RACK ATTACK: Arabidopsis leaves respond to a bacterial protease through an immune pathway involving the scaffolding protein RACK1. ZHENYU CHENG
The paper Z. Cheng et al., “Pathogen-secreted proteases activate a novel plant immune pathway,” Nature, doi:10.1038/nature14243, 2015. The question In his quest to uncover the ways organisms ward off pathogens, Fred Ausubel at Massachusetts General Hospital and his lab had been looking for molecules (referred to by those in the field as MAMPs—microbe-associated molecular patterns) present in the pathogenic bacterium Pseudomonas aeruginosa that could spark a response in Arabidopsis. The answer What the team turned up was unusual: a P. aeruginosa–secreted protease. Other MAMPs known to trigger an innate immune response in plants don’t exhibit enzymatic activity. “It was kind of surprising,” says postdoc Zhenyu Cheng, who led the study. “So we tried to identify the components involved in detecting this protease.” The new pathway ...
