Engineering precision defense: Fusaric acid-based wilt screening and chitosan nanoparticles for inducing resistance in sugarcane

Saccharum officinarum (Sugarcane) is a leading cash crop due to its bioeconomic value. The crop is vulnerable to fungal pathogens, which necessitate the development of targeted and environmentally friendly fungicides. Current strategies embrace biotic origin materials in which the nanoparticles have presented several horizons for sustainable agriculture applications. This work investigates the efficacy of foliar application of fungal chitosan-origin chitosan nanoparticles (FCHNPs) on sugarcane plants challenged with mycotoxin- Fusaric acid (FA). To circumvent the menace associated with the direct spread of pathogen - Fusarium spp. to the environment, the mycotoxin was sprayed on the sugarcane leaves. FCHNPs were synthesized using fungal chitosan extracted from Cunninghamella echinulata NCIM 691. The in-vivo assays demonstrated the potency of FCHNPs at 100 μg/ml concentration on sugarcane var. Co86032. The FCHNPs-treated leaves showed high chlorophylls at 100 μg/ml, indicating substantial improvement in the photosynthetic activity. The relative electrolyte leakage was reduced in FCHNPs-treated plants, indicating a reduction in membrane damage. Additionally, the lower malondialdehyde (MDA) content indicated lower oxidative stress with the treatments. The activity of the enzymes that contribute in the defence system of plants, viz polyphenol oxidase, chitinase and β-1,3-glucanase was substantially enhanced in treated settlings. Overall, in-vivo studies supported the efficacy of FCHNPs in sugarcane challenged with FA. Consequently, this research demonstrates a proactive and sustainable approach using the foliar application of FCHNPs to enhance sugarcane resilience against phytopathogens in a sustainable way. This strategy may help in determining the resistance to Fusarium at an early stage of varietal developments in sugarcane.