What would nature do?

Guillaume Wegria 
Co-founder & CEO of Fyteko

A Belgian agtech start-up asked this very question – and lifted the lid on the little-known science of plant ‘signal’ molecules. Guillaume Wegria, CEO and co-founder of Fyteko, looks at their potential and application.

Climate change remains one of the biggest threats to global crop production, not least because we don’t yet know how significant a problem it may become.

While some scientists suggest that climate change may benefit agriculture – warmer temperatures lengthening growing seasons, and higher levels of carbon dioxide improving photosynthesis – its other possible effects remain uncertain. In growing food, farmers have always had to contend with weather, but climate change brings with it more extreme weather events and new patterns.

Of most concern is the likely greater occurrence of drought events. Crops in parts of the world already struggle – and even fail – owing to inadequate rainfall and high temperatures. If this becomes the norm, we face a monumental challenge to global food security.

Yet these incidences of abiotic stress, as such environmental factors are called, are not new. Plants have evolved to survive, after all. But what is their secret weapon? At Fyteko, we decided to go back to square one: we wanted to discover how nature itself deals with these events.

It’s an unconventional way to tackle the problem facing conventional agriculture, but it’s at the heart of our approach: creating a bio-based economy for agriculture in which safer, smarter and more sustainable practices can flourish.

Hiding in plain sight

We found our first answer in hydrocinnamic acid oligomers: a class of plant compounds that make up part of the plant’s cell wall structure. Cell walls surround all plant cells, providing structural integrity, water regulation and physical protection against damage and pathogenic attack. During periods of abiotic stress, they are one of the first plant organs to be affected.

But while the structural function of hydrocinnamic acid oligomers is well known, our original research discovered a hitherto unknown property, and demonstrated for the first time how this ‘agri-biomolecule’ could be applied to crops as a natural biostimulant.

Our research revealed how hydrocinnamic acid acts as a ‘signal’ molecule. When applied to a healthy crop – soybeans, for example – it appears to ‘prime’ the crop, making it more resilient to subsequent extremes of weather. It stimulates a far quicker reaction to abiotic stress, firing up the plant’s own defence systems to deliver better protection and speedier recovery.

Our discovery is all the more remarkable because this is a single molecule. The vast majority of commercial biostimulants – a fast-growing category in crop protection products – are based on a mixture of different molecules. Often the mode of action of such multi-compound biostimulants is unclear, making it difficult to generate consistent results for analysis and refinement, but Fyteko’s signal molecule, now successfully patented, defines a fully identifiable mode of action.

Plant responses to the signal molecule

Fyteko’s research has shown that plants respond to the signal molecule when it is applied either in foliar form, or as a seed treatment.

It’s the seed treatment that perhaps presents the most interest: it appears to be effective in accelerating germination and early seedling establishment, ‘biopriming’ the crop seeds. Successful early establishment is known to be essential for optimising the crop’s yield potential, but the signal molecule appears to take this a step further, offering additional protection against subsequent abiotic stress.

Figure 1. Growth enhancement of pepper seedling under lab growth conditions. Seed treatment with the signal molecule developed by Fyteko promoted germination and early seed establishment

In experiments where plant seeds were treated with the signal molecule, it triggered a faster response to stress from young plants’ internal defence mechanisms. Osmoprotection increased, as did antioxidant synthesis.

In trials with wheat plants, the Fyteko bioactive was applied as a seed treatment. The objective was to increase plants’ resistance to lack of water (drought stress) and to improve the recovery rate once water became available again. The results (Figure 2) show how a simulated severe drought stress has irreversibly injured the tissue of the untreated plants. Those growing from treated seed, however, show an improved rate of recovery. These results suggest the bioactive could have a role to play in improving crop resilience in the face of episodic drought or prolonged irrigation intervals. With trials showing a yield increase of up to 5%, there’s a clear agronomic benefit too.

Figure 2. Enhanced tolerance to a simulated drought stress of wheat plants growing from seed treated with the signal molecule developed by Fyteko.

Mode of action

So, how does it work?

When applied to seeds, the signal molecule is absorbed by cells. Here, it effects a change in gene transcription which prompts a significant ‘remapping’ of metabolic processes, pathways and cell functions. Effectively, we’re reprogramming the plant’s metabolism, ‘supercharging’ its ability to counter abiotic stress.

Amongst the metabolic changes we’ve observed are the accumulation of osmoprotectants such as proline and other metabolites of low molecular weight; hormone-like active molecules; and low molecular weight organic acids. All these substances are instrumental in the plant’s primary metabolism. Meanwhile, genes affected by the signal molecule include many involved in plant growth as well as others responsible for managing tolerance to saline stress, the presence of heavy metals and phytotoxic chemicals.

Seed treatment formulations

The sometimes sluggish commercialisation of biostimulants is often attributed to the formulation challenge they present. The mixture of substances comprising a biostimulant, the relatively high dosage rates and an often incomplete understanding of interactions with other agrochemicals can add expense and delay in migrating a product safely from the lab into the field.

Not so for Fyteko’s bioactive: its single molecule nature and low application rate eliminate two of the most intractable obstacles, while we’ve invested significantly in research and trials – supported by the deep knowledge of agrochemicals that exists within the Fyteko team – to understand the molecule’s behaviour and performance when incorporated into seed treatment processes. What’s more, despite its biological origins, it displays excellent compatibility across all other chemical and biological products.

This precise understanding of the signal molecules has allowed Fyteko to commercialise two specific formulations to meet the demands of the two largest segments of treated seeds. NURSEED^®HC satisfies the requirements of raw crop seed treatment recipes, employing low volumes of slurry for low-cost solutions. Higher value crops, reliant on higher slurry volumes, can benefit from NURSEED^®Max.

In use, both formulations come with the full support of Fyteko’s technical team, working closely with customers to ensure full compatibility with seed treatment recipes. But the team’s work doesn’t stop there; of vital importance is helping customers validate results from treated crops. It’s clear that customers value this kind of ‘hand holding’ to maximise the benefit they can extract from a new technology such as this signal molecule – and to explore the ‘brave new world’ of the agri-biomolecule.

Figure 3. Features and benefits of the Fyteko signal molecule formulations