Thioredoxins m are major players in the multifaceted light-adaptive response in Arabidopsis thaliana

Thioredoxins (TRXs) are well-known redox signalling players, which carry out post-translational modifica-tions in target proteins. Chloroplast TRXs are divided into different types and have central roles in lightenergy uptake and the regulation of primary metabolism. The isoforms TRX m1, m2, and m4 f...

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Bibliographic Details
Authors: Serrato, Antonio J., Rojas González, José A., Torres Romero, Diego, Vargas, Paola, Mérida, Ángel, Sahrawy, Mariam
Format: article
Status:Published version
Publication Date:2021
Country:España
Institution:Universidad de Sevilla (US)
Repository:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/183229
Online Access:https://hdl.handle.net/11441/183229
https://doi.org/10.1111/tpj.15429
Access Level:Open access
Keyword:thioredoxins
Arabidopsis thaliana
chloroplast
light acclimation
redox regulation
chlorophyllfluorescence
anthocyanins.
Description
Summary:Thioredoxins (TRXs) are well-known redox signalling players, which carry out post-translational modifica-tions in target proteins. Chloroplast TRXs are divided into different types and have central roles in lightenergy uptake and the regulation of primary metabolism. The isoforms TRX m1, m2, and m4 from Arabidop-sis thaliana are considered functionally related. Knowing their key position in the hub of plant metabolism,we hypothesized that the impairment of the TRX m signalling would not only have harmful consequenceson chloroplast metabolism but also at different levels of plant development. To uncover the physiologicaland developmental processes that depend on TRX m signalling, we carried out a comprehensive study ofArabidopsis single, double, and triple mutants defective in the TRX m1, m2, and m4 proteins. As light andredox signalling are closely linked, we investigated the response to high light (HL) of the plants that aregradually compromised in TRX m signalling. We provide experimental evidence relating the lack of TRX mand the appearance of novel phenotypic features concerning mesophyll structure, stomata biogenesis, andstomatal conductance. We also report new data indicating that the isoforms of TRX m fine-tune theresponse to HL, including the accumulation of the protective pigment anthocyanin. These results revealnovel signalling functions for the TRX m and underline their importance for plant growth and fulfilment ofthe acclimation/response to HL conditions.