期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2022
卷号：119
期号：6
DOI：10.1073/pnas.2120219119
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Significance
Living organisms continuously rebalance their growth and defense/tolerance machineries upon environmental perturbation and energy limitation, which appear as trade-offs. The unfolded protein response (UPR) is a supposed underlying machinery for those trade-offs, responding to a broad spectrum of stress categories and modulating the fundamental growth in both animal and plant systems. We here report the incorporation of general transcription factor NOBIRO6/TAF12b into the UPR-mediated plant root growth control. This indicates that the gene regulation by UPR itself is a key to elucidate the growth trade-offs. Given previously reported roles of NOBIRO6/TAF12b in the signaling of two phytohormones, cytokinin and ethylene, our report proposes how multichannel signals interactively shape plants to survive and thrive in the wild.
Plant root growth is indeterminate but continuously responds to environmental changes. We previously reported on the severe root growth defect of a double mutant in
bZIP17 and
bZIP28 (
bz1728) modulating the unfolded protein response (UPR). To elucidate the mechanism by which
bz1728 seedlings develop a short root, we obtained a series of
bz1728 suppressor mutants, called
nobiro, for rescued root growth. We focused here on
nobiro6, which is defective in the general transcription factor component TBP-ASSOCIATED FACTOR 12b (TAF12b). The expression of hundreds of genes, including the bZIP60-UPR regulon, was induced in the
bz1728 mutant, but these inductions were markedly attenuated in the
bz1728nobiro6 mutant. In view of this, we assigned transcriptional cofactor activity via physical interaction with bZIP60 to NOBIRO6/TAF12b. The single
nobiro6/
taf12b mutant also showed an altered sensitivity to endoplasmic reticulum stress for both UPR and root growth responses, demonstrating that NOBIRO6/TAF12b contributes to environment-responsive root growth control through UPR.
关键词：enunfolded protein responsestress-responsive growth regulationgeneral transcription factorroot growth
