Catabolism of Glucosinolates into Nitriles Revealed by RNA Sequencing of Arabidopsis thaliana Seedlings after Non-Thermal Plasma-Seed Treatment

Abstract

Non-thermal plasma-seed treatments could be an environmentally friendly method to modulate plant properties. Since it remains unclear how plasmas affect seeds, RNA sequencing was used here to analyze gene transcription changes in 7-day-old Arabidopsis thaliana (L.) Heynh. seedlings grown from surface dielectric barrier discharge plasma-treated seeds. In a previous study, seeds were analyzed 6 days after plasma exposure and a plant stress and defense response was observed. Here, we performed a pathway analysis on differentially expressed genes and our results revealed again an increased expression of plant stress and defense, specifically glucosinolate pathway-related compounds. The main difference was that a different part of the plant defense response changed at 7 days, which was not previously observed at 6 days. With a 24-h delayed extraction time point, the glucosinolates were selectively broken down into nitriles among all of the glucosinolates catabolic products. Although information about nitriles is limited, it protects plants against biotic stresses and has variable toxicity depending on the interacting organism. More work needs to be performed to better understand which plasma seed treatment parameters affect plant defense; however, these preliminary findings suggest that an optimized plasma treatment could be used to elicit a plant defense response.

Plasma Treatment Modifies Element Distribution in Seed Coating and Affects Further Germination and Plant Growth through Interaction with Soil Microbiome

“…thaliana seedlings, grown from plasma-treated seeds, revealed a notable upregulation of genes associated with plant stress and defense, and also the breakdown of glucosinolates into nitriles. This observation suggests a novel mechanism of plant defense activation, specifically through the plasma seed treatment …”

“…Moreover, Waskow et al conducted an RNA-seq analysis on the plasma treated seeds and discovered that this treatment can trigger distinct defense pathways in plants, including the glucosinolate pathway and the phenylpropanoid pathway . In the following study conducted by Waskow et al, the RNA sequencing analysis of 7 day old A. thaliana seedlings, grown from plasma-treated seeds, revealed a notable upregulation of genes associated with plant stress and defense, and also the breakdown of glucosinolates into nitriles.…”

“…This observation suggests a novel mechanism of plant defense activation, specifically through the plasma seed treatment. 24 Although the current focus has been primarily on germination and surface modifications, a holistic view of the plant's life cycle, including growth, development, yield, and defense responses, is crucial to fully grasp the potential of plasma treatment in agriculture. In addition, there are significant differences and inconsistencies between different studies in the methodology of plasma application, in the characterization of the plasma dose itself, and in the assessment of plant response among studies, making the generalized conclusions less relevant.…”