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Dr Robert A. Ingle
BA (Hons) Biological Science (Oxford 1998), PhD Plant Sciences (Oxford 2004)
MOLECULAR BASIS OF PLANT STRESS RESPONSES |
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| RESEARCH |
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I am interested in the interactions between plants and their environment. As sessile organisms plants are unable to escape from unfavourable conditions and have consequently evolved an array of molecular mechanisms to cope with biotic and abiotic stresses. In my group we use a variety of genetic and biochemical approaches to study these responses, focusing on the following areas:
Disease resistance in Arabidopsis |
Plant pathogens cause substantial yield losses in agriculture across the world, and there is much interest in engineering crop plants with improved disease resistance. This aim will be facilitated by an understanding of the molecular basis of plant innate immunity. To this end, we are using the Arabidopsis-Pseudomonas syringae and Arabidopsis-Botrytis cinerea interactions to investigate the signalling pathways involved in the establishment of a successful immune response in plants following pathogen detection. Projects currently underway include:
1) The role of HSPRO1 & HSPRO2 in plant innate immunity
HSPRO2 was originally identified as a component of the plant defence response against P. syringae through gene expression profiling of the Arabidopsis defence mutant CIR1. HSPRO2 has a single homologue in Arabidopsis, HSPRO1, which appears to play an antagonistic role to that of HSPRO2 in response to both biotic and abiotic stress. We are attempting to determine the exact biological function of these proteins, and whether they may play a role in metabolic reprogramming of Arabidopsis in response to environmental stress.
2) The OXI1 signalling pathway
OXI1 is a Ser/Thr protein kinase required for full resistance to several plant pathogens. We are attempting to identify upstream regulators of OXI1 expression and investigating the role of this protein in programmed cell death.
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The molecular basis of Ni hyperaccumulation in Senecio coronatus
Extremophile plants such as metal hyperaccumulators are useful model systems to identify genes or patterns of gene expression underlying the molecular basis of extreme tolerance responses, and possible strategies to engineer such tolerance in other plant species. Senecio coronatus (Asteraceae) is a widely distributed geophyte endemic to the grasslands of Southern Africa, southwards from Angola and Tanzania. The Ni rich serpentine outcrops of the Barberton region (Mpumulanga, South Africa) constitute only a small part of this species’ range, but may offer great insight into the evolution of Ni hyperaccumulation in plants. Ni hyperaccumulation is a rare trait, known from some 300 species to date, and is defined as the accumulation of Ni to over 1% dry biomass in the above ground tissues. In marked contrast to other known Ni hyperaccumulating species, where all individuals accumulate Ni whenever it is present in the soil, S. coronatus is apparently unique in that some serpentine populations of this species hyperaccumulate Ni, while adjacent populations do not. We are using S. coronatus as a model system to identify the molecular basis of Ni hyperaccumulation in plants, utilising an –omics approach. This approach will be informed by phylogenetic studies, using neutral genetic markers. We are currently examining the evolutionary relationships between populations in the Barberton region in order to trace the evolution of Ni hyperaccumulation in this species. |
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Histidine biosynthesis in plants
Histidine plays a critical role in plant growth and development as one of the standard twenty amino acids in proteins, and is also an important Ni-binding ligand in several Ni hyperaccumulating species such as Alyssum lesbiacum. High constitutive expression of the first enzyme in the pathway (ATP-phosphoribosyl transferase) correlates with elevated levels of free His in the root tissue of A. lesbiacum, and over-expression of ATP-PRT in Arabidopsis results in both increased free His content and tolerance to Ni. We have recently identified the first histidinol-phosphate phosphatase enzyme from plants, completing the pathway of His biosynthesis. This enzyme is a member of the myo-inositol monophosphatase superfamily, and we are investigating its potential role in other metabolic pathways. We are also interested in determining the pathway of His catabolism in plants, which has yet to be elucidated. |
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| If you are interested in working on any of the projects above, please contact me via email (robert.ingle@uct.ac.za). |
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| RECENT PUBLICATIONS |
Moffat CS, Ingle RA, Wathugala DL, Saunders NJ, Knight H & Knight MR (2012) ERF5 and ERF6 play redundant roles as positive regulators of JA/Et-mediated defense against Botrytis cinerea in Arabidopsis. PLoS ONE 7: e35995. doi:10.1371/journal.pone.0035995
Bhardwaj V, Meier S, Petersen LN, Ingle RA & Roden LC (2011) Defence responses of Arabidopsis thaliana to infection by Pseudomonas syringae are regulated by the circadian clock. PLoS ONE 6: e26968. doi:10.1371/journal.pone.0026968
Ingle RA (2011) Histidine Biosynthesis. The Arabidopsis Book 9:e0141. doi:10.1043/tab.0141
Petersen LN, Marineo S, Mandala S, Davids F, Sewell BT & Ingle RA (2010) The missing link in plant histidine biosynthesis: Arabidopsis myoinositol monophosphatase-like 2 encodes a functional histidinol-phosphate phosphatase. Plant Physiology 152: 1186-1196.
Roden LC & Ingle RA (2009) Lights, rhythms, infection: The role of light and the circadian clock in determining the outcome of plant-pathogen interactions. Plant Cell 21: 2546-2552.
Petersen LN, Ingle RA, Knight MR & Denby KJ (2009) OXI1 protein kinase is required for plant immunity against Pseudomonas syringae in Arabidopsis. Journal of Experimental Botany 60: 3727-3735.
Rees JD, Ingle RA & Smith JAC (2009) Relative contributions of nine genes in the pathway of histidine biosynthesis to control of free histidine concentrations in Arabidopsis thaliana. Plant Biotechnology Journal 7: 499-511.
Ingle RA, Collett H, Cooper K, Takahasi Y, Farrant JM & Illing N (2008) Chloroplast biogenesis during rehydration of the resurrection plant Xerophyta humilis: Parallels to the etioplast-chloroplast transition. Plant, Cell & Environment 31: 1813-1824.
Ingle RA, Fricker MD & Smith JAC (2008) Evidence for nickel-proton antiport activity at the tonoplast of the hyperaccumulator plant Alyssum lesbiacum. Plant Biology 10: 746-753.
Murray SL, Ingle RA, Petersen LN & Denby KJ (2007) Basal resistance against Pseudomonas syringae in Arabidopsis involves WRKY53 and a protein with homology to a nematode resistance protein. Molecular Plant-Microbe Interactions 20:1431-1438.
Ingle RA, Schmidt U, Farrant JM, Thomson JA & Mundree SG (2007) Proteomic analysis of leaf proteins during dehydration of the resurrection plant Xerophyta viscosa. Plant, Cell & Environment 30:435-446.
Ingle RA, Carstens M & Denby KJ (2006) PAMP recognition and the plant-pathogen arms race. BioEssays 28: 880-889.
Ingle RA, Smith JAC & Sweetlove LJ (2005) Responses to nickel in the proteome of the hyperaccumulator plant Alyssum lesbiacum. BioMetals 18: 627-641.
Ingle RA, Mugford ST, Rees JD, Campbell MM & Smith JAC (2005). Constitutively high expression of the histidine biosynthetic pathway contributes to nickel tolerance in hyperaccumulator plants. Plant Cell 17: 2089-2106.
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| LAB MEMBERS |
Delroy Guzha (PhD student)
Anastashia Diener (MSc student)
Michael Wolf (MSc student)
Lance Anders (MSc student, co-supervised with Prof. Gade, Zoology)
Emang Molojwane (MSc student)
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Prof. Kevin Balkwill (University of the Witwatersrand) |
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A/Prof. Katherine Denby (University of Warwick) |
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Prof. Marc Knight (University of Durham) |
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Dr Sandra Marineo (University of Palermo) |
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Prof. Andrew Smith (University of Oxford) |
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| CONTACT |
Dr Robert. A Ingle
Department of Molecular & Cell Biology
University of Cape Town
Private Bag
Rondebosch 7701
SOUTH AFRICA
Tel: +27 21 650 2408
Fax: +27 21 689 7573
Email: robert.ingle@uct.ac.za |
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