Extracts of the marine brown macroalga, Ascophyllum nodosum, induce jasmonic acid dependent systemic resistance in Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000 and Sclerotinia sclerotiorum

Abstract

We studied the mechanism of Ascophyllum nodosum (a brown macroalga) induced resistance in Arabidopsis thaliana against Pseudomonas syringae pv. tomato DC3000. Root treatment of A. thaliana Col-0 plants with extracts of A. nodosum [aqueous (ANE), chloroform (C-ANE) and ethylacetate fractions, (E-ANE)] reduced the development of disease symptoms on the leaves. These extracts also induced resistance in salicylic acid deficient NahG and ics1 plants. However, the extracts did not elicit an effect on jar1 (jasmonic acid resistance 1) mutant. A. nodosum extract induced resistance to Pst DC3000 correlated with increased expression of jasmonic acid related gene transcripts PDF1.2 while PR1 and ICS1 expression were less affected. Additionally, pretreatment of Arabidopsis plants with ANE, protected the plants from a necrotroph, Sclerotinia sclerotiorum. The results suggest that the A. nodosum extracts can induce resistance in Arabidopsis to different pathogens which is largely jasmonic acid dependent.

Morphological and Biochemical Responses of Glycine max (L.) Merr. to the Use of Seaweed Extract

“…The concentration of these products is an important factor in this regard [49]. This issue may be caused directly by elements that are included in the extract [50], or it might be a consequence of modifications in the regular physiological growth of the plant [51,52]. Improvement of commercial-product formulas, and knowing the mechanisms of active substances in plants and their persistence, should mitigate such negative effects.…”

Produtos naturais disponíveis comercialmente induzem o acúmulo de fitoalexinas em cotilédones de soja e mesocótilos de sorgo

“…A aplicação do extrato nas doses 0,5 e 1,0%, em pepineiros parasitados pelo oomiceto Phytophthora melonis, foi suficiente para aumentar a atividade de enzimas de defesa das plantas como a β-1,3-glucanase, peroxidase e polifenoloxidase, alterando, inclusive, a transcrição de vários genes de defesa (1). Adicionalmente, os trabalhos realizados por Subramanian et al (30) demonstraram que o extrato de A. nodosum apresenta inespecificidade de indução, uma vez que plantas de Arabidopsis thaliana apresentaram-se resistentes tanto contra a bactéria Pseudomonas syringae pv. tomato quanto contra o fungo necrotrófico Sclerotinia sclerotiorum.…”

A Biostimulant Preparation of Brown Seaweed Ascophyllum nodosum Suppresses Powdery Mildew of Strawberry

“…Several reports show that ANE acts as a potential elicitor and possesses disease suppressive activities (Jayaraman et al, 2011; Khan et al, 2009). The ANE has been known to suppress diseases in several plants such as Arabidopsis, carrot, cucumber and tomato (Abkhoo and Sabbagh, 2016; Ali et al, 2016; Jayaraj et al, 2008; Jayaraman et al, 2011; Subramanian et al, 2011). Previously published reports suggest that ANE induces plant defense systems against broad ranges of pathogens (Khan et al, 2009).…”

“…Plants were sprayed with ANE (0.1%, 0.2%, and 0.3%) until dripping and leaves were harvested 24, 48, 72, 96, and 120 h post-inoculation, weighed and frozen in liquid nitrogen. The phenylalanine ammonia lyase (PAL) activity was determined as described by Subramanian et al (2011). Briefly, the leaf tissue was ground in 25 mM borate buffer (pH 8.8) containing 0.5 g/l polyvinylpyrrolidone (PVP).…”

“…The supernatant was used as the crude enzyme extract. The activity of PAL was estimated based on the amount of cinnamic acid formed with phenylalanine as the substrate following the protocol described by Subramanian et al (2011). The amount of cinnamic acid was calculated using a standard graph of cinnamic acid and expressed as μg cinnamic acid/min/mg protein.…”