Chitin is the second most abundant biopolymer in nature after cellulose, and it forms an integral part of insect exoskeletons, crustacean shells, krill and the cell walls of fungal spores, where it is present as a high-molecular-weight molecule. In this study, we showed that a chitin oligosaccharide of lower molecular weight (tetramer) induced genes in Arabidopsis that are principally related to vegetative growth, development and carbon and nitrogen metabolism. Based on plant responses to this chitin tetramer, a low-molecular-weight chitin mix (CHL) enriched to 92% with dimers (2mer), trimers (3mer) and tetramers (4mer) was produced for potential use in biotechnological processes. Compared with untreated plants, CHL-treated plants had increased in vitro fresh weight (10%), radicle length (25%) and total carbon and nitrogen content (6% and 8%, respectively). Our data show that low-molecular-weight forms of chitin might play a role in nature as bio-stimulators of plant growth, and they are also a known direct source of carbon and nitrogen for soil biomass. The biochemical properties of the CHL mix might make it useful as a non-contaminating bio-stimulant of plant growth and a soil restorer for greenhouses and fields.

No abstract

No abstract

Mycorrhizae have been key living microorganisms in the plant colonization of terrestrial environments. The crucial roles of mycorrhizae are to provide plant nutrition and stress resistance for plant growth and development. Potassium (K + ) shows important functions in different metabolic processes and physiological functions and is the third crucial component of most crop fertilizers (after nitrogen and phosphorus). This chapter discusses the current state of knowledge about the role of mycorrhizal symbiosis in the release, solubilization, and transport of potassium from the soil to plants. Improved metagenomic analyses and the availability of transcriptome data provide promising tools for studying fungal weathering and the mycorrhizal contributions to K + solubilization and K + transport to plants. Additionally, some benefits of mycorrhizal potassium uptake in plants are described.

No abstract