Abstract
In an elaborate form of inter-species exploitation, many insects hijack plant development to induce galls—novel plant ‘organs’ resulting from dramatic reprograming of plant cell biology. Insects induce galls by introducing unidentified molecules into plants. Here we identify an aphid gene, determinant of gall color (dgc), that is genetically associated with variation in a gall phenotype, providing the first example of an insect gene implicated in gall development. Dgc encodes a BICYCLE protein, a new family of secreted proteins. Bicycle genes are strongly expressed specifically in galling aphid salivary glands, suggesting they control many aspects of gall development. Bicycle genes have experienced unusually strong diversifying selection, consistent with their potential role controlling gall development in a molecular arms race between aphids and their host plants.
One Sentence Summary Aphid bicycle genes, which encode diverse secreted proteins, contribute to plant gall development.
Competing Interest Statement
HHMI has filed a provisional patent, number 63/092,942, for the inventors AK and DLS covering unique aphid polypeptides for use in modifying plants.