I am a principal investigator within the Hans Merensky Chair in Avocado Research. My work utilises genomic and transcriptomic data to identify genes and pathways crucial to a successful defense response against established and emerging avocado pathogens such asPhytophthora cinnamomi, Dematophora necatrixandthe avocado sunblotch viroid.
My other research activities include the development of tools to study avocado-pathogen interactions, such as a callose quantification assay which can be utilised in avocado rootstock screening programmes. The establishment of a model tobacco system within our research group has provided an avenue for the functional characterisation of avocado NLR genes as well as P. cinnamomi RxLR and CRN effectors.
In order to address the need for improved control of White root rot disease, we have several glasshouse and field trials (in South African avocado orchards) underway to assess the efficacy of fungicides and biological control agents against D. necatrix. I am also involved in a project studying the effect of P. cinnamomi and D. necatrix infection on the avocado rhizosphere microbiome.
My Publications
Journal Articles (22)
Joubert M, van den Berg N, Theron J, Swart V (2026) Leaf bleaching is associated with extensive transcriptional reprogramming in avocado trees with sunblotch disease. Virology. 620. doi: 10.1016/j.virol.2026.110903
Joubert M, van den Berg N, Theron J, Swart V (2025) Small RNAs derived from avocado sunblotch viroid and their association with bleaching symptoms: implications for pathogenesis in avocado sunblotch disease. Archives of Virology. 170. doi: 10.1007/s00705-025-06360-z
van den Berg N, Magagula P, Backer R, Swart V (2025) Towards developing an integrated approach for the treatment of white root rot in commercial avocado orchards. Phytoparasitica. 53. doi: 10.1007/s12600-025-01250-1
Magagula P, Swart V, Fourie A, Vermeulen A, Nelson JH, van Rooyen Z, van den Berg N (2025) Avocado rhizosphere community profiling: white root rot and its impact on microbial composition. Frontiers in Microbiology. 16. doi: 10.3389/fmicb.2025.1583797
Fick A, Swart V, Van den Berg N (2025)In silico prediction method for plant Nucleotide-binding leucine-rich repeat- and pathogen effector interactions. The Plant Journal. 122. doi: 10.1111/tpj.70169
Harvey A, van den Berg N, Swart V (2025) In silico characterisation of the avocado WAK/WAKL gene family with a focus on genes involved in defence against Phytophthora cinnamomi. Frontiers in Plant Science. 15. doi: 10.3389/fpls.2024.1474781
Harvey A, van den Berg N, Swart V (2024) Describing and characterizing the WAK/WAKL gene family across plant species: a systematic review. Frontiers in Plant Science. 15. doi: 10.3389/fpls.2024.1467148
van der Nest MA, Steenkamp ET, De Vos L, Wienk R, Swart V, van den Berg N (2024) Complete mitochondrial genome sequence of the white root rot pathogen Dematophora necatrix (Xylariaceae: Xylariales). Mitochondrial DNA Part B: Resoures. 9. doi: 10.1080/23802359.2024.2403411
Midgley KA, van den Berg N, Swart V (2024) Identification of Phytophthora cinnamomi CRN effectors and their roles in manipulating cell death during Persea americana infection. BMC Genomics. 25. doi: 10.1186/s12864-024-10358-3
Fick A, Swart V, Bombarely A, van den Berg N (2024) Comparative transcriptional analysis of Persea americana MYB, WRKY and AP2/ERF transcription factors following Phytophthora cinnamomi infection. Molecular Plant Pathology. 25. doi: 10.1111/mpp.13453
Joubert M, van den Berg N, Theron J, Swart V (2024) Global transcriptomic analysis in avocado nursery trees reveals differential gene expression during asymptomatic infection by avocado sunblotch viroid (ASBVd). Virus Research. 339. doi: 10.1016/j.virusres.2023.199263.
Anbu SP, Swart V, van den Berg N (2023) Unmasking the invaders: NLR-mal function in plant defense. Frontiers in Plant Science. 14. doi: 10.3389/fpls.2023.1307294
Joubert M, van den Berg N, Theron J, Swart V (2022) Transcriptomics Advancement in the Complex Response of Plants to Viroid Infection. International Journal of Molecular Sciences. 23. doi: 10.3390/ijms23147677
Midgley KA, van den Berg N, Swart V (2022) Unraveling plant cell death during Phytophthora Infection. Microorganisms. 10. doi: 10.3390/microorganisms10061139
Fick A, Swart V, Van den Berg N (2022) The ups and downs of plant NLR expression during pathogen infection. Frontiers in Plant Science. 13. doi: 10.3389/fpls.2022.921148
Fick A, Swart V, Backer R, Bombarely A, Engelbrecht J, van den Berg N (2022) Partially Resistant Avocado Rootstock Dusa® Shows Prolonged Upregulation of Nucleotide Binding-Leucine Rich Repeat Genes in Response to Phytophthora cinnamomi Infection. Frontiers in Plant Science. 13. doi: 10.3389/fpls.2022.793644
Magagula P, Taylor N, Swart V, Van den Berg N (2021) Efficacy of Potential Control Agents Against Rosellinia necatrix and Their Physiological Impact on Avocado. Plant Disease. 105. doi: 10.1094/PDIS-08-20-1751-RE
van den Berg, N, Swart, V, Backer, R, Fick, A, Wienk, R, Engelbrecht, J, Prabhu, SA (2021) Advances in understanding defense mechanisms in Persea americana against Phytophthora cinnamomi. Frontiers in Plant Science. 12. doi: 10.3389/fpls.2021.636339
Welgemoed T, Pierneef R, Sterck L, Van de Peer Y, Swart V, Scheepers KD, Berger DK (2020) De novo assembly of transcriptomes from a B73 maize line introgressed with a QTL for resistance to gray leaf spot disease reveals a candidate allele of a lectin receptor-like kinase. Frontiers in Plant Science.
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. doi: 10.1371/journal.pone.0205705
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. doi: 10.1094/MPMI-03-17-0054-R
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-C, 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. doi: 10.5598/imafungus.2017.08.02.10
My Publications
Joubert M, van den Berg N, Theron J, Swart V. (2026) Leaf bleaching is associated with extensive transcriptional reprogramming in avocado trees with sunblotch disease. Virology 10.1016/j.virol.2026.110903
Joubert M, van den Berg N, Theron J, Swart V. (2025) Small RNAs derived from avocado sunblotch viroid and their association with bleaching symptoms: implications for pathogenesis in avocado sunblotch disease. Archives of Virology 10.1007/s00705-025-06360-z
Fick A, Swart V, Van den Berg N. (2025) In silico prediction method for plant Nucleotide-binding leucine-rich repeat- and pathogen effector interactions. The Plant Journal 10.1111/tpj.70169
Harvey A, van den Berg N, Swart V. (2025) In silico characterisation of the avocado WAK/WAKL gene family with a focus on genes involved in defence against Phytophthora cinnamomi. Frontiers in Plant Science 10.3389/fpls.2024.1474781
Harvey A, van den Berg N, Swart V. (2024) Describing and characterizing the WAK/WAKL gene family across plant species: a systematic review. Frontiers in Plant Science 10.3389/fpls.2024.1467148
Midgley KA, van den Berg N, Swart V. (2024) Identification of Phytophthora cinnamomi CRN effectors and their roles in manipulating cell death during Persea americana infection. BMC Genomics 10.1186/s12864-024-10358-3
Fick A, Swart V, Bombarely A, van den Berg N. (2024) Comparative transcriptional analysis of Persea americana MYB, WRKY and AP2/ERF transcription factors following Phytophthora cinnamomi infection. Molecular Plant Pathology 10.1111/mpp.13453
