Shoot phenotyping of cytokinin receptors mutants revealed fluorescence parameters as early markers of drought stress

Plant phenotyping represents an increasing promise in plant research by providing a complex picture of plant development and fitness. In research focused on various environmental stresses, phenotyping can uncover markers that can sensitively assess the stress impact in very early stages before morphological changes. PlantScreenTM System represents a tool dedicated for shoot and root phenotyping in soil enabling high-precision, high-throughput phenotyping of small, mid-size and large plants. The system offers wide range of sensors providing the number of non-invasive analyses of morphological and physiological parameters as well as of pigments, water, or metabolite content. In our work, we combined phenotyping approaches to determine morphological changes and the status of the photosynthetic apparatus in Arabidopsis plants exposed to drought stress. Focused on morphology, the rosette area became smaller after seven days of drought stress when compared to control conditions. Interestingly, cytokinin signalling mutant ahk2 ahk3 revealed drought resistance compared to other genotypes. The fluorescent parameters showed higher sensitivity even in wild type. Non-photochemical quenching displayed values connected to reduced activity of photosynthetic apparatus after five days of drought stress. Taken together, acquired fluorescence parameters can serve as a marker of drought stress detection before morphological alterations occur. HighlightFluorescence parameters can serve as early markers of drought stress before morphological alterations appear. Shoot phenotyping of cytokinin receptor mutants showed drought resistance in the ahk2 ahk3 double mutant.