Dataset Information

A New Role for Plastid Thioredoxins in Seed Physiology in Relation to Hormone Regulation.

ABSTRACT: In Arabidopsis seeds, ROS have been shown to be enabling actors of cellular signaling pathways promoting germination, but their accumulation under stress conditions or during aging leads to a decrease in the ability to germinate. Previous biochemical work revealed that a specific class of plastid thioredoxins (Trxs), the y-type Trxs, can fulfill antioxidant functions. Among the ten plastidial Trx isoforms identified in Arabidopsis, Trx y1 mRNA is the most abundant in dry seeds. We hypothesized that Trx y1 and Trx y2 would play an important role in seed physiology as antioxidants. Using reverse genetics, we found important changes in the corresponding Arabidopsis mutant seeds. They display remarkable traits such as increased longevity and higher and faster germination in conditions of reduced water availability or oxidative stress. These phenotypes suggest that Trxs y do not play an antioxidant role in seeds, as further evidenced by no changes in global ROS contents and protein redox status found in the corresponding mutant seeds. Instead, we provide evidence that marker genes of ABA and GAs pathways are perturbed in mutant seeds, together with their sensitivity to specific hormone inhibitors. Altogether, our results suggest that Trxs y function in Arabidopsis seeds is not linked to their previously identified antioxidant roles and reveal a new role for plastid Trxs linked to hormone regulation.

SUBMITTER: Nee G

PROVIDER: S-EPMC8508614 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature

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A New Role for Plastid Thioredoxins in Seed Physiology in Relation to Hormone Regulation.

Née Guillaume G Châtel-Innocenti Gilles G Meimoun Patrice P Leymarie Juliette J Montrichard Françoise F Satour Pascale P Bailly Christophe C Issakidis-Bourguet Emmanuelle E

International journal of molecular sciences 20210927 19

In Arabidopsis seeds, ROS have been shown to be enabling actors of cellular signaling pathways promoting germination, but their accumulation under stress conditions or during aging leads to a decrease in the ability to germinate. Previous biochemical work revealed that a specific class of plastid thioredoxins (Trxs), the y-type Trxs, can fulfill antioxidant functions. Among the ten plastidial Trx isoforms identified in Arabidopsis, Trx y1 mRNA is the most abundant in dry seeds. We hypothesized t ...[more]

PMID: 34638735

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Project description:Persulfidation, a posttranslational modification of cysteines to persulfides, is the best characterized molecular mechanism of H2S signaling. This study is focused on new functions for thioredoxins (TRXs) in plants beyond those of thiol disulfide (S-S) exchange, including the regulation of protein persulfidation as it has been described in animal systems. To elucidate the impact of TRXo1 deficiency on the protein persulfidation pattern in plants of Arabidopsis thaliana L. wild-type (WT) and two Attrxo1 T-DNA insertion mutants grown under non stress conditions, a quantitative proteomic approach was performed. The proteomic analysis revealed a higher number of proteins that were more persulfidated in the mutants compared to WT plants, suggesting a role for TRXo1 in protein depersulfidation. Interestingly, most of the differentially persulfidated proteins were located in the chloroplast, implying a coordination between chloroplast H2S-dependent persulfidation and mitochondrial TRXo1 depersulfidation. Among the differentially persulfidated proteins located in mitochondria, the antioxidant enzymes sAPX, DHAR1, and MDAR6 were selected for further studies. The effect of H2S-dependent persulfidation on their enzymatic activities and its reversibility by the NADPH/thioredoxin reductase (NTRB)/TRXo1 system was analyzed, as well as their persulfidation levels were quantified. Sulfide treatment brought about increases in the activity levels of the enzymes, that match with a raise on the persulfidation levels. Interestingly, both activations declining after treatment with the thioredoxin system, indicating regulation of their persulfidation by TRXo1. These results point to a positive effect of persulfidation on the enzymatic activities and also to a new depersulfidase activity for TRXo1. All together these results give a new insight of the mechanism of elimination of -SSH groups in plants exerted by TRXo1, and the involvement of a redox regulation on the protein persulfidation.

Dataset Information

A New Role for Plastid Thioredoxins in Seed Physiology in Relation to Hormone Regulation.

Publications

A New Role for Plastid Thioredoxins in Seed Physiology in Relation to Hormone Regulation.

Similar Datasets

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