Effect of the light on adenine nucleotide content of georeacting maize roots

Abstract

Apical segments from maize roots of LG 11 and Orla 264 varieties georeacted, at least for the first few hours, only in light, while those of the Anjou 210 variety were georeactive both in light and darkness. The energy charge in the apical end of the two light geo-sensitive (LG and Orla) maize roots significantly increased in the light. In contrast, in Anjou root tips, the energy charge was already high in the dark and did not change significantly after light exposure. The time course of light-induced changes in adenine nucleotide contents in root tips was compared with varietal differences in georeactivity in light and darkness. The present data corroborate the hypothesis that a high energy state in the root tip is a prerequisite for the expression of the root reaction to gravity.

Light and Gravity Effects on Adenine Nucleotide Content and Energy Charge in Maize Roots

“…Root segments, from 0 to 2 mm, were cut and rapidly frozen in liquid nitrogen. Ten lyophilised segments were ground then completed with 7 ml boiling TRIS buffer pH 7.4 (containing MgSO 4 , K 2 SO 4 and EDTA) , Steck and Pilet 1979, Wagner et al 1974). The extraction was performed for lOmin.…”