Plant disease resistance (R) genes mediate specific pathogen recognition, leading to a successful immune response. Downstream responses include ion fluxes, an oxidative burst, transcriptional reprogramming, and, in many cases, hypersensitive cell death at the infection site. We used transgenic Arabidopsis line carrying bacterial avirulence gene avrRpm1 under control of steroid-inducible promoter select for mutations required RPM1-mediated recognition and signal transduction. identified...

A 69-kDa proteinase (P69), a member of the pathogenesis-related proteins, is induced and accumulates in tomato (Lycopersicon esculentum) plants as consequence pathogen attack. We have used polymerase chain reaction to identify clone cDNA from that represent P69 proteinase. The nucleotide sequence analysis revealed synthesized preproenzyme form, 745-amino acid polypeptide with 22-amino signal peptide, 92-amino propolypeptide, 631-amino mature polypeptide. Within region most salient feature...

The Arabidopsis RPM1 gene confers resistance against Pseudomonas syringae expressing either the AvrRpm1 or AvrB type III effector protein. We present an exhaustive genetic screen for mutants that no longer recognize avrRpm1. Using inducible avrRpm1 expression system, we identified 110 independent mutations. These mutations represent six complementation groups. None discriminates between and avrB recognition. 95 rpm1 alleles a detailed structure–function analysis of Several retain partial...

By using biochemical, immunological, and molecular strategies we have identified cloned a cDNA encoding protease from tomato (Lycopersicon esculentum) plants (P69B) that is part of proteolytic system activated in the plant as result infection with citrus exocortis viroid. This new closely related, terms amino acid sequence structural organization, to previously pathogenesis-related subtilisin-like (Tornero, P., Conejero, V., Vera, P. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 6332–6337). The...

Pathogenesis-related (PR) proteins form a heterogeneous family of plant that are likely to be involved in defense and inducible by pathogen attacks. One group PRs, represented the subfamily PR-1, low-molecular-weight unknown biochemical function. Here we describe cloning characterization two closely related genes encoding basic an acidic PR-1 protein (PR1b1 PR1a2) from tomato (Lycopersicon esculentum). We present comparative study mode transcriptional regulation these transgenic tobacco...

Summary Measuring the growth of pathogenic bacteria in leaves is a mainstay plant pathology studies. We have made significant improvements to standard methods that will not only increase throughput but also reduce space limitations. Additionally, method described here as accurate method. Briefly, we infected by dipping whole seedlings Arabidopsis into bacterial solution containing surfactant. After harvest, were then simply shaken buffer. The resulting solutions diluted microtitre plates and...

Salicylic acid (SA) signaling acts in defense and plant development. The only gene demonstrated to be required for the response SA is Arabidopsis thaliana NON-EXPRESSER OF PATHOGENESIS-RELATED GENE 1 (NPR1), npr1 mutants are insensitive SA. By focusing on effect of analogs development, we identified additional genes acting response. In this work, describe a necessary Non-Recognition-of-BTH4 (NRB4). Three nrb4 alleles recovered from screen cause phenotypes similar wild type tested conditions,...

Salicylic acid (SA) is responsible for certain plant defence responses and NON EXPRESSER OF PATHOGENESIS RELATED 1 (NPR1) the master regulator of SA perception. In Arabidopsis thaliana there are five paralogs NPR1. this work we tested role these in perception by generating combinations mutants transgenics. NPR2 was only paralog able to partially complement an npr1 mutant. The null npr2 reduces combination with or other paralogs. NPR1 interacted all conditions tested, also SA-related proteins...

Both plants and animals require the activity of proteins containing nucleotide binding (NB) domain leucine-rich repeat (LRR) domains for proper immune system function. NB-LRR in (NLR animals) also conserved regulation via SGT1 cytosolic HSP90. RAR1, a protein specifically required plant innate immunity, interacts with HSP90 to maintain steady-state levels. Here, we present identification characterization specific mutations Arabidopsis HSP90.2 that suppress all known phenotypes rar1. These...

ABSTRACT Salicylic acid (SA) is necessary for plant defence against some pathogens, whereas NPR1 SA perception. Plant can be induced to an extreme by several applications of benzothiadiazole (BTH), analogue SA. Thus, plants that do not perceive BTH grow unaffected, wild‐type stunted. This feature allows us screen mutants in Arabidopsis thaliana show insensitivity a high‐throughput fashion. Most the are npr1 alleles, with similar phenotypes weight and pathogen growth. The mutations clustered...

Chitin, a major component of fungal cell walls, is well-known pathogen-associated molecular pattern (PAMP) that triggers defense responses in several mammal and plant species. Here, we show two chitooligosaccharides, chitin chitosan, act as PAMPs grapevine (Vitis vinifera) they elicit immune signalling events, gene expression resistance against diseases. To identify their cognate receptors, the family LysM receptor kinases (LysM-RKs) was annotated profiles were characterized. Phylogenetic...

SUMMARY Ovule development is a key process for plant reproduction, helping to ensure correct seed production. Several molecular factors and hormones such as gibberellins are involved in ovule initiation development. Gibberellins control by the destabilization of DELLA proteins, whereas activity has been shown act positive factor primordia emergence. But mechanism which acts remained unknown. In this study we report that proteins participate formation protein complex with CUC2 transcription...

This paper describes the isolation and characterization of LRP , a new gene from tomato plants. The deduced amino acid sequence showed that encoded protein is enriched in leucine, contains interesting structural motifs. four tandem repeats canonical 24 leucine‐rich repeat (LRR) present different proteins mediates molecular recognition and/or interaction processes. Genomic organization intron‐exon arrangement favor hypothesis LRR domains evolved by exon duplication shuffling. expression...

Salicylic acid (SA) is an essential hormone for plant defence and development. SA perception usually measured by counting the number of pathogens that grow in planta upon exogenous application hormone. A biological model based on fresh weight reduction caused disease resistance Arabidopsis thaliana proposed. This effect more noticeable when a chemical analogue used, like Benzothiadiazole (BTH). By spraying BTH several times, substantial difference biomass observed compared with mock...

The plant hormone salicylic acid (SA) is required for defense responses. NON EXPRESSER OF PATHOGENESIS RELATED 1 (NPR1) and RECOGNITION BTH-4 (NRB4) are the response to SA in Arabidopsis (Arabidopsis thaliana). Here, we isolated several interactors of NRB4 using yeast two-hybrid assays. Two these interactors, βCA1 βCA2, β-carbonic anhydrase family proteins. Since double mutant βca1 βca2 plants did not show any obvious phenotype, investigated other βCAs found that also interacts with βCA3...

Ovule primordia formation is a complex developmental process with strong impact on the production of seeds. In Arabidopsis this controlled by gene network, including components signalling pathways auxin, brassinosteroids (BRs) and cytokinins. Recently, we have shown that gibberellins (GAs) also play an important role in ovule initiation, inhibiting both tomato. Here reveal BRs participate control initiation tomato, promoting increase formation. Moreover, molecular genetic analyses...

The Arabidopsis genome contains 28 genes with sequence homology to the NDR1 gene and tobacco HIN1 gene. Expression analysis of eight these identified two (NHL25 NHL3 for NDR1/HIN1-like) that show pathogen-dependent mRNA accumulation. Transcripts did not accumulate during infection virulent Pseudomonas syringae pv. tomato DC3000 but specifically when bacteria carried any four avirulence avrRpm1, avrRpt2, avrB, or avrRps4. Furthermore, expression avrRpt2 in plants containing corresponding...

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A 23-kD pathogenesis-related protein (P23) is induced in tomato (Lycopersicon esculentum Mill, cv Rutgers) plants when infected with citrus exocortis viroid. This homologous to the salt-induced NP24 (I. Rodrigo, P. Vera, R. Frank, V. Conejero [1991] Plant Mol Biol 16: 931-934). Further characterization of P23 has shown that this accumulates vacuoles association dense inclusion bodies. In vitro assays indicated purified inhibits growth several phytopathogenic fungi. P23-coding cDNA clones...

Antisense suppression in transgenic tomato plants of H52, a gene encoding new homeodomain protein the HD-Zip class, produces conditional lethal phenotype. The lines that survive exhibit spontaneous misregulation cell death control leaves, which, once initiated, propagates and engulfs entire leaf. Activation defence genes, over-accumulation ethylene conjugated salicylic acid, growth reduction virulent pathogens also occurs these plants. In wild-type plants, H52 is up-regulated upon infection,...

This review focuses on the hormonal regulation of ovule development, especially initiation, patterning, and morphogenesis. Understanding genetic molecular basis development is essential from both scientific economic perspective. The represents an attractive system to study lateral organ in plants, and, since ovules are precursors seeds, full comprehension this process can be key improvement crops, those depending high production seeds grains. Ovule morphogenesis governed by complex networks...

Summary This paper reports the isolation and characterization of a homeobox gene ( VAHOX1 ) from Lycopersicon esculentum encoding homeodomain protein that contains leucine zipper motif. The bipartite homeodomain‐leucine (HD‐Zip) motif has only been found in genes dicotyledonous plants, indicating this type transcription factor regulates particular developmental processes these plant species. Here, genomic organization, sequence comparison expression analysis are described. Transcriptional...