Elucidating the multifunctional role of the cell wall components in the maize exploitation

Abstract

Background Besides the use of maize grain as food and feed, maize stover can be a profitable by-product for cellulosic ethanol production, whereas the whole plant can be used for silage production. However, yield is reduced by pest damages, stem corn borers being one of the most important yield constraints. Overall, cell wall composition is key in determining the quality of maize biomass, as well as pest resistance. This study aims to evaluate the composition of the four cell wall fractions (cellulose, hemicellulose, lignin and hydroxycinnamates) in diverse maize genotypes and to understand how this composition influences the resistance to pests, ethanol capacity and digestibility. Results The following results can be highlighted: (i) pests’ resistant materials may show cell walls with low p-coumaric acid and low hemicellulose content; (ii) inbred lines showing cell walls with high cellulose content and high diferulate cross-linking may present higher performance for ethanol production; (iii) and inbreds with enhanced digestibility may have cell walls poor in neutral detergent fibre and diferulates, combined with a lignin polymer composition richer in G subunits. Conclusions Results evidence that there is no maize cell wall ideotype among the tested for optimal performance for various uses, and maize plants should be specifically bred for each particular application.

Cell Wall Composition Impacts Structural Characteristics of the Stems and Thereby the Biomass Yield

“…The composition and proportion of the subunits highly influence the molecular structure of lignin. It affects the degree of crosslinking with the polysaccharides and also the branching of the polymer, affecting, as it has been demonstrated, economically important processes such as biofuel production and digestibility. , In addition, some other related phenylpropanoids also contributed to biomass yield and anatomical traits of the stems. We have shown that a great concentration of PCA in the cell wall is unfavorable for increasing biomass yield and rind puncture resistance.…”

“…The set of inbred lines evaluated can be subdivided into three subsets: (i) inbreed lines included in previous evaluations for resistance to Sesamia nonagrioides or Ostrinia nubilalis, (ii) inbreds used in hybrid combinations for bioenergy and for silage, and (iii) inbreds that perform well in hybrid combinations. A complete and detailed description of the inbreds evaluated can be found in ref .…”

“…Rind puncture resistance, the total number of internodes, and internode diameter were recorded 55 days after flowering, and the rest of the stem description traits were studied 70 days after flowering. A more detailed description of the methodology can be found in López-Malvar et al…”

“…The complete characterization of the cell wall was performed in the second internode below the main ear from five plants per plot, collected 55 days after silking. The complete description of the methodology can be found in López-Malvar et al…”

Genomics of maize resistance to kernel contamination with fumonisins using a multiparental advanced generation InterCross maize population (MAGIC)

“…In the current study, a genome-wide association study (GWAS) approach has been used to find QTL for resistance to fumonisin contamination in an eight-way MAGIC population previously used for locating QTL for FER [ 10 ]. In this MAGIC population founders have shown high diversity for specific traits, FER and fumonisin content among those traits [ 10 , 19 – 25 ]. In addition, MAGIC populations could be used to obtain superior breeding lines for resistance to FER and to fumonisin contamination [ 26 ], or as base materials to perform genomic selection [ 27 ].…”