Maize a-L-Fucosidase WILTING LEAF1 confers abiotic stress tolerance by acting in vascular development
The yield of crops is often affected by various abiotic stresses, such as heat and drought. In this study, we identified and characterized a novel maize mutant, wilting leaf1 (wl1-ref), which exhibited leaf wilting, dwarfism, and impaired production. The wilting phenotype was exacerbated under multiple abiotic stresses, including high temperature, drought, and salt conditions. The wl1-ref showed severe defects in vascular bundle development, with abnormal or absent protoxylem vessels, leading to compromised water translocation. WL1 encodes a GDSL family a-L-fucosidase localized to the endoplasmic reticulum and cytoplasm, and is highly expressed in vascular-rich tissues including roots, stems, and leaf sheaths. Transcriptome profiling revealed substantial changes in the expression of cell wall biosynthesis-related genes, accompanied by reduced lignin content and disrupted cell wall architecture. Taken together, our results demonstrate that WL1 contributes to water translocation and abiotic stress tolerance in maize by affecting cell wall integrity and vascular development, highlighting its potential as a target for breeding stress-resilient maize varieties.