Plant biologists uncover genetic controls of birds’ feeding behavior

Sorghum is a globally important crop grown on every inhabited continent. Although it is resistant to many abiotic stressors, like drought, it is extremely vulnerable to predation by birds. Now, scientists have uncovered the segment of the plant’s genome that makes some strains of sorghum resistant to bird predation (Mol. Plant 2019, DOI: 10.1016/j.molp.2019.08.004). The study encompassed 571 lines of sorghum, explains plant molecular biologist Qi Xie of the Institute of Genetics and Developmental Biology at the Chinese Academy of Sciences. Xie noticed that there were certain lines of sorghum that birds seemed to hardly touch, even though they grew next to crops that the birds devoured. By examining the genomes of the various lines, the researchers identified the Tannin1 gene as the locus connected with birds’ feeding behavior. The researchers then analyzed the seed coatings and the volatile organics emitted by the plants and revealed the key difference between the sorghum strains: those that the birds preferred emitted more fatty acid–derived volatiles, while those that birds avoided had high levels of condensed tannins, such as tannic acid. Xie hopes that the study will lead to the use of tannic acid as a low-cost, low-toxicity bird repellent. The team is also working on a breeding program to create more lines of bird-resistant sorghum.