Copper and chitosan nanoparticles as potential elicitors of innate immune response in date palm: a comparative study

Abstract

The innate immunity of a plant represents the first defense line against any invading pathogen. This innate immunity is triggered by the infected plant once it detects a pathogenic infection. Peroxidase, catalase, and total phenols are considered among the main components of the plant’s innate immunity. In this regard, copper (CuNPs) and chitosan (CsNPs) nanoparticles showed a potency to modulate that innate immunity. The present work aims to compare between CuNPs and CsNPs in terms of their potencies to modulate the levels of peroxidase, catalase, and total phenols in date palm (Phoenix dactylifera L.) seedlings. Results showed that both CuNPs and CsNPs enhanced the innate immunity of date palm seedlings, wherein treating date palm seedlings with 50 mL of CuNPs (1 g/L) increased peroxidase and catalase levels by 199% and 4.15%, respectively; while total phenols level was decreased by 28.7%. On the other hand, the same treatment regime with CsNPs increased peroxidase, catalase, and total phenols levels by 12.5%, 12.4%, and 7.83%, respectively. These findings provide a possibility to use CuNPs and CsNPs for enhancing the innate immunity of date palm seedlings. In addition, this paper reports for the first time the ability of CuNPs to inhibit the formation of phenolics in date palm seedlings, which may be useful in reducing the oxidative browning caused by these phenolics in date palm explants during In vitro micropropagation.