Title : Metabolites changing in maize inbred lines grain under water deficit condition
Abstract:
In temperate regions worldwide, ongoing climate change has led to frequent and severe summer droughts, resulting in a significant reduction in maize grain yields. The activation of specific physiological processes enables plants to acclimate and adapt to challenging environmental conditions, resulting in metabolic changes that minimise stress-related damage. This study aimed to evaluate the status of secondary metabolites in the grain of maize inbred lines under irrigation treatment (i.e., 75% of full irrigation) and non-irrigation treatment (considered a water deficit condition). The tested inbred lines are components of maize hybrids developed at the Maize Research Institute “Zemun Polje”, belonging to different heterotic groups. Water stress can trigger the plant's defence mechanisms, including the synthesis of carotenoids and tocopherols, which possess antioxidant properties and protect the plant from the harmful effects of reactive oxygen species (ROS) produced during stress. High-performance liquid chromatography (HPLC) was employed to determine the carotenoid and tocopherol content in maize kernels. A contrasting trend in carotenoid levels was observed under water deficit conditions; two inbreds exhibited an increase in the levels of lutein + zeaxanthin and β-carotene, while the other two displayed a decrease. With regard to tocopherol content, water deficit conditions indicated increased levels of all three tocopherols (δ, α, and γ-tocopherol), with the exception of one inbred line. However, the pronounced increase in secondary metabolite content under water deficit conditions indicates their crucial role in mitigating the harmful effects of water deficit stress, which may be useful in maize breeding for drought tolerance selection.
