Doctor Jamie Waterman


Graduated PhD 2022

Thesis Title

Integrating Simulated and True Herbivory with an Emphasis on Rapidly Deployed Anti-herbivore Silicon Defences

Research Project

Silicon (Si) is the second most abundant element in earth’s crust and is thus ubiquitous in soil systems. This considered, certain classes of plants have evolved the ability to uptake and transport Si between tissues. Nevertheless, the functional role of Si in plant biology remains ambiguous.

Although it has been well documented that Si may modify chemical defence capabilities of plants, the mechanisms through which this is achieved have not been well documented. Further, when a plant is attacked by an insect herbivore, numerous stimuli are introduced such as mechanical stimulation, wounding, and chemical elicitation from both insect- and microbial symbiont-derived compounds. Using simulated herbivory techniques (see Waterman et al., 2019 (opens in a new window) ), I will investigate the role of Si in defence responses against each of the aforementioned stimuli in order to understand the mechanisms through which Si helps to confer resistance against herbivore attack. Additionally, Si might also assist with defence against herbivory by acting as a physical barrier, abrading the insect alimentary tract and/or hindering nutrient absorption; beyond solely chemical defences, I will attempt to realise the influence of Si on the nutritional qualities of plant tissue. By identifying the functional role of Si in mediating plant defences, it may be possible to determine the evolutionary basis for the accumulation and transport of Si by plants, and may help to inform useful pest mitigation strategies that avoid the use of costly and potentially harmful chemical treatments.


Johnson SN, Cibils-Stewart X, Waterman JM, Biru FN, Rowe RC, Hartley SE, (2022) 'Elevated atmospheric CO 2 changes defence allocation in wheat but herbivore resistance persists', Proceedings of the Royal Society B: Biological Sciences, vol.289, no.1969, Article no.20212536

Putra R, Waterman JM, Mathesius U, Wojtalewicz D, Powell JR, Hartley SE, Johnson SN, (2022) 'Benefits of silicon-enhanced root nodulation in a model legume are contingent upon rhizobial efficacy', Plant and Soil, vol.477, pp 201–217

Johnson SN, Waterman JM, Wuhrer R, Rowe RC, Hall CR, Cibils-Stewart X, (2021) 'Siliceous and non-nutritious: Nitrogen limitation increases anti-herbivore silicon defences in a model grass', Journal of Ecology, (in press)

Waterman JM, Cibils-Stewart X, Cazzonelli CI, Hartley SE, Johnson SN, (2021) 'Short-term exposure to silicon rapidly enhances plant resistance to herbivory', Ecology, vol.102, no.9, Article no.e03438

Waterman JM, Hall CR, Mikhael M, Cazzonelli CI, Hartley SE, Johnson SN, (2021) 'Short-term resistance that persists: Rapidly induced silicon anti-herbivore defence affects carbon-based plant defences', Functional Ecology, vol.35, no.1, pp 82-92

Hall CR, Dagg V, Waterman JM, Johnson SN, (2020) 'Silicon alters leaf surface morphology and suppresses insect herbivory in a model grass species', Plants, vol.9, no.5, Article no.643

Johnson SN, Waterman JM, Hall CR, (2020) 'Increased insect herbivore performance under elevated CO2 is associated with lower plant defence signalling and minimal declines in nutritional quality', Scientific Reports, vol.10, no.1, Article no.14553

Waterman JM, D'Amato AW, Foster DR, Orwig DA, Pederson N, 'Historic forest composition and structure across an old-growth landscape in New Hampshire, USA', Journal of the Torrey Botanical Society, vol.147, no.4, pp 291-303

Waterman JM, Mann TJ, Cazzonelli CI, Hartley SE, Johnson SN, (2020) 'Microbes in Helicoverpa armigera oral secretions contribute to increased senescence around plant wounds', Ecological Entomology, vol.45, no.5, pp 1224-1229

Hall CR, Waterman JM, Vandegeer RK, Hartley SE, Johnson SN, (2019) 'The Role of Silicon in Antiherbivore Phytohormonal Signalling', Frontiers in Plant Science, vol.10, Article no.1132

Waterman JM, Cazzonelli CI, Hartley SE, Johnson SN, (2019) 'Simulated Herbivory: The Key to Disentangling Plant Defence Responses', Trends in Ecology & Evolution, vol.34, no.5, pp 447-458


Assoc. Prof. Scott Johnson, Dr. Chris Cazzonelli, Prof. Susan Hartley (University of York)