InfoCoBuild

Plant Development

Why We Need to Understand Plant Development: Meyerowitz begins his talk by reminding us of the critical role that plants play in human and global health. Undernutrition is a huge global problem that is only likely to worsen as the world's population grows and global warming reduces arable land and plant yields. To breed for specific traits such as plant size, growth rate or yield, we urgently need to better understand plant biology; this includes the ability to predict the effects of genetic changes on plant traits. Meyerowitz and his collaborators have developed live imaging techniques to record dynamic changes in plant development, including changes in gene expression and protein localization, in response to genetic or environmental intervention.

Modeling Arabidopsis Phyllotaxis: Meyerowitz describes how his lab is using live imaging to study phyllotaxis, the regular positioning of leaves or flowers around the developing apical shoot meristem. The plant hormone auxin has been known for years to induce flower and leaf growth. Meyerowitz and colleagues tracked the concentration of auxin and the auxin transporter protein, and the position of flower growth. Using this information they were able to develop a computer model that accurately reproduced auxin gradients and phyllotactic patterns in the apical meristem. The model also can predict how changing parameters such as rates of auxin diffusion or meristem size, will impact flower patterning.

Physical Force as a Signaling Mechanism: The model described in Part 2 for determing phyllotactic patterning, requires that cells sense the concentration of auxin in neighboring cells. How do they do this? In his last lecture, Meyerowitz presents some fascinating data indicating that increased auxin concentration in a cell causes it to grow and expand, and expansion produces a physical force on neighboring cells. This mechanical force is sensed by cells and causes a redistribution of both microtubules and the auxin transporter forming a positive feedback loop. This is an amazing example of cell morphology influencing cell-cell communication, gene expression, and cell behavior.

Elliot Meyerowitz is the George W. Beadle Professor of Biology at Caltech and a Howard Hughes Medical Institute/ Gordon and Betty Moore Foundation Investigator. (from ibiology.org)

1. Why We Need to Understand Plant Development
Elliot Meyerowitz begins his talk by reminding us of the critical role that plants play in human and global health.

2. Modeling Arabidopsis Phyllotaxis
Elliot Meyerowitz describes how his lab is using live imaging to study phyllotaxis, the regular positioning of leaves or flowers around the developing apical shoot meristem.

3. Physical Force as a Signaling Mechanism
Meyerowitz presents some fascinating data indicating that increased auxin concentration in a cell causes it to grow and expand, and expansion produces a physical force on neighboring cells.