What is NBS LRR?
NBS-LRR proteins are some of the largest proteins known in plants, ranging from about 860 to about 1,900 amino acids. They have at least four distinct domains joined by linker regions: a variable amino-terminal domain, the NBS domain, the LRR region, and variable carboxy-terminal domains (Figure 1).
What are R proteins?
Plants deploy a large number of resistance (R) proteins to detect invading pathogens. The R proteins are encoded by resistance genes that contain cell surface-localized receptors and intracellular receptors.
What is NB arc domain?
The NB-ARC domain is a functional ATPase domain, and its nucleotide-binding state is proposed to regulate activity of the R protein. A highly conserved methionine-histidine-aspartate (MHD) motif is present at the carboxy-terminus of ARC2.
What is R gene in plants?
R genes are among the most highly variable plant genes known, both within and between populations. Plant genomes encode hundreds of R genes that code for NB-LRR proteins, so named because they posses nucleotide-binding (NB) and leucine-rich repeat (LRR) domains.
What is plant NLR?
In plants, NLR proteins function as intracellular receptors that detect pathogen effector proteins directly, or indirectly by recognizing effector-induced modifications to other host proteins. NLR activation triggers a suite of defense responses associated with programed cell death (PCD).
What do AVR genes encode?
Viral Avr genes encode for coat proteins, replicase or movement proteins.
What is RNA silencing in plants?
RNA SILENCING PATHWAYS IN PLANTS. RNA silencing is an evolutionarily conserved mechanism in eukaryotes. It is induced by double-stranded RNA (dsRNA) or hairpin structured RNA (hpRNA), involving common factors including Dicer or Dicer-like (DCL) and Argonaute (AGO) family proteins [1-3].
What is the guard hypothesis?
The guard hypothesis postulates that the requirement for a specific protein to activate the plant resistance gene when it encounters an avirulence gene of a pathogen and it guards against the suppression of the plant defense mechanism by any bacterial effector.
What is an elicitor in plants?
Elicitors are pathogen signal metabolites, recognized by plant cells, which trigger plant defenses. They are produced either by the pathogen or by plant cell components, such as cell wall, upon hydrolyzing action of the pathogen.
What is the role of AVR gene in pathogenesis?
Avr genes have dual functions: Pathogens containing Avr genes are avirulent to plants carrying the matching R genes, while they are virulent in race, strain, pathovar or species-specific way to plants without carrying the matching R genes.
What are the types of gene silencing?
Types
- Genomic Imprinting.
- Paramutation.
- Transposon silencing (or Histone Modifications)
- Transgene silencing.
- Position effect.
- RNA-directed DNA methylation.
Do neutrophils have NOD-like receptors?
The Nod-like receptors (nucleotide-binding domain leucine-rich repeat containing family; NLRs) constitute a recently discovered group of PRRs whose role in the neutrophil immune responses is not yet characterized. The present study aimed to investigate the expression and function of NLRs in neutrophils.