Sugar signals and molecular networks controlling plant growth.

In recent years, several regulatory systems that link carbon nutrient status to plant growth and development have emerged. In this paper, we discuss the growth promoting functions of the hexokinase (HXK) glucose sensor, the trehalose 6-phosphate (T6P) signal and the Target of Rapamycin (TOR) kinase pathway, and the growth inhibitory function of the SNF1-related Protein Kinase1 (SnRK1) and the C/S1 bZIP transcription factor network. It is crucial that these systems interact closely in regulating growth and in several cases crosstalk has been demonstrated. Importantly, these nutrient controlled systems must interact with other growth regulatory pathways.