title: Massively Parallelized Pollen Tube Guidance and Mechanical Measurements on a Lab-on-a-Chip Platform.
abstract: Pollen tubes are used as a model in the study of plant morphogenesis, cellular differentiation, cell wall biochemistry, biomechanics, and intra- and intercellular signaling. For a "systems-understanding" of the bio-chemo-mechanics of tip-polarized growth in pollen tubes, the need for a versatile, experimental assay platform for quantitative data collection and analysis is critical. We introduce a Lab-on-a-Chip (LoC) concept for high-throughput pollen germination and pollen tube guidance for parallelized optical and mechanical measurements. The LoC localizes a large number of growing pollen tubes on a single plane of focus with unidirectional tip-growth, enabling high-resolution quantitative microscopy. This species-independent LoC platform can be integrated with micro-/nano-indentation systems, such as the cellular force microscope (CFM) or the atomic force microscope (AFM), allowing for rapid measurements of cell wall stiffness of growing tubes. As a demonstrative example, we show the growth and directional guidance of hundreds of lily (Lilium longiflorum) and Arabidopsis (Arabidopsis thaliana) pollen tubes on a single LoC microscopy slide. Combining the LoC with the CFM, we characterized the cell wall stiffness of lily pollen tubes. Using the stiffness statistics and finite-element-method (FEM)-based approaches, we computed an effective range of the linear elastic moduli of the cell wall spanning the variability space of physiological parameters including internal turgor, cell wall thickness, and tube diameter. We propose the LoC device as a versatile and high-throughput phenomics platform for plant reproductive and development biology using the pollen tube as a model.
authors.affiliation: Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland.
authors.forename: Naveen
authors.identifier: http://orcid.org/0000-0002-2819-2687
authors.initials: N
authors.lastname: Shamsudhin
authors.affiliation: Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland.
authors.forename: Nino
authors.initials: N
authors.lastname: Laeubli
authors.affiliation: Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland.
authors.forename: Huseyin Baris
authors.initials: HB
authors.lastname: Atakan
authors.affiliation: Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.|Zurich-Basel Plant Science Center, Zurich, Switzerland.
authors.forename: Hannes
authors.initials: H
authors.lastname: Vogler
authors.affiliation: Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland.
authors.forename: Chengzhi
authors.initials: C
authors.lastname: Hu
authors.affiliation: IBM Research - Zurich, Switzerland.
authors.forename: Walter
authors.initials: W
authors.lastname: Haeberle
authors.affiliation: IBM Research - Zurich, Switzerland.
authors.forename: Abu
authors.initials: A
authors.lastname: Sebastian
authors.affiliation: Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.|Zurich-Basel Plant Science Center, Zurich, Switzerland.
authors.forename: Ueli
authors.initials: U
authors.lastname: Grossniklaus
authors.affiliation: Multi-Scale Robotics Lab, ETH Zurich, Zurich, Switzerland.
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Nelson
mesh_terms: D002473:Cell Wall / Q000502:physiology*; D055119:Elastic Modulus; D056656:Lab-On-A-Chip Devices; D027762:Lilium / Q000502:physiology*; D053205:Pollen Tube / Q000254:growth & development*; D054817:Pollination / Q000502:physiology