Brassinosteroid Homeostasis in Arabidopsis Is Ensured by Feedback Expressions of Multiple Genes Involved in Its Metabolism

Tanaka, Kiwamu; Asami, Tadao; Yoshida, Shigeo; Nakamura, Yasushi; Matsuo, Tomoaki; Okamoto, Shigehisa

doi:10.1104/pp.104.058040

Cited by 221 publications

(214 citation statements)

References 45 publications

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“…Biosynthesis and inactivation are coordinated via BR-dependent transcriptional control of the genes involved in both processes. All BR-biosynthetic P450 genes of Arabidopsis are under negative feedback regulation by active BRs (Bancos et al, 2002;Tanaka et al, 2005), whereas of those encoding inactivating enzymes only BAS1 was found BR inducible (Choe et al, 2001;Takahashi et al, 2005). Feedback regulation of CPD is abolished in the BR-insensitive bin2 and brassinosteroid insensitive 1-2 (bri1-2)/cbb2 mutants (Li et al, 2001;Bancos et al, 2002), indicating a key role of BR signaling in the hormonal self-regulation of BR biosynthesis and perhaps also inactivation.…”

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confidence: 91%

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

et al. 2006

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Plant steroid hormones, brassinosteroids (BRs), are essential for normal photomorphogenesis. However, the mechanism by which light controls physiological functions via BRs is not well understood. Using transgenic plants carrying promoter-luciferase reporter gene fusions, we show that in Arabidopsis (Arabidopsis thaliana) the BR-biosynthetic CPD and CYP85A2 genes are under diurnal regulation. The complex diurnal expression profile of CPD is determined by dual, light-dependent, and circadian control. The severely decreased expression level of CPD in phytochrome-deficient background and the red light-specific induction in wildtype plants suggest that light regulation of CPD is primarily mediated by phytochrome signaling. The diurnal rhythmicity of CPD expression is maintained in brassinosteroid insensitive 1 transgenic seedlings, indicating that its transcriptional control is independent of hormonal feedback regulation. Diurnal changes in the expression of CPD and CYP85A2 are accompanied by changes of the endogenous BR content during the day, leading to brassinolide accumulation at the middle of the light phase. We also show that CPD expression is repressed in extended darkness in a BR feedback-dependent manner. In the dark the level of the bioactive hormone did not increase; therefore, our data strongly suggest that light also influences the sensitivity of plants to BRs.

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confidence: 91%

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

et al. 2006

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“…Thus, the phosphorylation status of BES1 and/or BZR1 has been used as a direct biochemical marker for BR signaling outputs (18). BZR1 and BES1 can bind directly to the promoter regions of the BR biosynthetic genes, CPD and DWF4, and inhibit their expression, forming a negative feedback loop (25,29). Therefore, the transcript levels of CPD and DWF4 are excellent molecular markers, and have been widely used for determining the strength of BR signaling outputs (18).…”

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confidence: 99%

The primary signaling outputs of brassinosteroids are regulated by abscisic acid signaling

Zhang

Cai

Wang

2009

Proc. Natl. Acad. Sci. U.S.A.

255

209

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Phytohormones have essential roles in coordinately regulating a large array of developmental processes. Studies have revealed that brassinosteroids (BRs) and abscisic acid (ABA) interact to regulate hundreds of expression in genes, governing many biological processes. However, whether their interaction is through modification or intersection of their primary signaling cascades, or by independent or parallel pathways remains a big mystery. Using biochemical and molecular markers of BR signaling and ABA biosynthetic mutants, we demonstrated that exogenous ABA rapidly inhibits BR signaling outputs as indicated by the phosphorylation status of BES1 and BR-responsive gene expression. Experiments using a bri1 null-allele, bri1-116, and analysis of subcellular localization of BKI1-YFP further revealed that the BR receptor complex is not required for ABA to act on BR signaling outputs. However, when the BR downstream signaling component BIN2 is inhibited by LiCl, ABA failed to inhibit BR signaling outputs. Also, using a set of ABA insensitive mutants, we found that regulation of ABA on the BR primary signaling pathway depends on the ABA early signaling components, ABI1 and ABI2. We propose that the signaling cascades of ABA and BR primarily cross-talk after BR perception, but before their transcriptional activation. This model provides a reasonable explanation for why a large proportion of BR-responsive genes are also regulated by ABA, and provides an insight into the molecular mechanisms by which BRs could interact with ABA.cross-talk ͉ gene expression ͉ phosphorylation ͉ seed germination ͉ signal transduction U nlike animals, plants are sessile and need to constantly regulate their developmental and physiological processes to respond to various internal and external stimuli. Studies have revealed that many biological processes result from integrating multiple hormonal signals, and extensive cross-talk among different hormonal signaling pathways is present in plants (1, 2). Recently, a large set of microarray data verified that many genes are coregulated by multiple hormones, suggesting the importance of hormones to coordinately regulate biological processes in plants (3,4). A few studies have also elucidated specific molecular mechanisms of hormonal cross-talk. They include the role of auxin and ethylene in regulating root meristem development (1), the antagonistic relationship between abscisic acid (ABA) and gibberellins (GAs) on seed dormancy and germination (5, 6), and integration of the primary signaling pathways of auxin and brassinosteroids (BRs) by auxin response factor 2 (ARF2) (7).Studies have indicated that BRs and ABA can coregulate the expression of hundreds of genes (4), and they interact physiologically in controlling many developmental processes (5,(8)(9)(10). It is also well known that ABA is required to establish seed dormancy during embryo maturation and to inhibit seed germination (5), whereas BRs promote seed germination, likely through enhancing the embryo growth potential to antagonize the effect...

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“…Reduced expression of the genes associated with secondary metabolism may partially contribute to the observed decrease in membrane integrity under high temperatures for Sicala 45 (Cottee et al 2012). This may limit photosynthetic capacity (Sullivan 1971) and subsequently reduced tolerance to nutrient (Ryan et al 2007) and heat stress (Tanaka et al 2005).…”

Section: Cultivar Differences For Expression Of Energy Productionassomentioning

confidence: 99%

Understanding the molecular events underpinning cultivar differences in the physiological performance and heat tolerance of cotton (Gossypium hirsutum)

Cottee

Wilson

Tan

et al. 2014

Functional Plant Biol.

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Abstract. Diurnal or prolonged exposure to air temperatures above the thermal optimum for a plant can impair physiological performance and reduce crop yields. This study investigated the molecular response to heat stress of two high-yielding cotton (Gossypium hirsutum L.) cultivars with contrasting heat tolerance. Using global gene profiling, 575 of 21854 genes assayed were affected by heat stress,~60% of which were induced. Genes encoding heat shock proteins, transcription factors and protein cleavage enzymes were induced, whereas genes encoding proteins associated with electron flow, photosynthesis, glycolysis, cell wall synthesis and secondary metabolism were generally repressed under heat stress. Cultivar differences for the expression profiles of a subset of heat-responsive genes analysed using quantitative PCR over a 7-h heat stress period were associated with expression level changes rather than the presence or absence of transcripts. Expression differences reflected previously determined differences for yield, photosynthesis, electron transport rate, quenching, membrane integrity and enzyme viability under growth cabinet and field-generated heat stress, and may explain cultivar differences in leaf-level heat tolerance. This study provides a platform for understanding the molecular changes associated with the physiological performance and heat tolerance of cotton cultivars that may aid breeding for improved performance in warm and hot field environments.

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Brassinosteroid Homeostasis in Arabidopsis Is Ensured by Feedback Expressions of Multiple Genes Involved in Its Metabolism

Cited by 221 publications

References 45 publications

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

The primary signaling outputs of brassinosteroids are regulated by abscisic acid signaling

Understanding the molecular events underpinning cultivar differences in the physiological performance and heat tolerance of cotton (Gossypium hirsutum)

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