1. Cold-light interaction in Arabidopsis cold acclimation: ontogenic and phyllotactic perspective
Supervisor: prof. RNDr. Břetislav Brzobohatý, CSc.
Consultant: Mgr. Jan Novák, Ph.D.
Keywords: cold acclimation, light, frost tolerance, multifactorial stress, signaling pathways, plant hormones, phyllotaxy, ontogenesis, Arabidopsis thaliana, transcriptomics, proteomics, metabolomics, lipidomics
Knowledge of mechanisms controlling plant acclimation to cold is of high importance because of recent raise of abundance of temperature extremes. We will use a suite of omics approaches to get a deeper insight into the subject. As light intensity is often low during cold acclimation and thus represents an additional stress factor, we will compare cold responses in Arabidopsis thaliana exposed to standard and low light intensities. To address roles of phyllotaxy and ontogenesis, the cold responses will be analyzed in leaves 6 and 14 when their cells are completing cell proliferation stage and in leaf 6 when its cells complete cell expansion and differentiation stage. Molecular networks governing leaf responses to the stress treatments will be revealed. Relative physiological significance of key nodes of the networks will be assessed by genetic and pharmacological approaches.
To judge effects of the stress treatments on plant fitness and frost tolerance, we will evaluate immediate plant recovery under standard conditions and recovery following an intervening frost period.
2. Biological control in plant adaptation to biotic and abiotic stress
Supervisor: prof. RNDr. Břetislav Brzobohatý, CSc.
Consultant: Mgr. Martin Černý, Ph.D.
Biological control is an environmentally friendly approach to improving crop plants' resistance and mitigating pest effects through the use of a wide variety of biological control agents. Biological control relies on natural mechanisms, including among others predation, parasitism or herbivory. Further, it has been shown that besides pest protection, the biotic interaction between plants and a biological agent may promote plants' growth. The main objective of this PhD project is the evaluation of biological agents effects on plant resistance to abiotic stressors and biotic stress effectors. The first part will predominantly employ the established model interaction between Arabidopsis and endophytic fungi Acremonium. The resistance stress will be evaluated on the physiological and molecular level, including proteomics, metabolomics, lipidomics, hormonomics and transcriptomics. Based on the obtained results, the next experiment will be extended to crop plants or alternative biological agents (oomycete, bacteria).
3. Heat shock proteins and their role in plant signalling and biotic interactions
Supervisor: prof. RNDr. Břetislav Brzobohatý, CSc.
Consultant: Mgr. Martin Černý, Ph.D.
HSPs were first discovered in the heat shock response, but the accumulated evidence indicates that these proteins are involved in diverse processes. Besides their chaperon functions, HSPs may also participate in signalling cascades and protein-protein interactions.
It has been demonstrated that HSP90 and HSP70 play an essential role in plant defence signal transduction pathways and that a mutation in HSP genes may increase susceptibility to pathogens and our previous analyses have revealed a putative role of HSP proteins in plant hormone cytokinin signalling and plant interaction with Plasmodiophora brassicae. The main objective of this PhD project is the validation of these roles in a model plant Arabidopsis. Several independent techniques will be harnessed to shed light into the role of HSPs in signalling and plant resistance. We will employ mutant and transgenic lines, protein engineering and recombinant protein expression, interactomics, and proteomics and metabolomics.
