Plants use engineering principles to push through hard soil
University of Copenhagen
image:
Cross-section of plant root in normal vs dense media.
view moreCredit: Figure from the scientific article in Nature
Across the globe, soil compaction is becoming an ever more serious challenge. Heavy vehicles and machinery in modern agriculture compress the soil to such an extent that crops struggle to grow. In many regions, the problem is aggravated by drought linked to climate change.
But plants may in fact be able to solve part of the problem themselves – with a little help from us. It is already known that when soil becomes dense and difficult to penetrate, plants can respond by thickening their roots. Until now, however, it has remained unclear how they manage this, beyond the fact that the plant hormone ethylene plays a key role.
Researchers from the University of Copenhagen, Shanghai Jiao Tong University, the University of Nottingham and partners have now pieced together the mechanism. Their results have been published in the prestigious journal Nature.
“Because we now understand how plants ‘tune’ their roots when they encounter compacted soil, we may prime them to do it more effectively,” says Staffan Persson, professor at the University of Copenhagen and senior author of the study.
A biological wedge in the soil
The team found that when soil is compacted and ethylene accumulates around the root, the hormone activates a gene called OsARF1. This gene reduces the production of cellulose in certain root cells, making the middle layer of the root thinner, softer and more flexible. This allows the cells to swell and the root to expand. At the same time, the outermost layer of the root (the epidermis) becomes thicker and stiffer.
“In other words, the root changes its structure in line with a basic engineering principle: the larger a pipe’s diameter and the stronger its outer wall, the better it can resist buckling when pushed into a compact material,” explains Bipin Pandey, senior author and associate professor at the University of Nottingham.
The combination of root swelling and a reinforced outer layer allows the root to act as a kind of biological wedge, easing its way down through the soil.
“It’s fascinating to see how plants draw on mechanical concepts familiar from construction and design to solve biological challenges,” says Staffan Persson.
Helping plants grow better in hard soil
The study also reveals how this mechanism can be amplified:
“Our results show that by increasing the levels of a specific protein – a transcription factor – the root becomes better able to penetrate compact soil. With this new knowledge, we can begin redesigning root architecture to cope more effectively with compacted soils. This opens new avenues in crop breeding,” says first author Jiao Zhang, postdoc at Shanghai Jiao Tong University.
Although the experiments were conducted in rice, the researchers believe the mechanism applies broadly across plant species. Parts of the same mechanism have also been identified in Arabidopsis, which is evolutionarily distant from rice.
“Our results could help develop crops that are better equipped to grow in soils compacted by agricultural machinery or climate-related drought. This will be crucial for future sustainable agriculture,” says professor and senior author Wanqi Liang from Shanghai Jiao Tong University.
The work also opens new opportunities in plant breeding more generally. The team has identified many additional transcription factors that appear to be key regulators of cellulose production – with far-reaching implications for plant form and structure. For example, it may become possible to design plants with different shapes, which could benefit certain crops.
“The transcription factors we’ve discovered are a goldmine for cell-wall biology. There’s more than enough here to keep me busy until retirement,” concludes Staffan Persson.
The study is the result of a collaboration between researchers in China, the UK, Japan, Argentina and Denmark, drawing on laboratory experiments, genetic analyses and advanced microscopy.
WHAT THE RESEARCHERS FOUND
- When soil becomes compacted, the plant hormone ethylene accumulates around the roots, triggering a chain reaction that alters root structure.
- Ethylene activates the gene OsARF1 in the root cortex (the middle layer), reducing production of cellulose – a key cell-wall component.
- Lower cellulose levels make cortex cell walls thinner and more flexible, allowing cells to swell and the root to expand.
- Meanwhile, the epidermis (the outer root layer) becomes thicker and more robust. The combination of a soft cortex and a strong epidermis helps roots push through hard soil.
ABOUT THE STUDY
- The research article is published in Nature.
- Contributing institutions include Shanghai Jiao Tong University; the University of Nottingham; Universidad Argentina de la Empresa; the National Institute of Advanced Industrial Science and Technology; Zhejiang University; Duke University; Ludwig Maximilian University; and the University of Copenhagen.
The compacted soil (right) triggers shorter root length than non-compacted soil (left) condition.
Credit
Figure from the scientific article in Nature
Journal
Nature
Article Title
Ethylene modulates cell wall mechanics for root responses to compaction
Article Publication Date
26-Nov-2025
Making LAZY plants stand up: Research reveals new pathway plants use to detect gravity
image:
With their gravity-detecting genes turned off, these grassy plants grow along the soil’s surface. The inset image shows SLQ1 proteins that have been fluorescently tagged in a cell.
view moreCredit: Edgar Spalding/University of Wisconsin–Madison
A study by researchers at the University of Wisconsin–Madison has revealed a previously unknown pathway plants use to detect gravity and orient the direction they grow in. Publishing this week in Proceedings of the National Academy of Sciences, the study may one day open the door for improvements in crop cultivation.
Prior studies have already established that a suite of genes, nicknamed LAZY, control a pathway plants use for detecting gravity. In a typical plant, cells within the stem use LAZY genes to detect the force of gravity. The plant can then guide the stem to grow upwards, branches to grow outwards, and roots to grow downwards. These controlled directions of growth help a plant optimize its shape for energy production, stability and overall survival.
When LAZY genes are turned off, the mutated plant cannot properly orient itself. Instead, it sprawls along the soil surface, its stem bending in all the wrong directions. These specimens are aptly nicknamed LAZY plants.
Coauthors Edgar Spalding, an emeritus professor of botany, and Takeshi Yoshihara, a research scientist at UW–Madison, wanted to learn more about the genetics behind plants’ ability to detect gravity. Using Arabidopsis, a kind of plant commonly used in research, they turned off the plants’ LAZY genes and got to work.
“We decided to mutate these LAZY plants, this plant that doesn’t know which way it’s going, and hope we hit a gene that somehow corrects the problem,” says Spalding.
Spalding and Yoshihara began randomly mutating the LAZY plants. They went through thousands of mutations before finally finding an unstudied gene called SLQ1, or suppressor of LAZY quadruple 1.
“Two wrongs can make a right sometimes,” Spalding says.
Spalding and Yoshihara found that when both LAZY genes and the SLQ1 gene are turned off, the resulting plant stem didn’t crawl along the soil but instead reached up into the air. They also found the genes controlling the two pathways are located in different parts of the cell and that the pathways function independently of each other.
Spalding says there are many reasons plants may need more than one way of detecting gravity. This SLQ1 pathway could be a backup process waiting in the wings to step in, should something malfunction with the LAZY genes. Further research is needed to investigate how the pathways function together, but Spalding thinks they likely work together to optimize the plant’s growth and fine-tune its architecture over time.
“Gravity guides plant growth through a more complicated mechanism than ever appreciated before,” Spalding says.
With more research, understanding how gravity influences the way a plant grows could help producers breed crops with finely tuned root, stem and branch architectures that make it easier for growers to harvest, maximize yield and grow more resistant crops.
This research was supported by a grant from the National Science Foundation (2124689).
Journal
Proceedings of the National Academy of Sciences
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
SUPPRESSOR OF LAZY QUADRUPLE 1 acts at ER–plasma membrane contact sites to control a gravitropism pathway in the Arabidopsis stem
Article Publication Date
26-Nov-2025
How plants search for nutrients
Lateral roots as an adaptation
image:
Plants are able to develop lateral roots when nutrients are scarce.
view moreCredit: Andreas Heddergott / TUM
What makes plants tolerant to nutrient fluctuations? An international research team led by the Technical University of Munich (TUM) and involving the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) has investigated this question on the micronutrient boron. The researchers analyzed 185 gene data sets from the model plant Arabidopsis. Their goal is to then be able to transfer the findings to the important crop plant rapeseed.
Boron is one of the key micronutrients for the growth and fertility of many plants. However, extreme weather events reduce the availability of this nutrient: drought reduces boron uptake, while flooding washes the nutrient out of the soil – less boron reaches the plants. In the context of climate change, this deficiency represents an additional stressor for plants. Their tolerance to these fluctuations is a decisive factor in determining their yields.
Lateral roots extend search radius
Researchers at TUM analyzed 185 subgroups of the species Arabidopsis thaliana from all over the world and searched for boron-efficient plants. Seven of them—especially those from boron-poor soils in Northern Europe—were able to grow well even with little boron. “Each of these plants may have developed different strategies to cope well with boron deficiency,” explains Prof. Patrick Bienert, Professor of Crop Physiology at TUM. Some are particularly good at absorbing boron, while others make better use of even these small amounts of boron.
The team's analysis revealed a common adaptation in the root architecture. When boron is scarce, boron-efficient plants go in search of food: they are able to grow long, lateral roots, thus increasing their radius for nutrient uptake.
Genes for boron efficiency identified
The genetic mechanisms that control boron efficiency in plants are still poorly understood. In their work, the researchers identified gene regions responsible for boron utilization and uptake in roots and shoots. These findings could help breed nutrient-resilient plants.
Transfer to crop plants
Building on these results, the researchers are now investigating the crop plant rapeseed. Since rapeseed, like Arabidopsis, is a cruciferous plant, the researchers are optimistic that they will be able to transfer the findings and soon obtain promising results.
“Crop plants are usually more sensitive to abiotic stressors, such as fluctuating micronutrient supply,” explains Patrick Bienert. “We want to find particularly efficient individuals, identify their strategies, and then breed these traits into lines that deliver high yields. This could result in plants that are both high-yielding and more climate-resilient.”
Journal
New Phytologist
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Arabidopsis thaliana exhibits wide within-species variation in tolerance to boron limitation and root and shoot trait resilience associate with a pleiotropic locus
Article Publication Date
26-Nov-2025
