Brassinosteroids enhance salicylic acid-mediated immune responses by inhibiting BIN2 phosphorylation of clade I TGA transcription factors in Arabidopsis.

Salicylic acid (SA) plays an important role in plant immune response, including resistance to pathogens and systemic acquired resistance. Two major components, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES (NPRs) and TGACG motif-binding transcription factors (TGAs), are known to mediate SA signaling, which might also be orchestrated by other hormonal and environmental changes. Nevertheless, the molecular and functional interactions between SA signaling components and other cellular signaling pathways remain poorly understood.

Inhibition of 4-HYDROXYPHENYLPYRUVATE DIOXYGENASE expression by brassinosteroid reduces carotenoid accumulation in Arabidopsis.

Unlike the indispensable function of the steroid hormone brassinosteroid (BR) in regulating plant growth and development, the metabolism of secondary metabolites regulated by BR is not well known. Here we show that BR reduces carotenoid accumulation in Arabidopsis seedlings. BR-deficient or BR-insensitive mutants accumulated higher content of carotenoids than wild-type plants, whereas BR treatment reduced carotenoid content.

Seed-Specific Expression of Produces Biologically Active Brassinosteroids Such as Castasterone and Brassinolide to Improve Grain Yield and Quality in Seeds of .

is a monocotyledonous model plant that contains castasterone (CS) but no brassinolide (BL) as the end product of brassinosteroids (BR) biosynthesis, indicating dysfunction of BL synthase, which catalyzes the conversion of CS to BL. To increase BR activity, () encoding BR 6-oxidase/BL synthase was introduced into with the seed-specific promoters , and . RT-PCR analysis and GUS activity revealed that was only expressed in the seeds of the transgenic plants , and .

Establishment of Biosynthetic Pathways To Generate Castasterone as the Biologically Active Brassinosteroid in .

Gas chromatography-mass spectrometry (GC-MS) analysis revealed that castasterone and its biosynthetic precursors are found in . In vitro conversion experiments with crude enzyme solutions prepared from demonstrated the presence of the following biosynthetic sequences: campesterol → campesta-4-en-3-one → campesta-3-one → campestanol → 6-deoxocathasterone → 6-deoxoteasterone → teasterone ↔ 3-dehydroteasterone ↔ typhasterol → castasterone. campesterol → 22-hydroxycampesterol → 22-hydroxy-campesta-4-en-3-one → 22-hydroxy-campesta-3-one → 6-deoxo-3-dehydroteasterone → 3-dehydroteasterone.

Brassinosteroids signaling via BZR1 down-regulates expression of to control growth of seedlings.

expression and RT-PCR analysis revealed that is predominantly expressed in shoots of Arabidopsis seedlings under light conditions. -overexpressed mutant produced more ethylene relative to the wild-type, which resulted in reduced growth of Arabidopsis seedlings. The abnormal growth of seedlings recurred after the application of Co ions, suggesting that is a functional necessary to regulate the growth and development of Arabidopsis seedlings.

BES1 directly binds to the promoter of the ACC oxidase 1 gene to regulate gravitropic response in the roots of .

Brassinosteroids (BRs) are known to be endogenous regulators of ethylene production, suggesting that some BR activity in plant growth and development is associated with ethylene. Here, we demonstrated that ethylene production in roots is increased by BR signaling via the ethylene biosynthetic gene for ACC oxidase 1 (). Electrophoretic mobility shift and chromatin immune-precipitation assays showed that the BR transcription factor BES1 directly binds to two E-box sequences located in the intergenic region of .

Arabidopsis ACC Oxidase 1 Coordinated by Multiple Signals Mediates Ethylene Biosynthesis and Is Involved in Root Development.

Ethylene regulates numerous aspects of plant growth and development. Multiple external and internal factors coordinate ethylene production in plant tissues. Transcriptional and post-translational regulations of ACC synthases (ACSs), which are key enzymes mediating a rate-limiting step in ethylene biosynthesis have been well characterized.

Function and molecular regulation of DWARF1 as a C-24 reductase in brassinosteroid biosynthesis in Arabidopsis.

DWARF1 (DWF1) is a sterol C-24 reductase that catalyses the conversion of 24-methylenecholesterol (24-MCHR) to campesterol (CR) in Arabidopsis. A loss-of-function mutant, dwf1, showed similar phenotypic abnormalities to brassinosteroid (BR)-deficient mutants. These abnormalities were reversed in the wild-type phenotype by exogenous application of castasterone (CS) and brassinolide (BL), but not dolichosterone (DS).

Overexpression of Arabidopsis thaliana brassinosteroid-related acyltransferase 1 gene induces brassinosteroid-deficient phenotypes in creeping bentgrass.

Brassinosteroids (BRs) are naturally occurring steroidal hormones that play diverse roles in various processes during plant growth and development. Thus, genetic manipulation of endogenous BR levels might offer a way of improving the agronomic traits of crops, including plant architecture and stress tolerance. In this study, we produced transgenic creeping bentgrass (Agrostis stolonifera L.

TOR Signaling Promotes Accumulation of BZR1 to Balance Growth with Carbon Availability in Arabidopsis.

For maintenance of cellular homeostasis, the actions of growth-promoting hormones must be attenuated when nutrient and energy become limiting. The molecular mechanisms that coordinate hormone-dependent growth responses with nutrient availability remain poorly understood in plants [1, 2]. The target of rapamycin (TOR) kinase is an evolutionarily conserved master regulator that integrates nutrient and energy signaling to regulate growth and homeostasis in both animals and plants [3-7].

SLG controls grain size and leaf angle by modulating brassinosteroid homeostasis in rice.

Grain size and leaf angle are two important traits determining grain yield in rice. However, the mechanisms regulating the two traits remain largely unknown. Here, we characterized a rice gain-of-function mutant, slender grain Dominant (slg-D), which exhibited longer and narrower grains and larger leaf angles, similar to plants with elevated brassinosteroid (BR) levels or strengthened BR signaling.