Adenine Nucleotide Changes during Cold Acclimation of Winter Rape Plants.

During the first stage of hardening of winter rape plants (Brassica napus L. var. oleifera L., cv. Górczanski), marked increase of ATP content in leaves was observed. Lowering the temperature from 5 to 0 C (the second stage of hardening) had no further effect on ATP content. In roots, not capable of hardening, pronounced decrease of ATP content was noted after prolonged exposure to cold. It was found that increased ATP content and higher energy charge in cold-treated leaves were due to light and dark processes.