Bacterial Genomics and Host Pathogen Interactions


The bacterial genomics and host pathogen interactions group is based at the University of Pretoria Department of Microbiology and Plant Pathology under the leadership of Dr Lucy Moleleki. Potato is an economically important crop plant contributing significantly to the South African economy. Pests and pathogens contribute significantly to annual production losses. Currently, the research group focuses on the Soft Rot Enterobacteriaceae and Root Knot Nematodes (Meloidogyne spp) of potatoes. To increase productivity, accurate identification of these pathogens is essential hence one of the focus areas of the research is molecular identification of potato pathogens. Pathogens overcome host defences by interfering with various host surveillance system. Hence, we endeavour to use genomics and transcriptomics to identify bacterial virulence factors as well as elucidate host defence mechanisms being targeted by these virulence factors.

Completed and Current project

Root Knot Nematodes

We recently completed a survery of root knot nematode species infecting potato plants in different growing regions across South Africa. In this survey the genetic diversity of the different Meloidogyne spp was profiled. Future studies will focus on understanding interactions of Meloidogyne spp and other potato pathogens as well as host plant potato.

Soft Rot Pathogens

We are currently using a variety of functional and comparative genomic tools to study the interaction of Pectobacterium spp in host plant potato during colonisation in a susceptible vs resistant host.

Group Leader: Dr Lucy Moleleki

New Publications

Chepsergon J, Moleleki LN. (2023) “Order from disordered”: Potential role of intrinsically disordered regions in phytopathogenic oomycete intracellular effector proteins. Current Opinion in Plant Biology 75:102402. 10.1016/j.pbi.2023.102402
Macharia TN, Duong TA, Moleleki LN. (2023) n silico secretome analyses of the polyphagous root-knot nematode Meloidogyne javanica: a resource for studying M. javanica secreted proteins. BMC Genomics 24:296. 10.1186/s12864-023-09366-6
Chepsergon J, Lucy N Moleleki. (2023) Rhizosphere bacterial interactions and impact on plant health. Current Opinion in Microbiology 73:102297. 10.1016/j.mib.2023.102297
Jane Chepsergon, Celiwe Nxumalo, Brenda Salasini, Aquillah Kanzi, Lucy Moleleki. (2022) Short Linear Motifs (SLiMs) in “Core” RxLR effectors of Phytophthora parasitica var. nicotianae: A case of PpRxLR1 effector. Microbiology Spectrum 10(2) 10.1128/spectrum.01774-21
Maphosa S and Moleleki LN. (2021) Isolation and Characterization of Outer Membrane Vesicles of Pectobacterium brasiliense 1692. Microorganisms 9:1-20. 10.3390/ microorganisms9091918
Jane Chepsergon, Thabiso E. Motaung, Lucy Novungayo Moleleki. (2021) “Core” RxLR effectors in phytopathogenic oomycetes: A promising way to breeding for durable resistance in plants?. Virulence 12(1):1921-1935. 10.1080/21505594.2021.1948277
Collins Kipngetich Tanui, Divine Yutefar Shyntum, Precious K. Sedibane, Daniel Bellieny-Rabelo, Lucy N. Moleleki. (2021) Pectobacterium brasiliense 1692 chemotactic responses and the role of methyl-accepting chemotactic proteins in ecological fitness. 12 10.3389/fpls.2021.650894 PDF
Teresia N. Macharia, Daniel Bellieny-Rabelo, Lucy N. Moleleki. (2020) Transcriptome Profiling of Potato (Solanum tuberosum L.) Responses to Root-Knot Nematode (Meloidogyne javanica) Infestation during A Compatible Interaction. 10.3390/microorganisms8091443
Chepsergon J, Motaung TE, Bellieny-Rabelo D, Moleleki LN. (2020) Organize, Don’t Agonize: Strategic Success of Phytophthora Species. Microorganisms 8(6):917. 10.3390/microorganisms8060917
Shin G, Schacterle JK, Shyntum DY, Moleleki LN, Coutinho T, Sundin GW. (2019) Functional characterization of a global virulence regulator Hfq and identification of Hfq-dependent sRNAs in the plant pathogen Pantoea ananatis. Frontiers in Microbiology 10:1-19. 10.3389/fmicb.2019.02075
Shutt VM, Shin G, van der Waals JE, Goszczynska T, Coutinho T. (2018) Characterization of Ralstonia strains infecting tomato plants in South Africa. Crop Protection 112:56-62. 10.1016/j.cropro.2018.05.013
Siphathele Sibanda, Stanford Kwenda, Collins K. Tanui, Divine Shyntum, Teresa Coutinho, Lucy Moleleki. (2018) Transcriptome profiling reveals the EanI/R quorum sensing regulon in Pantoea ananatis LMG 2665T. Genes 9(3):148. 10.3390/genes9030148
Siphathele Sibanda, Lucy Moleleki, Divine Shyntum, Teresa Coutinho. 2018. Quorum Sensing in Gram-Negative Plant Pathogenic Bacteria. In: Advances in Plant Pathology. Intechopen., London SE1 9SG, United Kingdom, pp 67-89.
Tanui CK, Shyntum DY, Priem SL, Theron J, Moleleki LN. (2017) Influence of the ferric uptake regulator (Fur) protein on pathogenicity in Pectobacterium carotovorum subsp. brasiliense. Plos One 5(12) 10.1371/journal.pone.0177647
Gorshkov V, Kwenda S, Petrova O, Osipova E, Gogolev Y, Moleleki LN. (2017) Global Gene Expression Analysis of Cross-Protected Phenotype of Pectobacterium atrosepticum. PLoS ONE 12(1) 10.1371/journal.pone.0169536
Weller-Stuart T, Toth I, De Maayer P, Coutinho T. (2017) Swimming and twitching motility are essential for attachment and virulence of Pantoea ananatis in onion seedlings. Molecular Plant Pathology 18(5):734-745. 10.1111/mpp.12432
Kwenda S, Motlolometsi TV, Birch PRJ, Moleleki LN. (2016) RNA-seq profiling reveals defense responses in a tolerant potato cultivar to stem infection by Pectobacterium carotovorum ssp. brasiliense. Frontiers in Plant Science 7(1905) 10.3389/fpls.2016.01905
Kwenda S, Birch PRJ, Moleleki LN. (2016) Genome-wide identification of potato long intergenic noncoding RNAs responsive to Pectobacterium carotovorum subspecies brasiliense infection. BMC Genomics 17(614) 10.1186/s12864-016-2967-9
Sibanda S, Theron J, Shyntum DY, Moleleki LN, Coutinho TA. (2016) Characterization of two LuxI/R homologs in Pantoea ananatis LMG 2665 T. Canadian Journal of Microbiology 62(11):893-903. 10.1139/cjm-2016-0143
Moleleki LN, Pretorius RG, Tanui CK, Mosina G, Theron J. (2016) A quorum sensing‐defective mutant of Pectobacterium carotovorum subsp. brasiliense 1692 is attenuated in virulence and unable to occlude xylem tissue of susceptible potato plant stems. Molecular Plant Pathology 10.1111/mpp.12372
Kwenda S, Gorshkov V, Ramesh AM, Naidoo S, Rubagotti E, Birch PRJ, Moleleki LN. (2016) Discovery and profiling of small RNAs responsive to stress conditions in the plant pathogen Pectobacterium atrosepticum. BMC Genomics 17(1) 10.1186/s12864-016-2376-0
Onkendi EM, Ramesh AM, Kwenda S, Naidoo S, Moleleki LN. (2016) Draft Genome Sequence of a Virulent Pectobacterium carotovorum subsp. brasiliense Isolate Causing Soft Rot of Cucumber. Genome Announcements 4(1) 10.1128/genomeA.01530-15 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
Mongae A, Moleleki L. (2015) The effect of β-aminobutyric acid (BABA) on root knot nematode and soft rot pathogen disease complexes in Solanum tuberosum plants. European Journal of Plant Pathology 142(1):117-124. 10.1007/s10658-015-0596-9
Shyntum D, Theron J, Moleleki L, Toth I, Venter SN, Coutinho TA. (2015) Pantoea ananatis utilizes a type VI secretion system for pathogenesis and bacterial competition. Molecular Plant-Microbe Interactions 28(4):420-431. 10.1094/MPMI-07-14-0219-R
De Maayer P, Chan WY, Rubagotti E, Venter SN, Toth IK, Birch PR, Coutinho TA. (2014) Analysis of the Pantoea ananatis pan-genome reveals factors underlying its ability to colonize and interact with plant, insect and vertebrate hosts. BMC Genomics 15:404. 10.1186/1471-2164-15-404 PDF
Onkendi EM, Moleleki LN. (2014) Characterization of Pectobacterium carotovorum subsp. carotovorum and brasiliense from diseased potatoes in Kenya. European Journal of Plant Pathology 139:557-566. 10.1007/s10658-014-0411-z
Shyntum DY, Venter SN, Moleleki LN, Toth I, Coutinho TA. (2014) Comparative genomics of type VI secretion systems in strains of Pantoea ananatis from different environments. BMC Genomics 15:163. 10.1186/1471-2164-15-163
Onkendi EM, Kariuki GM, Marais M, Moleleki LN. (2014) Threat of root-knot nematodes (Meloidogyne spp.) in Africa: a review. Plant Pathology 63(4):727-737. 10.1111/ppa.12202
Petrova O, Gorshkov V, Daminova A, Ageeva M, Moleleki LN, Gogolev Y. (2014) Stress response in Pectobacterium atrosepticum SCRI1043 under starvation conditions: adaptive reactions at a low population density. Research Microbiology 165(2):119-127. 10.1016/j.resmic.2013.11.004
Onkendi EM, Maluleke N, Moleleki LN. (2013) First report of Pectobacterium carotovorum subsp. brasiliense causing soft rot and blackleg diseases of potatoes in Kenya. Plant Disease 98(5):684. 10.1094/PDIS-09-13-0988-PDN
Kubheka GC, Coutinho T, Moleleki N, Moleleki LN. (2013) Colonisation patterns of a mCherry-tagged Pectobacterium carotovorum subsp. brasiliense in potato. Phytopathology 103(12):1269-1279. 10.1094/PHYTO-02-13-0049-R
Onkendi EM, Moleleki LN. (2013) Genetic diversity of root-knot nematodes (Meloidogyne spp.) in potatoes from South Africa. Plant Pathology 62 :1184–1192. 10.1111/ppa.12035
Amy Charkowski, Sylvie Reverchon, Pablo Rodr´ıguez Palenzuela, Michael San Francisco, Ian Toth, Shinji Tsuyumu, Jacquie van der Waals, Jan van der Wolf, Fr´ed´erique Van Gijsegem, Ching-Hong Yang, Nicole Perna, Andrew Pitman, Minna Pirhonen, Carlos Blanco, Guy Condemine, Dominique Expert, Thierry Franza, Christopher Hayes, Nicole Hugouvieux-Cotte-Pattat, Emilia L´ opez Solanilla, David Low, Lucy Moleleki, Iris Yedidia. (2012) The role of secretion systems and small molecules in soft rot Enterobacteriaceae pathogenicity. Annual Review of Phyotopathology 50:425-49. 10.1146/annurev-phyto-081211-173013
Mongae A, Kubheka GC, Moleleki N, Moleleki LN. (2012) The use of fluorescent protein tagging to study interactions between Root Knot Nematodes and Soft Rot Enterobacteriaceae. Letters in Applied Microbiology 56(4):258-63. 10.1111/lam.12045
Onkendi EM, Moleleki LN. (2012) Detection of Meloidogyne enterolobii in potatoes in South Africa and phylogenetic analysis based on intergenic region and the mitochondrial DNA sequences. European Journal of Plant Pathology 135(1):1-5. 10.1007/s10658-012-0142-y
Bulani IS, Moleleki LN, Albertyn J, Moleleki N. (2012) Development of a novel rDNA based plasmid for enhanced cell surface display on Yarrowia lipolytica. AMB Express 2:27. 10.1186/2191-0855-2-27
Moleleki LN, Mongae A, Onkendi EM, Kubheka GC. (2012) Characterisation of Pectobacterium wasabiae causing blackleg and soft rot diseases in South Africa. European Journal of Plant Pathology 135:279-288. 10.1007/s10658-012-0084-4
De Maayer P, Chan WY, Venter SN, Toth IK, Birch PRJ, Joubert F, Coutinho TA. (2010) Genome Sequence of Pantoea ananatis LMG20103, the Causative Agent of Eucalyptus Blight and Dieback. Journal of Bacteriology 192(11):2936-2937. 10.1128/JB.00060-10 PDF
van den Berg N, Berger DK, Hein I, Birch PRJ, Wingfield MJ, Viljoen A. (2009) Genes up-regulated in tolerant cavendish banana roots in response to Fusarium oxysporum f. sp. cubense infection. Acta Horticulturae 828:273-282. PDF
Toth IK , Birch PRJ , Liu H , Pritchard L , Humphries s, Ravensdale M , Moleleki L , Gilroy EM. (2008) What will a genome sequence do for fire blight research? Pectobacterium atrosepticum and potato - A case study. Acta Horticulturae 793:157-162.
Whisson SC, Pritchard L, Toth IK, Hein I, Chapman S, van West P, Grouffaud S, Armstrong MR, Gilroy EM, Morales JG, Avrova AO, Moleleki L, Boevink PC, Birch PR. (2007) A translocation signal for delivery of oomycete effector proteins into host plant cells. Nature 7166 :115-8. 10.1038/nature06203
Toth IK, Birch PRJ, Liu H, Pritchard L, Humphris S, Ravensdale M, Moleleki L, Gilroy EM. (2007) What will a genome sequence do for fire blight research? Pectobacterium atrosepticum and potato - A case study. Acta Horticulturae 793:157-162.
van den Berg N, Berger DK, Hein I, Birch PRJ, Wingfield MJ, Viljoen A. (2007) Tolerance in banana to Fusarium wilt is associated with early up-regulation of cell wall-strengthening genes in the roots. Molecular Plant Pathology 8(3):333-341. 10.1111/j.1364-3703.2007.00389.x PDF
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.
Heinze B, Thokoane LN, Williams NJ, Barnes JM, Rutherford RS. (2001) The smut-sugarcane interaction as a model system for the integration of marker discovery and gene isolation. Proc. S. Afr. Sug. Technol. Ass 75 :88-93.
Thokoane LN, Rutherford RS. (2001) cDNA-AFLP differential display of sugarcane (Saccharum spp, hybrids) genes induced by challenge with the fungal pathogen Ustilago scitaminea (sugarcane smut). Proc. S. Afr. Sug. Technol. Ass 75:104-107.
Watt MP, Thokoane LN, Mycock D, Blakeway F. (2000) In vitro storage of Eucalyptus grandis germplasm under minimal growth conditions. Plant Cell Tissue and Organ Culture 61 (2 ):161-164.
Thokoane LN, Butterfield MK, Harvey M, Huckett BI. (1999) Progress towards a fingertyping database for sugarcane varieties. Proc S Afr Sug Technol. Ass 73:165-.
Pectobacterium brasiliense 1692 Chemotactic Responses and the Role of