Genetius

The study reveals that the Arabidopsis O-GlcNAc transferase SEC is essential for timely ABA‑induced stomatal closure and drought tolerance, with sec-5 mutants showing delayed closure and increased water loss, while SEC overexpression enhances responsiveness. SEC influences guard‑cell microtubule remodeling, as loss of SEC impairs microtubule reorganization and SEC directly interacts with tubulin α‑4, suggesting tubulin as a target of O‑GlcNAcylation.

The study mapped drought-responsive gene regulatory networks across Arabidopsis thaliana, Arabidopsis lyrata, and Eutrema salsugineum using yeast one-hybrid screening, revealing 1,137 high‑confidence TF‑promoter interactions. Comparative analysis showed that the drought‑tolerant relatives share greater regulatory similarity and network connectivity, including species‑specific expansions in bZIP interactions and rewiring of ABA‑signalling edges, highlighting candidate TFs for improving crop drought tolerance.

The study characterizes the five Arabidopsis SCAMP proteins, identifying conserved tyrosine motifs that mediate anterograde transport and NPF motifs essential for endocytosis, and shows that SCAMPs dimerize for internalization. SCAMP5 interacts with plasma‑membrane aquaporins (PIPs), and scamp mutants exhibit mild developmental delays but increased drought tolerance, likely due to altered PIP trafficking or stability.

Loss‑of‑function mutations in the drought‑induced genes GASA3 and AFP1 confer enhanced drought tolerance in Arabidopsis thaliana, primarily through smaller stomatal apertures and increased ABA accumulation via hydrolysis of ABA‑GE. Constitutive overexpression of these genes heightens drought sensitivity, indicating that the AFP1/GASA3 module negatively regulates stomatal closure and ABA signaling.