Combined application of Ascophyllum nodosum extract and chitosan synergistically activates host-defense of peas against powdery mildew

Abstract

Background: Powdery mildew (PM) is an important disease of pea that reduce yield. Ascophyllum nodosum extract (ANE) and chitosan (CHT) are biostimulants used to improve plant health. Efficacy of ANE and CHT was assessed individually and in combination against pea powdery mildew. Results: Combined applications of ANE and CHT had a significant inhibitory effect on pathogen development and it reduced disease severity to 35%, as compared to control (90.5%). The combination of ANE and CHT enhanced the activity of plant defense enzymes; phenylalanine ammonia lyases (PAL), peroxidase (PO) and production of reactive oxygen species (ROS) and hydrogen peroxide (H 2 O 2). Further, the treatment increased the expression of a number of plant defense genes in jasmonic acid (JA) signaling pathway such as LOX1 and COI and salicylic acid (SA)mediated signaling pathway such as NPR1 and PR1. Other genes involved in defense mechanisms like NADPH oxidase and C4H were also upregulated by the combination treatment. Conclusion: The combination of ANE and CHT suppresses pea powdery mildew largely by modulating JA and SAmediated signaling pathways.

Seaweed-Based Compounds and Products for Sustainable Protection against Plant Pathogens

“…The levels of mycotoxins, deoxynivalenol and sambucinol, were found to be lower in those wheat grains harvested from the plants treated with a combination of liquid seaweed extract and chitosan [150]. Similarly, the combination of liquid seaweed extract prepared from A. nodosum and chitosan inhibited the growth of Erisyphe pisi causing powdery mildew in pea [172]. Seasol Commercial ® (Seasol International, Bayswater, Australia), is an alkaline hydrolysis product prepared from Duvillaea potatorum and A. nodosum and was found to reduce the progression of Plasmodiophora brassicae, causing club-root in broccoli [144].…”

Commercial Algae Products as Biocide Treatments for Controlling Squash Powdery Mildew Disease

“…It is clear from these results the effective role of algae extracts in combating fungal diseases affecting plants, and this has been proven by several previous studies. Patel et al (2020) stated that the combination of the extract of Ascophyllum nodosum and chitosan owned a respectable inhibitory effect on powdery mildew of peas since it reduced disease severity to 35%, as compared to control (90.5%). Esserti et al (2016) found that extracts of the brown algae Cystoseira myriophylloides, Laminaria digitata, and Fucus spiralis significantly reduced disease severity of Verticillium dahliae and Agrobacterium tumefaciens in tomato plants.…”

Sustainable Agriculture Systems in Vegetable Production Using Chitin and Chitosan as Plant Biostimulants

“…There are numerous examples of chitosan application on vegetable crops; however, the obtained results are not always consistent since the various studies differ in their methodological approach (time and dose of application), while chitosanbased biostimulant products may also differ in chemical composition and chitosan content, which further increases heterogeneity in biological effects [77,78,[81][82][83]. The primary use of chitosan in agriculture is based on its eliciting effects on the biosynthesis of protective biomolecules against pests and pathogens [14,84,85], as well as on the up-regulation of defensive genes [86,87].…”