Pathosystems currently under study include grey leaf spot in maize (GLS) caused by Cercospora zeina, and northern corn leaf blight (NCLB) in maize and sorghum caused by Exserohilum turcicum.

Grey leaf spot in Africa is caused by the fungal pathogen Cercospora zeina. This widespread and destructive pathogen causes millions of rands worth of loss to maize yields every year. In collaboration with Professor Dave Berger (UP) and Professor Burt Bluhm (University of Arkansas), the research group is focussed on functional genomics of virulence factors of C. zeina. Previously characterised Dothideomycete as well as C. zeina specific effector genes, responsible for disease in maize, are identified in the recently assembled African C. zeina genome, and effector function is established through creating knock-out fungal mutants. Following maize infection, we monitor maize plants' response to these mutant strains compared to wild type C. zeina strains. In addition, we have constructed strains of C. zeina containing the green fluorescent protein in order to elucidate the exact mode of infection of this fungus using confocal microscopy, and determine whether it is similar to the closely related maize pathogen C. zeae-maydis.

Northern corn leaf blight (NCLB), caused by the fungus Exserohilum turcicum, is a devastating leaf foliar pathogen that occurs in most maize growing areas throughout the world. As part of a long term project to identify and isolate virulence factors from maize foliar fungal pathogens, CFPR is interested in characterising E. turcicum isolates from South Africa using simple sequence repeats (SSRs) as molecular markers. Setosphaeria turcica, the telomorph form of E. turcicum, has been sequenced as part of a Dothidiomycete sequencing project at the Joint Genome Initiative (http://www.jgi.doe.gov/genome-projects/). We used this sequence to identify single strand repeats, and design primers to conserved flanking regions for use in molecular characterisation of South African E. turcicum isolates. In addition, we are working together with Dr Maryke Craven from the ARC Grain Crops Institute in order to develop molecular markers to identify the various races of E. turcicum present in South African maize fields.

New Publications

Malefo M, Mathibela O, Makgopa E, Crampton BG. (2020) Investigating the role of Bowman-Birk serine protease inhibitor in Arabidopsis plants under drought stress. Plant Physiology and Biochemistry 149:286-293. 10.1016/J.PLAPHY.2020.02.007
Human MP, Berger DK, Crampton BG. (2020) Time-course RNAseq reveals Exserohilum turcicum effectors and pathogenicity determinants. Frontiers in Microbiology 11(360) 10.3389/fmicb.2020.00360
Devnarain N, Crampton BG, Olivier N, van der Westhuizen C, Becker JVW, O'Kennedy MM. (2019) Transcriptomic analysis of a Sorghum bicolour landrace identifies a role for beta-alanine betaine biosynthesis in drought tolerance.. South African Journal of Botany 127 10.1016/j.sajb.2019.08.049
van den Berg N, Mohamed W, Olivier NA, Swart V, Crampton B. (2018) Transcriptome analysis of an incompatible Persea americana-Phytophthora cinnamomi interaction reveals the involvement of SA- and JA-pathways in a successful defense response. PLoS ONE 13(10):e0205705. 10.1371/journal.pone.0205705
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 32(2):86-103. 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 PDF
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
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
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
Naidoo SIM, Laurie SM, Odeny DA, Vorster BJ, Mphela WM, Greyling MM, Crampton BG. (2016) Genetic analysis of yield and flesh colour in sweetpotato. African Crop Science Journal 24(1):61-73. 10.4314/acsj.v24i1.5 PDF
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
Korsman J, Meisel B, Kloppers F, Crampton B, Berger D. (2012) Quantitative phenotyping of grey leaf spot disease in maize using real-time PCR. European Journal of Plant Pathology 133:461-471. 10.1007/s10658-011-9920-1
Crampton BG, Hein I, Berger DK. (2009) Salicylic acid confers resistance to a biotrophic rust pathogen, Puccinia substriata, in pearl millet (Pennisetum glaucum). Molecular Plant Pathology 10:291-304.
Meisel B, Korsman J, Kloppers F, Berger DK. (2009) Cercospora zeina is the causal agent of grey leaf spot disease of maize in southern Africa. European Journal of Plant Pathology 124:577-583. 10.1007/s10658-009-9443-1
Crampton BG, van den Berg N, Hein I, Birch PRJ, Berger DK. (2004) High-throughput screening of suppression subtractive hybridization cDNA libraries using DNA microarray analysis. BioTechniques 37(5):818-824.