Agroinfiltration Is a Versatile Tool That Facilitates Comparative Analyses ofAvr9/Cf-9-Induced andAvr4/Cf-4-Induced Necrosis

Hoorn, R.A.L. van der; Laurent, François; Roth, Ronelle; Wit, P.J.G.M. de

doi:10.1094/mpmi.2000.13.4.439

Cited by 309 publications

(285 citation statements)

References 41 publications

Supporting

Mentioning

279

Contrasting

Order By: Relevance

“…1B). Amplified fragments were inserted into the NcoI and PstI restriction sites of pRH80 (22), between the 35S promoter and the terminator (T). The 35S-9DC-T cassette subsequently was inserted into the binary plasmid pMOG800 (22), with the use of the XbaI and KpnI restriction sites.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Intragenic recombination generated two distinct Cf genes that mediate AVR9 recognition in the natural population of Lycopersicon pimpinellifolium

Hoorn

Kruijt

Roth

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Resistance gene Cf-9 of cultivated tomato (Lycopersicon esculentum) confers recognition of the AVR9 elicitor protein of the fungal pathogen Cladosporium fulvum. The Cf-9 locus, containing Cf-9 and four homologs (Hcr9s), originates from Lycopersicon pimpinellifolium (Lp). We examined naturally occurring polymorphism in Hcr9s that confer AVR9 recognition in the Lp population. AVR9 recognition occurs frequently throughout this population. In addition to Cf-9, we discovered a second gene in Lp, designated 9DC, which also confers AVR9 recognition. Compared with Cf-9, 9DC is more polymorphic, occurs more frequently, and is more widely spread throughout the Lp population, suggesting that 9DC is older than Cf-9. The sequences of Cf-9 and 9DC suggest that Cf-9 evolved from 9DC by intragenic recombination between 9DC and another Hcr9. The fact that the 9DC and Cf-9 proteins differ in 61 aa residues, and both mediate recognition of AVR9, shows that in nature Hcr9 proteins with the same recognitional specificity can vary significantly. R ecognition of a diverse range of pathogens, followed by an adequate defense response, is crucial for the survival of plants. Resistance (R) genes, which mediate recognition of products of matching avirulence (Avr) genes, play a key role in the recognition of pathogens (1). Most R gene products contain a leucine-rich repeat (LRR) domain with putative solventexposed amino acid residues that decorate the surface of the protein, where specific interactions with other proteins are thought to occur (2). R proteins with different specificities differ predominantly at putative solvent-exposed positions, which are often thought to result from adaptive evolution (3).Plants need to generate R genes with new specificities because pathogens continuously try to circumvent recognition by the host plant. New R genes are thought to evolve by sequence exchange between homologous genes and by accumulation of random point mutations in codons that encode amino acids located at putative solvent-exposed positions (3, 4).The continuous generation of new recognitional specificities by the host, followed by subsequent adaptation of the pathogen to circumvent this recognition, can be seen as an ''arms race'' between plants and pathogens (5). Recent observations suggest that in nature, this arms race is a slow process and that the battle between plants and pathogens is more likely to be similar to ''trench warfare.'' In this model, frequencies of R genes in the plant population fluctuate in time, following the frequency of the matching Avr gene in the pathogen population (6). Consistent with this model, gene-for-gene pairs like AvrRpm1-RPM1 and AvrPto-Pto are ancient (6, 7), and plants carrying or lacking the RPM1 gene coexist in the plant population (6).The tomato R genes Cf-9 and Cf-4 mediate recognition of strains of the leaf mold fungus Cladosporium fulvum carrying the Avr9 or Avr4 gene, respectively (8). Recognition by resistant plants results in the activation of multiple defense responses that limit further fun...

show abstract

Section: Methodsmentioning

confidence: 99%

“…Petite Havana SR1) was performed as described (22). To compare the activity of 9DC with Cf-9, dilution series of Agrobacterium cultures were infiltrated, and necrotic responses were quantified as described (10).…”

Section: Methodsmentioning

confidence: 99%

Intragenic recombination generated two distinct Cf genes that mediate AVR9 recognition in the natural population of Lycopersicon pimpinellifolium

Hoorn

Kruijt

Roth

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…For agroinfiltration experiments, Agrobacterium tumefaciens strain pMOG101 was cultured in 1 L YEB medium (5 g beef extract, 1 g yeast [Saccharomyces cerevisiae] extract, 5 g bactopeptone, 5 g Suc, and 2 mL MgSO 4 ) with the appropriate antibiotics as described earlier (Van der Hoorn et al, 2000). After growing overnight at 28°C, the bacteria was pelleted by centrifugation, resuspended in 1 L infiltration medium (5 g Murashige and Skoog salts, 1.95 g MES, and 20 g Suc, pH 5.6, with NaOH and 200 mM acetosyringone), and incubated at room temperature for 2 h. For agroinfiltration, the bacterial suspensions were diluted to final concentrations between optical density at 600 nm (OD 600 ) of 0.2 and 1.0.…”

Section: Plant Expressionmentioning

confidence: 99%

Structural Determinants at the Interface of the ARC2 and Leucine-Rich Repeat Domains Control the Activation of the Plant Immune Receptors Rx1 and Gpa2

et al. 2013

View full text Add to dashboard Cite

Many plant and animal immune receptors have a modular nucleotide-binding-leucine-rich repeat (NB-LRR) architecture in which a nucleotide-binding switch domain, NB-ARC, is tethered to a LRR sensor domain. The cooperation between the switch and sensor domains, which regulates the activation of these proteins, is poorly understood. Here, we report structural determinants governing the interaction between the NB-ARC and LRR in the highly homologous plant immune receptors Gpa2 and Rx1, which recognize the potato cyst nematode Globodera pallida and Potato virus X, respectively. Systematic shuffling of polymorphic sites between Gpa2 and Rx1 showed that a minimal region in the ARC2 and N-terminal repeats of the LRR domain coordinate the activation state of the protein. We identified two closely spaced amino acid residues in this region of the ARC2 (positions 401 and 403) that distinguish between autoactivation and effector-triggered activation. Furthermore, a highly acidic loop region in the ARC2 domain and basic patches in the N-terminal end of the LRR domain were demonstrated to be required for the physical interaction between the ARC2 and LRR. The NB-ARC and LRR domains dissociate upon effector-dependent activation, and the complementary-charged regions are predicted to mediate a fast reassociation, enabling multiple rounds of activation. Finally, we present a mechanistic model showing how the ARC2, NB, and N-terminal half of the LRR form a clamp, which regulates the dissociation and reassociation of the switch and sensor domains in NB-LRR proteins.Resistance (R) proteins play a central role in the recognition-based immune system of plants. Unlike vertebrates, plants lack an adaptive immune system with highly specialized immune cells. Instead, they rely on an innate immune system in which each cell is autonomous. Two types of immune receptors can be distinguished in plants, pathogen-associated molecular patterns recognition receptors that detect conserved molecular patterns in plant pathogens and intracellular R proteins that recognize specific effectors employed by pathogens as modifiers of host metabolism or defense mechanisms (Jones and Dangl, 2006). Effector-triggered activation of R proteins leads to an array of protective responses, often culminating in programmed cell death at the site of infection (Greenberg and Yao, 2004), thereby preventing further ingress of the pathogen. Pathogens have evolved mechanisms to evade recognition by R proteins and to regain their virulence (Dodds and Rathjen, 2010). This continuous coevolutionary process between host and pathogen has resulted in a reservoir of highly diverse R proteins in plants, enabling them to counteract a wide range of pathogens and pests.The most common class of R proteins consists of nucleotide-binding (NB)-leucine-rich repeat (LRR) proteins with a tripartite domain architecture, which roughly corresponds to an N-terminal response domain (a coiled coil [CC] or Toll/Interleukin-1 receptor [TIR] domain) involved in downstream signaling, a central molecula...

show abstract

“…Transient expression assays (Bendahmane et al, 2000;Van der Hoorn et al, 2000) were conducted to identify which member(s) of the LeEix gene family control(s) the plant's response to the EIX elicitor. LeEix1 and LeLeEix2 cDNAs were cloned independently in the sense orientation into the binary vector pBINPLUS between the 35S-V promoter containing the translation enhancer signal and the Nos terminator.…”

Section: Genetic Complementationmentioning

confidence: 99%

The Receptor for the Fungal Elicitor Ethylene-Inducing Xylanase Is a Member of a Resistance-Like Gene Family in Tomato

2004

View full text Add to dashboard Cite

An ethylene-inducing xylanase (EIX) is a potent elicitor of plant defense responses in specific cultivars of tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum). The LeEix locus in tomatoes was characterized by map-based cloning, which led to the identification of a novel gene cluster from which two members (LeEix1 and LeEix2) were isolated. Similar to the tomato Ve resistance genes in tomato plants, the deduced amino acid sequences encoded by LeEix1 and LeEix2 contain a Leu zipper, an extracellular Leu-rich repeat domain with glycosylation signals, a transmembrane domain, and a C-terminal domain with a mammalian endocytosis signal. Silencing expression of the LeEix genes prevented the binding of EIX to cells of an EIX-responsive plant and thus inhibited the hypersensitive response. Overexpression of either LeEix1 or LeEix2 genes in EIX-nonresponsive tobacco plants enabled the binding of EIX, although only LeEix2 could transmit the signal that induced the hypersensitive response. Overexpressing LeEix2 in mammalian COS-7 cells enables binding of EIX, indicating physical interaction between the EIX elicitor and LeEix2 gene product. Structural analysis of the LeEix proteins suggests that they belong to a class of cell-surface glycoproteins with a signal for receptor-mediated endocytosis. Mutating the endocytosis signal in LeEix2 (Tyr 993 to Ala) abolished its ability to induce the hypersensitive response, suggesting that endocytosis plays a key role in the signal transduction pathway

show abstract

Agroinfiltration Is a Versatile Tool That Facilitates Comparative Analyses ofAvr9/Cf-9-Induced andAvr4/Cf-4-Induced Necrosis

Cited by 309 publications

References 41 publications

Intragenic recombination generated two distinct Cf genes that mediate AVR9 recognition in the natural population of Lycopersicon pimpinellifolium

Intragenic recombination generated two distinct Cf genes that mediate AVR9 recognition in the natural population of Lycopersicon pimpinellifolium

Structural Determinants at the Interface of the ARC2 and Leucine-Rich Repeat Domains Control the Activation of the Plant Immune Receptors Rx1 and Gpa2

The Receptor for the Fungal Elicitor Ethylene-Inducing Xylanase Is a Member of a Resistance-Like Gene Family in Tomato

Contact Info

Product

Resources

About