Molecular and functional analysis of the mechanism driving cytoplasmic streaming in Arabidopsis thaliana

• Applicant: Professor Dr. Martin Hülskamp
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 386855441

Cytoplasmic streaming is important to distribute intracellular compounds or for their strategic positioning in the cell. In plants, cytoplasmic streaming is governed by myosins. Three types of principles have been discussed: the mobilization of each cellular compound through specific interactions with myosins, the mobilization of few organelles/RNPs and comobilization of others by association and stirring of the liquid phase by some organelles/RNPs. To address this, we have expressed myosins fused to specific anchors in an Arabidopsis mutant (mya1 mya2 xi-k) that exhibits virtually no cytoplasmic streaming. Mutant myosin lines expressing myosin-anchor proteins but not lines expressing the negative control carrying an YFP-YFP instead of an anchor show growth rescue. We propose to use these lines to study the ability of different organelles/RNPs to rescue cytoplasmic streaming. In addition we will assess the biological significance of the movement of different organelles/RNPs by studying the rescue of the cell morphogenesis phenotypes, the rescue of the organization of the actin cytoskeleton and ROP2 signaling in root hairs in mutant and rescued lines.

• DFG Programme: Research Grants