Distinctive in-planta acclimation responses to basal growth and acute heat stress were induced in Arabidopsis by cattle manure biochar

Abstract

In-planta mechanisms of biochar (BC)-mediated improved growth were evaluated by examining oxidative stress, metabolic, and hormonal changes of Arabidopsis wild-type plants under basal or acute heat stress (–HS/ + HS) conditions with or without BC (+ BC/–BC). The oxidative stress was evaluated by using Arabidopsis expressing redox-sensitive green fluorescent protein in the plastids (pla-roGFP2). Fresh biomass and inflorescence height were greater in + BC(‒HS) plants than in the –BC(‒HS) plants, despite similar leaf nutrient levels, photosystem II (PSII) maximal efficiencies and similar oxidative poise. Endogenous levels of jasmonic and abscisic acids were higher in the + BC(‒HS) treatment, suggesting their role in growth improvement. HS in ‒BC plants caused reductions in inflorescence height and PSII maximum quantum yield, as well as significant oxidative stress symptoms manifested by increased lipid peroxidation, greater chloroplast redox poise (oxidized form of roGFP), increased expression of DNAJ heat shock proteins and Zn-finger genes, and reduced expression of glutathione-S-transferase gene in addition to higher abscisic acid and salicylic acid levels. Oxidative stress symptoms were significantly reduced by BC. Results suggest that growth improvements by BC occurring under basal and HS conditions are induced by acclimation mechanisms to ‘microstresses’ associated with basal growth and to oxidative stress of HS, respectively.

Biostimulants for the Regulation of Reactive Oxygen Species Metabolism in Plants under Abiotic Stress

“…Although POD activity increased by 70% when treated with S. constrictum under drought stress, SOD activity nearly doubled under HTs with the same inoculant compared with control. In addition, Kumar et al [127] observed biochar effects under HTs in Arabidopsis. Results revealed that, under HTs (50 • C), lipid peroxidation significantly increased compared with control samples.…”

Hydrogen peroxide sulfenylates and inhibits the photorespiratory enzyme PGLP1 to modulate plant thermotolerance

“…The roGFP2 reporter is particularly promising because, unlike HyPer, it is not sensitive to pH. Heat stress was shown to increase oxidation in chloroplasts using roGFP2 as a redox sensor ( Kumar et al., 2021 ). Because roGFP2 does not readily react with H 2 O 2 , yeast GPX Orp1 was fused to roGFP2 to enhance its specificity for H 2 O 2 ( Gutscher et al., 2009 ).…”