Lack of K-Dependent Oxidative Stress in Cotton Roots Following Coronatine-Induced ROS Accumulation

Abstract

Coronatine [COR] is a novel type of plant growth regulator with similarities in structure and property to jasmonate. The objective of this study was to examine the relationship between increased root vitality induced by 10nM COR and reactive oxygen species scavenging under potassium (K)-replete (2.5mM) and K-deficient (0.05mM) conditions in hydroponic cultured cotton seedlings. K-replete and K-deficient conditions increased root vitality by 2.7- and 3.5-fold, respectively. COR treatment significantly decreased lipid peroxidation in cotton seedlings determined by reduction in MDA levels. These results suggest that COR improves the functioning of both enzymatic and non-enzymatic antioxidant systems. Under K-replete and K-deficient conditions, COR significantly increased the activities of antioxidant enzymes SOD (only for K-repletion), CAT, GPX, and APX comparing; COR also significantly increased DPPH-radical scavenging activity. However, COR led to 1.6- and 1.7-fold increases in superoxide anion (O2 •-) concentrations, and 5.7- and 2.1-fold increases in hydrogen peroxide (H2O2) levels, respectively. Additionally, COR intensified the DAB staining of H2O2 and the NBT staining of O2 •-. Therefore, our results reveal that COR-induced ROS accumulation stimulates the activities of most antioxidant enzymes but does not induce oxidative stress in cotton roots.

Transcriptome analysis reveals the cotton defense mechanism in response to Verticillium dahliae in the presence of the biocontrol fungus Chaetomium globosum CEF-082

“…The cotton seeds were planted in vermiculite and transferred to plastic pots (25 cm × 15 cm) that contained 2000 mL of liquid culture solution after emergence. The cultivation solution was prepared according to the methods of Zhang et al [21], with some modifications. In this study, 2 mM NaCl was used instead of 2.5 mM KCl, while the other 9 mineral nutrients were the same.…”

GhMAP3K65, a Cotton Raf-Like MAP3K Gene, Enhances Susceptibility to Pathogen Infection and Heat Stress by Negatively Modulating Growth and Development in Transgenic Nicotiana benthamiana

“…Root vitality was determined using a root TTC reduction method in tissues following treatment with a red-coloured insoluble complex [ 69 , 70 ]. A TTC solution (0.25 mL of 0.4%) and a small Na 2 S crystal were added to a 10-mL volumetric flask, which was shaken immediately after the addition of red triphenylformazan (TF) and 95% ethanol.…”

“…A blank tube (0 mL of TF) served as the control, and a standard curve was formed. TTC reduction was examined using an improved method described by Zhang et al [ 70 ]. Root segments (0.5 g fresh weight (FW)) were incubated for 6 h in the dark at 37 °C with a mixture comprising 10 mL of 0.4% TTC and 10 mL of tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl, pH 8.4).…”

Transcriptome analysis reveals the defense mechanism of cotton against Verticillium dahliae in the presence of the biocontrol fungus Chaetomium globosum CEF-082

“…The cotton seeds were planted in vermiculite and transferred to plastic pots (25 cm × 15 cm) that contained 2000 mL of liquid culture solution after emergence. The cultivation solution was prepared according to the methods of Zhang et al [48], with some modifications. In this study, 2 mM NaCl was used instead of 2.5 mM KCl, while the other 9 mineral nutrients were the same.…”