Phosphate Accumulation in Plants: Signaling

The availability of mineral nutrients is vital for plant growth and survival, and, as such, plants have evolved elaborate mechanisms to maximize the sequestering and uptake of scarce minerals. This is especially true in the case of phosphorus (P), which, when limiting, induces changes in root architecture to aid in the uptake of this mineral nutrient. How this limiting condition is sensed and propagated in the plant is of much interest. The elucidation of the signaling pathway is the focus of two articles, from independent labs, published in the July 2006 issue: Aung et al. (2006), ‘‘pho2, a Phosphate Overaccumulator, Is Caused by a Nonsense Mutation in a MicroRNA399 Target Gene’’; and Bari et al. (2006), ‘‘PHO2, MicroRNA399, and PHR1 Define a PhosphateSignaling Pathway in Plants.’’