scholarly journals The MossPhyscomitrella patensas a Model System to Study Interactions between Plants and Phytopathogenic Fungi and Oomycetes

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Inés Ponce de León

The mossPhyscomitrella patenshas a great potential as a model system to perform functional studies of plant interacting with microbial pathogens.P. patensis susceptible to fungal and oomycete infection, which colonize and multiply in plant tissues generating disease symptoms. In response to infection,P. patensactivates defense mechanisms similar to those induced in flowering plants, including the accumulation of reactive oxygen species, cell death with hallmarks of programmed cell death, cell wall fortification, and induction of defense-related genes likePAL,LOX,CHS, andPR-1. Functional analysis of genes with possible roles in defense can be performed due to the high rate of homologous recombination present in this plant that enables targeted gene disruption. This paper reviews the current knowledge of defense responses activated inP. patensafter pathogen assault and analyzes the advantages of using this plant to gain further insight into plant defense strategies.

2015 ◽  
Vol 28 (10) ◽  
pp. 1102-1116 ◽  
Author(s):  
M. C. Magno-Pérez-Bryan ◽  
P. M. Martínez-García ◽  
J. Hierrezuelo ◽  
P. Rodríguez-Palenzuela ◽  
E. Arrebola ◽  
...  

Bacillus amyloliquefaciens CECT 8237 and CECT 8238, formerly known as Bacillus subtilis UMAF6639 and UMAF6614, respectively, contribute to plant health by facing microbial pathogens or inducing the plant’s defense mechanisms. We sequenced their genomes and developed a set of ad hoc scripts that allowed us to search for the features implicated in their beneficial interaction with plants. We define a core set of genes that should ideally be found in any beneficial Bacillus strain, including the production of secondary metabolites, volatile compounds, metabolic plasticity, cell-to-cell communication systems, and biofilm formation. We experimentally prove that some of these genetic elements are active, such as i) the production of known secondary metabolites or ii) acetoin and 2-3-butanediol, compounds that stimulate plant growth and host defense responses. A comparison with other Bacillus genomes permits us to find differences in the cell-to-cell communication system and biofilm formation and to hypothesize variations in their persistence and resistance ability in diverse environmental conditions. In addition, the major protection provided by CECT 8237 and CECT 8238, which is different from other Bacillus strains against bacterial and fungal melon diseases, permits us to propose a correlation with their singular genetic background and determine the need to search for additional blind biocontrol-related features.


2021 ◽  
Vol 12 ◽  
Author(s):  
Zahra Iqbal ◽  
Mohammed Shariq Iqbal ◽  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
Mohammad Israil Ansari

Plants are subjected to a plethora of environmental cues that cause extreme losses to crop productivity. Due to fluctuating environmental conditions, plants encounter difficulties in attaining full genetic potential for growth and reproduction. One such environmental condition is the recurrent attack on plants by herbivores and microbial pathogens. To surmount such attacks, plants have developed a complex array of defense mechanisms. The defense mechanism can be either preformed, where toxic secondary metabolites are stored; or can be inducible, where defense is activated upon detection of an attack. Plants sense biotic stress conditions, activate the regulatory or transcriptional machinery, and eventually generate an appropriate response. Plant defense against pathogen attack is well understood, but the interplay and impact of different signals to generate defense responses against biotic stress still remain elusive. The impact of light and dark signals on biotic stress response is one such area to comprehend. Light and dark alterations not only regulate defense mechanisms impacting plant development and biochemistry but also bestow resistance against invading pathogens. The interaction between plant defense and dark/light environment activates a signaling cascade. This signaling cascade acts as a connecting link between perception of biotic stress, dark/light environment, and generation of an appropriate physiological or biochemical response. The present review highlights molecular responses arising from dark/light fluctuations vis-à-vis elicitation of defense mechanisms in plants.


2020 ◽  
Author(s):  
Guillermo Reboledo ◽  
Astrid Agorio ◽  
Lucía Vignale ◽  
Ramón Alberto Batista-García ◽  
Inés Ponce De León

AbstractBryophytes were among the first plants that colonized earth and they evolved key defense mechanisms to counteract microbial pathogens present in the new environment. Although great advances have been made on pathogen perception and subsequent defense activation in angiosperms, limited information is available in early divergent land plants. In this study, a transcriptomic approach uncovered the molecular mechanisms underlying the defense response of the bryophyte Physcomitrium patens against the important plant pathogen Botrytis cinerea. A total of 3.072 differentially expressed genes were significantly affected during B. cinerea infection, including genes encoding proteins with known function in angiosperm immunity and involved in pathogen perception, signaling, transcription, hormonal signaling, metabolic pathways such as shikimate and phenylpropanoid, and proteins with diverse role in defense against biotic stress. Similarly as in other plants, B. cinerea infection leads to downregulation of genes involved in photosynthesis and cell cycle progression. These results highlight the existence of evolutionary conserved defense responses to pathogens throughout the green plant lineage, suggesting that they were probably present in the common ancestors of land plants. Moreover, several genes acquired by horizontal transfer from prokaryotes and fungi, and a high number of P. patens-specific orphan genes were differentially expressed during B. cinerea infection, indicating that they are part of the moss immune response and probably played an ancestral role related to effective adaptation mechanisms to cope with pathogen invasion during the conquest of land.Key MessageEvolutionary conserved defense mechanisms present in extant bryophytes and angiosperms, as well as moss-specific defenses are part of the immune response of the early divergent land plant Physcomitrium patens.


Biljni lekar ◽  
2020 ◽  
Vol 48 (5) ◽  
pp. 510-521
Author(s):  
Slobodan Krsmanović ◽  
Kristina Petrović ◽  
Boško Dedić ◽  
Ferenc Bagi ◽  
Vera Stojšin ◽  
...  

Sunflower plants show pronounced allelopathic traits and represent a suitable base for potential scientific research work. Understanding and exploiting precisely of that potential could greatly reduce the use of chemical products for plant protection that are intensively used in the production technology of this crop. Today, a big effort is made in sunflower breeding in order to produce the resistance to the economically most important pathogens, which are in most cases phytopathogenic fungi and parasitic weeds such as broomrape. Since sunflower is an increasingly popular crop within farmer fields in the Republic of Serbia, an overview of so far known, passive and active defense mechanisms, that are key for the crop resistance creating, is given. The study also describes in detail, the interactions among the most harmful fungal pathogens and sunflower plants, the expression of genes caused by their attack, and the production of metabolites that are crucial for the induced defense formation.


2006 ◽  
Vol 96 (2) ◽  
pp. 181-185 ◽  
Author(s):  
S. L. Woo ◽  
F. Scala ◽  
M. Ruocco ◽  
M. Lorito

Trichoderma-based biofungicides are a reality in agriculture, with more than 50 formulations today available as registered products worldwide. Several strategies have been applied to identify the main genes and compounds involved in this complex, three-way cross-talk between the fungal antagonist, the plant, and microbial pathogens. Proteome and genome analysis have greatly enhanced our ability to conduct holistic and genome-based functional studies. We have identified and determined the role of a variety of novel genes and gene-products, including ABC transporters, enzymes and other proteins that produce or act as novel elicitors of induced resistance, proteins responsible for a gene-for-gene avirulent interaction between Trichoderma spp. and plants, mycoparasitism-related inducers, plant proteins specifically induced by Trichoderma, etc. We have transgenically demonstrated the ability of Trichoderma spp. to transfer heterologous proteins into plant during root colonization, and have used green fluorescent protein and other markers to study the interaction in vivo and in situ between Trichoderma spp. and the fungal pathogen or the plant.


Author(s):  
Farid El Kasmi

Plants utilize cell-surface localized and intracellular leucine-rich repeat (LRR) immune receptors to detect pathogens and to activate defense responses, including transcriptional reprogramming and the initiation of a form of programmed cell death of infected cells. Cell death initiation is mainly associated with the activation of nucleotide-binding LRR receptors (NLRs). NLRs recognize the presence or cellular activity of pathogen-derived virulence proteins, so-called effectors. Effector-dependent NLR activation leads to the formation of higher order oligomeric complexes, termed resistosomes. Resistosomes can either form potential calcium-permeable cation channels at cellular membranes and initiate calcium influxes resulting in activation of immunity and cell death or function as NADases whose activity is needed for the activation of downstream immune signaling components, depending on the N-terminal domain of the NLR protein. In this mini-review, the current knowledge on the mechanisms of NLR-mediated cell death and resistance pathways during plant immunity is discussed.


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