Chitosan-Loaded Melatonin Carbon Dots-Copper Nanocomposite Improves Rice Seedling Salt Tolerance via...

Area of Science:

• Agricultural Science
• Nanotechnology
• Plant Physiology

Background:

• Soil salinity is a major constraint on global crop production, particularly for rice.
• Developing effective and eco-friendly strategies to mitigate salt stress in plants is crucial for food security.

Purpose of the Study:

• To develop and evaluate a chitosan-encapsulated melatonin carbon dots-copper nanocomposite (MT-CDs@Cs-Cu) for enhancing rice salt tolerance.
• To elucidate the "scavenging-regulation-repair" mechanism underlying the nanocomposite's action.

Main Methods:

• Synthesis and characterization of the MT-CDs@Cs-Cu nanocomposite.
• Application of the nanocomposite to rice under induced salt stress.
• Assessment of physiological parameters, ion accumulation, gene expression, and rhizosphere microbiome composition.

Main Results:

• The nanocomposite effectively scavenged reactive oxygen and nitrogen species, reducing oxidative damage.
• It improved stomatal conductance and water transport by suppressing ABA and upregulating aquaporins.
• Salt-stressed rice treated with the nanocomposite showed increased germination, biomass, chlorophyll, and K+/Na+ ratio, alongside reduced Na+ accumulation.
• Rhizosphere microbiome analysis revealed enrichment of beneficial bacteria like Sphingomonas and Actinobacteria.

Conclusions:

• The MT-CDs@Cs-Cu nanocomposite offers a multi-faceted approach to enhance rice salt tolerance.
• This nano-agricultural technology effectively mitigates salt stress through biochemical and physiological improvements.
• The strategy shows promise for sustainable agriculture and addressing soil salinization challenges.