麻豆淫院

A sensor that can measure hormone concentrations in plants precisely and in real time with minimal damage can shed light on how hormones affect plants' response to disease and stress. With further development, it could also be part of an agricultural toolkit for early detection of disease or stress, enabling farmers to intervene before extensive crop damage.

A paper describing this technology is in the journal Science Advances.

Plant hormones regulate key aspects of the plant life cycle, including growth and environmental response. In this study, KAUST researchers focused on two hormones related to stress and disease response: salicylic acid and auxin.

Existing techniques for measuring the concentration of these and other hormones rely on genetic engineering or destructive sampling and cannot be readily used in non-model plants. While effective for lab research, they are too laborious and expensive for use in agriculture. These techniques also provide a single snapshot in time rather than the possibility of continuous monitoring.

The new sensor overcomes these problems. It is an electrochemical sensor that detects the concentration of auxin and salicylic acid based on changes in the electro-oxidative current.

Electrodes are placed on the surface of a leaf, and microneedles poke through the leaf's outer surface. The platinum microneedles are coated with a matrix of carbon nanotubes and magnetite, making a complex surface that can bind with auxin and salicylic acid.

When a voltage is applied across the electrodes, electrons are transferred from the hormones to the microneedles. The sensor measures the transfer of electrons鈥攁n electric current鈥攖o determine the concentration of the hormones.

Researchers showed that the sensor could measure auxin and salicylic acid individually and together in tobacco and Arabidopsis plants. Unlike other detection methods, the sensor can also be used with non-model plants, making it a promising tool for agricultural field applications.

Measuring salicylic acid and auxin levels can indicate whether a plant is responding to stress or fighting off disease.

"This technology could be combined with other elements, such as sentinel plants engineered to be more susceptible to a specific type of stress," explains Abdullah Bukhamsin, who led the study.

"This is an exciting advancement for plant science and agriculture," says Khaled Salama, the study's senior author. "Being able to monitor plant stress in real time, without hurting the plant, provides a window into their responses to tough conditions.

"That's especially important for countries like Saudi Arabia, where extreme heat and limited water are challenges for farmers. Tools like this could help make agriculture more sustainable and resilient here and worldwide."

There remain hurdles to overcome before this technology could be used in the field. Repeated measurements are needed to track hormone levels over time, but the sensor's effectiveness drops as material accumulates on the electrodes. An electrochemical cleaning method was introduced to significantly extend the sensor's lifespan, but Bukhamsin says it is not yet sufficient for field use.

"It's currently a great research tool. Our goal is to adapt it for use on farms," says Bukhamsin. "Farmers would deploy it, detect stress, understand what's happening, and intervene early. For example, if there's a disease, they could catch it early enough to act before the pathogen spreads. This would reduce the area needing treatment and help mitigate both commercial and yield losses."