Killing two birds with one stone: transcriptional regulators coordinate development and stress responses in plants.

Plants, being immobile, must adjust development in response to various stresses, external and internal. Although much has been learned about the mechanisms that regulate development and sugar signaling and response, how the two processes are coordinated is poorly understood. GRAS-family transcriptional regulators SHORT-ROOT (SHR) and SCARECROW (SCR) are crucial to radial patterning and stem-cell renewal in the Arabidopsis root. We found that they directly control genes involved not only in development but also in stress responses and that SCR is pivotal in modulating sugar homeostasis and response. Our data suggest that SHR and SCR promote root growth by suppressing the deleterious effects of stress and that ABI4 has a dual role in sugar response and root growth. Other transcriptional regulators have also been reported to play dual roles in plant growth and stress responses. I therefore propose that regulation of both development and stress responses by single transcriptional regulators is a general and efficient mechanism of adaptive response in plants.