Oxidative Stress and Apoptosis of Gaeumannomyces graminis (Get) Induced by Carabrone

Abstract

Carabrone is isolated from Carpesium macrocephalum Franch. et Sav, which has good fungicidal activity, especially for Gaeumannomyces graminis (Get). According to previous studies, we speculated that carabrone targets the mitochondrial enzyme complex III of Get. To elucidate the mode of action, we used carabrone to induce oxidative stress and apoptosis in Get. Incubation with carabrone reduced the burst of reactive oxygen species (ROS) and mitochondrial membrane potential, as well as phosphatidylserine release. Carabrone caused ROS accumulation in mycelia by inhibiting the activity of antioxidase enzymes, among which inhibition of glutathione reductase (GR) activity was most obvious. The catalytic center of GR consists of L-cysteine residues that react with the α-methylene-γ-butyrolactone active site of carabrone. Additionally, a positive TUNEL reaction led to diffusion of the DNA electrophoresis band and upregulation of Ggmet1 and Ggmet2. We propose that carabrone inhibits antioxidant enzymes and promotes ROS overproduction, which causes membrane hyperpermeability, release of apoptotic factors, activation of the mitochondria-mediated apoptosis pathway, and fungal cell apoptosis.

Antibacterial Functions and Proposed Modes of Action of Novel 1,2,3,4-Tetrahydro-β-carboline Derivatives that Possess an Attractive 1,3-Diaminopropan-2-ol Pattern against Rice Bacterial Blight, Kiwifruit Bacterial Canker, and Citrus Bacterial Canker

“…Moreover, the designed compounds could strongly induce the generation of late apoptotic cells, with the proportion changing from 0.1 to 43.7% for Xoo cells and from 0.9 to 34.4% for Xac cells. The reactive oxygen species (ROS) in tested pathogens must be monitored using the ROS detection kit because excessive ROS is a key marker that can activate an apoptotic response . Notably, the amount of ROS in pathogens triggered by THC compounds gradually increased with the elevation of drug dosages (Figure ).…”

“…The reactive oxygen species (ROS) in tested pathogens must be monitored using the ROS detection kit because excessive ROS is a key marker that can activate an apoptotic response. 54 Notably, the amount of ROS in pathogens triggered by THC compounds gradually increased with the elevation of drug dosages (Figure 9). This finding indicated that these THC compounds can break the balance of redox systems of pathogens and subsequently induce the increment of ROS, eventually endowing the tested bacteria with distinct apoptotic behaviors.…”

Antifungal Activity of a Neodymium-Doped Yttrium Aluminum Garnet 1,064-Nanometer Laser against Sporothrix globosa by Inducing Apoptosis and Pyroptosis via the NLRP3/Caspase-1 Signaling Pathway: In Vitro and In Vivo Study

“…ROS are the major mediators of fungal apoptosis, causing cell death by oxidizing biological macromolecules ( 25 ). Early studies showed that the attack on mitochondria by ROS overproduction could inhibit the mitochondrial respiratory function, leading to fungal cell death ( 26 – 28 ). Those reports coincide with our results, which showed that the level of ROS in S. globosa was significantly increased after laser treatment.…”

A functional analysis of mitochondrial respiratory chain cytochrome bc1 complex in Gaeumannomyces tritici by RNA silencing as a possible target of carabrone

“…This is consistent with our previous study, as a burst of ROS appears 3 hr after carabrone treatment of the hyphae. At the same time, the activity of antioxidant enzymes is inhibited and gene expression is increased (Wang et al ., 2019). The activity of peroxidase in the ∆GtCytc 1 , ∆GtCytb, ∆GtIsp, and 24‐HN‐1 mutants was significantly increased (71%, 58%, 65%, and 94%, respectively) compared with the wild‐type strain (Figure 5b), which is consistent with earlier reports suggesting that the activity of peroxidase is significantly activated when organisms are subjected to biotic or abiotic stresses (Allen, 1995; Meloni et al ., 2003).…”