Lignin Nanoparticles: A Promising Tool to Improve Maize Physiological, Biochemical, and Chemical Traits

Abstract

Lignin, and its derivatives, are the subject of current research for the exciting properties shown by this biomass. Particularly attractive are lignin nanoparticles for their eco- and biocompatibility compared to other nanomaterials. In this context, the effect of nanostructured lignin microparticles (LNP), obtained from alkaline lignin by acid treatment, on maize plants was investigated. To this end, maize seeds were primed with LNP at five concentrations: 80 mg L−1 (T80), 312 mg L−1 (T312), 1250 mg L−1 (T1250), 5000 mg L−1 (T5000) and 20,000 mg L−1 (T20000). Concerning the dose applied, LNP prompted positive effects on the first stages of maize development (germination and radicle length). Furthermore, the study of plant growth, biochemical and chemical parameters on the developed plants indicated that concerning the dose applied. LNP stimulated beneficial effects on the seedlings (fresh weight and length of shoots and roots). Besides, specific treatments increased the content of chlorophyll (a and b), carotenoid, and anthocyanin. Finally, the soluble protein content showed a positive trend in response to specific dosages. These effects are significant, given the essential biological function performed by these biomolecules. In conclusion, this research indicates as the nanostructured lignin microparticles can be used, at appropriate dosages, to induce positive biological responses in maize. This beneficial action deserves attention as it candidates LNP for biostimulating a crop through seed priming.

Synthesis of a Lignin/Zinc Oxide Hybrid Nanoparticles System and Its Application by Nano-Priming in Maize

“…FTIR analysis of LNP, ZnO-NP, and ZnO@LNP was also conducted. The analysis results, reported in Figure 1 b, showed that in the case of LNP, the typical signals of the nanoscaled lignin already observed in previous investigations were found [ 11 ]. In detail, a broad band at 3600–3300 cm −1 , corresponding to hydroxyl groups in phenolic and carboxylic acids and bands around 2936 and 2840 cm −1 , attributed to C-H stretch present in methyl, methylene, and methoxyl groups, were found.…”

“…LNP suspension was obtained from alkali lignin by hydrochloric acid treatment. Based on the procedures reported in the literature, 4% ( w / v ) of alkali lignin in ethylene glycol was maintained under stirring for 2 h at 35 °C [ 11 ]. Afterwards, HCl (8 mL, 0.25 M) was mildly added to the solution at a rate of 3–4 drops/min.…”

“…From a structural point of view, lignin shows three central structural phenolic units, and their relative amounts depend on the plant botanical origin [ 9 ]. These main structural phenolic motives are indicated as guaiacyl (G), p-hydroxyphenyl (H), and syringyl (S) units [ 9 , 11 ].…”

Transcriptome Analysis Revealed the Key Genes and Pathways Involved in Seed Germination of Maize Tolerant to Deep-Sowing

“…ZmmiR528overexpressing transgenic maize plants had reduced lignin content and rind-penetrometer resistance and were prone to lodging under N-luxury conditions [21]. Besides, appropriate dosages of nanostructured lignin microparticles can be used to improve maize seed germination and radicle length [22]. In previous research, we also found several genes involved in cell-wall synthesis and cell elongation under deep sowing, which may also relate to the lignin metabolism [1,4].…”

Lignin Nanoparticles and Alginate Gel Beads: Preparation, Characterization and Removal of Methylene Blue

“…They are being extracted from a variety of sources, and large-scale production predominantly arises from the bioethanol and xylose/furfural industries [ 3 , 4 ]. Ironically, around 98% of lignin from the paper and/or pulp industries is being burned, considering it a waste by-product and non-optimized energy resource [ 5 , 6 ]. However, a plethora of applications could be envisioned from lignins, for example, in the synthesis of polymers, dyes and fertilizers, as well as as adhesives in ecological and low-carbon plywood [ 7 ].…”