Ravi Palanivelu

Assistant Professor of Plant Sciences
Ph.D., University of Georgia

Isolation and characterization of pollen tube guidance signals during plant reproduction.

Research Interests

Long-term goal of my lab is to understand the molecular basis of how cells communicate with each other. We are employing pollen tube guidance during Arabidopsis thaliana reproduction as a model system to achieve this goal. In the immediate future we are focused on identifying and characterizing the guidance signals generated by the A.thaliana pistils to guide pollen tubes to their final target.

A pollen tube's journey to an egg cell within the pistil involves a series of cell-cell interactions such as attraction, repulsion and adhesion. While these processes are likely mediated by several guidance signals, only a handful of guidance signals produced by female tissues have been identified. The guidance of pollen tubes into the ovule micropyle is highly reproducible, resembling the polarized migration of axons, yet sharing few genes in common. My lab is undertaking a multidisciplinary approach-Genetics, Cell biology and Biochemistry-to isolate and characterize these guidance signals in A. thaliana.

Characterization of pollen tube guidance in A. thaliana holds enormous potential as it focuses on a process that is (i) very unique to plants, (ii) poorly understood at the molecular level and (iii) amenable to genetic, cell biological and biochemical techniques and (iv) a rapid way to identify novel plant signals that allow communication between cells possible despite their thick extracellular walls. Additionally, we have recently developed an in vitro pollen tube guidance assay for A. thaliana that monitors both attractive and repulsive interactions between pollen tubes and ovules, processes normally difficult to discern by virtue of them occurring within opaque pistils. These attributes therefore make pollen tube guidance in A. thaliana an ideal model system to study cell-cell interaction in plants.

Select Publications

Any link on the below references will take you off of the BMCB site and to an abstract of that particular paper.

Qin Y, Leydon AR, Manziello A, Pandey R, Mount D, Denic S, Vasic B, Johnson MA and Palanivelu R. (2009). Penetration of the stigma and style elicits a novel transcriptome in pollen tubes identifying genes critical for growth in a pistil. PLoS Genetics, 5 (8): e1000621.

Geitmann, A. and Palanivelu, R.. Dec 2007. Fertilization Requires Communication: Signal Generation and Perception During Pollen Tube Guidance. Floriculture and Ornamental Biotechnology, 1 (2):77-89

Nikolova, N*., Palanivelu, R*., King, E., Copenhaver, G., and Drews, G. N. (*equally contributing authors). Aug 2007. Synergid cell death in Arabidopsis is triggered following direct interaction with the pollen tube. Plant Physiology, 144 (4):1753-1762

Palanivelu, R. and Preuss, D.. Apr 2006. Distinct short-range ovule signals attract or repel Arabidopsis thaliana pollen tubes in vitro. BioMedCentral Plant Biology, 6:7

Palanivelu, R., Brass, L., Edlund, A. and Preuss, D. Jul 2003. Pollen tube growth and guidance is regulated by POP2, an Arabidopsis gene that controls GABA levels. Cell, 114:47-59:47-59

Contact Information

Mailing:
Ravi Palanivelu , Assistant Professor
Department of Plant Sciences
University of Arizona
1140 E. South Campus Dr.
Forbes 303
Tucson, AZ 85721-0106

Telephone:
520-626-2229 (Office)

Email:

rpalaniv@ag.arizona.edu

Please e-mail any comments to:
bmcb@email.arizona.edu