Overexpression of thioredoxin m in chloroplasts alters carbon and nitrogen partitioning in tobacco
In plants, there is a complex interaction between carbon (C) and nitrogen (N) metabolism, and its coordination is fundamental for plant growth and development. Here, we studied the influence of thioredoxin (Trx) m on C and N partitioning using tobacco plants overexpressing Trx m from the chloroplast...
| Authors: | , , , , , , , , , |
|---|---|
| Format: | article |
| Publication Date: | 2021 |
| Country: | España |
| Institution: | Institut de Recerca i Tecnologia Agroalimentàries (IRTA) |
| Repository: | IRTA Pubpro. Open Digital Archive |
| OAI Identifier: | oai:repositori.irta.cat:20.500.12327/1443 |
| Online Access: | http://hdl.handle.net/20.500.12327/1443 https://doi.org/10.1093/jxb/erab193 |
| Access Level: | Open access |
| Keyword: | 633 |
| Summary: | In plants, there is a complex interaction between carbon (C) and nitrogen (N) metabolism, and its coordination is fundamental for plant growth and development. Here, we studied the influence of thioredoxin (Trx) m on C and N partitioning using tobacco plants overexpressing Trx m from the chloroplast genome. The transgenic plants showed altered metabolism of C (lower leaf starch and soluble sugar accumulation) and N (with higher amounts of amino acids and soluble protein), which pointed to an activation of N metabolism at the expense of carbohydrates. To further delineate the effect of Trx m overexpression, metabolomic and enzymatic analyses were performed on these plants. These results showed an up-regulation of the glutamine synthetase-glutamate synthase pathway; specifically tobacco plants overexpressing Trx m displayed increased activity and stability of glutamine synthetase. Moreover, higher photorespiration and nitrate accumulation were observed in these plants relative to untransformed control plants, indicating that overexpression of Trx m favors the photorespiratory N cycle rather than primary nitrate assimilation. Taken together, our results reveal the importance of Trx m as a molecular mediator of N metabolism in plant chloroplasts. |
|---|