Publikationen in Druck
Schulze, A.; Zimmer, M.; Mielke, S.; Stellmach, H.; Melnyk, C. W.; Hause, B.; Gasperini, D. Shoot-to-root translocation of the jasmonate precursor 12-oxo-phytodienoic acid (OPDA) coordinates plant growth responses following tissue damage bioRxiv (2019) DOI: 10.1101/517193
Multicellular organisms rely upon the movement of signaling molecules across cells, tissues and organs to communicate among distal sites. In plants, herbivorous insects, necrotrophic pathogens and mechanical wounding stimulate the activation of the jasmonate (JA) pathway, which in turn triggers the transcriptional changes necessary to protect plants against those challenges, often at the expense of growth. Although previous evidence indicated that JA species can translocate from damaged into distal sites, the identity of the mobile compound(s), the tissues through which they translocate and the consequences of their relocation remain unknown. Here, we demonstrated that endogenous JA species generated after shoot injury translocate to unharmed roots via the phloem vascular tissue in Arabidopsis thaliana. By wounding wild-type shoots of chimeric plants and by quantifying the relocating compounds from their JA-deficient roots, we uncovered that the JA-Ile precursor 12-oxo-phytodienoic acid (OPDA) is a mobile JA species. Our data also showed that OPDA is a primary mobile compound relocating to roots where, upon conversion to the bioactive hormone, it induces JA-mediated gene expression and root growth inhibition. Collectively, our findings reveal the existence of long-distance transport of endogenous OPDA which serves as a communication molecule to coordinate shoot-to-root responses, and highlight the importance of a controlled distribution of JA species among organs during plant stress acclimation.
Publikationen in Druck
Anwer, U.; Davis, A.; Davis, S. J.; Quint, M. Photoperiod sensing of the circadian clock is controlled by ELF3 and GI BioRxiv (2018) DOI: 10.1101/321794
ELF3 and GI are two important components of the Arabidopsis circadian
clock. They are not only essential for the oscillator function but are
also pivotal in mediating light inputs to the oscillator. Lack of either
results in a defective oscillator causing severely compromised output
pathways, such as photoperiodic flowering and hypocotyl elongation.
Although single loss of function mutants of ELF3 and GI have been
well-studied, their genetic interaction remains unclear. We generated an
elf3 gi double mutant to study their genetic relationship in
clock-controlled growth and phase transition phenotypes. We found that
ELF3 and GI repress growth during the night and the day, respectively.
We also provide evidence that ELF3, for which so far only a growth
inhibitory role has been reported, can also act as a growth promoter
under certain conditions. Finally, circadian clock assays revealed that
ELF3 and GI are essential Zeitnehmers that enable the oscillator to
synchronize the endogenous cellular mechanisms to external environmental
signals. In their absence, the circadian oscillator fails to
synchronize to the light-dark cycles even under diurnal conditions.
Consequently, clock-mediated photoperiod-responsive growth and
development is completely lost in plants lacking both genes, suggesting
that ELF3 and GI together convey photoperiod sensing to the central
oscillator. Since ELF3 and GI are conserved across flowering plants and
represent important breeding and domestication targets, our data
highlight the possibility of developing photoperiod-insensitive crops by
manipulating the combination of these two key genes.
Publikationen in Druck
Drost, H.-J.; Gabel, A.; Domazet-Lošo, T.; Quint, M.; Grosse, I. Capturing Evolutionary Signatures in Transcriptomes with myTAI BioRxiv (2016) DOI: 10.1101/051565
Combining transcriptome data of biological processes or response to
stimuli with evolutionary information such as the phylogenetic
conservation of genes or their sequence divergence rates enables the
investigation of evolutionary constraints on these processes or
responses. Such phylotranscriptomic analyses recently unraveled that
mid-developmental transcriptomes of fly, fish, and cress were dominated
by evolutionarily conserved genes and genes under negative selection and
thus recapitulated the developmental hourglass on the transcriptomic
level. Here, we present a protocol for performing phylotranscriptomic
analyses on any biological process of interest. When applying this
protocol, users are capable of detecting different evolutionary
constraints acting on different stages of the biological process of
interest in any species. For each step of the protocol, modular and
easy-to-use open-source software tools are provided, which enable a
broad range of scientists to apply phylotranscriptomic analyses to a
wide spectrum of biological questions.