A diverse range of plant proteases are implicated in pathogen perception and in subsequent signalling and execution of disease resistance. We demonstrate, using protease inhibitors and virus-induced gene silencing (VIGS), that the plant papain cysteine protease cathepsin B is required for the disease resistance hypersensitive response (HR). VIGS of cathepsin B prevented programmed cell death (P...

In our previous study, PevD1 was characterized as a novel protein elicitor produced by Verticillium dahliae inducing hypersensitive response (HR) and systemic acquired resistance (SAR) in tobacco plants; however, the detailed mechanisms of PevD1's elicitor activity remain unclear. In this study, five mutant fragments of PevD1 were generated by polymerase chain reaction-based mutagenesis and the...

Ca(2+) rise and nitric oxide (NO) generation are essential early steps in plant innate immunity and initiate the hypersensitive response (HR) to avirulent pathogens. Previous work from this laboratory has demonstrated that a loss-of-function mutation of an Arabidopsis (Arabidopsis thaliana) plasma membrane Ca(2+)-permeable inwardly conducting ion channel impairs HR and that this phenotype could...

Ca rise and nitric oxide (NO) generation are essential early steps in plant innate immunity and initiate the hypersensitive response (HR) to avirulent pathogens. Previous work from this laboratory has demonstrated that a loss-of-function mutation of an Arabidopsis (Arabidopsis thaliana) plasma membrane Ca-permeable inwardly conducting ion channel impairs HR and that this phenotype could be resc...

ABSTRACT Infection of Nicotiana obtusifolia plant introduction (PI) #555573 by the downy mildew pathogen Peronospora tabacina resulted in a compatible interaction, in which P. tabacina penetrated and freely colonized host leaf tissue. This interaction became incompatible 5 to 6 days later, with the appearance of necrotic lesions (NLs) and inhibition of pathogen growth and subsequent sporulation...

Harpins, encoded by hrp (hypersensitive response and pathogenicity) genes of Gram-negative plant pathogens, are elicitors of hypersensitive response (HR). HpaXm is a novel harpin-like protein described from cotton leaf blight bacteria, Xanthomonas citri subsp. malvacearum-a synonym of X. campestris pv. malvacearum (Smith 1901-1978). A putative signal peptide (1-MNSLNTQIGANSSFL-15) of hpaXm was ...

The Arabidopsis disease resistance (R) genes RPW8.1 and RPW8.2 couple the recognition of powdery mildew pathogens of this plant with the subsequent induction of a localized necrosis, or hypersensitive response (HR). The HR restricts the spread of the infection and renders the plant resistant. One-third of Arabidopsis plants transformed with a genomic fragment containing RPW8.1 and RPW8.2 develo...

Physiological races of powdery mildew (Podosphaera xanthii) cause different symptoms in eight melon lines. Infection by races 1, 2, and 5 was examined in different melon lines. After a compatible reaction, conidia germination, haustorium initiation from the germ tube, germ tube branching, and sporulation occurred within 12, 24, 48, and 120 h, respectively, and the conidia matured within 240 h. ...

The RPM1 protein confers resistance to Pseudomonas syringae pv tomato DC3000 expressing either of the Type III effector proteins AvrRpm1 or AvrB. Here, we describe the isolation and functional characterization of RPM1 Interacting Protein 13 (RIN13), a resistance protein interactor shown to positively enhance resistance function. Ectopic expression of RIN13 (RIN13s) enhanced bacterial restrictio...

The hypersensitive response (HR) is a localized programmed cell death phenomenon that occurs in response to pathogen recognition at the site of attempted invasion. Despite more than a century of research on HR, little is known about how it is so tightly regulated and how it can be contained spatially to a few cells. AtMC1 is an Arabidopsis thaliana plant metacaspase that positively regulates th...