We have previously shown that the acclimation process of roots may be equally important to leaf acclimation for whole plant survival since the uptake of water and mineral nutrients is carried out by the root system (Ahn et al., 1999). In this regard, it is also interesting to note that all the major abiotic stresses such as low as well as high temperatures, drought and salinity result in water stress (Holmberg and Bulow, 1998). In addition, even nutrient stresses such as nitrogen or phosphorus deficiencies decrease hydraulic conductance of the roots (Carvajal et al, 1996). Signals controlling water uptake as one of the acclimation processes upon low temperature treatment have not been studied. Cucumber and figleaf gourd plants as chilling root temperature sensitive and resistant species were used as model systems in the present study. We found that the influx and efflux of calcium in both species upon low root temperature are different and it is suggested that calcium plays an important role as a second messenger in the roots. However, the in-gel kinase assays using bovine myelin basic protein revealed that there are no distinguishable differences in the respective activities. It is inferred that the signals through kinase do exist in both plant species. However, the characteristics of water channel in both species are quite different, i.e. the chilling temperature resistant species appears to have closed water channels by low temperature while the sensitive species does not possess the ability to control water channels.