A team of scientists has identified a natural mechanism that helps plants limit water loss. These new findings, explained by Wong, SC et al, in a paper published by Nature, may help agricultural scientists and plant breeders develop more water-efficient crops.

The researchers believe that the discovered water conservation mechanism can be manipulated and, in turn, may hold the key to producing more water-efficient crops.

The scientists, from the Australian National University (ANU) and James Cook University (JCU), have identified an "exquisite" natural mechanism that helps plants limit their water loss with little effect on carbon dioxide (CO2) intake, an essential process for photosynthesis, plant growth and crop yield.

These findings will have significant implications for the agricultural industry and could lead to more resilient crops capable of withstanding extreme weather events, including drought.

How is water loss limited?

Plants continually lose water through pores in the epidermis of their leaves. These same pores allow CO2 to enter the leaves and are critical to their survival. For every unit of CO2 gained, plants typically lose hundreds of units of water.. That is why plants require a lot of water to grow and survive.

The mechanism scientists have shown kicks in when the environment is dry, such as on a hot summer day, to allow the plant to reduce water loss with little effect on CO2 uptake. The researchers believe that this water conservation mechanism can be manipulated and, in turn, may hold the key to producing more water-efficient crops.

Plant scientists have been grappling with this big question of how to increase CO2 uptake and reduce water loss without negatively affecting yields. Having this mechanism that can reduce water loss with little effect on CO2 uptake presents an opportunity for agricultural scientists and plant breeders investigating ways to improve water use efficiency and create drought-tolerant crops.

Although researchers have confirmed that there is a system that works to limit the amount of water lost from the leaf, they still don't know what is causing it.

It is believed that the water passages, called aquaporins, located in cell membranes are responsible for this control.

Once these facts are confirmed, you can start thinking about how to manage these systems and turn them into an asset for the agricultural industry.

Stomata are holes that connect the drier atmosphere to the interconnected network of moister air spaces that surround cells within a leaf. Accurate values ​​of humidities within the substomatal cavity, and in the air, are needed to estimate stomatal conductance and CO2 concentration in the internal air spaces of leaves..

Both are vital factors in understanding plant physiology and climatic, ecological and crop systems. However, there is no easy way to measure them directly.

It was suggested that as moisture variation (Δw) increases, the saturation edge recedes into the intercellular air spaces, accompanied by the progressive closure of aquaporins from the mesophyll to maintain the cytosolic water potential (which is what the main image shows).