Scientists have uncovered how plants modify their root systems during droughts, allowing them to dig deeper into the soil to find water reserves.
Scientists have uncovered how plants modify their root systems during droughts, allowing them to dig deeper into the soil to find water reserves.
A team of researchers from the University of Nottingham, working alongside Shanghai Jiao Tong University, has revealed how abscisic acid (ABA)—a hormone in plants critical for responding to drought—affects the angle at which roots grow in cereal crops such as rice and maize. Their findings are published in Current Biology.
The research shows that ABA and auxin, another significant hormone, cooperate to influence the angles of root growth, offering a promising approach for developing crops that can withstand drought conditions with enhanced root structures.
Drought is a significant threat to global food security, making it essential to improve crop resilience against water scarcity. Over the last decade, drought—an important environmental stressor—has led to losses in crop production amounting to about $30 billion. With the global population expected to reach 10 billion by 2050, coupled with severe depletion of freshwater resources, creating drought-resistant crops is incredibly important.
Plants depend on their root systems, which are vital for engaging with soil, to seek out water actively. During dry spells, water levels often drop in the topsoil, leaving only the deeper subsoil layers with moisture. Abscisic acid (ABA) plays a crucial role in assisting plants to adjust in these tough situations. This new research provides fresh insights into how ABA influences root growth angles, allowing plants to extend into deeper subsoils in search of water.
The researchers identified a novel mechanism in which ABA boosts auxin production, which in turn improves root gravitropism, enabling them to grow at steeper angles during drought. Results showed that plants with genetic mutations that hinder ABA production displayed shallower root angles and a reduced ability to bend in response to gravity compared to normal plants. This deficiency was associated with diminished auxin levels in their roots. When auxin was applied externally, the researchers were able to restore typical root growth in these mutant plants, highlighting auxin’s critical role in the process.
The results were consistent for both rice and maize, indicating that this mechanism may also be relevant for other cereal varieties.
Dr. Rahul Bhosal, an Assistant Professor at the School of Bioscience and one of the lead authors of the study, stated: “It is essential to find solutions for food insecurity, and the more we learn about the processes driving plant growth, the closer we get to creating systems that support plants and boost crop yields during drought conditions.”
