Abstract
Rice seedlings were exposed to cold (5°C) at a relative humidity of 100 % for 24 h and a subtracted CDNA Iibrary was constructed. Six clones isolated by differential screening of the subtracted cDNs library were designated as RC (responsive to cold) clones. Increase of RNA Ievel detected with these cDNA probes was observed within 3 h under cold treatment. Thereafter the RNA Ievel either remained high or decreased during the initial two days of cold treatment. Reincubation of plants at 28 °C following the 5 °Ctreatuent caused a rapid decrease of RNA Ievels detected with all the clones. RNAS detected with four of the RC clones (RC42, RCI04, RC114, RC235) were also accumulated when seedlings were subjected to drought, abscisic acid (ABA) and NaCl treatlnents. However, accumulation of RNAs detected with two of the RC clones (RC167 and RC179) under these stress treatments was not observed, suggesting the existence of a specific pathway that is generated only by cold treatment, but not by other stresses. Examination of chilling injury and cold-induced accumulation of these RNAs in 22 rice varieties using four cDNA probes suggests that the accumulation of RC167 and RC235 mRNAs was associated with chilling sensitivity.
