At first glance, plants may seem passive - but beneath their stillness lies a world of complexity and constant activity. Plants are highly sensitive to their surroundings, continuously monitoring environmental signals to adapt and survive. Think of them as nature's nosy neighbours, always alert to what's happening around them.
Author
- Miguel de Lucas
Associate Professor in Biosciences, Durham University
From subtle shifts in light and temperature to the presence of pollinators, microbes, or changes in soil salinity, plants can detect a range of cues . In response, they can alter growth direction, delay flowering or produce protective chemicals.
My colleagues and I have created a cell-by-cell map of how plants respond to signals from the soil. The map offers insight into plant behaviour in an unprecedented level of detail. It could change our understanding of how living things adapt to their environment and help plants survive climate change.
Many people think of plants as nice-looking greens. Essential for clean air, yes, but simple organisms. A step change in research is shaking up the way scientists think about plants: they are far more complex and more like us than you might imagine. This blossoming field of science is too delightful to do it justice in one or two stories.
This article is part of a series, Plant Curious , exploring scientific studies that challenge the way you view plantlife.
First it's important to understand how genes work within an organism.
The human genome contains roughly 20,000 genes . But, like other animals and plants, not all these genes are active at the same time or in every cell. It's called selective gene expression . For years, scientists believed that selective gene expression was the main explanation for why our skin cells differ from muscle cells even though they carry the same genetic blueprint. Each cell type activates a unique set of genes, producing proteins that define its structure and function.
But scientific discoveries over the last decade or so have been revealing that there's more to the story. It is becoming clearer that the function of a cell is also determined by what happens to those proteins afterwards.
Once a protein is made, it can undergo chemical modifications that alter its behaviour. Think of it like using a tool. If you need to see far away, you might pick up a telescope. You're still the same person, but now with enhanced vision. Similarly, a protein can be "upgraded" with a tag that boosts its activity. On the flip side, imagine being fitted with a ball and chain - your movement is restricted. Cells do something similar to proteins they produce, attaching molecules that either activate or suppress their function.
This process, known as post-translational modification (PTM), adds a new layer of complexity to biology. The first PTM identified was phosphorylation in 1906 . Scientists have since identified over 500 types of these modifications. For example, ubiquitination , a tag that often marks proteins for destruction. It's the cell's way of cleaning house, disposing of proteins that are no longer needed, much like washing and storing your coffee mug after use (though some of us are better at that than others!).
These tiny molecular tweaks help cells respond to changing conditions, regulate their internal machinery and maintain the organism's health.
Most PTMs involve complex processes that take place in different parts of the cell, making them difficult for scientists to track and understand. But sumoylation , a type of PTM, relies on a simpler set of enzymes. And researchers believe this streamlined system is closely tied to its role in helping cells respond to their environment.
This is especially important in plants, where environmental cues like light, temperature, humidity and drought influence developmental stages such as germination, flowering and leaf shedding. These cues also affect structure, like root complexity and stem branching. Understanding how plants use sumoylation to interpret and respond to these signals could pave the way for smarter, more sustainable agricultural practices.
To unravel how sumoylation operates in plants, a group of scientists in the UK - supported by the Biotechnology and Biological Sciences Research Council - formed a research consortium. This initiative brought together experts (including me) from four universities: Durham, Nottingham, Cambridge and Liverpool.
The consortium's first hurdle was to build a system that could track the activity of every enzyme involved in SUMO production within the model plant Arabidopsis thaliana. Many people also know this plant as thale cress and it is common to find it in the edge of roads and walking paths. This plant was chosen for its simple structure, well-studied genetic makeup, and predictable responses to environmental changes - making it ideal for studying complex biological processes.
This system allowed my colleagues and I to monitor when and where each component of the SUMO machinery was active, alongside the proteins it modifies. The platform also enabled deeper molecular analysis, such as identifying previously unknown molecular partners.
The next challenge was to explore how each component of the SUMO system behaves when plants face environmental stress. The team focused on drought, saltiness of soil or water and pathogen attack. Since roots are often the first part of the plant to sense and respond to these threats, we zoomed in on this organ to understand its role in stress adaptation.
Our findings revealed that drought stress triggers SUMO signalling deep within the root's inner tissues, while salt stress is sensed at the outer layers. And pathogen attacks activate responses in the root's dividing cells. Dividing cells are those that have just been made and have not reached maturity. All these stress signals appear to converge on a single protein, SCE1. This protein helps attach SUMO to molecular hubs that guide cellular changes.
This makes SCE1 a promising candidate for developing new strategies to boost plant resilience. If we enhance SCE1's function, it may be possible to help plants respond more swiftly to drought and initiate protective mechanisms to conserve water before damage becomes irreversible.
Understanding how PTMs shape cell adaptation and protein function opens new avenues for tackling stress in plants. But the implications go far beyond agriculture. The same principles apply to animal and human health, where PTMs play critical roles in immunity, development and disease resistance. Unlocking their secrets could change how we approach everything from crop resilience to medical therapies.
Miguel de Lucas receives funding from BBSRC
