Search results for "Biotic Stress"
showing 10 items of 86 documents
Role of glutathione in plant signaling under biotic stress
2012
International audience; Glutathione (GSH) is a non-protein thiol compound which has been repeatedly reported to play an important role in plant responses during biotic stresses. However, our knowledge of glutathione-related molecular mechanisms underlying plant defense responses still remains limited. We first discovered that the Arabidopsis thaliana phytoalexin deficient 2-1 (pad2-1) mutant was linked to glutathione deficiency since the mutation was identified in the GSH1 gene encoding the first enzyme of glutathione biosynthesis: Glutamate Cysteine Ligase (GCL). Interestingly, this glutathione-deficient mutant pad2-1 also displays a high susceptibility to a wide range of invaders. We rece…
Evaluating anthropogenic impacts on naturally stressed ecosystems: Revisiting river classifications and biomonitoring metrics along salinity gradients
2019
Naturally stressed ecosystems hold a unique fraction of biodiversity. However, they have been largely ignored in biomonitoring and conservation programmes, such as the EU Water Framework Directive, while global change pressures are threatening their singular values. Here we present a framework to classify and evaluate the ecological quality of naturally stressed rivers along a water salinity gradient. We gathered datasets, including aquatic macroinvertebrate assemblages and environmental information, for 243 river locations across the western Mediterranean to: a) gauge the role of natural stressors (salinity) in driving aquatic community richness and composition; b) make river classificatio…
Combined Stress Conditions in Melon Induce Non-additive Effects in the Core miRNA Regulatory Network
2021
Climate change has been associated with a higher incidence of combined adverse environmental conditions that can promote a significant decrease in crop productivity. However, knowledge on how a combination of stresses might affect plant development is still scarce. MicroRNAs (miRNAs) have been proposed as potential targets for improving crop productivity. Here, we have combined deep-sequencing, computational characterization of responsive miRNAs and validation of their regulatory role in a comprehensive analysis of response of melon to several combinations of four stresses (cold, salinity, short day, and infection with a fungus). Twenty-two miRNA families responding to double and/or triple …
Fungal-associated NO is involved in the regulation of oxidative stress during rehydration in lichen symbiosis
2010
[EN] Background Reactive oxygen species (ROS) are normally produced in respiratory and photosynthetic electron chains and their production is enhanced during desiccation/rehydration. Nitric oxide (NO) is a ubiquitous and multifaceted molecule involved in cell signaling and abiotic stress. Lichens are poikilohydrous organisms that can survive continuous cycles of desiccation and rehydration. Although the production of ROS and NO was recently demonstrated during lichen rehydration, the functions of these compounds are unknown. The aim of this study was to analyze the role of NO during rehydration of the lichen Ramalina farinacea (L.) Ach., its isolated photobiont partner Trebouxia sp. and Ast…
Nitric oxide inhibits the ATPase activity of the chaperone-like AAA+ ATPase CDC48, a target for S-nitrosylation in cryptogein signalling in tobacco c…
2012
NO has important physiological functions in plants, including the adaptative response to pathogen attack. We previously demonstrated that cryptogein, an elicitor of defence reaction produced by the oomycete Phytophthora cryptogea , triggers NO synthesis in tobacco. To decipher the role of NO in tobacco cells elicited by cryptogein, in the present study we performed a proteomic approach in order to identify proteins undergoing S-nitrosylation. We provided evidence that cryptogein induced the S-nitrosylation of several proteins and identified 11 candidates, including CDC48 (cell division cycle 48), a member of the AAA+ ATPase (ATPase associated with various cellular activities) family. In vit…
Effect of nitrogen nutrition on Medicago truncatula resistance against Aphanomyces euteiches
2016
Nitrogen (N) is a major limiting factor for plant growth. N availability can also impact plant resistance to pathogens by regulating plant immunity. To better understand the links between N nutrition and plant defense, we analyzed the impact of N availability of plant on Medicago truncatula resistance to the root pathogen, Aphanomyces euteiches, taking into account plant genetic variability. This oomycete is considered as the most limiting factor for legume production. Two conditions of N nutrition, non-limiting or deprived in N, and ten plant genotypes were tested in vitro. The results showed that the resistance is modulated by nutritional conditions, depending on plant genotype. Analysis …
Nitric oxide production in tobacco leaf cells: a generalized stress response?
2003
The function of nitric oxide (NO), a gaseous free radical emitted by many plants, is incompletely understood. In the present study the hypothesis that NO generation, like that of the reactive oxygen species, occurs as a general response to different environmental cues was tested. Leaf peels and mesophyll cell suspensions of Nicotiana tabacum cv. Xanthi were loaded with the NO-specific fluorophore, diaminofluorescein, and subjected to an abiotic stressor. Light stress and mechanical injury had no apparent effect on NO production. In contrast, high temperatures, hyperosmotic stress, salinity and epi-illumination in a microscope all led to rapid surges in NO-induced fluorescence. The fluoresce…
Multi-sensor spectral synergies for crop stress detection and monitoring in the optical domain: A review
2022
Remote detection and monitoring of the vegetation responses to stress became relevant for sustainable agriculture. Ongoing developments in optical remote sensing technologies have provided tools to increase our understanding of stress-related physiological processes. Therefore, this study aimed to provide an overview of the main spectral technologies and retrieval approaches for detecting crop stress in agriculture. Firstly, we present integrated views on: i) biotic and abiotic stress factors, the phases of stress, and respective plant responses, and ii) the affected traits, appropriate spectral domains and corresponding methods for measuring traits remotely. Secondly, representative result…
Effect of methyl jasmonate in gene expression, and in hormonal and phenolic profiles of holm oak embryogenic lines before and after infection with Ph…
2022
The dieback syndrome affecting Quercus ilex and other oak species impels the search for tolerant plant genotypes, as well as methods of plant immunization against such infections. Elicitation treatments can be an effective strategy to activate plant defense response and embryogenic lines represent a promising tool to generate new tolerant genotypes and also to study early markers involved in defense response. The aim of the presented work was to investigate changes in gene expression, and in hormonal and phenolic profiles induced in three holm oak embryogenic lines (ELs) elicited with methyl jasmonate (MeJA) before and after infection with the oomycete Phytophthora cinnamomi, which is the m…
Cadmium-induced changes in soil biochemical characteristics of oat (Avena sativa L.) rhizosphere during early growth stages
2011
A microcosm was assembled to physically separate soil from roots and was used to study both the impact of living roots on the soil–plant system during early stages of growth and plant responses to abiotic stress. Oat (Avena sativa L.) seedlings were grown in the microcosm unit for 44 days. Twenty-three days after planting, 0.154 mg CdSO4/g dry soil was added. Plants grown in Cd-treated microcosms showed considerable inhibition of shoot growth rates, and leaf chlorophyll content. Soil microbial biomass C and respiration increased with plant age, and most of the measured biochemical indicators decreased with increasing distance from the soil–root interface, thus demonstrating the rhizosphere …