The effect of five antioxidants (citric acid, salicylic acid, benzoic acid, ascorbic acid, and sodium citrate) on the resistance of tomato plants (Lycopersicon esculentum Mill) to early blight disease incited by Alternaria solani was investigated in vitro and in vivo. The results indicated that all of the antioxidants tested markedly inhibited the mycelial growth of A. solani in vitro. The degr...

Systemic acquired resistance (SAR) is an induced immune mechanism in plants. Unlike vertebrate adaptive immunity, SAR is broad spectrum, with no specificity to the initial infection. An avirulent pathogen causing local programmed cell death can induce SAR through generation of mobile signals, accumulation of the defense hormone salicylic acid, and secretion of the antimicrobial PR (pathogenesis...

When plants sense a pathogen attack, they activate defenses in the immediate area and in distaltissues;thissystemicacquiredresistance (SAR) requires salicylic acid (SA), which activatesNONEXPRESSEROFPATHOGENESISRELATED GENES1 (NPR1) in Arabidopsis thaliana (reviewed in Fu and Dong, 2013). This activation involves the release of NPR1 monomers from oligomers, which is also regulated by the cell’s...

Systemic acquired resistance (SAR) is a response to pathogen infection that renders plants more resistant to subsequent infection (reviewed in Grant and Lamb, 2006). It is characterized by salicylic acid (SA) accumulation both at the initial point of infection and throughout the plant and involves the induction of certain pathogenesis-related (PR) genes. The plant hormone abscisic acid (ABA) is...

Systemic acquired resistance (SAR) in Carica papaya L. is induced by benzothiadiazole (BTH). The response is manifested by increased tolerance to infection by the virulent pathogen Phytophthora palmivora, by increased b-1,3-glucanase and chitinase activities, and by increased accumulation of a PR1 mRNA. Infection of untreated papaya by P. palmivora also induced b-1,3-glucanase and chitinase act...

Arabidopsis nonexpresser of pathogenesis-related (PR) genes (NPR1) is the sole positive regulator that has been shown to be essential for the induction of systemic acquired resistance. In npr1 mutant plants, salicylic acid (SA)–mediated PR gene expression and pathogen resistance are abolished completely. NPR1 has been shown to interact with three closely related TGA transcription factors—TGA2, ...

Systemic acquired resistance (SAR) is an inducible defense mechanism in plants that confers enhanced resistance against a variety of pathogens. SAR is activated in the uninfected systemic (distal) organs in response to a prior (primary) infection elsewhere in the plant. SAR is associated with the activation of salicylic acid (SA) signaling and the priming of defense responses for robust activat...

background and objectives: bacterial bloodstream infections (bsis) and surgical site infections (ssis) are among the most common nosocomial infections with high mortality and morbidity. we aimed to evaluate the frequency of various species among bsis and ssis at tehran heart center, tehran, iran. methods: patients with localized or systemic infections that became evident 48 hours or more after ...

Transposon inactivation of Arabidopsis MAP kinase 4 produced the mpk4 mutant exhibiting constitutive systemic acquired resistance (SAR) including elevated salicylic acid (SA) levels, increased resistance to virulent pathogens, and constitutive pathogenesis-related gene expression shown by Northern and microarray hybridizations. MPK4 kinase activity is required to repress SAR, as an inactive MPK...

This study investigated the fitness effects of four mutations (npr1, cpr1, cpr5, and cpr6) and two transgenic genotypes (NPR1-L and NPR1-H) affecting different points of the systemic acquired resistance (SAR) signaling pathway associated with pathogen defense in Arabidopsis thaliana. The npr1 mutation, which resulted in a failure to express SAR, had no effect on fitness under growth chamber con...