Seeds integrate biological information about conspecific and allospecific neighbours

Numerous organisms integrate information from multiple sources and express adaptive behaviours, but how they do so at different developmental stages remains to be identified. Seeds, which are the embryonic stage of plants, need to make decisions about the timing of emergence in response to environmental cues related to survival. We investigated the timing of emergence of Plantago asiatica (Plantaginaceae) seed while manipulating the presence of Trifolium repens seed and the relatedness of neighbouring P. asiatica seed. The relatedness of neighbouring P. asiatica seed and the presence of seeds of T. repens did not on their own influence the timing of P. asiatica emergence. However, when encountering a T. repens seed, a P. asiatica seed emerged faster in the presence of a sibling seed than in the presence of a non-sibling seed. Water extracts of seeds gave the same result. We show that P. asiatica seeds integrate information about the relatedness of neighbouring P. asiatica seeds and the presence of seeds of a different species via water-soluble chemicals and adjust their emergence behaviour in response. These findings suggest the presence of kin-dependent interspecific interactions.