Increased Ethylene Production during Clinostat Experiments May Cause Leaf Epinasty

Ethylene production from tomato (Lycopersicum esculentum L. cv. Rutgers) plants based on a clinostat doubled during the first 2 hours of rotation. Carbon dioxide blocked the appearance of leaf epinasty normally associated with plants rotated on a clinostat. These results support the idea that epinasty of clinostated plants was due to increased ethylene production and not to the cancellation of the gravitational pull on auxin transport in the petiole.