My lab uses pollen tube growth and guidance as a model system to understand the mechanisms of invasive cell growth, guidance of cellular migration, and determination of cellular polarity. We study the fertilization process in flowering plants because the success of this fundamental component of the life cycle depends on a lengthy and precisely guided cellular journey.

Biography

Mark received his B.S. in Biology from Wake Forest University in 1993 and completed his graduate work in Microbiology/Cell and Molecular Biology at the MSU-DOE Plant Research Laboratory at Michigan State University (Ph.D. 2000) where he studied mRNA degradation with Dr. Pamela J. Green. Mark began working on plant reproductive development while he was an NIH Ruth L. Kirchstein National Research Service Award postdoctoral fellow at The University of Chicago with Dr. Daphne Preuss (2000-2004). Mark joined the faculty of Brown University in September of 2004.

Institutions

Michigan State University

Research Description

HOW DO CELLS FIND TARGETS?
I use pollen tube growth and guidance as a model system to understand the mechanisms of invasive cell growth, guidance of cellular migration, and determination of cellular polarity. I study the fertilization process in flowering plants because the success of this fundamental component of the life cycle depends on a lengthy and precisely guided cellular journey. Flowering plants have immotile sperm that must be delivered to female gametes by a pollen tube: a single cell that extends at remarkable growth rates, penetrates floral tissues, and responds to multiple precise and discrete signals that guide its growth. To understand the molecular mechanisms that mediate fertilization, I've taken a genetic approach in Arabidopsis thaliana and have identified a collection of about 30 pollen mutants that define genes involved in each of the critical steps in the pollen tube growth and guidance process. The major goal of my lab is to understand the functions of these and other genes responsible for plant fertilization.

Awards

NIH Ruth L. Kirschstein National Research Service Award, 2002-2004
Howard Hughes Medical Institute Postdoctoral Fellow, 2001
Anton Lang Research Excellence Award for Graduate Assistants, MSU-DOE Plant Research Laboratory, 2000
DuVall Scholar, Excellence in Graduate Research, Department of Microbiology, Michigan State University, 1999
Best graduate student presentation, Midwest Section of The American Society of Plant Physiologists 45th Annual Meeting, 1999

Affiliations

The American Society of Plant Biology

Funded Research

NSF, Molecular mechanisms of double fertilization: Analysis of the Arabidopsis HAP2 gene (under review)

Courses Taught

• Independent Research (BI0195)
• Plant Organism (BI0044)

Selected Publications

• Johnson MA, and Lord, E. Extracellular Guidance Cues and Intracellular Signaling Pathways that Direct Pollen Tube Growth. In, "The Pollen Tube: A Cellular and Molecular Perspective" Rui Malhó, editor. Plant Cell Monographs, Springer Berlin / Heidelberg pp. 223 – 242 (2006)(2006)
• Chiba Y, Johnson MA, Lidder, Vogel JT, van Erp HEG, GreenPJ. Identification and Characterization of AtPARN, an essential poly (A) ribonuclease in Arabidopsis. Gene. 2004 Mar 17;328:95-102.(2004)
• Lidder P, Johnson MA, Sullivan ML, Thompson DM, Perez-Amador MA, Howard CJ, Green PJ. Genetics of the DST-mediated mRNA decay pathway using a transgene-based selection. Biochem Soc Trans. 2004 Aug;32(Pt 4):575-7.(2004)
• Johnson MA, von Besser K, Zhou Q, Smith E, Aux G, Patton D, Levin J, Preuss D Arabidopsis hapless mutations define essential gametophyte functions. Genetics. 2004 Oct;168(2):971-82.(2004)
• Johnson MA and Preuss D. On your mark, get set, GROW! LePRK2-LAT52 interactions regulate pollen tube growth. Trends Plant Sci. 2003 Mar;8(3):97-9.(2003)
• Johnson MA and Preuss D. Plotting a course: Multiple signals guide pollen tubes to their targets. Developmental Cell. 2002 Mar;2(3):273-81.(2002)
• Pérez-Amador M, Lidder P, Johnson MA, Landgraf J, Wisman E, Green PJ. New Molecular Phenotypes in the dst Mutants of Arabidopsis Revealed by DNA Microarray Analysis. Plant Cell. 2001 Dec;13(12):2703-17.(2001)
• Kastenmayer JP, Johnson MA, and Green P.J. Analysis of XRN Orthologs by Complementation of Yeast Mutants and Localization of XRN-GFP Fusion Proteins. Methods Enzymol. 2001;342:269-82.(2001)
• Johnson MA, Perez-Amador M, Lidder P, Green PJ. Mutants of Arabidopsis defective in a sequence-specific mRNA degradation pathway. Proc Natl Acad Sci U S A. 2000 Dec 5;97(25):13991-6.(2000)
• Johnson MA, Baker EJ, Colbert JT, Green PJ Determinants of mRNA stability in plants. In J Bailey-Serres, DR Gallie, eds, A look beyond transcription: Mechanisms determining mRNA stability and translation in plants. 1998. Vol 19. American Society of Plant Physiologists Press, Rockville, pp 40-53.(1998)
• Kastenmayer JP, van Hoof A, Johnson MA, Green PJ. mRNA Decay Machinery in Plants: Approaches and Potential Components. In N Raikhel, R Last, G Morelli, and F LaShavo, eds, Plant Molecular Biology,. 1998. Vol 104. Springer-Verlag, Berlin, pp 125-133.(1998)