Special issue in honour of Prof. Reto J. Strasser - Structural and functional response of photosynthetic apparatus of radish plants to iron deficiency

Abstract

In this work, we tried to identify some specific chlorophyll a fluorescence (ChlF) parameters, that could enable detection of iron deficiency (Fedef) in radish plants (Raphanus sativus L.), before any visual symptoms appear. Changes in ChlF kinetics, JIP-test parameters, and chlorophyll content revealed that iron deficiency negatively affected PSII activity mainly via disruption of light absorption in light-harvesting complexes and by decreasing the activity of the primary quinone acceptor of PSII (QA). Iron deficiency was clearly reflected in the changes of some JIP-test parameters, such as time to reach maximal fluorescence (FM), Area, normalized total area under the OJIP curve, and number of QA redox turnovers until FM is reached. The visible symptoms of Fedef appeared after 7 d of stress application, while ChlF measurements allowed us to detect iron deficiency during 1-3 d. Our results suggest that analysis of ChlF signals has a high potential for early detection of iron deficiency in radish plants.

Keywords

• nutrient deficiency
• ojip curves
• photosynthetic efficiency
• plant physiological status
• principal component analysis