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Associate Professor, Faculty of Science
The main area of research in my group is gametophytic self-incompatibility with a ribonuclease-based mechanism. This is one of the most widely distributed genetic mechanisms that prevents self… read more
The main area of research in my group is gametophytic self-incompatibility with a ribonuclease-based mechanism. This is one of the most widely distributed genetic mechanisms that prevents self fertilization in angiosperms. Self pollen is rejected following a highly specific recognition between pollen and pistil. In the Solanaceae and Rosaceae families the inhibition of self pollen occurs in the style and a glycoprotein with homology to fungal ribonucleases has been shown to be the determinant of stylar specificity. We study self-incompatibility in both members of the Solanaceae (Petunia and Solanum) and Rosaceae (Prunus and Pyrus).
Self-incompatibility in the Solanaceae Our research in the Solanaceae was initially focussed on Petunia hybrida. A number of T-DNA insertions have been identified that are genetically linked to the S-locus on chromosome III . The S-RNase has been cloned for three functional S-alleles and protein studies have established polymorphism on IEF gels. As part of a collaboration with the Chinese Academy of Sciences (Beijing) an F-box candidate for the pollen-S gene has been identified (Qiao et al, 2004). Most cultivars of Petunia hybrida are in fact self-compatible and we are also studying the molecular basis of self-compatibility which is associated with a particular S-RNase (So). This work is being carried out by a BBSRC funded PhD student Rafal Czycyk. A new area of research in the Solanaceae is a collaboration with Dr Glenn Bryan at SCRI Dundee on the basis of self-incompatibility in wild species of Solanum. This work is being carried out by an SCRI/University of Nottingham PhD student Daniel Dzidzienyo.
Self-incompatibility in the Rosaceae Many sweet cherry cultivars are self-incompatible and over the years cherry breeders have assigned cultivars to different incompatibility groups. More recently it has been shown at East Malling Research that each group produces a distinct set of pistil S-RNases. In collaborative projects with Ken Tobutt and colleagues we have sequenced a wide range of S-RNases to study S-allele diversity in the genus Prunus. This work was carried out by two PhD students Bruce Sutherland and Tineke Sonneveld. The study of a two self-compatible mutants in sweet cherry (Prunus avium) has provided evidence confiming the role of S-linked F-box genes in self-incompatibility in the Rosaceae (Sonneveld et al, 2005). I have also collaborated with Dr Javier Sanzol and colleagues at CITA Zaragosa studying S-RNase diversity in the European pear (Pyrus communis). Self-incompatibility in the Rubiaceae The family Rubiaceae includes the genus Canephora. The two main species exploited in the genus are Coffea arabica L. and Coffea canephora Pierre. Coffea arabica is autogamous and therefore has relatively uniform characteristics. Unlike C. arabica, C. canephora is cross-fertilised (or self sterile). Self-incompatibility has been shown to be of the gametophytic type and to be controlled by a single locus with multiple alleles in C. canephora. Proteomic studies to test whether or not the GSI system displayed in C. canephora is controlled by an S-RNase system have been performed by a PhD student Sylvester Tumusiime.
In addition to my research I am the course director for the MSc in Plant Genetic Manipulation.
Websites of interest
The petunia platform www.petuniaplatform.net
University of NottinghamSutton Bonington Campus Loughborough, Leicestershire LE12 5RD
telephone: +44 (0)115 9516400 fax: +44 (0) 115 951 6020 email: biosciences-enquiries@nottingham.ac.uk