Target-site EPSPS Pro-106-Ser mutation in Conyza canadensis biotypes with extreme resistance to glyphosate in Ohio and Iowa, USA.

Documenting the diversity of mechanisms for herbicide resistance in agricultural weeds is helpful for understanding evolutionary processes that contribute to weed management problems. More than 40 species have evolved resistance to glyphosate, and at least 13 species have a target-site mutation at position 106 of EPSPS. In horseweed (Conyza canadensis), this p106 mutation has only been reported in Canada.

AvrRpm1 Functions as an ADP-Ribosyl Transferase to Modify NOI-domain Containing Proteins, Including Arabidopsis and Soybean RPM1-interacting Protein 4.

The Pseudomonas syringae effector protein AvrRpm1 activates the Arabidopsis intracellular innate immune receptor protein RPM1 via modification of a second Arabidopsis protein, RIN4. Prior work has shown that AvrRpm1 induces phosphorylation of AtRIN4, but homology modeling indicated that AvrRpm1 may be an ADP-ribosyl transferase. Here we show that AvrRpm1 induces ADP-ribosylation of RIN4 proteins from both Arabidopsis and soybean within two highly conserved nitrate-induced (NOI) domains.

Measuring Callose Deposition, an Indicator of Cell Wall Reinforcement, During Bacterial Infection in Arabidopsis.

The plant cell wall responds dynamically during interaction with various pathogens. Upon recognition of "nonself" components, plant cells deploy a variety of immune responses including cell wall fortification. Callose, a β-(1, 3)-D-glucan polymer, is a component of the material deposited at the site of infection between the plasma membrane and the preexisting cell wall that is hypothesized to serve as a physical barrier and platform for directed antimicrobial compound deposition.

WtsE, an AvrE-family effector protein from Pantoea stewartii subsp. stewartii, causes disease-associated cell death in corn and requires a chaperone protein for stability.

The pathogenicity of Pantoea stewartii subsp. stewartii to sweet corn and maize requires a Hrp type III secretion system. In this study, we genetically and functionally characterized a disease-specific (Dsp) effector locus, composed of wtsE and wtsF, that is adjacent to the hrp gene cluster.