Russeting in Apple is Initiated after Exposure to Moisture Ends

Molecular and Biochemical Evidence

authored by
Jannis Straube, Yun Hao Chen, Bishnu P. Khanal, Alain Shumbusho, Viktoria Zeisler-Diehl, Kiran Suresh, Lukas Schreiber, Moritz Knoche, Thomas Debener

Exposure of the fruit surface to moisture during early development is causal in russeting of apple (Malus × domestica Borkh.). Moisture exposure results in formation of microcracks and de-creased cuticle thickness. Periderm differentiation begins in the hypodermis, but only after discon-tinuation of moisture exposure. Expressions of selected genes involved in cutin, wax and suberin synthesis were quantified, as were the wax, cutin and suberin compositions. Experiments were con-ducted in two phases. In Phase I (31 days after full bloom) the fruit surface was exposed to moisture for 6 or 12 d. Phase II was after moisture exposure had been discontinued. Unexposed areas on the same fruit served as unexposed controls. During Phase I, cutin and wax synthesis genes were down-regulated only in the moisture-exposed patches. During Phase II, suberin synthesis genes were up-regulated only in the moisture-exposed patches. The expressions of cutin and wax genes in the moisture-exposed patches increased slightly during Phase II, but the levels of expression were much lower than in the control patches. Amounts and compositions of cutin, wax and suberin were con-sistent with the gene expressions. Thus, moisture-induced russet is a two-step process: moisture exposure reduces cutin and wax synthesis, moisture removal triggers suberin synthesis.

Institute of Plant Genetics
Institute of Horticultural Production Systems
Section Molecular Plant Breeding
External Organisation(s)
University of Bonn
No. of pages
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Ecology, Evolution, Behavior and Systematics, Ecology, Plant Science
Electronic version(s) (Access: Open)