scholarly journals Medicago truncatula in Interaction with Fusarium and Rhizoctonia Phytopathogenic Fungi: Fungal Aggressiveness, Plant Response Biodiversity and Character Heritability Indices

2021 ◽  
Vol 37 (4) ◽  
pp. 315-328
Author(s):  
Marwa Batnini ◽  
Imen Haddoudi ◽  
Wael Taamali ◽  
Naceur Djebali ◽  
Mounawer Badri ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Antioxidant Activities ◽  
Disease Incidence ◽  
Recombinant Inbred Lines ◽  
Resistance Mechanisms ◽  
Phytopathogenic Fungi ◽  
Disease Response ◽  
Fungal Strains ◽  
Small Collection

Fusarium and Rhizoctonia genera are important pathogens of many field crops worldwide. They are constantly evolving and expanding their host range. Selecting resistant cultivars is an effective strategy to break their infection cycles. To this end, we screened a collection of Medicago truncatula accessions against Fusarium oxysporum, Fusarium solani, and Rhizoctonia solani strains isolated from different plant species. Despite the small collection, a biodiversity in the disease response of M. truncatula accessions ranging from resistant phenotypes to highly susceptible ones was observed. A17 showed relative resistance to all fungal strains with the lowest disease incidence and ratings while TN1.11 was among the susceptible accessions. As an initiation of the characterization of resistance mechanisms, the antioxidant enzymes’ activities, at the early stages of infections, were compared between these contrasting accessions. Our results showed an increment of the antioxidant activities within A17 plants in leaves and roots. We also analyzed the responses of a population of recombinant inbred lines derived from the crossing of A17 and TN1.11 to the infection with the same fungal strains. The broad-sense heritability of measured traits ranged from 0.87 to 0.95, from 0.72 to 0.96, and from 0.14 to 0.85 under control, F. oxysporum, and R. solani conditions, respectively. This high estimated heritability underlines the importance of further molecular analysis of the observed resistance to identify selection markers that could be incorporated into a breeding program and thus improving soil-borne pathogens resistance in crops.

scholarly journals Characterization of the Interaction Between the Bacterial Wilt Pathogen Ralstonia solanacearum and the Model Legume Plant Medicago truncatula

2007 ◽  
Vol 20 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Fabienne Vailleau ◽  
Elodie Sartorel ◽  
Marie-Françoise Jardinaud ◽  
Fabien Chardon ◽  
Stéphane Genin ◽  
...  
Keyword(s):  
Plant Species ◽  
Medicago Truncatula ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Recombinant Inbred Lines ◽  
Model Legume ◽  
Legume Plant ◽  
Hrp Genes

The soilborne pathogen Ralstonia solanacearum is the causal agent of bacterial wilt and attacks more than 200 plant species, including some legumes and the model legume plant Medicago truncatula. We have demonstrated that M. truncatula accessions Jemalong A17 and F83005.5 are susceptible to R. solanacearum and, by screening 28 R. solana-cearum strains on the two M. truncatula lines, differential interactions were identified. R. solanacearum GMI1000 infected Jemalong A17 line, and disease symptoms were dependent upon functional hrp genes. An in vitro root inoculation method was employed to demonstrate that R. solanacearum colonized M. truncatula via the xylem and intercellular spaces. R. solanacearum multiplication was restricted by a factor greater than 1 × 105 in the resistant line F83005.5 compared with susceptible Jemalong A17. Genetic analysis of recombinant inbred lines from a cross between Jemalong A17 and F83005.5 revealed the presence of major quantitative trait loci for bacterial wilt resistance located on chromosome 5. The results indicate that the root pathosystem for M. truncatula will provide useful traits for molecular analyses of disease and resistance in this model plant species.

Resistance reaction of Medicago truncatula genotypes to Fusarium oxysporum: effect of plant age, substrate and inoculation method

2015 ◽  
Vol 66 (5) ◽  
pp. 506 ◽  
Author(s):  
Nicolas Rispail ◽  
Moustafa Bani ◽  
Diego Rubiales
Keyword(s):  
Fusarium Oxysporum ◽  
Medicago Truncatula ◽  
Fusarium Wilt ◽  
Early Stage ◽  
Disease Incidence ◽  
Rapid Change ◽  
Resistance Mechanisms ◽  
Plant Age ◽  
Growth Substrate ◽  
Model Legume

Fusarium wilt, caused by several formae speciales of Fusarium oxysporum, is an important disease of most crop and pasture legumes, including field pea (Pisum sativum), chickpea (Cicer arietinum), lucerne (alfalfa, Medicago sativa) and barrel medic (M. truncatula). Medicago truncatula is an important pasture legume and a model legume species. Hence, it can be used to increase our knowledge of resistance mechanisms efficient to block F. oxysporum infection if its response to the disease is characterised. We evaluated the physiological and susceptibility responses to the disease of two contrasting M. truncatula genotypes, and the effect of several cultural conditions known to affect the disease incidence, such as plant age at infection time, growth substrate and the method of inoculation. Our results indicated that the A17 accession harbours a moderate level of resistance to the disease. We also showed that the method of inoculation strongly affected development of fusarium wilt disease in this model species, whereas it was not significantly altered by plant age or the inorganic growth substrate tested. In addition, we describe a rapid change in leaf temperature after infection, which can be used as an indirect parameter to confirm fungal infection at a very early stage of the interaction.

scholarly journals Characterization of Resistance Mechanisms to Erysiphe pisi in Medicago truncatula

2007 ◽  
Vol 97 (9) ◽  
pp. 1049-1053 ◽  
Author(s):  
Elena Prats ◽  
María J. Llamas ◽  
Diego Rubiales
Keyword(s):  
Cell Death ◽  
Powdery Mildew ◽  
Medicago Truncatula ◽  
Defense Mechanisms ◽  
Colony Growth ◽  
Resistance Mechanisms ◽  
Epidermal Cells ◽  
Fungal Development ◽  
Papilla Formation

In this work, we studied the resistance of 277 Medicago truncatula accessions against powdery mildew and further characterized the defense mechanisms of resistant plants. Ten resistant accessions were selected according to macroscopic assessment. Histological studies showed a range of defense mechanisms, acting alone or combined, that impeded fungal development at different stages. Some accessions allowed a reduced spore germination frequency compared with that of the susceptible control. In others, the fungus was arrested at penetration stage due to papilla formation. Epidermal cells of several accessions were penetrated by the fungus but then hypersensitive response (HR) leading to cell death hampered fungal development. In some cases, cell death was very fast and no haustorium could be observed in epidermal cells, whereas in others, haustoria and secondary hyphae indicated a slow HR. Finally, in some accessions in which no HR was observed, colony growth was restricted through posthaustorial defense mechanisms. Characterization of defense mechanisms will be useful for further cellular and molecular studies to unravel the bases of resistance in this species in particular and in legume–powdery mildew interaction in general.

Characterization of white cabbages from different cultivations by isothiocyanates and antioxidant activities

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
A Śmiechowska ◽  
B Kusznierewicz ◽  
A Bartoszek ◽  
A Szumska ◽  
A Kawecka ◽  
...  
Keyword(s):  
Antioxidant Activities

scholarly journals Current Trends in Non-Invasive Imaging of Interactions in the Liver Tumor Microenvironment Mediated by Tumor Metabolism

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3645
Author(s):  
Isabel Theresa Schobert ◽  
Lynn Jeanette Savic
Keyword(s):  
Tumor Microenvironment ◽  
Liver Cancer ◽  
Cancer Cells ◽  
Imaging Techniques ◽  
Treatment Strategies ◽  
Tumor Metabolism ◽  
Resistance Mechanisms ◽  
Metabolic Reprogramming ◽  
Non Invasive

With the increasing understanding of resistance mechanisms mediated by the metabolic reprogramming in cancer cells, there is a growing clinical interest in imaging technologies that allow for the non-invasive characterization of tumor metabolism and the interactions of cancer cells with the tumor microenvironment (TME) mediated through tumor metabolism. Specifically, tumor glycolysis and subsequent tissue acidosis in the realms of the Warburg effect may promote an immunosuppressive TME, causing a substantial barrier to the clinical efficacy of numerous immuno-oncologic treatments. Thus, imaging the varying individual compositions of the TME may provide a more accurate characterization of the individual tumor. This approach can help to identify the most suitable therapy for each individual patient and design new targeted treatment strategies that disable resistance mechanisms in liver cancer. This review article focuses on non-invasive positron-emission tomography (PET)- and MR-based imaging techniques that aim to visualize the crosstalk between tumor cells and their microenvironment in liver cancer mediated by tumor metabolism.

Characterization of carbapenem resistance mechanisms inKlebsiella pneumoniaeandin vitrosynergy of the colistin–meropenem combination

2014 ◽  
Vol 27 (5) ◽  
pp. 277-282 ◽  
Author(s):  
Lakshmana Gowda Krishnappa ◽  
Mohammed Ali M. Marie ◽  
Yazeed A. Al Sheikh
Keyword(s):  
Carbapenem Resistance ◽  
Resistance Mechanisms

scholarly journals Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shixing Liu ◽  
Renchi Fang ◽  
Ying Zhang ◽  
Lijiang Chen ◽  
Na Huang ◽  
...  
Keyword(s):  
Lipid A ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Enterobacter Cloacae ◽  
Resistance Mechanisms ◽  
Colistin Resistance ◽  
Carbapenem Resistant ◽  
Horizontal Spread

Abstract Background The emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains. Results This study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found. Conclusions This study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

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