Methods for Elucidation of Plant Senescence in Response to C/N-Nutrient Balance

Carbon (C) and nitrogen (N) are essential elements for metabolism, and the ratio of C to N availability is called the C/N balance. C/N balance is very important for plant growth, but little is known about the detailed mechanisms of plant C/N responses. Previously a method of treating Arabidopsis plants with sugar-supplemented medium for studying C/N responses at early post-germinative growth stages has been developed. This method, however, cannot be used to determine physiological C/N effects in plants of mature growth stages, including senescence. Here we present two methods of analyzing responses to C/N treatments in senescing plants: transient C/N treatment with liquid medium and long-term C/N treatment with elevated atmospheric CO₂.