Phytophthora cinnamomi

Phytophthora root rot (PRR) is the most severe and damaging disease in avocado plantations in South Africa. The causal agent, Phytophthora cinnamomi, is an oomycete that also causes disease on thousands of other plant species. The pathogen is a heterothallic species that can reproduce by sexual or asexual means. It can persist in soil or infected plant material for extended periods of time, and there is no means to eradicate this oomycete from infected areas once the pathogen has successfully established in soils. Currently, phosphite injections, along with the use of good agricultural practices, are commonly used as methods of control for PRR.

Given the severity of the disease, however, little is known regarding the biology, population diversity, and the molecular basis for the P. cinnamomi - avocado interaction. Current research of ARP therefore focuses on characterizing the genetic diversity and monitoring pathogen populations using microsatellite markers, and using genomics and genetics tools to characterize effectors genes (RxLR and Crinkler) as well as other genes that are known to contribute to the pathogenicity of the oomycete. The sensitivity and effectiveness of phosphite control and its mode of action towards P. cinnamomi is also being investigated.

 

 * Read more about Phytophthora cinnamomi on our Fact sheet.

 

ARP Team Members

Aaron Maringa: Investigating the adhesion of the oomycete Phytophthora cinnamomi during the early infection of avocado.

Katelyn Baird: Characterising the role of Phytophthora cinnamomi NLP proteins in plant cell infection.

Ncobile Kunene: Development of a transformation system for Phytophthora cinnamomi.

Dr Sylvans Ochola: Establishment of Nicotiana benthamiana pathosystem for functional characterization of Phytophthora cinnamomi effectors and avocado R genes.

Kayla Midgley: Characterising the role of Phytophthora cinnamomi CRN effector proteins in host plant cell death.

Susanna Anbu: -Expression profiling of Nep-like protein (NLP) effector genes during infection in avocado.

Shalya Moodley: Assessing the virulence of dominant Phytophthora cinnamomi genotypes from South African avocado orchards.

 

 

New Publications

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. 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
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
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