Differential regulation of cell wall diferulates in drought-tolerant and sensitive maize lines
ANA LOPEZ-MALVAR (Spain)1; MOHAMED DHIA EDDINE HAMMAMI (Spain)2; NOEMI GESTEIRO (Spain)3; XOSE CARLOS SOUTO (Spain)4; VALERIE MECHIN (France)1; MATTHIEU REYMOND (France)1; ROGELIO SANTIAGO (Spain)3;
1 - INRAE, Institut Jean-Pierre Bourgin for Plant Sciences (IJPB); 2 - University of Vigo, Facultad de Biología, As Lagoas Marcosende, Spain; 3 - MBG-Spanish National Research Council (CSIC); 4 - E.E. Forestal, Department of Natural Resources and Environmental Engineering; Environmental Agro-biology: Soils and Plants Quality (UVIGO), Associated Unit with MBG (CSIC), Vigo, Spain;
Keywords: Maize leaves; Cell wall remodeling; Drought tolerance mechanisms;
Abstract Topics: Theme 9: Cell Wall Function and Signaling in plant adaptation to Biotic and Abiotic Stresses
Type of Presentation: Poster

Abstract text: It is well known that drought stress triggers profound biochemical remodeling of the plant cell wall; however, the functional role of diferulic acids (DFAs) in drought responses under field conditions remains unclear. We investigated drought-induced changes in cell wall–bound hydroxycinnamates in maize leaves, emphasizing diferulate-mediated cross-linking, using 15 inbred lines contrasting in drought tolerance (primarily biomass preservation) grown under severe water deficit in the field. Water deficit consistently increased total diferulates and specific DFA dimers (8–O–4 and 8–5), indicating enhanced ferulate cross-linking within the wall polysaccharide network, while lignin content remained unchanged. Importantly, the magnitude of diferulate accumulation varied markedly among genotypes: drought-sensitive lines showed pronounced increases in diferulates and a reduced ferulic acid to diferulate ratio, reflecting intensified wall dimerization, whereas tolerant lines exhibited limited compositional changes in diferulates. Multivariate and regression analyses identified reduced DFA 8–5 accumulation and higher nitrogen retention as key determinants of biomass maintenance under drought. These findings indicate that diferulate-mediated wall stiffening represents a biochemical signature of drought sensitivity rather than tolerance, highlighting diferulates as central regulators of drought-induced cell wall remodeling in maize leaves under agronomically realistic conditions.