Plants “smell” siblings, scale back competition

A study out in Communicative and Integrative Biology shows the mechanism behind plants that can recognize their own siblings.  These plants send out fewer roots when planted next to siblings than when they’re planted next to strangers, a phenomenon the researchers think lessens competition among sibs but increases competition among unrelated plants. The study was done in the lab of Harsh Bais, a researcher at the University of Delaware, on the common laboratory plant Arabidopsis thaliana. Bais and his graduate student Meredith Biedrzycki, the lead author on the paper,  exposed seedlings to exudates, or root secretions, of siblings and of unrelated plants.  The plants exposed to strangers’ exudates had greater lateral root formation — that is, their roots spread further away from the plant. The ecologists used wild-collected strains of Arabidopsis in the study to avoid the potential of lab-reared strains having unknown siblings.  It’s interesting that a well-studied lab plant would show this ability to sense its siblings. It would be interesting also to know what other wild plants have this heightened sense of family. Is it common, or specific to certain groups?  Are there traits in Arabidopsis that make it a good lab plant and also give it advanced sensory capabilities? Read the abstract...

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