Plant Biotechnology
Research
Calcium signalling during hypoxia
Calcium is an important second messenger in diverse processes within the cell. This also applies to hypoxic stress, which is accompanied by a rapid influx of calcium ions. In our group, we investigate how calcium-dependent proteins participate during hypoxia signalling, e.g. by regulating crucial transcription factors.
Mitochondrial retrograde signalling under hypoxia
The first cell compartment affected by hypoxia is the mitochondrion since oxygen serves as the final electron acceptor in the mitochondrial electron transport chain. Thus, oxygen deficiency leads to a rapid drop in the cellular ATP level and a subsequent energy crisis. To allow metabolic adjustment to hypoxia, communication between mitochondrion and nucleus, the so-called mitochondrial retrograde signalling is required. We are investigating early-acting transcription factors under hypoxia which are activated by a mitochondrial signal.
Integration of hypoxia signalling pathways
Hypoxia is a huge threat to the plant’s survival due to inducing a severe energy crisis. Therefore, plants need to sense hypoxia rapidly through initiating transcriptional reprogramming regulated by the ERFVII family. We are investigating repressors of ERFVII factors which are redox-controlled and which act as entry point for multiple signals produced under hypoxia.
Prolyl hydroxylation in hypoxia response
Prolyl hydroxylases (PHDs) are involved in hypoxia sensing in human by catalysing an oxygen-dependent key-step in the degradation of transcription factors responsible for adaptation to hypoxia. While this process is well understood in human, the function of plant PHD homologues (P4Hs) is yet to be characterized. Plants activate hypoxia responses through transcription factors of the ERFVII family. We are currently investigating the link between hypoxia, P4Hs and ERFVII factors in planta.
Priming
Plants are exposed to various biotic and abiotic stresses during their lifetime. The ability to memorize past stress events has crystallized as one important aspect to allow sufficient stress responses in order to survive critical situations. Through priming by a first stress, a plant can be capable to respond faster and stronger to a recurring stress, thus, exhibiting a higher tolerance. We would like to understand the mechanisms of priming and stress memory in the context of flooding stress in the important crop plant Hordeum vulgare (barley).