The increasing scarcity of water derived from the lack of precipitation caused by climate change, together with high temperatures and soil salinity, are some of the major problems facing agriculture today. The water deficit caused by drought and salinity causes osmotic stress that, added to the toxicity of sodium and chloride, produces deficiencies in the intake of some essential nutrients such as potassium, affecting the growth of plants and greatly limiting their agricultural potential, even leading to the death of plants, causing failed harvests. Almost a quarter of all irrigated agricultural land is affected by salinization, which is exacerbated by rising sea levels, increased drought and rising temperatures.

Saline soil impairs the development of lateral roots, which the plant uses to absorb water and nutrients, since salt hinders the plant's ability to recognize the signals of the hormone that regulates their growth, called auxin, causing it to There are fewer lateral roots and, therefore, affecting the health of the plant.

For this reason, much of the scientific research that is being carried out in this regard seeks solutions that allow plants to grow in hostile environments. In this work, researchers from Wageningen University wondered why some plant species are more resistant to salinity than others, for which they chose the Thale cress as a model.

"Previous research already revealed that the LBD16 protein acts as a switch between the plant hormone auxin and lateral root development. LBD16 activates the genes responsible for lateral root development. In saline soil, the functioning of auxin is expected affected, but the levels of the LBD16 protein would also be expected to decrease," says plant physiology professor Christa Testerink. However, as a result of the research, it was discovered that, in watercress, despite the drastic decrease in auxins in a saline environment, the levels of LBD16 increased, allowing the plant to continue producing, although to a lesser extent, lateral roots, which which suggested an alternative process driving the growth of the protein.

"There are tens of thousands of possible candidates that could regulate LBD16 in a plant. You are looking for a needle in a haystack. The predictions make a more specific search possible," explains Aalt-Jan van Dijk, researcher in the Bioinformatics group. Therefore, to do this, they used a computational method in which a machine learning model was fed with transcription factor data from experiments and patterns were used to predict whether a particular transcription factor regulates another or not, which reduced the list of possible candidates to regulate the LBD16 protein.

"We managed to find this route by discovering another activator, the protein ZAT6. This protein assumes the role of auxin regulator," highlights Testerink.

A finding that lays the foundation for future studies on similar local molecular networks related to the growth of lateral roots, helping plants to grow in hostile environments of salinity, drought or high temperatures, which could be of great help to plant breeders. when creating new varieties more resistant to abiotic stress.