Stress Affects Plant Growth and Development Patterns

Developmental pattern of plant parts depends on localized growth, which is controlled by the plant hormone auxin, and directional growth governed by the cells' microtubule cytoskeleton. However, Marcus Heisler of the California Institute of Technology and colleagues observed that when the cell walls of Arabidopsis thaliana are agitated mechanically, the orientation of shoot tip microtubules shows a corresponding stress pattern. To check if stress affects the clustering of auxin export protein (PIN1), the researchers applied isoxaben to Arabidopsis to weaken cell walls through inhibition of cellulose synthesis.

Results confirmed that mechanical stress affects the orientation of PIN1. Through mathematical modeling, the researchers revealed than an auxin transport system coordinated by mechanical signals similar to those observed in living samples is enough to derive the patterns of organ outgrowth in Arabidopsis. It would also be interesting to explore on other potential functions of mechanical signaling in normal growth and development as well as wound repair.

Read the full article released by PLoS Biology journal at http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000516.