Dr Chandana Pandey is plant physiologist with an interest in plant interactions with beneficial and/or pathogenic microbes. She completed her PhD in India and moved to Copenhagen University in 2018. Since then, she has worked at the UoC initially as a Postdoctoral researcher and now as an Assistant professor. Her work is focused on host-pathogen interactions, disease physiology, varietal resistance and integrated disease management of cereal diseases including net blotch and powdery mildew. She uses molecular, biochemical and cell-physiological approaches that combine with non-invasive high-throughput phenotyping techniques to elucidate the underlying physiological mechanisms and regulatory networks and to establish cost efficient and robust predictors for yield and quality of crop plants.
The external phenotype of a plant is determined by the sum of interactions of metabolism and regulation that mirror the internal, biochemical and molecular phenotype. For a holistic understanding of pathogen resistance, these various scales of interactions should be considered, and genotyping and image-based phenotyping must be linked to the physiology at the cellular and tissue level (1). The pathogen response of barley genotypes differing in their resistance to two fungal pathogens, the obligate biotroph Blumeria graminis and the hemi-biotroph Pyrenophora teres (2), causal agents of powdery mildew and net blotch, were characterized by macro- and microscopic phenotyping using high-throughput multispectral imaging in the automated phenotyping facility PhenoLab and confocal microscopy. Through analysis of reflectance and fluorescence patterns it was possible to relate spatial and temporal dynamics at certain wavelength bands to specific resistance types and compare whole leaf changes with those at the cellular level. The non-invasive phenotyping was complemented with molecular and metabolic fingerprinting via the determination of activity signatures of key enzymes of the carbohydrate and antioxidative metabolism, phytohormone profiles and transcriptomics. Indeed, different resistance mechanisms could be related to distinct temporal dynamics of physiological and molecular responses. By combining drought and pathogen infection we identified the impact of abiotic stress on the immune signaling network by transcriptome and phytohormones analysis. This is a proof-of-concept study to show the potential of a holistic functional phenomics approach by complementing non-invasive imaging with deep physiological and molecular phenotyping (2). Thus the identification of predictive bio-signatures for barley pathogen resistance based on spectral imaging is combined with a mechanistic verification at the cellular level.