeding and Genetics of Ornamental Geophytes Jaap M. van Tuyl, Paul Arens, and Agnieszka Marasek-Ciolakowska Biotechnology for the Modification of Horticultural Traits in Geophytes Kathryn K. Kamo, Frans A. Krens, and Meira Ziv Florogenesis Rina Kamenetsky, Michele Zaccai, and Moshe A. Flaishman Dormancy Hiroshi Okubo Propagation of Ornamental Geophytes: Physiology and Management Systems Anna Bach and Dariusz Sochacki Production Chain, Forcing Physiology, and Flower Production Systems William B. Miller Postharvest: Cut Flowers and Potted Plants Michael S. Reid and Cai-Zhong Jiang Sustainable Production and Integrated Management: Environmental Issues Gary A. Chastagner, Gordon R. Hanks, Margery L. Daughtrey, Iris Yedidia, Timothy W. Miller, and Hanu R. Pappu Geophyte Research and Production in Asia Seiichi Fukai Geophyte Research and Production in Brazil Antonio F. C. Tombolato, Roberta P. Uzzo, Antonio H. Junqueira, Marcia da S. Peetz, and Giulio C. Stancato Geophyte Research and Production in Chile Eduardo A. Olate and Flavia Schiappacasse Geophyte Research and Production in New Zealand Keith A. Funnell, Ed R. Morgan, Glenn E. Clark, and Joo Bee Chuah Geophyte Research and Production in South Africa Graham D. Duncan Geophyte Research and Production in Turkey Ibrahim Baktir Conclusions and Future Research Rina Kamenetsky, Gary A. Chastagner, and Hiroshi Okubo Appendix: Botanical Names Mentioned in This Book Index

From Basic Science to Sustainable Production, 2012