Transient Inhibition of Translocation in Ipomoea alba L. by Small Temperature Reductions

Abstract

The response of translocation in I. alba to stepwise heating and cooling of 80-mm segments of stem was studied by pulse labelling with naturally loaded 11C. Translocation was indifferent to positive- going temperature steps within its normal physiological range; it was, however, momentarily disrupted by negative-going steps, even as small as that from 27.1°C to 21.4°C, i.e. 5.7°C.