Organ-specific effects of the auxin herbicide 2,4-D on the oxidative stress and senescence-related parameters of the stems of pea plants

Abstract

Oxidative stress and senescence have been shown to participate in the toxicity mechanism of auxin herbicides in the leaves and roots of sensitive plants. However, their role in stem toxicity has not been studied yet. In this work, we report the effect of foliar or root applications of the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the parameters of oxidative stress and senescence of stems of pea (Pisum sativum L.) plants. Contrary to their effect on the pea leaves, in the stems 2,4-D applications did not cause oxidative stress, as shown by the parameters of lipid peroxidation, protein carbonyls, and total and protein thiols. Moreover, they inhibited the superoxide radical (O 2 .-)-producing xanthine oxidase (XOD) activity and stimulated the antioxidant activities of catalase (CAT), guaiacol peroxidase (GPOX), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST) and Krebs cycle NAD ? -isocitrate dehydrogenase (IDH). Applications of 2,4-D also did not induce senescence in the pea stems, as shown by the increase of proteins, the lack of stimulation of proteolytic activity, and the inhibition of senescence-related isocitrate lyase (ICL) activity. However, they stimulated the H 2 O 2 -producing acyl-CoA oxidase (ACOX) activity of fatty acid beta oxidation. Results suggest that oxidative stress and senescence are not involved in the mechanism of toxicity of 2,4-D in the stems of pea plants, and that these phenomena are not whole-plant toxicity mechanisms for auxin herbicides in susceptible plants.Results also suggest that the effect of 2,4-D on the oxidative metabolism of pea plants might be organ-specific.

Understanding and optimizing the addition of phytohormones in the culture of microalgae for lipid production

“…These results in microalgae match with the effects promoted by the herbicide in vascular plants, where 2,4‐D induces antioxidant activity (catalase, superoxide dismutase), reducing intracellular reactive oxygen species . These discover are supported on the evolutionary theory (microalgae are plant precursors).…”

Influence of herbicides on indexes of yield of hybrid of corn Orzhitsa 237 MV

“…The least reduction in the weight of seeds (2.4% below control) and protein content (7.6%) were detected by the action of herbicide Harnes, and the greatest decrease (correspondingly, 4.2% and 13.1%) -due to herbicide action Master . The obtained results are consistent with the known data on the negative effects of herbicides, including glyphosate, which leads to a decrease in the similarity and mass of pea seedlings, as well as to the damage to the growth and conservation of micronutrients in soybeans [13,14]. Support for oxidative-reducing homeostasis of plant organisms due to environmental factors, including herbicides, is provided by an antioxidant defense system.…”

Lipids and proteins—major targets of oxidative modifications in abiotic stressed plants

“…Transgenic N. tabacum, overexpressing citrus (Citrus unshiu) dehydrin could exhibit a lower lipid peroxidation (measured as MDA content), compared with the control, under freeze (−4°C, 3-24 h) stress (Hara et al 2003). Plant exposure to herbicides also showed linkage with increase in lipid peroxidation (McCarthy-Suárez et al 2011;Pazmiño et al 2011). The degree of lipid peroxidation was used effectively as a biomarker of environmental pollution due to herbicides (Spoljaric et al 2011).…”