Monday, November 5, 2007
103-8
Remote sensing of Phosphorus Deficiency in Legume-Grass Cover Crops.
Jeffrey Ball, Jagadeesh Mosali, and Billy Cook. The Samuel Roberts Noble Foundation, The Noble Foundation, PO Box 2180, Ardmore, OK 73402-2180
In many agricultural production systems, P has been identified as the most deficient essential nutrient after nitrogen (N). Without a sufficient supply of phosphorus, plant growth is severely inhibited, leading to significant crop yield loss. Even though the average is 21 kg ha-1 for cereals, these inputs may become excessive where there were already high levels of soil P leading to many environmental concerns, especially pollution issues. To address this problem, we need to develop an early-detection system using genetically engineered plants designed to report the soil phosphorus availability in the field. These “phosphate-smart” plants will serve as an early-warning system for farmers to implement appropriate fertilization programs before phosphorus levels become limiting to crop growth, thereby increasing crop yield, and, at the same time, optimizing the use of phosphate-based fertilizer, thus reducing the negative impact of over-fertilization on the environment. One criteria is that the sensor is specifically turned on by phosphate starvation, but not by deficiencies in other nutrients. The other component is a reporter gene that triggers detectable signals when turned on. The inducibility of the At4 promoter by phosphorus starvation has been tested in the model plant Arabidopsis thaliana. Noble Foundation is now in the process of generating genetically engineered forage crops to integrate these reporter gene constructs.