The first research project of my lab deals with the investigation of environmental gene regulation in the model plant Arabidopsis (Arabidopsis thaliana), and since 2006, the crop plant rice (Oryza sativa). We identified the hybrid proline-rich protein (HyPRP)-encoding gene EARLI1 and some EARLI1 homologs as stress-responsive genes (to cold, salt, and oxidative stresses). We determined that EARLI1 protects Arabidopsis tissues from freezing-induced cellular damage, suggesting a role in cold acclimation/freezing tolerance. Because the Arabidopsis genome has 25 and the rice genome a minimum of 28 HyPRPs, we are initiating a genomics projects with the goal to identify the tissue- and stress-specific expression pattern of all HyPRP genes in the two plant species. Our hypothesis is that these HyPRPs will cluster into subgroups of co-expressed genes with similar functions in different stress tolerance pathways. Our long-term goal is to use sets of related genes from the HyPRP family to tailor the response of agricultural plants to environmental stresses.
My second research project deals with specific flowering time
genes in Arabidopsis. Through genetic crosses and molecular biology approaches
I have recently identified naturally occurring allelic variations in FRIGIDA-LIKE
1 (FRL1) and FRIGIDA-LIKE 2 (FRL2), two flowering
time regulator genes in Arabidopsis (Schläppi, 2006). At least one
of these genes together with FRIGIDA (FRI) is required to
activate the floral repressor gene FLOWERING LOCUS C (FLC).
Because neither FRI nor FRL proteins have similarities to known transcription
factors, but are predicted to have coiled-coil domains, I hypothesize that
they interact with a transcription factor to form an active regulatory
complex. Indeed, FRI and FRL homologs in rice share a high
degree of similarity with B3-type transcription factor-interacting proteins.
My long-term goal is to identify this transcription factor in Arabidopsis
and rice. This will allow the future identification of its target genes
and contribute to the understanding of flowering-time regulation in the
important crop plant rice.