April 23, 2012

I love plants. I support our local botanical garden, I’ve been a vegetarian for almost 17 years, and I talk to (and hug) our yard’s new trees to welcome them to the family. Clearly I’m pro-plants. So why aren’t there more plant cell biology pictures on my blog? I have no excuses. Today, enjoy this lovely image from Arabidopsis, the go-to model plant in cell biology.

Rapid growth in a developing organism can provide challenges for the tissue, especially in tissues where the cells adhere to each other as they do in plants. In a developing plant, this rapid growth combined with differences in cell growth throughout the tissue causes mechanical strain and stress on the cells. A recent paper describes how katanin, a microtubule severing protein, is key in allowing the cells to respond to mechanical stress in the plant Arabidopsis. In this paper, Uyttewaal and colleagues imaged cell growth the in the plant’s stem cell niche, the shoot apical meristem, and found heterogeneity in the cell growth rates. Katanin mutants, however, had decreased growth variability in this same tissue. In normal plants, cortical microtubule arrays arrange themselves toward the regions of high mechanical stress, and this in turn affects growth. Uyttewaal and colleagues found that this directional arrangement of microtubule arrays is affected in katanin mutants, as seen in the images above. Images show shoot apical meristem tissue with microtubule arrays fluorescently tagged in green and their orientation marked in red. Microtubule arrays in wild type tissue (left) have a circumferential orientation in the peripheral zone (bottom, zoomed), while microtubule arrays in katanin mutants lacked a similar pattern (right images).

Uyttewaal, M., Burian, A., Alim, K., Landrein, B., Borowska-Wykręt, D., Dedieu, A., Peaucelle, A., Ludynia, M., Traas, J., Boudaoud, A., Kwiatkowska, D., & Hamant, O. (2012). Mechanical Stress Acts via Katanin to Amplify Differences in Growth Rate between Adjacent Cells in Arabidopsis Cell, 149 (2), 439-451 DOI: 10.1016/j.cell.2012.02.048
Copyright ©2012 Elsevier Ltd. All rights reserved.