Agrobacterium-mediated transient assays for gene function are increasingly being used as alternatives to genetic complementation and stable transformation. However, such variable not equally successful in different plant species. We analysed a range of physiological factors affecting expression following agroinfiltration, developed protocol efficient routine several Lettuce exhibited high levels was at least easy work with Nicotiana benthamiana. Transient occurred the majority cells within...

Toll/interleukin receptor (TIR) domain-containing proteins encoded in the Arabidopsis (Arabidopsis thaliana) genome include TIR-nucleotide binding site (TN) and TIR-unknown site/domain (TX) families. We investigated function of these proteins. Transient overexpression five TX TN genes tobacco (Nicotiana benthamiana) induced chlorosis. This chlorosis was dependent on ENHANCED DISEASE RESISTANCE1, a dependency conserved both Arabidopsis. Stable transgenic lines produced variety phenotypes...

Species of Orobanchaceae parasitize the roots nearby host plants to rob them water and other nutrients. Parasitism can be debilitating plant, some world's most pernicious agricultural pests are parasitic weeds. We demonstrate here that interfering hairpin constructs transformed into silence expression targeted genes in parasite. Transgenic hemi-parasitic plant Triphysaria versicolor expressing GUS reporter gene were allowed transgenic lettuce a RNA containing fragment (hpGUS). When stained...

Summary Host‐induced gene silencing ( HIGS ) is an RNA interference‐based approach in which small interfering s (si s) are produced the host plant and subsequently move into pathogen to silence genes. As a proof‐of‐concept, we generated stable transgenic lettuce plants expressing si targeting potentially vital genes of Bremia lactucae , biotrophic oomycete that causes downy mildew, most important disease worldwide. Transgenic plants, inverted repeats fragments either Highly Abundant Message...

Summary The RGC2 gene cluster in lettuce ( Lactuca sativa ) is one of the largest known families genes encoding nucleotide binding site–leucine‐rich repeat (NBS–LRR) proteins. One its members, RGC2B , encodes Dm3 which determines resistance to downy mildew caused by oomycete Bremia lactucae carrying cognate avirulence gene, Avr3 . We developed an efficient strategy for analysis this large family low expressed using post‐transcriptional silencing (PTGS). transformed cv. Diana (carrying...

Abstract Bacterial plant pathogens manipulate their hosts by injection of numerous effector proteins into host cells via type III secretion systems. Recognition these effectors the leads to induction a defense reaction that often culminates in hypersensitive response manifested as cell death. Genes encoding can be exchanged between different strains bacteria horizontal transfer, and individual are capable infecting multiple hosts. Host species express diverse repertoires resistance mediate...

The ability to induce a defense response after pathogen attack is critical feature of the immune system any organism. Nucleotide-binding leucine-rich repeat receptors (NLRs) are key players in this process and perceive occurrence nonself-activities or foreign molecules. In plants, coevolution with variety pests pathogens has resulted repertoires several hundred diverse NLRs single individuals many more populations as whole. However, mechanism by which signaling triggered these plants poorly...

Abstract Genome-wide motif searches identified 1134 genes in the lettuce reference genome of cv. Salinas that are potentially involved pathogen recognition, which 385 were predicted to encode nucleotide binding-leucine rich repeat receptor (NLR) proteins. Using a maximum-likelihood approach, we grouped NLRs into 25 multigene families and 17 singletons. Forty-one percent these NLR-encoding belong three families, largest being RGC16 with 62 Salinas. The majority located five major resistance...

Phylogeographic studies inform about routes of pathogen dissemination and are instrumental for improving import/export controls. Genomes 17 isolates the bacterial wilt potato brown rot Ralstonia solanacearum race 3 biovar 2 (R3bv2), a Select Agent in United States, were thus analyzed to get insight into phylogeography this pathogen. Thirteen fourteen from Europe, Africa, Asia found belong single clonal lineage while South America genetically diverse tended carry ancestral alleles at genomic...

The major cluster of resistance genes in lettuce cv. Diana contains approximately 32 nucleotide binding site—leucine-rich repeat encoding genes. Previous molecular dissection this complex region had identified a large gene, RGC2B, as candidate for the downy mildew Dm3. This article describes genetic and transgenic complementation data that demonstrated RGC2B is necessary sufficient to confer with Dm3 specificity. Ethylmethanesulphonate was used induce mutations susceptibility (Dm1, Dm3, Dm7,...

Abstract The region corresponding to the ABI1-Rps2-Ck1 segment on chromosome 4 of Arabidopsis thaliana was sequenced in Brassica oleracea. Similar A. thaliana, B. oleracea homolog BoRps2 is present single copy. orthologous located and can be distinguished by presence an N-myristoyl transferase coding gene (N-myr) between Rps2 Ck1 (BoCk1a) genes. N-myr homologs are chromosomes 2 5. Additional for these two chromosomes. A second found (BoCk1b) 7 served define another 1. segments displayed...

Abstract Transient expression following agroinfiltration of plant tissue was investigated as a system for producing recombinant protein. As model system, Agrobacterium tumefaciens containing the β‐glucuronidase (GUS) gene vacuum infiltrated into lettuce leaf disks. Infiltration with suspension 10 9 colony forming units/mL followed by incubation 72 h at 22°C in continuous darkness produced maximum 0.16% GUS protein based on dry or 1.1% total soluble This compares favorably to levels...

RPM1-interacting protein 4 (RIN4), a negative regulator of the basal defense response in plants, is targeted by multiple bacterial virulence effectors. We show that RIN4 degradation induced effector AvrPto from Pseudomonas syringae and this Solanaceous plants dependent on resistance protein, Pto, kinase, Prf, nucleotide binding site-leucine-rich repeat protein. Our data demonstrate overlap between two best-characterized pathways for recognition pathogen effectors plants. interacts with plant...

Of the over 50 phenotypic resistance genes mapped in lettuce, 25 colocalize to three major clusters (MRC) on chromosomes 1, 2, and 4. Similarly, majority of candidate encoding nucleotide binding-leucine rich repeat (NLR) proteins genetically with loci. MRC1 MRC4 span 66 63 Mb containing 84 21 NLR-encoding genes, respectively, as well 765 627 that are not related NLR genes. Forward reverse genetic approaches were applied dissect MRC4. Transgenic lines exhibiting silencing selected using...

The experimental induction of RNA silencing in plants often involves expression transgenes encoding inverted repeat (IR) sequences to produce abundant dsRNAs that are processed into small RNAs (sRNAs). These sRNAs key mediators post-transcriptional gene (PTGS) and determine its specificity. Despite application agriculture broad utility plant research, the mechanism IR-PTGS is incompletely understood. We generated four sets 60 Arabidopsis plants, each containing IR expressing different...

Plant-parasitic nematodes cause significant damage to major crops throughout the world. The small number of genes conferring natural plant resistance and limitations chemical control require development new protective strategies. RNA interference or inducible over-expression nematicidal provides an environment-friendly approach this problem. Candidate include NGB, which encodes a GTP-binding protein, NAB/ERabp1, auxin-binding were identified as being up-regulated in tomato roots...

Background Whole genome duplication, which results in polyploidy, is a common feature of plant populations and recurring event the evolution flowering plants. Polyploidy can result changes to gene expression epigenetic instability. Several phenomena, occurring at transcriptional or post-transcriptional level, have been documented allopolyploids (polyploids derived from species hybrids) Arabidopsis thaliana, yet findings autopolyploids duplication single species) are limited. Here, we tested...

Plants obtained from in vitro culture can show increased susceptibility to environmental stress conditions. In the process of their adaptation natural conditions it requires monitoring physiological state. The methods used check this phenomenon should estimate quickly and exactly tolerance suboptimal factors. Such requirements are satisfied by measuring chlorophyll luminescence vivo, e.g. fluorescence induction delayed luminescence. objects our studies were cucumber plants regenerated...

Summary. The association between genes encoding for two serum protein antigens (G9 and G16) α‐protease inhibitors was analysed in pigs. A recombination frequency PI locus controlling G9 G16 allotypes varied from 0 to 4.8cM. Data appropriate matings are consistent with a gene order of PII‐POIA‐POIB‐P12‐(G9, G16).