title: Water-Soluble Lignins from Different Bioenergy Crops Stimulate the Early Development of Maize (Zea mays, L.).
abstract: The molecular composition of water-soluble lignins isolated from four non-food bioenergy crops (cardoon CAR, eucalyptus EUC, and two black poplars RIP and LIM) was characterized in detail, and their potential bioactivity towards maize germination and early growth evaluated. Lignins were found to not affect seed germination rates, but stimulated the maize seedling development, though to a different extent. RIP promoted root elongation, while CAR only stimulated the length of lateral seminal roots and coleoptile, and LIM improved only the coleoptile development. The most significant bioactivity of CAR was related to its large content of aliphatic OH groups, C-O carbons and lowest hydrophobicity, as assessed by (31)P-NMR and (13)C-CPMAS-NMR spectroscopies. Less bioactive RIP and LIM lignins were similar in composition, but their stimulation of maize seedling was different. This was accounted to their diverse content of aliphatic OH groups and S- and G-type molecules. The poorest bioactivity of the EUC lignin was attributed to its smallest content of aliphatic OH groups and largest hydrophobicity. Both these features may be conducive of a EUC conformational structure tight enough to prevent its alteration by organic acids exuded from vegetal tissues. Conversely the more labile conformational arrangements of the other more hydrophilic lignin extracts promoted their bioactivity by releasing biologically active molecules upon the action of exuded organic acids. Our findings indicate that water-soluble lignins from non-food crops may be effectively used as plant biostimulants, thus contributing to increase the economic and ecological liability of bio-based industries.
authors.affiliation: Interdepartmental Research Center of Nuclear Magnetic Resonance for the Environment, Food Processing and New Materials (CERMANU), Via Università 100, Portici 80055, Italy. davide.savy@unina.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Savy
authors.affiliation: Interdepartmental Research Center of Nuclear Magnetic Resonance for the Environment, Food Processing and New Materials (CERMANU), Via Università 100, Portici 80055, Italy. cozzolino.vincenza@libero.it.
authors.forename: Vincenza
authors.initials: V
authors.lastname: Cozzolino
authors.affiliation: Interdepartmental Research Center of Nuclear Magnetic Resonance for the Environment, Food Processing and New Materials (CERMANU), Via Università 100, Portici 80055, Italy. giovannivinci83@libero.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vinci
authors.affiliation: Interdepartmental Research Center of Nuclear Magnetic Resonance for the Environment, Food Processing and New Materials (CERMANU), Via Università 100, Portici 80055, Italy. antonio.nebbioso@unina.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Nebbioso
authors.affiliation: Interdepartmental Research Center of Nuclear Magnetic Resonance for the Environment, Food Processing and New Materials (CERMANU), Via Università 100, Portici 80055, Italy. alessandro.piccolo@unina.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Piccolo
mesh_terms: D018556:Crops, Agricultural / Q000737:chemistry*; D018525:Germination / Q000187:drug effects; D008031:Lignin / Q000737:chemistry* / Q000494:pharmacology*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012639:Seeds / Q000187:drug effects; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D003313:Zea mays / Q000187:drug effects* / Q000254:growth & development*
chemical_list: D010936:Plant Extracts; D008031:Lignin
keywords: 13C-CPMAS-NMR; 31P-NMR; black poplar; cardoon; eucalyptus; infrared spectrometry; maize growth; maize seed germination; plant biostimulants; water-soluble lignins