Tobias Baskin
Professor
Lab 375
Education
B.Sc., Yale, 1980
Ph.D., Stanford University, 1986
Postdoctoral:
University of California, Berkeley 1987-1990
Australian National University, 1990-1992
Professional Bio and Publications
Research Interests:
Regulation of Plant Morphogenesis During Growth & Development
Plant forms have long delighted artists and naturalists with their variety and beauty. These forms arise through morphogenesis in a process that depends on growth. Cells specify their growth rates in each spatial dimension and these rates are usually different from one another, that is, the growth of plant cells is anisotropic. To build an organ with a defined shape, the plant must control precisely the direction of maximal expansion and the magnitude of expansion anisotropy. Understanding the mechanisms whereby plant cells govern growth anisotropy is the crux of my research.
To unearth these mechanisms I am digging in three types of terrain. The first is to understand how cell division and expansion are regulated coordinately. Cell division supplies the plant with building blocks whereas cell expansion determines the shape of the blocks and hence of the whole structure. These processes must be coordinated precisely for morphogenesis to succeed, but those interested in division have typically ignored expansion, and vice versa. My laboratory is quantifying the spatial profiles of cell expansion and division at high spatio-temporal resolution and studying how these change in different environments or in different genetic backgrounds. As part of this effort, I collaborated with a computer scientist to develop a novel image processing routine allowing growth profiles to be measured algorithmically.
The second terrain is the role of the cytoskeleton in regulating anisotropic expansion. For years, the cytoskeleton has been known to be important for morphogenesis by virtue of the aberrant morphology that results when the cytoskeleton is disrupted by chemical inhibitors. But how does the cytoskeleton act? This question requires more than inhibitors to answer. My laboratory has isolated mutants of arabidopsis in which root morphology is aberrant and we are using those to identify proteins that make up the pathway for the control of organ shape. Additionally, we have designed a novel in vitro assay specifically for cortical microtubules, where there behavior can be studied readily and the function of putative players tested directly.
The third terrain is the cell wall, the ultimate regulator of cell and organ shape. Cells can expand anisotropically only when the cell wall is mechanically anisotropic. The mechanical anisotropy is provided by cellulose microfibrils, long polymers of glucose crystallized into microfibrils with the tensile strength of steel; however, it is not known how cellulose alignment is controlled. In addition to the mutational approach mentioned above, my laboratory uses several approaches to study the ultrastructure of the cell wall, including quantitative polarized-light microscopy, field-emission scanning electron microscopy, and atomic force microscopy. The overall goal here is to uncover how anisotropic wall yielding is conditioned by the structural elements of the cell wall.
Representative Publications:
Li P, Yu Q, Gu X, Xu C, Qi S, Wang H, Zhong F, Baskin TI, Rahman A, Wu S (2018) Construction of a functional Casparian strip in non-endodermal lineages is orchestrated by two parallel signaling systems in Arabidopsis thaliana. Current Biology 28: 2777-2786.
Edwards J, Laskowski M, Baskin TI, Mitchell N, DeMeo B (2019) The role of water in fast plant movements. Integrative and Comparative Biology 59: 1525 - 1534. [Editor’s choice].
Baskin TI, Preston S, Zelinsky E, Yang X, Elmali M, Bellos D, Wells DM, Bennett MJ (2020) Positioning the root elongation zone is saltatory and receives input from the shoot. iScience 23, 101309.
Ufuktepe DK, Palaniappan K, Elmali M, Baskin TI (2020) RTip: A fully automated root tip tracker for measuring plant growth with intermittent perturbation. 2020 IEEE International Conference on Image Processing (ICIP), Abu Dhabi, United Arab Emirates, pp. 2516-2520, doi: 10.1109/ICIP40778.2020.9191008.
Zimmermann MJ, Bose, J, Kramer EM, Atkin OK, Tyerman SD, Baskin TI (2022) Oxygen uptake rates have contrasting responses to temperature in the root meristem and elongation zone. Physiologia Plantarum, 174: e13682.
Stoynova-Bakalova EZ, Bakalov DV, Baskin TI (2022) Ethylene represses the promoting influence of cytokinin on cell division and expansion of cotyledons in etiolated Arabidopsis thaliana seedlings. PeerJ, 10:e14315 DOI 10.7717/peerj.14315.
Laskowski MJ, Tiley HC, Fang Y, Epstein A, Fu Y, Ramos R, Drummond TJ, Heidstra R, Bhakhri P, Baskin TI, Leyser O (2022) The miR156 juvenility factor & PLETHORA 2 form a regulatory network and influence timing of meristem growth and lateral root emergence. Development, 149, dev199871 doi:10.1242/dev.199871.
Lehman TA, Rosas MA, Brew Appiah RAT, Solanki S, York ZB, Dannay R, Wu Y, Roalson EH, Zheng P, Main D, Baskin TI, Sanguinet KA (2023) BUZZ: an essential gene for post-initiation root hair growth and a mediator of root architecture in Brachypodium distachyon. New Phytologist, 239: 1723 - 1739 doi: 10.1111/nph.19079.
Saffer AM, Baskin TI, Verma A, Stanislas T, Oldenbourg R, Irish VF (2023) Cellulose assembles into helical bundles of uniform handedness in cell walls with abnormal pectin composition. The Plant Journal, 116: 855 - 870. doi: 10.1111/tpj.16414.
Zimmermann MJ, Jathar VD, Baskin TI (2024) Thermomorphogenesis of the Arabidopsis thaliana root: Flexible cell division, constrained elongation, and the role of cryptochrome. Plant & Cell Physiology, in press.