Influence of glutamic acid and 2,2′-Dipyridyl on the protochlorophyllide and protoporphyrin IX accumulation and their photodynamic action in green monocotyledons and dicotyledons

Abstract

The influence of δ-aminolevulinic acid (ALA), glutamic acid (Glu) and 2,2′-dipyridyi (2,2′-DP) on the accumulation of the tetrapyrrole precursors of the chlorophyll (Chl) synthesis in wheat, oats, mustard and bean plants has been investigated. The photodynamic reaction that occurs after the treatment was studied as an effect of accumulated tetrapyrroles. The photodynamic damage of the sensitive plants, treated with Glu and 2,2′-DP, is caused by tetrapyrroles, which accumulate after 17h in the dark period, followed by 24 h of irradiation with white light. The effect of accumulated Chl precursors is accompanied by changes in the water content, proteins, chlorophyll and carotenoids in the treated leaves. Parallel analyses were made on the specific action of ALA and 2,2′-DP as well as Glu and 2,2′-DP treatment in dependence of the sensitivity and the pathway of precursor synthesis in the different plants. The molecular nature of the specific photodynamic sensitivity of the different plants under the influence of 2,2′-DP and the precursors that were used is estimated in respect to the suggestion that accumulated tetrapyrroles are necessary, but they are not the only reason for photodynamic damage of the plants. The degree of leaf damage is related to the amount and chemical nature of accumulated tetrapyrroles, and the greening group to which the investigated plants belong.