METHYLENE BLUE SENSITIVITY 1 (MBS1) is required for acclimation of Arabidopsis to singlet oxygen and acts downstream of β‐cyclocitral

Abstract

Singlet oxygen ( O ) signalling in plants is essential to trigger both acclimatory mechanisms and programmed cell death under high light stress. However, because of its chemical features, O requires mediators, and the players involved in this pathway are largely unknown. The β-carotene oxidation product, β-cyclocitral, is one such mediator. Produced in the chloroplast, β-cyclocitral induces changes in nuclear gene expression leading to photoacclimation. Recently, the METHYLENE BLUE SENSITIVITY protein MBS has been identified as a key player in O signalling leading to tolerance to high light. Here, we provide evidence that MBS1 is essential for acclimation to O and cross-talks with β-cyclocitral to mediate transfer of the O signal to the nucleus, leading to photoacclimation. The presented results position MBS1 downstream of β-cyclocitral in O signalling and suggest an additional role for MBS1 in the regulation of plant growth and development under chronic O production.

Insight on a comprehensive profile of volatile compounds of Chlorella vulgaris extracted by two “green” methods

“…The third significant group detected in the microalgae samples was terpenes with a total terpene content varying from 13 μg/L (sample D) to 51 μg/L (sample B). These compounds are products of the carotenoid degradation (Baldermann, Kato, Fleischmann, & Watanabe, ; Shumbe et al., ).…”

Photo-Oxidative Stress during Leaf, Flower and Fruit Development

“…Furthermore, a small zinc finger protein, MBS, is required to induce 1 O 2 -dependent gene expression (Shao et al, 2013). Interestingly, however, mbs1 mutants supplemented with b-cyclocitral are unable to positively regulate antioxidant-related genes that are usually activated in the wild type, in which the zinc finger transcription factor MBS1 is fully active and enhances plant tolerance to high levels of light (Shumbe et al, 2017).…”

β-cyclocitric acid: a new apocarotenoid eliciting drought tolerance in plants

“…1 A ). This relative accumulation of β-CCA compared to β-CC was amplified under stress conditions: when plants were exposed to drought stress, the β-CC concentration rose by a factor of 3, revealing a condition of excessive light and photooxidative stress 1,16 , while a 15-fold increase in β-CCA was observed (Fig. 1 B ).…”

“…In the mbs1 mutant that lacks the MBS1 protein, the expression of 1 O 2 marker genes was shown to be markedly deregulated 37 . For some genes, induction by β-CC was blocked while the induction of other genes was enhanced 16 . When exposed to drought stress, the mbs1 mutant behaved as WT, with β-CCA providing a marked protection against water stress deprivation (Fig.…”

“…Unfortunately, the β-CC-dependent signaling pathway is still largely unknown. Nevertheless, the role of METHYLENE BLUE SENSITIVITY 1 ( MBS1 ) 37 and of the SCARECROW LIKE 14 (SCL14)-dependent detoxification pathway in the response to β-cc have been recently described 16,38 . MBS1 is a cytosolic zinc finger protein essential for the regulation of the expression of 1 O 2 -responsive genes 37 .…”