Wounding induces a peroxisomal H O decrease via glycolate oxidase-catalase switch dependent on glutamate receptor-like channel-supported Ca signaling in plants.

Sensing of environmental challenges, such as mechanical injury, by a single plant tissue results in the activation of systemic signaling, which attunes the plant's physiology and morphology for better survival and reproduction. As key signals, both calcium ions (Ca ) and hydrogen peroxide (H O ) interplay with each other to mediate plant systemic signaling. However, the mechanisms underlying Ca -H O crosstalk are not fully revealed.

Dynamic and fluctuating generation of hydrogen peroxide via photorespiratory metabolic channeling in plants.

The homeostasis of hydrogen peroxide (H O ), a key regulator of basic biological processes, is a result of the cooperation between its generation and scavenging. However, the mechanistic basis of this balance is not fully understood. We previously proposed that the interaction between glycolate oxidase (GLO) and catalase (CAT) may serve as a molecular switch that modulates H O levels in plants.

Glycolate oxidase-dependent HO production regulates IAA biosynthesis in rice.

Background: Glycolate oxidase (GLO) is not only a key enzyme in photorespiration but also a major engine for HO production in plants. Catalase (CAT)-dependent HO decomposition has been previously reported to be involved in the regulation of IAA biosynthesis. However, it is still not known which mechanism contributed to the HO production in IAA regulation.

MALDI-TOF MS analysis of condensed tannins with potent antioxidant activity from the leaf, stem bark and root bark of Acacia confusa.

The structures of the condensed tannins from leaf, stem bark and root bark of Acacia confusa were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and their antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant power (FRAP) assays. The results showed that the condensed tannins from stem bark and root bark include propelargonidin and procyanidin, and the leaf condensed tannins include propelargonidin, procyanidin and prodelphinidin, all with the procyanidin dominating. The condensed tannins had different polymer chain lengths, varying from trimers to undecamers for leaf and root bark and to dodecamers for stem bark.