Changes in Ribonuclease Activity of Wheat Plants during Water Stress

RNases from control and water-stressed wheat seedlings were purified by ion exchange chromatography, gel filtration and gel electrophoresis. The enzyme appeared to be identical from both treatments and only one species was found. Subcellular distribution between soluble and particulate fractions was not changed by water stress treatment. Total quantity of RNase per plant was similar in control and water-stressed plants, although since the dry weight of treated plants was less, the activity per gram was significantly higher. Crude homogenates of leaf extracts contained an RNase inhibitor with a greater amount being present in control leaves. No evidence was found to indicate that new types of RNases are synthesized during water stress.