A Biostimulant Obtained from the Seaweed Ascophyllum nodosum Protects Arabidopsis thaliana from Severe Oxidative Stress

Abstract

Abiotic stresses cause oxidative damage in plants. Here, we demonstrate that foliar application of an extract from the seaweed Ascophyllum nodosum, SuperFifty (SF), largely prevents paraquat (PQ)-induced oxidative stress in Arabidopsis thaliana. While PQ-stressed plants develop necrotic lesions, plants pre-treated with SF (i.e., primed plants) were unaffected by PQ. Transcriptome analysis revealed induction of reactive oxygen species (ROS) marker genes, genes involved in ROS-induced programmed cell death, and autophagy-related genes after PQ treatment. These changes did not occur in PQ-stressed plants primed with SF. In contrast, upregulation of several carbohydrate metabolism genes, growth, and hormone signaling as well as antioxidant-related genes were specific to SF-primed plants. Metabolomic analyses revealed accumulation of the stress-protective metabolite maltose and the tricarboxylic acid cycle intermediates fumarate and malate in SF-primed plants. Lipidome analysis indicated that those lipids associated with oxidative stress-induced cell death and chloroplast degradation, such as triacylglycerols (TAGs), declined upon SF priming. Our study demonstrated that SF confers tolerance to PQ-induced oxidative stress in A. thaliana, an effect achieved by modulating a range of processes at the transcriptomic, metabolic, and lipid levels.

Phaeophyceaean (Brown Algal) Extracts Activate Plant Defense Systems in Arabidopsis thaliana Challenged With Phytophthora cinnamomi

“…Other publications have compared the transcriptional profiles of plants treated with seaweed extracts derived from the brown seaweed A. nodosum (Nair et al, 2012;GonñI et al, 2016;Santaniello et al, 2017;Jithesh et al, 2019;Omidbakhshfard et al, 2020). The extracts used in these studies varied in their chemical nature (including alkaline, neutral and acid extracts) and extraction approaches.…”

“…High throughput RNA-sequencing was used at key plant response time points. This approach complimented the excellent transcriptomics reports on the action of biostimulant extracts (Nair et al, 2012;GonñI et al, 2016;Jithesh et al, 2019;Omidbakhshfard et al, 2020), particularly with respect to the ability of biostimulants to alter the outcome of root pathogen infection. To further confirm the defense transcriptome induction, Reactive Oxygen Species (ROS) were investigated by staining for hydrogen peroxide in the seaweed extract treated plants at 12 h post-inoculation (hpi) with P. cinnamomi.…”

Reactive Oxygen Species and Abiotic Stress in Plants

“…Luckily, the recent advances in technologies allowing large-scale “–omics” analyses accelerate this process. The studies in this Special Issue add valuable pieces of the puzzle related to stress responses by: (i) reporting novel potent regulators and the mechanisms through which they exert their effects [ 15 , 17 , 18 , 19 ]; (ii) throwing light on previously unexplored components [ 16 ] or the pathways involved in particular stress types [ 11 , 12 , 13 ]; or (iii) exploring strategies to mitigate the detrimental effects [ 14 ]. We are confident that they will inspire further productive research in the future.…”

“…In another study, focused directly on oxidative stress, Omidbakhshfard et al (2020) investigated how the biostimulant SuperFifty (SF), prepared from the brown alga Ascophyllum nodosum , can fully protect against oxidative damage induced by the herbicide paraquat (PQ) in A. thaliana [ 14 ]. While PQ treatment alone resulted in necrotic lesions, growth inhibition, and eventual cell death in the plants, these negative effects were completely prevented by pre-treatment with SF.…”

“…Further metabolomic analyses revealed accumulation of the stress-protective metabolite maltose and the tricarboxylic acid cycle intermediates fumarate and malate. Lipidome analysis conducted in parallel indicated that triacylglycerols (TAGs) are accumulated during oxidative stress but decline upon SF priming [ 14 ]. Overall, this study demonstrated that SF can completely prevent oxidative damage, an effect associated with transcriptome reprogramming and metabolome reconfigurations.…”