Maize roots modulate microbial functional traits in the rhizosphere to mitigate drought stress

作者：María Martín Roldán, Henrike Würsig, Mika Tarkka, Roman Paul Hartwig, Monika Wimmer, Еvgenia Blagodatskaya · 发表于：Soil Biology and Biochemistry · 年份：2025 · DOI：10.1016/j.soilbio.2025.109837 · 被引用次数：9 · 研究领域：Soil Carbon and Nitrogen Dynamics、Agronomic Practices and Intercropping Systems、Plant-Microbe Interactions and Immunity

Drought affects soil C sequestration by altering the availability of nutrients to plants and microorganisms. However, the mechanisms of plant-microbe interactions and the potential role of root hairs, which enlarge the root-soil interface, in maintaining rhizosphere processes under drought remain uncertain. We investigated the effect of a 7-day drought on root gene expression in two maize plants, a root hair-deficient mutant and its corresponding wild-type, and its correlation with rhizosphere functions: microbial growth and enzyme kinetics related to organic matter decomposition. Under drought, roots reduced the expression of several chitinase , acid phosphatase and pathogenesis-related genes. In parallel, drought reduced the maximum enzymatic rate of β-glucosidase and acid phosphatase by 3.5- and 1.9-fold, respectively, while the affinity of these enzymes in the rhizosphere increased by 35 and 71 %, respectively, compared to the well-watered treatment. The effect of drought was more pronounced in the rhizosphere of wild-type maize than in that of the mutant. Notably, leucine aminopeptidase and N-acetylglucosaminidase did not respond to drought. Inhibition by high substrate concentrations was observed for β-glucosidase and acid phosphatase only under drought, highlighting the potential use of the substrate inhibition model as a complementary indicator of altered enzyme systems in response to environmental regulators. Finally, drought prolonged the microbial lag phase by up t...