The advent of next-generation sequencing (NGS) technologies has revolutionised research capacity and its broad applicability over the past decade. These technologies have directly impacted researchers’ ability to understand host-pathogen interactions, holistically, and on a molecular scale. Recently, the avocado industry has begun to unravel some of the underlying mysteries that pertain to prevalent avocado pests and diseases; the Avocado Research Programme (ARP) has been highly influential in this space.

As a founding member of the Avocado Genome Consortium - an international collaborative effort which was established in 2016 - the ARP has directly contributed to the development of a high quality, chromosome-level reference genome assembly for Persea americana (avocado). The Avocado Genome Consortium has used this new reference genome to re-sequence more than 10 additional cultivars and rootstocks as part of an ongoing project, with plans to increase this number soon. Provided with this data, researchers will be able to accelerate the arduous process of selecting rootstocks and cultivars with desirable traits.

As part of the broader objectives of the Avocado Genome Consortium, transcriptomic data has also been generated. This data will be utilized to answer fundamental questions pertaining to the evolutionary biology, gene expression, physiological processes, and molecular pathways in avocado. Transcriptomic data from a dual RNA-sequencing experiment - involving both susceptible and partially resistant avocado rootstocks challenged with Phytophthora cinnamomi - was also used to identify avocado defence targets and discovery of pathogen effectors involved in disease development. The data from this work has been published across several research articles and will be used to further our understanding of the avocado-P. cinnamomi interaction.

 

The researchers involved are:

  • David Kuhn, USDA, Florida
  • Patricia Manosalva, UCR, California
  • Noëlani van den Berg, UP, South Africa
  • Antonio Javier Matas Arroyo, Departamento de Biología Vegetal, University of Malaga, Spain
  • Aureliano Bombarley Gomez, Virginia Tech Horticulture, USA
  • Randy Ploetz, University of Florida, USA
  • Alan Chambers, University of Florida, USA

 

New Publications

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 10.3389/fmicb.2025.1583797
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(32) 10.1007/s12600-025-01250-1 PDF
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 15:1474781. 10.3389/fpls.2024.1474781 PDF
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 15:1467148. 10.3389/fpls.2024.1467148 PDF
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 339:199263. 10.1016/j.virusres.2023.199263. PDF
Anbu SP, Swart V, van den Berg N. (2023) Unmasking the invaders: NLR-mal function in plant defense. Frontiers in Plant Science 14:1307294. 10.3389/fpls.2023.1307294 PDF
Backer R, Naidoo S, van den Berg N. (2023) The expression of the NPR1-dependent defense response pathway genes in Persea americana (Mill.) following infection with Phytophthora cinnamomi. BMC Plant Biology 23(1):548. 10.1186/s12870-023-04541-z PDF
Wingfield BD, Berger DK, Coetzee MPA, Duong TA, Martin A, Pham NQ, Van den Berg N, Wilken PM, Arun-Chinnappa KS, Barnes I, Buthelezi S, Dahanayaka BA, Durán A, Engelbrecht J, Feurtey A, Fourie A, Fourie G, Hartley J, Kabwe ENK, Maphosa M, Narh Mensah DL, Nsibo DL, Potgieter L, Poudel B, Stukenbrock EH, Thomas C, Vaghefi N, Welgemoed T, Wingfield MJ. (2022) IMA genome‑F17 Draft genome sequences of an Armillaria species from Zimbabwe, Ceratocystis colombiana, Elsinoë necatrix, Rosellinia necatrix, two genomes of Sclerotinia minor, short‑read genome assemblies and annotations of four Pyrenophora teres isolates from barley grass, and a long-read genome assembly of Cercospora zeina. 13:19. 10.1186/s43008-022-00104-3
Wienk R, Mostert‑O’Neill M, Abeysekara N, Manosalva P, Freeman B, van den Berg N. (2022) Genetic diversity, population structure and clonal verification in South African avocado cultivars using single nucleotide polymorphism (SNP) markers. Tree Genetics and Genomes 18(41) 10.1007/s11295-022-01573-8 PDF
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(7677) 10.3390/ijms23147677 PDF
Backer R, Engelbrecht J, van den Berg N. (2022) Differing Responses to Phytophthora cinnamomi Infection in Susceptible and Partially Resistant Persea americana (Mill.) Rootstocks: A Case for the Role of Receptor-Like Kinases and Apoplastic Proteases. Frontiers in Plant Science 13 10.3389/fpls.2022.928176 PDF
Kooverjee BB, Soma P, Neser FWC, Van der Nest MA, Scholtz MM. (2022) Selection Signatures in South African Nguni and Bonsmara Cattle Populations Reveal Genes Relating to Environmental Adaptation.. Frontiers in Genetics 13:909012. 10.3389/fgene.2022.909012 PDF
Hartley J, Engelbrecht J, Van den Berg N. (2022) Detection and prevalence of Rosellinia necatrix in South African avocado orchards. European Journal of Plant Pathology 10.1007/s10658-022-02532-8
Fick A, Swart V, Van den Berg N. (2022) The ups and downs of plant NLR expression during pathogen infection. Frontiers in Plant Science 13:921148. 10.3389/fpls.2022.921148
Midgley KA, van den Berg N, Swart V. (2022) Unraveling plant cell death during Phytophthora Infection. Microorganisms 10(6) 10.3390/microorganisms10061139 PDF
Miyambo TM, Backer R, Engelbrecht J, Joubert F, van der Merwe NA, van den Berg N. (2022) The Identification and Characterization of Endopolygalacturonases in a South African Isolate of Phytophthora cinnamomi. Microorganisms 10(1061) 10.3390/microorganisms10051061 PDF
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 13:793644. 10.3389/fpls.2022.793644
Wingfield BD, De Vos L, Wilson AM, Duong AT, Vaghefi N, Botes A, Kharwar RN, Chand R, Poudel B, Aliyu H, Barbetti MJ, Chen S, de Maayer P, Liu F, Navathe S, Sinha S, Steenkamp ET, Suzuki H, Tshisekedi KA, van der Nest MA, Wingfield MJ. (2022) Draft genome assemblies of Fusarium marasasianum, Huntiella abstrusa, two Immersiporthe knoxdaviesiana isolates, Macrophomina pseudophaseolina, Macrophomina phaseolina, Naganishia randhawae, and Pseudocercospora cruenta. IMA Fungus 13(1):3. 10.1186/s43008-022-00089-z
Engelbrecht J, Duong TA, Paap T, Hulbert JM, Hanneman J, Van den Berg N. (2022) Population genetic analyses of Phytophthora cinnamomi reveals three lineages and movement between natural vegetation and avocado orchards in South Africa. 10.1094/PHYTO-10-21-0414-R
Kooverjee BB, Soma P, Neser FWC, Van der Nest MA, Scholtz MM. 2022. Copy number variation analysis in Nguni and Bonsmara crossbred cattle. In: Proceedings of 12th World Congress on Genetics Applied to Livestock Production (WCGALP). Veerkamp RF, de Haas Y. (eds). Wageningen Academic Publishers, pp 2187-2190. PDF
Soal NC, Coetzee MPA, Van der Nest MA, Hammerbacher A, Wingfield BD. (2022) Phenolic degradation by catechol dioxygenases is associated with pathogenic fungi with a necrotrophic lifestyle in the Ceratocystidaceae. G3. 12:jkac008. 10.1093/g3journal/jkac008
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(11):PDIS-08. 10.1094/PDIS-08-20-1751-RE
Duong AT, Aylward J, Ametrano CG, Poudel E, Santana QC, Wilken PM, Martin A, Arun-Chinnappa KS, De Vos L, DiStefano I, Grewe F, Huhndorf S, Lumbsch HT, Rakoma JR, Steenkamp ET, Sun Y, van der Nest MA, Wingfield MJ, Yilmaz N, Wingfield BD. (2021) Draft genome assembly of Fusarium pilosicola, Meredithiella fracta, Niebla homalea, Pyrenophora teres hybrid WAC10721, and Teratosphaeria viscida. IMA Fungus 12(1):30. 10.1186/s43008-021-00077-9
Joubert M, Backer R, Engelbrecht J, Van den Berg N. (2021) Expression of several Phytophthora cinnamomi putative RxLRs provides evidence for virulence roles in avocado. PLoS ONE 16(7):e0254645. 10.1371/journal.pone.0254645 PDF
Engelbrecht J, Duong TA, Prabhu AS, Seedat M, van den Berg N. (2021) Genome of the destructive oomycete Phytophthora cinnamomi provides insights into its pathogenicity and adaptive potential. BMC Genomics 22:302. 10.1186/s12864-021-07552-y
van der Nest MA, Chávez R, De Vos L, Duong TA, Gil-Durán C, Ferreira MA, Lane FA, Levicán G, Santana QC, Steenkamp ET, Suzuki H, Tello M, Rakoma JR, Vaca I, Valdés N, Wilken PM, Wingfield MJ, Wingfield BD. (2021) Draft genome sequences of Penicillium roqueforti, Fusarium sororula, Chrysoporthe puriensis, and Chalaropsis populi. IMA Fungus 12:5. 10.1186/s43008-021-00055-1 PDF
Van der Nest M, Hlongwane N, Hadebe K, Chan W, Van der Merwe N, De Vos L, Greyling B, Kooverjee B, Soma P, Dzomba E, Bradfield M, Muchadeyi F. (2021) Breed ancestry, divergence, admixture, and selection patterns of the Simbra crossbreed. Frontiers in Genetics 11:1796. 10.3389/fgene.2020.608650 PDF
Wilson AM, Gabriel R, Singer SW, Schuerg T, Wilken PM, van der Nest MA, Wingfield MJ, Wingfield BD. (2021) Doing it alone: Unisexual reproduction in filamentous ascomycete fungi. Fungal Biology Reviews 35:1-13. 10.1016/j.fbr.2020.12.003
Sayari M, van der Nest MA, Steenkamp ET, Rahimlou S, Hammerbacher A, Wingfield BD. (2021) Characterization of the Ergosterol Biosynthesis Pathway in Ceratocystidaceae. Journal of Fungi 7(3):237.
Van den Berg N, Swart V, Backer R, Fick A, Wienk R, Engelbrecht J, Prabhu S. (2021) Advances in understanding defense mechanisms in Persea americana against Phytophthora cinnamomi. Frontiers in Plant Science 12:123. 10.3389/fpls.2021.636339