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Title: Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis

Abstract

The immutans (im) variegation mutant of Arabidopsis is an ideal model to gain insight into factors that control chloroplast biogenesis. im defines the gene for PTOX, a plastoquinol terminal oxidase that participates in control of thylakoid redox. Here, we report that the im defect can be suppressed during the late stages of plant development by gigantea (gi2), which defines the gene for GIGANTEA (GI), a central component of the circadian clock that plays a poorly-understood role in diverse plant developmental processes. imgi2 mutants are late-flowering and display other well-known phenotypes associated with gi2, such as starch accumulation and resistance to oxidative stress. We show that the restoration of chloroplast biogenesis in imgi2 is caused by a developmental-specific de-repression of cytokinin signaling that involves crosstalk with signaling pathways mediated by gibberellin (GA) and SPINDLY (SPY), a GA response inhibitor. Suppression of the plastid defect in imgi2 is likely caused by a relaxation of excitation pressures in developing plastids by factors contributed by gi2, including enhanced rates of photosynthesis and increased resistance to oxidative stress. Interestingly, the suppression phenotype of imgi can be mimicked by crossing im with the starch accumulation mutant, sex1, perhaps because sex1 utilizes pathways similar to gi. Wemore » conclude that our studies provide a direct genetic linkage between GIGANTEA and chloroplast biogenesis, and we construct a model of interactions between signaling pathways mediated by gi, GA, SPY, cytokinins, and sex1 that are required for chloroplast biogenesis.« less

Authors:
Publication Date:
Research Org.:
Iowa State Univ., Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1225973
Report Number(s):
DOE-ISU-20147
DOE Contract Number:  
FG02-94ER20147
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English

Citation Formats

Rodermel, Steven. Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis. United States: N. p., 2015. Web. doi:10.2172/1225973.
Rodermel, Steven. Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis. United States. doi:10.2172/1225973.
Rodermel, Steven. Mon . "Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis". United States. doi:10.2172/1225973. https://www.osti.gov/servlets/purl/1225973.
@article{osti_1225973,
title = {Regulation of chloroplast biogenesis: the immutans mutant of Arabidopsis},
author = {Rodermel, Steven},
abstractNote = {The immutans (im) variegation mutant of Arabidopsis is an ideal model to gain insight into factors that control chloroplast biogenesis. im defines the gene for PTOX, a plastoquinol terminal oxidase that participates in control of thylakoid redox. Here, we report that the im defect can be suppressed during the late stages of plant development by gigantea (gi2), which defines the gene for GIGANTEA (GI), a central component of the circadian clock that plays a poorly-understood role in diverse plant developmental processes. imgi2 mutants are late-flowering and display other well-known phenotypes associated with gi2, such as starch accumulation and resistance to oxidative stress. We show that the restoration of chloroplast biogenesis in imgi2 is caused by a developmental-specific de-repression of cytokinin signaling that involves crosstalk with signaling pathways mediated by gibberellin (GA) and SPINDLY (SPY), a GA response inhibitor. Suppression of the plastid defect in imgi2 is likely caused by a relaxation of excitation pressures in developing plastids by factors contributed by gi2, including enhanced rates of photosynthesis and increased resistance to oxidative stress. Interestingly, the suppression phenotype of imgi can be mimicked by crossing im with the starch accumulation mutant, sex1, perhaps because sex1 utilizes pathways similar to gi. We conclude that our studies provide a direct genetic linkage between GIGANTEA and chloroplast biogenesis, and we construct a model of interactions between signaling pathways mediated by gi, GA, SPY, cytokinins, and sex1 that are required for chloroplast biogenesis.},
doi = {10.2172/1225973},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2015},
month = {11}
}