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Bruce A. McClure

Bruce McClure

Department of Biochemisty

E-mail: mcclureb at missouri dot edu
Office address: 117 Schweitzer Hall
Office phone: 573-882-3932
Lab address: 108/111 Schweitzer Hall
Lab phone: 573-882-3939

Research in the McClure lab is focused on understanding how pollen pistil communication controls plant mating. We study S-RNase-based self-incompatibility in Nicotiana and interspecific pollen recognition and rejection between tomato and its wild relatives.  The genus Nicotiana is useful because of its ease of experimental manipulation, and the inter- and intra-specific compatibility relationships are well known. For example, N. alata displays gametophytic self-incompatibility (SI). Self-pollen and pollen from closely related plants are rejected, thus maintaining hybrid vigor. N. alata also has specific mechanisms for recognizing and rejecting pollen from related species, such as N. plumbaginifolia and N. tabacum. Likewise, tomato, Solanum lycopersicum (formerly Lycopersicon esculentum), also has well-defined crossing relationships with its wild relatives such as SI S. habrochaities and SI S. pennellii. In addition, there are many powerful genetic tools available for studies of tomato.

We use genetic and biochemical techniques to identify factors that contribute to inter- and intra-specific pollen recognition and rejection. A theme for pollen-pistil interactions is that the pistil secretes factors into the extracellular matrix that pollen tubes use as a guide to the ovary. Our challenge is to identify these factors, and the pollen factors they interact with, to control mating. In SI, for example, the pistil produces potentially cytotoxic proteins, called S-RNases, that are taken up by growing pollen tubes. When pollen is rejected, S-RNase is released into the pollen tube cytoplasm, and growth is inhibited. Thus, our research involves biochemical and genetic experiments to identify critical pollen and pistil proteins and cell biological experiments to determine how their cellular context contributes to their functions. By understanding the natural systems that control pollination, plant breeders can design new strategies to control plant breeding behavior to their own purposes.

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McClure BA, Haring V, Ebert PR, Anderson MA, Simpson RJ, Sakiyama F, Clarke AE. (1989). Style self-incompatibility gene products of Nicotiana alata are ribonucleases. Nature 342: 955–957.

McClure BA, Gray JE, Anderson MA, Clarke AE. (1990). Self-incompatibility in Nicotiana alata involves degradation of pollen rRNA. Nature 347: 757–760.

Gray JE, McClure BA, Bönig I, Anderson MA, Clarke AE. (1991). Action of the style product of the self-incompatibility gene of Nicotiana alata (S-RNase) on in vitro grown pollen tubes. Plant Cell 3:271–283.

Murfett J, Atherton TL, Mou B, Gasser CS, McClure BA. (1994). S-RNase expressed in transgenic Nicotiana causes S-allele specific pollen rejection. Nature 367:563–566.

Murfett J, Strabala TJ, Zurek DM, Mou B, Beecher B, McClure BA. (1996). S-RNase and interspecific pollen rejection in the genus Nicotiana: Multiple pollen rejection pathways contribute to unilateral incompatibility between self-incompatible and self-compatible species. Plant Cell 8:943–958.

McClure BA, Mou B, Canevascini S, Bernatzky R. (1999). A small asparagine-rich protein required for S-allele-specific pollen rejection in Nicotiana. Proc. Natl. Acad. Sci. USA 96:13548–13553.

Hancock CN, Kent L, McClure BA. (2005) The 120kDa glycoprotein is required for S-specific pollen rejection in Nicotiana. Plant J. 43:716-723.

Goldraij A, Kondo K, Lee CB, Hancock CN, Sivaguru M, Vasquez-Santana S, Kim S, Phillips TE, Cruz-Garcia F, McClure B. (2006) Compartmentalization of S-RNase and HT-B degradation in self-incompatible Nicotiana. Nature. 439:805-810.

Juarez-Diaz JA, McClure B, Vazquez-Santana S, Guevara-Garcia A, Leon-Mejia P, Marquez-Guzman J, Cruz-Garcia F. (2006). A novel extracellular thioredoxin h from N. alata reduces S-RNases. J. Biol. Chem. 281:3418-3424. Featured on the cover.

McClure B. (2006) New views of S-RNase-based self-incompatibility. Curr. Op. Plant Biol. 9:639-646.

McClure B. (2007) Pollen-pistil signaling in self-incompatible poppy: does it allow more efficient resource allocation in the pistil? Sci. STKE 2007, pe17 (2007).

Kondo K, McClure B. (2008) New microsome-associated HT-family proteins from Nicotiana respond to pollination and define an HT/NOD-24 protein family. Mol. Plant 1: 634-644. doi:10.1093/mp/ssn018

Lee CB, Page LE, McClure BA, Holtsford TP. (2008) Postpollination hybridization barriers in Nicotiana Section Alatae. Sex. Plant Reprod. 21:183-95. doi 10.1007/s00497-008-0077-9

Lee CB, Swatek KN, McClure BA. (2008) Pollen proteins bind to the C-terminal domain of Nicotiana alata pistil arabinogalactan proteins. J. Biol. Chem. 283:26965-73. doi:10.1074/jbc.M804410200

Busot GY, McClure  B, Ibarra-Sanchez CP, Jimenez-Duran K, Vazquez-Santana S,  Cruz-Garcıa F. (2008) Pollination in Nicotiana alata stimulates synthesis and transfer to the stigmatic surface of NaStEP, a vacuolar Kunitz proteinase inhibitor homologue. J. Exp. Bot.  59:3187-3201. doi:10.1093/jxb/ern175

Lee CB, Kim S, McClure B. (2009) A pollen protein, NaPCCP, that binds pistil arabinogalactan proteins also binds phosphatidylinositol 3-phosphate and associates with the pollen tube endomembrane system.  Plant Physiol. 149:791-802 doi:10.1104/pp.108.127936

McClure B. (2009) Darwin’s foundation for investigating self-incompatibility and the progress toward a physiological model for S-RNase-based SI. J. Exp. Bot. 60:1069-81. doi:10.1093/jxb/erp024.

McClure B, Franklin-Tong N. (2010). Journal of Experimental Botany: Preface. Journal of Experimental Botany 61(7):iii-iv.

Kumar A, McClure B. (2010). Pollen-pistil interactions and the endomembrane system. Journal of Experimental Botany 61(7):2001-2013.

Covey PA, Kondo K, Welch L, Frank E, Sianta S, Kumar A, Nunez R, Lopez-Casado G, Van Der Knaap E, Rose JKC, McClure BA, Bedinger PA (2010). Multiple features that distinguish unilateral incongruity and self-incompatibility in the tomato clade. Plant Journal 64(3):367-378.

Bedinger PA, Chetelat RT, McClure B, Moyle LC, Rose JKC, Stack SM, van der Knaap E, Baek YS, Lopez-Casado G, Covey PA, Kumar A, Li W, Nunez R, Cruz-Garcia F, Royer S. (2010). Interspecific reproductive barriers in the tomato clade: opportunities to decipher mechanisms of reproductive isolation. Sexual Plant Reproduction (in press).

Rebello CM, Siegel MA, Witzig SB, Freyermuth SK and McClure BA. (2010) Epistemic beliefs and conceptual understanding in biotechnology: A case study. Research in Science Education 2010 (in press, DOI: 10.1007/s11165-010-9201-6).

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  • Program Director, Developmental Systems Cluster, National Science Foundation (2010-present)
  • Mizzou ADVANCE STRIDE Committee (2007-2010). STRIDE members are trained in practices that increase the promotion and success of women faculty in STEM fields.
  • Fellow, American Association for the Advancement of Science (2008)
  • Board Member, Science Teachers of Missouri (Director of College Division)