Metabolic changes in iron‐deficient apple seedlings

Abstract

Metabolic changes in Fe‐deficient apple seedlings were investigated. Apple seedlings released reducing compounds into the root environment and reduced Fe³⁺ when set into an agar FE‐EDTA plus BPDS (batho‐phenanthroline disulfonate) mixture. Reduction of Fe was clearly visible as a red color around the root‐zone. Leakage from the root was also demonstrated by pH changes and increased electrical conductivity. Iron‐deficient plants had chlorotic leaves, photosynthesis (Pn) was decreased, sugar content was lower but acid content was higher throughout the entire plant. Succinic, malic and citric acids were all increased in the leaves that developed under Fe‐stress conditions, compared to pre‐stressed levels.. The reason for the increase in acid content was not apparent but it helps to explain the leakage of reducing compounds from the roots of Fe‐deficient plants.

Key words:

• Halus domestica Borkh.
• photosynthates
• root reduction
• sugars