Abstract text: Stem lodging represents a major agronomic constraint in maize (Zea mays L.), leading to yield losses. Because stem mechanical strength is closely linked to the biochemical architecture of the secondary cell wall[1], understanding how phenolic and polysaccharide components contribute to structural integrity is essential. In this study, we investigate the relationship between cell wall composition and lodging susceptibility in four maize genotypes with contrasting resistance levels. Cell walls isolated from the stem cortex were characterized using a multidisciplinary approach combining FTIR-ATR, lignin quantification/histochemical staining and HPLC-PDA analysis of hydroxycinnamic acids.

Multivariate analysis of FTIR-ATR spectra revealed structural variability among genotypes but did not clearly separate resistant and susceptible lines. Although some genotypes differed in lignin content and S/G ratio, lignin/polysaccharide ratios were not associated with lodging resistance. In contrast, susceptible genotypes showed a tendency to accumulate higher levels of p-coumaric acid.

To further elucidate the structural basis of lodging resistance, ongoing analyses by IC and GC-MS are focusing on the composition and substitution pattern of cell wall arabinoxylans, including their feruloylation and potential cross-linking capacity. These data will provide new insights into how arabinoxylan–phenolic interactions contribute to the mechanical properties of maize stems.

[1] Manga-Robles et al (2021) Plant Science 307:110882.