The influence of signals from chilled roots on the proteome of shoot tissues in rice seedlings.

Low root temperature causes a decrease in water uptake, which leads to mineral and nutrient deficiencies with potentially decreased root and shoot growth. Differential temperature effects in plants have been studied extensively, however, the effect of root chilling on the global protein expression in shoots has not been explored. In this study, we imposed chilling temperatures on roots of rice plants while maintaining shoots at optimum atmospheric temperature. Shoot materials (growing zones and leaves) were harvested at five points over a time course of four days, including a two-day recovery period. Proteins were quantified by tandem mass tags and triple stage MS, using a method developed to overcome ratio compression in isobaric-labelled quantitation. Over 3000 proteins in each of the tissues were quantified by multiple peptides. Proteins significantly differentially expressed as compared with the control included abscisic acid-responsive and drought-associated proteins. The data also contained evidence of a possible induction of a sugar signalling pathway.