THE EFFECT OF CHILLING MAIZE SHOOTS AND ROOTS ON THE ELECTRIC-POTENTIAL, COMPOSITION OF FATTY-ACIDS AND THE ATPASE ACTIVITY IN THE NON-CHILLED ORGANS OF SEEDLINGS

The effect of separate chilling (5 degrees C for 2 and 4 days) on the shoots and roots of two maize hybrid seedlings on the electric potenti al, the composition of fatty acids and the ATPase activity in the micr osomes of non-chilled leaves and roots (20 degrees C) was investigated . It has been found that the low temperatures induced on the non-chill ed organs gave similar changes to organs exposed to a reduced temperat ure. The changes consisted of a parallel depolarization of leaf and ro ot membranes and similarly a decrease in the ATPase activity as well a s changes in the unsaturation of the membranes' fatty acids. The reduc tion of the acid content 18:2 was particularly significant, which in t he leaf microsomes correlated with a drop in the ATPase activity. The similarity between the reactions of the chilled and non-chilled parts of the plant gives evidence of a 'communication' between the organs wh ich may facilitate a coordinated reaction of the entire organism to st ress. The background for these phenomena could be the action potential of the chilled parts of seedlings which, in the non-chilled pacts, mi ght produce changes in the structure of biomembranes and in the activi ty of enzymes.