The phytotoxin coronatine (COR) promotes various aspects of Pseudomonas syringae virulence, including invasion through stomata, growth in the apoplast, and induction of disease symptoms. COR is a structural mimic of active jasmonic acid (JA) conjugates. Known activities of COR are mediated through its binding to the F-box-containing JA coreceptor CORONATINE INSENSITIVE1. By analyzing the intera...

Landraces of maize (Zea mays ssp. mays) and its wild teosinte relatives (Zea mays spp. parviglumis and mexicana) were surveyed for sensitivity to fumonisin B(1), a phytotoxin produced by the maize pathogen Gibberella moniliformis. Only two of 42 Z. mays samples were highly insensitive to FB(1) (ED(50) = ca. 200 microM). The teosintes and 76% of the maize landraces were moderately or highly sens...

Tagetitoxin, a chlorosis-inducing phytotoxin produced by Pseudomonas syringae pv. tagetis, inhibits RNA synthesis directed by chloroplast RNA polymerase. In isolated chloroplasts, tagetitoxin quickly and specifically reduced the incorporation of [3H]uridine into RNA. When it was added to transcriptionally active chloroplast protein extracts, the toxin directly inhibited incorporation of [32P]UT...

Thaxtomin A is a phytotoxin produced by Streptomyces scabies and other Streptomyces species, the causative agents of common scab disease in potato and other taproot crops. At nanomolar concentrations, thaxtomin causes dramatic cell swelling, reduced seedling growth, and inhibition of cellulose synthesis in Arabidopsis. We identified a mutant of Arabidopsis, designated txr1, that exhibits increa...

Pseudomonas syringae is the most widespread bacterial pathogen in plants. Several strains of P. syringae produce a phytotoxin, coronatine (COR), which acts as a jasmonic acid mimic and inhibits plant defense responses and contributes to disease symptom development. In this study, we found that COR inhibits early defense responses during nonhost disease resistance. Stomatal closure induced by a ...

The albA gene of Klebsiella oxytoca encodes a protein of 221 amino acids that binds the albicidin phytotoxin with a high affinity (dissociation constant = 6.4 x 10(-8) M). For this study, circular dichroism (CD) spectrometry and an alanine scanning mutagenesis approach were used in combination to investigate the molecular and conformational mechanisms of this high-affinity protein-ligand intera...