Nuclear calcium oscillations induced by chitin oligomers

Chitin has high recycling potential, not only as a biocompatible and biodegradable material, but also as a source of biologically active oligosaccharides. For instance, Chitin oligosaccharides (COs) have been reported to possess anticancer and anti-inflammatory activities. However, the most thoroughly investigated activities of COs are, by far, those contributing to plant defense and plant growth. COs, according to their degree of polymerization present different activities in plants that led to differentiate them into two classes. COs up to the pentasaccharides are commonly referred to as short-chain COs, while higher oligomers are referred to as long-chain COs. Long-chain COs have long been known as plant elicitors. They are recognized as microbe-associated molecular patterns and trigger immunity signaling in several species, with CO8 being the most active. Short-chain COs induce oscillations of the calcium concentration in the plant cell nucleus, which is a hall-mark of early arbuscular mycorrhizal and rhizobial symbioses signaling. Mutual-istic relationships between a host plant and nitrogen-fixing bacteria or arbuscular mycor-rhizal fungi enhance the supply of essential nutrients such as nitrogen, potassium or water to the host. These symbioses are of high interest in the development of more sustainable agricultural practices, a recent work has established that all COs from CO4 to CO8 have this ability

Calcium (Ca²⁺) is a universal regulatory element that intimately couples primary biotic and abiotic signals to many cellular processes, allowing plants and animals to develop and adapt to environmental stimuli. Each Ca²⁺ response can be specified by the spatial release of Ca²⁺ in specific cell types and cellular compartments, which enables the compartmentalisation of the signal transduced and/or the selective activation of temporally and spatially regulated Ca²⁺-binding proteins. Within the same cellular compartment, it is postulated that the Ca²⁺ signature, defined by its amplitude, frequency, and duration, specifies the activation of downstream components.

In plants, nuclear Ca²⁺ signals are essential to establish nitrogen-fixing and phosphate-delivering arbuscular mycorrhizal (AM) endosymbioses6. The nuclear Ca²⁺ release is mediated by a complex of nuclear membrane-localised ion channels including DOES NOT MAKE INFECTIONS 1 (DMI1) and the cyclic nucleotide-gated channels (CNGC) 15a, b, c. the nuclear Ca²⁺ signal can be modulated genetically by removing or overexpressing the cation channel DMI1, leading to the production of different nuclear Ca²⁺ signatures and differences in primary root growth. In addition, nuclear Ca²⁺ signals contribute to and can be modulated by root auxin homoeostasis.

Reference: A combination of chitooligosaccharide and lipochitooligosaccharide recognition promotes arbuscular mycorrhizal associations in Medicago truncatula

https://doi.org/10.1038/s41467-019-12999-5

Our chitin oligosaccharide series standard substances：

https://www.marine-oligo.com/chitosan-oligosaccharide-group/