Molecular Stress Physiology

The department focuses on the analysis of the physiological and metabolic responses of crops to abiotic stress and how the knowledge gained from these studies can be employed to enhance the tolerance of such crops to stressful conditions. Translational approaches (from model species to crops, from crop to crop) will form a constitutional basis of the research conducted by the group.
One of the research lines followed by the Department is identification and characterization of genes involved in modulating oxidative stress responses and reactive oxygen species (ROS)-induced programmed cell death. Recently, a team lead by Prof. Dr. T. Gechev identified a novel plant-specific gene that regulates the tolerance to oxidative and abiotic stresses (Sujeeth et al. 2021). As this gene has homologs in major crops, this finding may have an impact on the management of stress tolerance in crop species and increasing their productivity under unfavorable environmental conditions.

Another research direction studied in the department is a process known as molecular priming: natural products and synthetic chemicals that can protect model and crop plants against abiotic and oxidative stresses through induction of molecular and physiological defense mechanisms (Kerchev et al. 2020). In addition to their stress-protective effect, some of these compounds can also stimulate plant growth. Using an array of “-omics” approaches, including RNA-seq analysis, GC-MS and LC-MS metabolomics, and lipidomics, Dr. Gechev’s team has identified genes, metabolites, and biochemical pathways with a possible role in the molecular priming induced by a biostimulant and is aiming at functionally validating some of these genes Rasul et al. 2021; Staykov et al. 2021; Omidbakhshfard et al. 2020).

Fig. 1. Principle of plant defense activation by priming. Treatment with priming agents (left) induces endogenous plant defense mechanisms (middle), leading to subsequent stress tolerance in the primed plants. Agrochemicals are predominantly applied as a uniform spray solution (broadcast application) that can easily result in chemical waste, excessive carryovers, and damage to the vegetation. In contrast, directed application targets individual plants. Technological advances, such as computer vision and machine learning, make directed application more efficient than ever. Specific spraying of individual plants allows reduction of the dosage that can eliminate up to 90% of the used chemical and mitigate its environmental impact. Another exciting technology that will soon be available to the farmers combines agrochemicals with nanobodies as formulation agents that specifically target leaves or pests, improving retention limiting the input of chemicals for the environment.

A third research focus of Dr. Gechev’s team is the resurrection species Haberlea rhodopensis. This plant is tolerant not only to desiccation but also to other environmental stresses such as long-term darkness and low temperatures. The team studies molecular mechanisms of tolerance to these abiotic stresses, using “-omics” technologyes such as transcriptomics, metabolomics, and lipidome analysis (Durgud et al. 2018).