Office: 245 Schweitzer Hall
117 Schweitzer Hall
University of Missouri
Columbia, MO 65211
|BS||Cornell University||Ithaca, N.Y.||Biochemistry|
|PhD||Duke University||Durham, N.C.||Biochemistry|
Emeritus Professor Joe Polacco has ‘de-emphasized’ research somewhat, but retains ties with labs in Europe and South America. He co-advises Brazilian students at MU or as a visiting professor (e.g. Wiebke-Ströhm et al. 2012), and pursues his long-standing interest in Ni activation (Polacco et al. 2011) of plant (mainly soybean) ureases.
Ni roles in plant metabolism remain an interest (Polacco et al. 2013; Fabiano et al. 2015), esp. in economically important coffee and soybean. However, Polacco has turned more attention to urease roles in plant defense (insecticidal, inflammatory, and fungitoxic) (Tezotto et al. 2016) and rhizosphere signaling (Medeiros-Silva et al, 2014). Understanding defense roles was the aim of a Mizzou Advantage Undergraduate Research Team project in which Polacco, Dr. Gary Weisman (Biochemistry) and Dr. Qisheng Song (Entomology), directed a 6-member undergraduate research team to examine these properties. Intact Helicobacter pylori urease was found to work through the P2Y2R signaling pathways stimulating intracellular Ca2+ mobilization and mitogen-activated protein kinase (MAPK) activation in cultured astrocytes.
The insecticidal effect of a specific urease sub-peptide is still being tested in Drosophila, an insect that lacks the gut cathepsins that release this peptide in urease-sensitive insects. If Drosophila proves sensitive, it will be subjected to genetic manipulation to identify the peptide’s target and mode of action.
Polacco runs one or more sections in the Biochemistry capstone course for seniors. As a Visiting Professor (Sept/November, 2014) in the College of Agriculture (Escola Superior de Agricultura Luiz Queiroz) of the State University of São Paulo in Piracicaba, São Paulo (USP-ESALQ), Polacco lectured and advised agronomy graduate students.
Polacco JC, Hyten DL, Medeiros-Silva M, Sleper DA, Bilyeu KD (2011) Mutational analysis of the major soybean UreF paralogue involved in urease activation. Journal of Experimental Botany 62: 3599–3608.
Wiebke-Ströhm B, Pasquali G, Margis-Pinheiro M, Bencke M, Bücker-Neto L, Becker-Ritt AB, Martinelli AHS, Rechenmacher C, Polacco JC, et al. (2012) Ubiquitious urease affects soybean susceptibility to fungi. Plant Molecular Biology 79: 75-87.
Polacco JC, Mazzafera P, Tezotto T (2013) Opinion - Nickel and urease in plants: still many knowledge gaps. Plant Science 199-200: 79-90.
Medeiros-Silva M, Franck W, Borba M, Pizzato S, Strodtman KN, Emerich DW, Stacey G, Polacco JC, Carlini C (2014) Soybean ureases, but not that of Bradyrhizobium japonicum, are involved in the process of soybean root nodulation. Journal of Agricultural and Food Chemistry 62: 3517−3524.
Fabiano CC, Tezotto T, Favarin JL, Polacco JC, Mazzafera P (2015) Essentiality of nickel in plants: a role in plant stresses. PERSPECTIVE ARTICLE. Frontiers of Plant Science. Vol 6, Article 754 23 September
Tiago Tezotto T, Ribeiro Souza SC, Mihail J, Laércio Favarin J, Mazzafera P, Bilyeu K, Polacco JC (2016) Deletion of the Single UreG Urease Activation Gene in Soybean NIL Lines: Characterization and Pleiotropic Effects. Theoretical and Experimental Plant Physiology, accepted