The Molecular Plant-Pathogen Interactions (MPPI) Group is located in the Plant Sciences Complex at the University of Pretoria. The group is part of the Department of Plant Science and the Forestry and Agricultural Biotechnology Institute (FABI) and is headed by Prof Dave Berger. Research focuses on the molecular basis of plant-pathogen interactions and the mechanisms of plant defence using a range of approaches from whole plant phenotyping to functional genomics, as well as developing bioinformatics tools. The MPPI group has particular experience in transcriptomics using microarrays and is now increasingly using RNAseq.

There are two major research projects in the MPPI lab, The first involves maize, the staple food of sub-Saharan Africa. We are interested in understanding mechanisms underlying quantitative disease resistance in maize to grey leaf spot (GLS) disease. GLS is an important constraint to maize production in many maize growing regions of the world, particularly in Africa.

We collaborate with maize breeders and field pathologists to understand the disease in its Agricultural context, which gives postgraduate students the opportunity to temporarily "escape" from the lab. Apart from glasshouse bioassays, the MPPI group is employing genomics, such as high density molecular markers, and transcriptomics to study maize defence mechanisms against GLS, with the long term aim to develop tools for maize improvement, such as marker assisted selection.

The MPPI group, together with the CFPRG in FABI, is also elucidating pathogenicity strategies employed by Cercospora zeina, the causal agent of GLS. We are taking a comparative genomics approach, through whole genome sequencing of C. zeina isolates. The research is followed up using functional genomics tools developed in the CFPRG. In addition, we are carrying out genetic diversity studies of C.zeina.

The second project area is study of the pathosystem between Ralstonia solanacearum, the causal agent of bacterial wilt and the model plant Arabidopsis thaliana. We are taking a genetic approach. This exploits the natural diversity of Arabidopsis accessions as well as the many molecular tools available for Arabidopsis research.

The MPPI group is hosted in the Plant Sciences Complex with excellent laboratories for plant biotechnology research, dedicated Arabidopsis growth rooms and access to phytotron and glasshouse facilities. Several bioinformatics software packages and databases have been developed by the group in collaboration with the Bioinformatics and Computational Biology Unit at the University of Pretoria.

New Publications

Liversage J, Coetzee MPA, Bluhm BH, Berger DK, Crampton BG. (2018) LOVe across kingdoms: Blue light perception vital for growth and development in plant–fungal interactions. Fungal Biology Reviews 10.1016/j.fbr.2017.11.003
Wingfield BD, Berger DK, Steenkamp ET, Lim H-J, Duong TA, Bluhm BH, De Beer ZW, De Vos L, Fourie G, Naidoo K, Olivier NA, Lin Y, Van der Peer Y, Joubert F, Crampton BG, Swart V, Soal N, Tatham C, Van der Nest MA, Van der Merwe NA, Van Wyk S, Wilken PM, Wingfield MJ. (2017) IMA Genome-F 8 Draft genome of Cercospora zeina, Fusarium pininemorale, Hawksworthiomyces lignivorus, Huntiella decipiens and Ophiostoma ips. IMA Fungus 8 (2):385‑396. 10.5598/imafungus.2017.08.02.10
Meyer J, Berger DK, Christensen SA, Murray SL. (2017) RNA-Seq analysis of resistant and susceptible sub-tropical maize lines reveals a role for kauralexins in resistance to grey leaf spot disease, caused by Cercospora zeina. BMC Plant Biology 17:197. 10.1186/s12870-017-1137-9
Amuge T, Berger DK, Katari MS, Myburg AA, Goldman SL, Ferguson ME. (2017) A time series transcriptome analysis of cassava (Manihot esculenta Crantz) varieties challenged with Ugandan cassava brown streak virus. Scientific Reports 7:9747. 10.1038/s41598-017-09617-z
Swart V, Crampton BG, Ridenour JB, Bluhm BH, Olivier NA, Meyer JJM, Berger DK. (2017) Complementation of CTB7 in the maize pathogen Cercospora zeina overcomes the lack of in vitro cercosporin production. Molecular Plant-Microbe Interactions 30(9):710-724. 10.1094/MPMI-03-17-0054-R
Zwart L, Berger DK, Moleleki LN, Van der Merwe NA, Myburg AA, Naidoo S. (2017) Evidence for salicylic acid signalling and histological changes in the defence response of Eucalyptus grandis to Chrysoporthe austroafricana. Scientific Reports 7:45402. 10.1038/srep45402 PDF
Christie N, Myburg AA, Joubert F, Murray SL, Carstens M, Lin Y-C, Meyer J, Crampton BG, Christensen SA, Ntuli JF, Wighard SS, Van de Peer Y, Berger DK. (2017) Systems genetics reveals a transcriptional network associated with susceptibility in the maize-gray leaf spot pathosystem. The Plant Journal 89(4):746-763. 10.1111/tpj.13419
Reitmann A, Berger DK, Van den Berg N. (2017) Putative pathogenicity genes of Phytophthora cinnamomi identified via RNA-Seq analysis of pre-infection structures. European Journal of Plant Pathology 147(1):211-228. 10.1007/s10658-016-0993-8
Human MP, Barnes I, Craven M, Crampton BG. (2016) Lack of population structure and mixed reproduction modes in Exserohilum turcicum from South Africa. Phytopathology 106(11):1386-1392. 10.1094/PHYTO-12-15-0311-R
Muller MF, Barnes I, Kunene NT, Crampton BG, Bluhm B, Phillips S, Olivier NA, Berger DK. (2016) Cercospora zeina from maize in South Africa exhibits high genetic diversity and lack of regional population differentiation. Phytopathology 106(10):1194-1205. 10.1094/PHYTO-02-16-0084-FI
Oelofse D, Gazendam I, Veale A, Djami-Tchatchou A, Berger D, Dubery I. (2016) Functional characterization of a defense-related class-III chitinase promoter from Lupinus albus, active in legume and monocot tissues. European Journal of Plant Pathology 146(4):923-936. 10.1007/s10658-016-0970-2
Daru B, Berger DK, Van Wyk AE. (2016) Opportunities for unlocking the potential of genomics for African trees. New Phytologist 210:772-778. 10.1111/nph.13826
Meyer FE, Shuey LS, Ramsuchit S, Mamni T, Berger DK, van den Berg N, Myburg AA, Naidoo S. (2016) Dual RNA-sequencing of Eucalyptus nitens during Phytophthora cinnamomi challenge reveals pathogen and host factors influencing compatibility. Frontiers in Plant Science 7:191. 10.3389/fpls.2016.00191 PDF
Meyer J, Murray SL, Berger DK. (2016) Signals that stop the rot: Regulation of secondary metabolite defences in cereals. Physiological and Molecular Plant Pathology 94:156-166. 10.1016/j.pmpp.2015.05.011 PDF
Ronishree Magwanda, Lizahn Zwart, Nicolaas A. van der Merwe, Lucy Moleleki, Dave Kenneth Berger, Alexander A. Myburg, Sanushka Naidoo. (2016) Localization and Transcriptional Responses of Chrysoporthe austroafricana in Eucalyptus grandis Identify Putative Pathogenicity Factors. Front. Microbiol. 10.3389/fmicb.2016.01953
Carstens M, Berger DK. 2016. Biotechnology and Crop Disease Resistance in South Africa. In: Biotechnology for Plant Disease Control. Collinge DB. (eds). Wiley, New York and London, pp 16 (Chapter).
Hussey SG, Mizrachi E, Groover A, Berger DK, Myburg AA. (2015) Genome-wide mapping of histone H3 lysine 4 trimethylation in Eucalyptus grandis developing xylem. BMC Plant Biology 15:117. 10.1186/s12870-015-0499-0 PDF
Mizrachi E, Maloney VJ, Silberbauer J, Hefer CA, Berger DK, Mansfield SD, Myburg AA. (2014) Investigating the molecular underpinnings underlying morphology and changes in carbon partitioning during tension wood formation in Eucalyptus. New Phytologist 204(6):1351-1363. 10.1111/nph.13152
Berger DK, Carstens M, Korsman JN, Middleton F, Kloppers FJ, Tongoona P, Myburg AA. (2014) Mapping QTL conferring resistance in maize to gray leaf spot disease caused by Cercospora zeina. BMC Genetics 15:60. 10.1186/1471-2156-15-60
Haasbroek MP, Craven M, Barnes I, Crampton BG. (2014) Microsatellite and mating type primers for the maize and sorghum pathogen, Exserohilum turcicum. Australasian Plant Pathology 43(5):577-581. 10.1007/s13313-014-0289-4 PDF