Lanthanum interferes with the fundamental rhythms of stomatal opening, expression of related genes, and evapotranspiration in Arabidopsis thaliana

Abstract

The accumulation of rare earth elements (REEs) in the global environment poses a threat to plant health and ecosystem stability. Stomata located on leaves serve as the primary site for plant responses to REE-related threats. This study focused on lanthanum [La(III)], a prevalent REE in the atmospheric environment. Using interdisciplinary techniques, it was found that La(III) (≤80 µM) interfered with the fundamental rhythms of stomatal opening, related gene expression, and evapotranspiration in plants. Specifically, when exposed to low concentrations of La(III) (15 and 30 µM), the expression levels of six genes were increased, stomatal opening was enhanced, and the evapotranspiration rate was accelerated. The interference on stomatal rhythms was enhanced with higher concentrations of La(III) (60 and 80 µM), increasing the expression levels of six genes, stomatal opening, and evapotranspiration rate. To counter the interference of low concentrations of La(III) (15 and 30 μM), plants accelerated nutrient replenishment through La(III)-induced endocytosis, which the redundant nutrients enhanced photosynthesis. However, replenished nutrients failed to counter the disruption of plant biological rhythms at higher concentrations of La(III) (60 and 80 μM), thus inhibiting photosynthesis due to nutrient deficit. The interference of La(III) on these biological rhythms negatively affected plant health and ecosystem stability.

Keywords

• Rare earth element lanthanum
• Emerging environmental pollutants
• Interfering fundamental biological rhythm
• Stomatal opening
• Evapotranspiration rate
• Metal element contents