Understanding touch-induced priming of plant resilience

Supervisors: Dr Naomi Nakayama, Dr Steven Spoel

Project Description:

Plants are highly adaptive; they can adjust their development and physiology according to the environment. Intriguingly, exposure to one type of stress seems to be able to enhance their resilience. For example, gentle physical stimulation via stomping or stroking of young seedlings result in boosting of structural strength (shorter and stiffer shoots), as well as tolerance against various types of biotic and abiotic stressors [1]. In fact, for many centuries farmers in Japan have used such natural plant responses as a crop pre-conditioning method (called ‘mugifumi’), which is effective enough to increase the yields of wheat and barley by 20-50% [2]. Such thigmo (touch in Greek)-priming strategy is accessible, low-input, and immediately applicable, and thus has a great potential to catalyse sustainable food security. However, how plants confer the cross-stress-resistance in response to touch stimuli remains unknown.

With this project a PhD student will explore the molecular mechanisms behind touch-induced enhancement of general resilience in plant systems. In Arabidopsis it has been shown that an array of biotic and abiotic stressors share the immediate response factors with the strong compression/wounding of the leaves [3]. Employing RNA-seq technology, global gene expression will be profiled over several days after exposure to stomping or stroking of Arabidopsis seedlings will be monitored and compared to changes induced by drought, water logging, or extreme temperatures. Early phase responses will be characterised especially in detail.

The host lab has a range of synthetic biology tools, having developed some of them in-house (e.g. Mobius Assembly for Plant Systems). Synthetic biology approaches will be taken to create a suite of reporter lines for different early stages of stress responses, and the dynamics of the gene expression will be characterized, using another bespoke platform being developed in the group – a microfluidic single cell trap. In this trap, thousands of single cells can be individually held in a soft polymer ‘cage’, and they can be exposed to chemical or physical stimuli (e.g. compression, temperature change) with high precision, and their responses can be visually monitored by quantitative microscopy. The cells will be compressed, and the chances in the key gene expression will be assessed, alongside the dynamic translocation of Calcium ions and burst of reactive oxygen species.

The student will be trained in molecular and systems investigations of plant stress responses. The student will become familiar to state-of-art methods at the interface of biological and engineering sciences, such as synthetic biology approaches and lab-on-a-chip microfluidic single cell studies. S/he will also be well trained in the RNA-seq analyses of transcriptomics.

[1] Chehab et al. (2012) Arabidopsis touch-induced morphogenesis is jasmonate mediated and protects against pests. Current Biology. 22: 701.
[2] Iida. (2014) Mugifumi, a beneficial farm work of adding mechanical stress by treading to wheat and barley seedlings.. Frontiers in Plant Science. 5: 453.
[3] Walley et al. (2007) Mechanical stress induces biotic and abiotic responses via a novel cis-eement. PLoS Genetics. Doi.org/10.1371/journal.pgen.0030172

If you wish to apply for this project, please go to this link.