The 30th International Conference on Arabidopsis Research (ICAR 2019)

462 / 2019-02-27 01:32:29

Expanding Without Exploding: Modeling the Biomechanics of Pollen Hydration

pollen,modeling,mechanics,hydration,sexual reproduction

Plenary track > Cell Biology

Pollen carries the male gametes to the female to accomplish sexual reproduction in flowering plants. To survive travel, the pollen grain is desiccated to slow metabolism prior to release from the anther. It then rehydrates on the stigma before extending a tube that carries out fertilization. This process involves dramatic changes in both the turgor pressure and cell wall properties of the pollen. A significant amount of study has been conducted on pollen tube growth mechanics; however, little is known about the mechanics of the prior hydration step. Considering the importance of pollen success for plant survival, it is crucial to understand the mechanisms through which it tolerates these forces. Here we examine two main forces that pollen experience: hydrostatic pressure and cell wall expansion. First, we combine mathematical modeling with experimental data to elucidate the role of a membrane-bound, pollen-specific mechanosensitive ion channel (MSL8) during hydration which is previously shown to be essential for pollen survival during hydration. Current model predictions and preliminary experimental data suggest that MSL8 is required for pollen to recover from over-swelling upon hydration with water. Second, we are using Atomic Force Microscopy, Finite Element Modeling, and a series of Arabidopsis cell wall mutants to understand the changes in cell wall thickness and stiffness that guide shape change through hydration. The results of these experiments will be presented.