The Use of Carbohydrate Biopolymers in Plant Protection against Pathogenic Fungi

Adhesion Peptide-Functionalized Biobased Microgels for Controlled Delivery of Pesticides

Widespread use of plant protection agents in agriculture is a major cause of pollution. Apart from active ingredients, the environmental impact of auxiliary synthetic polymers should be minimized if they are highly persistent. An alternative to synthetic polymers is the use of natural polysaccharides, which are abundant and biodegradable. In this study, we explore pectin microgels functionalized with anchor peptides (P-MAPs) to be used as an alternative biobased pesticide delivery system. Using copper as the active ingredient, P-MAPs effectively prevented infection of grapevine plants with downy mildew under semi-field conditions on par with commercial copper pesticides. By using anchor peptides, the microgels tightly bind to the leaf surface, exhibiting excellent rain fastness and prolonged fungicidal activity. Finally, P-MAPs are shown to be easily degradable by enzymes found in nature, demonstrating their negligible long-term impact on the environment.

Integrative omics studies revealed synergistic link between sucrose metabolic isogenes and carbohydrates in poplar roots infected by Fusarium wilt

Advances in carbohydrate metabolism prompted its essential role in defense priming and sweet immunity during plant-pathogen interactions. Nevertheless, upstream responding enzymes in the sucrose metabolic pathway and associated carbohydrate derivatives underlying fungal pathogen challenges remain to be deciphered in Populus, a model tree species. In silico deduction of genomic features, including phylogenies, exon/intron distributions, cis-regulatory elements, and chromosomal localization, identified 59 enzyme genes (11 families) in the Populus genome. Spatiotemporal expression of the transcriptome and the quantitative real-time PCR revealed a minuscule number of isogenes that were predominantly expressed in roots. Upon the pathogenic Fusarium solani (Fs) exposure, dynamic changes in the transcriptomics atlas and experimental evaluation verified Susy (PtSusy2 and 3), CWI (PtCWI3), VI (PtVI2), HK (PtHK6), FK (PtFK6), and UGPase (PtUGP2) families, displaying promotions in their expressions at 48 and 72 h of post-inoculation (hpi). Using the gas chromatography-mass spectrometry (GC-MS)-based non-targeted metabolomics combined with a high-performance ion chromatography system (HPICS), approximately 307 metabolites (13 categories) were annotated that led to the quantification of 46 carbohydrates, showing marked changes between three compared groups. By contrast, some sugars (e.g., sorbitol, L-arabitol, trehalose, and galacturonic acid) exhibited a higher accumulation at 72 hpi than 0 hpi, while levels of α-lactose and glucose decreased, facilitating them as potential signaling molecules. The systematic overview of multi-omics approaches to dissect the effects of Fs infection provides theoretical cues for understanding defense immunity depending on fine-tuned Suc metabolic gene clusters and synergistically linked carbohydrate pools in trees.

Nano/Micro-Structural Supramolecular Biopolymers: Innovative Networks with the Boundless Potential in Sustainable Agriculture

Sustainable agriculture plays a crucial role in meeting the growing global demand for food while minimizing adverse environmental impacts from the overuse of synthetic pesticides and conventional fertilizers. In this context, renewable biopolymers being more sustainable offer a viable solution to improve agricultural sustainability and production. Nano/micro-structural supramolecular biopolymers are among these innovative biopolymers that are much sought after for their unique features. These biomaterials have complex hierarchical structures, great stability, adjustable mechanical strength, stimuli-responsiveness, and self-healing attributes. Functional molecules may be added to their flexible structure, for enabling novel agricultural uses. This overview scrutinizes how nano/micro-structural supramolecular biopolymers may radically alter farming practices and solve lingering problems in agricultural sector namely improve agricultural production, soil health, and resource efficiency. Controlled bioactive ingredient released from biopolymers allows the tailored administration of agrochemicals, bioactive agents, and biostimulators as they enhance nutrient absorption, moisture retention, and root growth. Nano/micro-structural supramolecular biopolymers may protect crops by appending antimicrobials and biosensing entities while their eco-friendliness supports sustainable agriculture. Despite their potential, further studies are warranted to understand and optimize their usage in agricultural domain. This effort seeks to bridge the knowledge gap by investigating their applications, challenges, and future prospects in the agricultural sector. Through experimental investigations and theoretical modeling, this overview aims to provide valuable insights into the practical implementation and optimization of supramolecular biopolymers in sustainable agriculture, ultimately contributing to the development of innovative and eco-friendly solutions to enhance agricultural productivity while minimizing environmental impact.

Biopolymers as Seed-Coating Agent to Enhance Microbially Induced Tolerance of Barley to Phytopathogens

Infections of agricultural crops caused by pathogen ic fungi are among the most widespread and harmful, as they not only reduce the quantity of the harvest but also significantly deteriorate its quality. This study aims to develop unique seed-coating formulations incorporating biopolymers (polyhydroxyalkanoate and pullulan) and beneficial microorganisms for plant protection against phytopathogens. A microbial association of biocompatible endophytic bacteria has been created, including Pseudomonas flavescens D5, Bacillus aerophilus A2, Serratia proteamaculans B5, and Pseudomonas putida D7. These strains exhibited agronomically valuable properties: synthesis of the phytohormone IAA (from 45.2 to 69.2 µg mL-1), antagonistic activity against Fusarium oxysporum and Fusarium solani (growth inhibition zones from 1.8 to 3.0 cm), halotolerance (5-15% NaCl), and PHA production (2.77-4.54 g L-1). A pullulan synthesized by Aureobasidium pullulans C7 showed a low viscosity rate (from 395 Pa·s to 598 Pa·s) depending on the concentration of polysaccharide solutions. Therefore, at 8.0%, w/v concentration, viscosity virtually remained unchanged with increasing shear rate, indicating that it exhibits Newtonian flow behavior. The effectiveness of various antifungal seed coating formulations has been demonstrated to enhance the tolerance of barley plants to phytopathogens.

Establishment and application of quantitative detection of Bacillus velezensis HMB26553, a biocontrol agent against cotton damping-off caused by Rhizoctonia

A highly sensitive quantitative PCR (qPCR) method was developed for detection and quantification of Bacillus velezensis HMB26553 in cotton rhizosphere. The study aimed to develop a quantitative detection method for the strain HMB26553, and explore the relationship between its colonization of the cotton rhizosphere and its control effect. The whole genome sequence of strain HMB26553 was obtained by genome sequencing and a unique specific sequence pB-gene0026 on plasmid plaBV2 was identified by using high-throughput alignment against NCBI. Plasmid plaBV2 could be stably genetically inherited. Based on this sequence, specific primers for amplifying 106 bp and a minor groove binder (MGB) TaqMan probe for enhancing sensitivity were designed. The copy number of plaBV2 in strain HMB26553, which was 2, was confirmed by internal reference primers and the MGB TaqMan probe based on housekeeping gene gyrB. The established detection technique based on these primers and probes had high specificity and sensitivity compared to traditional plate counting method, with a detection limit of 1.5 copy genome. Using this method, the study discovered a likely correlation between the quantity of colonization in cotton rhizosphere and efficacy against cotton damping-off caused by Rhizoctonia after seed soaking and irrigation with strain HMB26553. Thus, this method provides scientific support for the rational application of strain HMB26553 in the future.

Exploring the diverse applications of Carbohydrate macromolecules in food, pharmaceutical, and environmental technologies

Carbohydrates are a class of macromolecules that has significant potential across several domains, including the organisation of genetic material, provision of structural support, and facilitation of defence mechanisms against invasion. Their molecular diversity enables a vast array of essential functions, such as energy storage, immunological signalling, and the modification of food texture and consistency. Due to their rheological characteristics, solubility, sweetness, hygroscopicity, ability to prevent crystallization, flavour encapsulation, and coating capabilities, carbohydrates are useful in food products. Carbohydrates hold potential for the future of therapeutic development due to their important role in sustained drug release, drug targeting, immune antigens, and adjuvants. Bio-based packaging provides an emerging phase of materials that offer biodegradability and biocompatibility, serving as a substitute for traditional non-biodegradable polymers used as coatings on paper. Blending polyhydroxyalkanoates (PHA) with carbohydrate biopolymers, such as starch, cellulose, polylactic acid, etc., reduces the undesirable qualities of PHA, such as crystallinity and brittleness, and enhances the PHA's properties in addition to minimizing manufacturing costs. Carbohydrate-based biopolymeric nanoparticles are a viable and cost-effective way to boost agricultural yields, which is crucial for the increasing global population. The use of biopolymeric nanoparticles derived from carbohydrates is a potential and economically viable approach to enhance the quality and quantity of agricultural harvests, which is of utmost importance given the developing global population. The carbohydrate biopolymers may play in plant protection against pathogenic fungi by inhibiting spore germination and mycelial growth, may act as effective elicitors inducing the plant immune system to cope with pathogens. Furthermore, they can be utilised as carriers in controlled-release formulations of agrochemicals or other active ingredients, offering an alternative approach to conventional fungicides. It is expected that this review provides an extensive summary of the application of carbohydrates in the realms of food, pharmaceuticals, and environment.

Biodegradable trimethyl chitosan nanofiber mats by electrospinning as bioabsorbable dressings for wound closure and healing

The paper aimed to prepare quaternary chitosan-based nanofibers as bioabsorbable wound dressings. To this aim, fully biodegradable chitosan/N,N,N-trimethyl chitosan (TMC) nanofibers were designed and prepared via electrospinning, using poly(ethylene glycol) as sacrificial additive. The new biomaterials were structurally and morphologically characterized by FTIR and NMR spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy, and their properties required for wound dressings application were investigated and discussed in detail. Thus, the nanofiber behavior was investigated by swelling, dynamic vapor sorption, and in vitro biodegradation in media mimicking the wound exudate. The mechanical properties were analysed from the stress-strain curves, the bioadhesivity from the texture analysis and the mucoadhesivity from the Zeta potential and transmittance measurements. The antimicrobial activity was assessed against S. aureus and E. coli strains, and the biocompatibility was tested in vitro on normal human dermal fibroblasts, and in vivo on rats. The application of the fiber mats with the best balance of properties as dressings on deep burn wound models in rats showed wound closure and active healing, with fully restoration of epithelia. It was concluded that the combination of chitosan with TMC into nanofibers provides new potential bioabsorbable wound dressing, opening new perspectives in regenerative medicine.

Chitin and Chitosan as Polymers of the Future-Obtaining, Modification, Life Cycle Assessment and Main Directions of Application

Natural polymers are very widespread in the world, which is why it is so important to know about the possibilities of their use. Chitin is the second most abundant reproducible natural polymer in nature; however, it is insoluble in water and basic solvents. Chitin is an unused waste of the food industry, for which there are possibilities of secondary management. The research led to obtaining a soluble, environmentally friendly form of chitin, which has found potential applications in the many fields, e.g., medicine, cosmetics, food and textile industries, agriculture, etc. The deacetylated form of chitin, which is chitosan, has a number of beneficial properties and wide possibilities of modification. Modification possibilities mean that we can obtain chitosan with the desired functional properties, facilitating, for example, the processing of this polymer and expanding the possibilities of its application, also as biomimetic materials. The review contains a rich description of the possibilities of modifying chitin and chitosan and the main directions of their application, and life cycle assessment (LCA)-from the source of the polymer through production materials to various applications with the reduction of waste.