Brassinosteroids play a critical role in the regulation of pesticide metabolism in crop plants

Abstract

Pesticide residues in agricultural produce pose a threat to human health worldwide. Although the detoxification mechanisms for xenobiotics have been extensively studied in mammalian cells, information about the regulation network in plants remains elusive. Here we show that brassinosteroids (BRs), a class of natural plant hormones, decreased residues of common organophosphorus, organochlorine and carbamate pesticides by 30–70% on tomato, rice, tea, broccoli, cucumber, strawberry, and other plants when treated externally. Genome-wide microarray analysis showed that fungicide chlorothalonil (CHT) and BR co-upregulated 301 genes, including a set of detoxifying genes encoding cytochrome P450, oxidoreductase, hydrolase and transferase in tomato plants. The level of BRs was closely related to the respiratory burst oxidase 1 (RBOH1)-encoded NADPH oxides-dependent H2O2 production, glutathione biosynthesis and the redox homeostasis, and the activity of glutathione S-transferase (GST). Gene silencing treatments showed that BRs decreased pesticide residues in plants likely by promoting their metabolism through a signaling pathway involving BRs-induced H2O2 production and cellular redox change. Our study provided a novel approach for minimizing pesticide residues in crops by exploiting plants' own detoxification mechanisms.

Herbicide-related signaling in plants reveals novel insights for herbicide use strategies, environmental risk assessment and global change assessment challenges

“…However, as pointed out by Zhou et al (2015), sensing and signal transduction mechanisms that underlie xenobiotic-related gene regulation remain elusive in plants, in contrast with mammalian cells and yeast where xenobiotic sensors have been characterized. Moreover, even herbicide metabolites that are considered to be inactive cause major metabolomic and molecular modifications under conditions of no observable adverse effects (Serra et al, , 2015a(Serra et al, , 2015b and non-herbicidal synthetic compounds used as herbicide safeners in some monocotyledonous crops (Riechers et al, 2010) provide protection through induction of plant defence and detoxification gene expression (Ramel et al, 2012;Riechers et al, 2010).…”

“…The dynamics of abscisic acid (ABA), auxins, brassinosteroids, cytokinins, gibberellins, ethylene, jasmonate, and salicylate are thus likely to be directly or indirectly involved in plant responses to herbicide treatments. Conversely, treatments with hormones such as auxins (Kerchev et al, 2015), brassinosteroids (Zhou et al, 2015), or salicylate (Cui et al, 2010) can interfere with the effects of herbicides or pesticides. Brassinosteroids (Zhou et al, 2015) and salicylate (Cui et al, 2010) directly regulate genes that are related to herbicide detoxification, and activation of auxin signaling (Kerchev et al, 2015) counteracts the cell death effects of photorespiration, which is involved in the responses to several herbicides (Serra et al, , 2015a(Serra et al, , 2015bVivancos et al, 2011).…”

“…Conversely, treatments with hormones such as auxins (Kerchev et al, 2015), brassinosteroids (Zhou et al, 2015), or salicylate (Cui et al, 2010) can interfere with the effects of herbicides or pesticides. Brassinosteroids (Zhou et al, 2015) and salicylate (Cui et al, 2010) directly regulate genes that are related to herbicide detoxification, and activation of auxin signaling (Kerchev et al, 2015) counteracts the cell death effects of photorespiration, which is involved in the responses to several herbicides (Serra et al, , 2015a(Serra et al, , 2015bVivancos et al, 2011). Analysis of transcriptomic, proteomic or metabolomic modifications also shows that herbicide treatments have major impacts on genes and proteins involved in stress and nutrition signaling pathways: ROS signaling, membrane stress signaling, photosystem and light stress signaling, endoplasmic reticulum stress signaling, drought and salinity signaling, nutritional starvation signaling, and cell death signaling (Duhoux et al, 2015;Faus et al, 2015;Gaines et al, 2014;Goossens et al, 2001;Horn et al, 2013;Li et al, 2015;Ozgur et al, 2014;Ramel et al, 2007Ramel et al, , 2009aSerra et al, 2013Serra et al, , 2015aSerra et al, , 2015bWalley et al, 2015;.…”

“…Red and orange arrows and boxes respectively correspond to potential environmental (Köster et al, 2012;Ramel et al, 2012;Sharkhuu et al, 2014) and endogenous (Cui et al, 2010;Faus et al, 2015;Köster et al, 2012;Ramel et al, 2012;Zhou et al, 2015) signaling processes. Black arrows represent processes that can integrate converging herbicide, environmental and endogenous signaling (Cortleven et al, 2014;Cui et al, 2010;Rong Tan et al, 2015).…”

“…Herbicides are part of the range of chemicals that enable crop protection, maintenance of crop yields and economic viability of agriculture (Arias-Estévez et al, 2008;Zhou et al, 2015). The impact of herbicides on plant communities in the field or in the environment at large is often considered in classical toxicological or ecotoxicological terms of a single mode of action on a particular biochemical target with a straightforward dose-response dynamics (Délye, 2013;Délye et al, 2013;Saika et al, 2014).…”