Research interests Dr. Mariana Romeiro Motta

Mechanical control of plant development

During plant development, cell division, growth, and differentiation must be coordinated in time and space to ensure robust organ formation. Traditionally, the coordination of these processes has been studied by cell biological, biochemical, and genetic approaches. Long neglected, mechanical signals have unique features and prominence in plant development. For example, mechanical signals typically travel three to six orders of magnitude faster than biochemical signals. Additionally, plant cells experience exceptionally high mechanical loads arising from turgor pressure, enabled by their rigid cell walls. Accordingly, the importance of mechanical signals in orienting the plane of cell division in plants is relatively well established. However, despite the emerging fundamental role of mechanical forces in plant development, how mechanical signals are integrated into cell-cycle regulation remains poorly understood.

A central focus of my research is to understand how mechanical stress (force per unit area) is translated into biochemical signals that control cell cycle progression and morphogenesis. In particular, I am testing the hypothesis that microtubules are key integrators of mechanical and biochemical signals. Microtubules are crucial for both cell division and directional cell growth and are known to respond to mechanical stress. Microtubule organization is also closely coupled to the cell cycle and has been shown to depend on phosphorylation by kinases. Therefore, microtubules may serve as a central interface between mechanical stress, kinase signaling, and morphogenesis. My group investigates how mechanical signals control kinase activity and microtubule organization to coordinate plant growth.

For our studies, we use Arabidopsis thaliana as a model system and combine controlled mechanical perturbations with live-cell imaging, genetic approaches, and biophysical analyses. Our goal is to identify general principles of mechanochemical regulation that allow plants to form functional organs and adapt cell division and growth to physical challenges.

Previous results

• We demonstrated that cyclin-dependent kinase–cyclin complexes containing B-type cyclins control microtubule organization during cell division, including spindle architecture. In this way, cell cycle regulators play a key role in ensuring proper plant development (Romeiro Motta et al., 2022; 2024).
• We demonstrated that the microtubule-associated protein MAP65-1 preferentially recognizes and reinforces microtubules bearing structural signatures of mechanical stress. These findings provide a molecular mechanism by which mechanical stress can be directly coupled to microtubule organization (Romeiro Motta et al., 2025).

Research goals

• We aim to understand how mechanical stress affects cell cycle progression. To address this, we analyze cell cycle dynamics under defined mechanical perturbations in living plant tissues.
• We plan to identify signaling pathways that translate mechanical signals into cell cycle control.
• We further aim to determine how mechanically induced phosphorylation of microtubule-associated proteins influences cell division, growth and thereby tissue growth. Ultimately, this work will define mechanochemical feedback loops that ensure robust morphogenesis at the cellular and tissue levels.

Methods

Confocal live-cell imaging using fluorescent reporters

Quantitative image analysis to follow cell cycle progression and microtubule dynamics

Mechanical perturbations and biophysical measurements

Phosphoproteomics to identify mechanosensitive signaling networks

In vitro microtubule reconstitution and kinase assays