Professor Leslie A. Weston

Professor Weston co-founded and currently leads a large multidisciplinary research team, the Plant Interactions Research Group, investigating plant/plant, plant/microbial, plant/herbivore and insect/soil interactions with a focus on invasion ecology and genetics, chemical ecology and signalling, use of biocontrol organisms for pest management, allelopathy and plant interactions with herbivores resulting in toxicity.

Professor Weston has focused on the study of bioactive natural plant products that are involved in plant defence strategies, with a particular emphasis on bioherbicides and phytotoxins. Ground-breaking research techniques employing analytical chemistry, metabolomics, separation science, genomics and population and field ecology has resulted in advances in our understanding of how plants employ secondary products as chemical signalling agents, in defence strategies against pests including weeds and grazing herbivores, localization of these metabolites in the plant and soil rhizosphere and their impact on the function and dynamics of soil microbial communities. Recent studies have also focused on a greater understanding of their role in toxicity to grazing livestock and specific mode of action as herbicides, cytotoxins and photosensitisers.

From an applied standpoint, our laboratory focuses on understanding how weeds and invasive plants adapt to novel environments and spread. Emphasis has been placed on the development of alternative and integrated weed management strategies to limit the spread of herbicide resistant weeds. We study the use of competitive crops, rotational crops, and both chemical, cultural and mechanical approaches to effectively manage weed invaders in crops and pastures. Particular emphasis on study of the biology and ecology of newly emerging weeds such as panic grasses, wild melons, annual ryegrass, fleabane, Paterson’s curse and mikania or mile-a-minute vine have resulted in improved identification and management strategies, and understanding of why these weeds have become successful invaders, both in Australia and more globally.

Plant interactions research group

Research

• Activity and mode of action of natural plant products and their analogues as bioherbicides, pesticides, pheromones & signaling compounds, cytotoxins and photosensitizers
• Biology and genetics of invasive weed species of importance in food, cereal and pasture crops
• Development of integrated weed management strategies to reduce herbicide resistance in crops and pastures in Australia
• The role of plant- and microbially-produced metabolites in the rhizosphere in plant growth regulation and pest resistance
• Use of dung beetles for pest management in grazing livestock in Australia and New Zealand
• The chemistry of plant toxicity in grazing livestock
• Weed seed dispersal and carcass contamination in livestock
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Teaching

Professor Weston provides occasional lectures in Introduction to Science, Weed and Pest Management and Natural Products Chemistry/Separation Science. She supervises honours, Masters and PhD students in weed science, metabolomics, plant and microbial interactions and biomedicinal crop physiology

Plant interactions research group

• Member of the American Chemical Society, Royal Australian Chemical Society, Council of Australasian Weed Science Societies, NSW Weed Science Society.
• Scientific Advisor to Grain Weeds Advisory Committee, a national committee supported by GRDC Australia
• President and past-president of the International Allelopathy Society, Board of Directors of IAS
• Associate Editor of Plant and Soil, Journal of Allelochemical Interactions, Allelopathy Journal and reviewer for numerous plant physiology, chemistry and phytochemistry journals

Plant interactions research group

Localisation, transport and mode of action of allelochemicals and toxins, metabolomics, photosensitisation, plant rhizosphere interactions, ecology and genetic diversity of invasive weeds, weed suppressive crops.

Plant interactions research group

Read Professor Weston's full list of publications CSU Research Output

(Selected publications are listed below)

1. Bertin, C., L. A. Weston, J. Meinwald and F. Schroeder. 2007. Grass roots chemistry: a novel herbicidal compound isolated from fine fescue root exudates. Proc. of the National Academy of Science 104 (43):16964-16969. (The cover article reporting on a novel bioherbicide produced by roots of fine fescue and resulted in selection of weed suppressive fine fescue cultivars and the patented use of m-tyrosine as a bioherbicide).
2. Yang, X., B. Scheffler and L. A. Weston. 2004. SOR1, a gene associated with bioherbicide production in sorghum root hairs. J. Exp. Bot. 55:2251-2259. (The first root hair specific desaturase gene identified representing a key step in the sorgoleone biosynthetic pathway).
3. Zhu, X., D Skoneczny, J.D. Weidenhamer, J. M. Mwendwa, P.A. Weston and L. A. Weston. 2016. Identification and localization of bioactive napthoquinones in the roots and rhizosphere of Paterson’s curse (Echium plantagineum), a noxious invader. J. Experimental Botany 67 (12): 3777-3788. (Cover article outlining the localization and identification of highly bioactive metabolites produced by a noxious invasive species in Australia using novel techniques for separation and characterization).
4. Bertin, C., X. H. Yang, and L. A. Weston. 2003. The role of root exudates and allelochemicals in the rhizosphere. Plant and Soil 256(1):67-83. (A ground-breaking paper that first described the role of plant root exudates and their impacts on allelopathy and soil rhizosphere processes). Now has over 1000 citations.
5. Czarnota, M. A., R.N. Paul, S.O. Duke and L. A. Weston. 2003. Anatomy of sorgoleone-secreting root hairs of sorghum spp. Int. J. Plant Sci. 164: 861-866. (The mechanism of root hair exudation in sorghum seedlings was described for the first time using cellular localization studies).
6. Weston, L.A. and S. O. Duke. 2003. Weed and crop allelopathy. Critical Rev. Plant Sci. 22:367-389. (The first critical review on allelopathy to be published for the broader science community).
7. Czarnota, M.A., R.N. Paul, F.E. Dayan, C.I. Nimbal and L.A. Weston. 2001. Mode of action, localization of production, chemical nature and activity of sorgoleone: a potent PSII inhibitor produced in Sorghum spp. root exudates. Weed Technology 15: 813-825. (In this study, 3D structural activity models were developed to explain the specific mode of action of sorgoleone at the PQ binding site).
8. Barney, J. N., DiTommaso, A.  and L.A. Weston. 2005. Differences in invasibility of two contrasting habitats and invasiveness of two mugwort (Artemisia vulgaris) populations. J. Appl. Ecol. 42:567-576. (This study showed the extraordinary invasion by an introduced perennial Artemisia spp. in field conditions; environment x genetic interactions were involved in production of volatile allelochemicals).
9. Weston, L. A. and U. Mathesius. 2013. Flavonoids: their structure, biosynthesis and role in the rhizosphere, including allelopathy. J. Chemical Ecology 39(2), 283-297. A discussion of the critical and diverse role of flavonoids in impacting plant and microbial interactions through chemical signaling and allelopathy.
10. 1Weston, L. A., P. Ryan and M. Watt. 2012. Mechanisms for cellular transport and release of allelochemicals from plant roots into the rhizosphere. J. Exp. Bot. doi:10.1093/jxb.ers054. (An examination of the molecular and physiological mechanisms utilized by living plant roots to concentrate and release secondary metabolites into the rhizosphere with research in 3 plant systems, suggesting the need for additional studies on gene regulation of transport in plants).