Gibberellin biosynthesis and its regulation

Hedden, Peter; Thomas, Stephen G.

doi:10.1042/bj20120245

Cited by 702 publications

(628 citation statements)

References 203 publications

Supporting

Mentioning

573

Contrasting

Unclassified

Order By: Relevance

“…Consistent with earlier results that genes encoding DELLA proteins are feed-forward regulated by GA Hedden and Thomas, 2012), we found that Fv GAI was upregulated in Fv SOC1 overexpression plants compared with SD strawberry and, again, that the response was opposite in the RNAi line (see Supplemental Figure 15 online). Strawberry homologs of positive regulators of GA signaling, GIBBERELLIN INSENSITIVE DWARF1 and SLEEPY (Harberd et al, 2009), were not clearly affected in transgenic lines (see Supplemental Figure 15 online).…”

Section: Fv Soc1 Activates Ga Biosynthesissupporting

confidence: 80%

TheFragaria vescaHomolog of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 Represses Flowering and Promotes Vegetative Growth

et al. 2013

View full text Add to dashboard Cite

In the annual long-day plant Arabidopsis thaliana, SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) integrates endogenous and environmental signals to promote flowering. We analyzed the function and regulation of the SOC1 homolog (Fragaria vesca [Fv] SOC1) in the perennial short-day plant woodland strawberry (Fragaria vesca). We found that Fv SOC1 overexpression represses flower initiation under inductive short days, whereas its silencing causes continuous flowering in both short days and noninductive long days, similar to mutants in the floral repressor Fv TERMINAL FLOWER1 (Fv TFL1). Molecular analysis of these transgenic lines revealed that Fv SOC1 activates Fv TFL1 in the shoot apex, leading to the repression of flowering in strawberry. In parallel, Fv SOC1 regulates the differentiation of axillary buds to runners or axillary leaf rosettes, probably through the activation of gibberellin biosynthetic genes. We also demonstrated that Fv SOC1 is regulated by photoperiod and Fv FLOWERING LOCUS T1, suggesting that it plays a central role in the photoperiodic control of both generative and vegetative growth in strawberry. In conclusion, we propose that Fv SOC1 is a signaling hub that regulates yearly cycles of vegetative and generative development through separate genetic pathways.

show abstract

Section: Fv Soc1 Activates Ga Biosynthesissupporting

confidence: 80%

TheFragaria vescaHomolog of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 Represses Flowering and Promotes Vegetative Growth

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Biosynthesis of GA 12 , the common precursor for all GAs in plants, is catalyzed by ent-kaurene oxidase (KO) and ent-kaurenoic acid oxidase (KAO) (34). The GA 12 content was strongly increased in E17 seeds as compared with WT (Fig.…”

Section: Resultsmentioning

confidence: 98%

“…Interestingly, only KAO2-but not KAO1-expression is affected by DOG1 overexpression (SI Appendix, Fig. S9), indicating that different mechanisms are involved in the regulation of these two genes, as has been shown for duplicated KAO genes in pea and sunflower (34). KO expression is directly regulated by the bZIP transcription factor REPRESSION OF SHOOT GROWTH (RSG) (39), which also has been suggested to regulate KAO expression (40).…”

Section: Dog1 Determines the Temperature Window For Germination By Rementioning

confidence: 99%

DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

Graeber

Linkies

Steinbrecher

et al. 2014

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

166

182

View full text Add to dashboard Cite

Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMI-NATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapping experiments between Brassicaceae species we show that the DOG1-mediated dormancy mechanism is conserved. Biomechanical analyses show that this mechanism regulates the material properties of the endosperm, a seed tissue layer acting as germination barrier to control coat dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-regulated genes encoding cell-wall remodeling proteins in a temperaturedependent manner. Furthermore we demonstrate that DOG1 causes temperature-dependent alterations in the seed GA metabolism. These alterations in hormone metabolism are brought about by the temperature-dependent differential expression of genes encoding key enzymes of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm weakening and determine the optimal temperature for germination. The conserved DOG1-mediated coat-dormancy mechanism provides a highly adaptable temperature-sensing mechanism to control the timing of germination.dormancy gene DOG1 | gibberellin metabolism | germination temperature | cell-wall remodelling | Lepidium sativum

show abstract

“…6A). Then, we used quantitative reverse transcription (RT)-PCR to measure the expression levels of the four genes of GA 3-oxidases and the five genes of GA 20-oxidases in Arabidopsis, whose induction could explain the high level of GA accumulated in the athb25-1D mutant (Hedden and Thomas, 2012). The expression levels of GA3OX1 and GA3OX3 were below detection, but we found a 2.5-fold induction of GA3OX2 in this mutant (Fig.…”

Section: Ga-dependent Phenotypes In Athb25-overexpressing Linesmentioning

confidence: 99%

ARABIDOPSIS THALIANA HOMEOBOX25 Uncovers a Role for Gibberellins in Seed Longevity

et al. 2013

View full text Add to dashboard Cite

Seed longevity is crucial for agriculture and plant genetic diversity, but it is limited by cellular damage during storage. Seeds are protected against aging by cellular defenses and by structures such as the seed coat. We have screened an activation-tagging mutant collection of Arabidopsis (Arabidopsis thaliana) and selected four dominant mutants with improved seed longevity (isl1-1D to isl4-1D) under both natural and accelerated aging conditions. In the isl1-1D mutant, characterized in this work, overexpression of the transcription factor ARABIDOPSIS THALIANA HOMEOBOX25 (ATHB25; At5g65410) increases the expression of GIBBERELLIC ACID3-OXIDASE2, encoding a gibberellin (GA) biosynthetic enzyme, and the levels of GA 1 and GA 4 are higher (3.2-and 1.4-fold, respectively) in the mutant than in the wild type. The morphological and seed longevity phenotypes of the athb25-1D mutant were recapitulated in transgenic plants with moderate (4-to 6-fold) overexpression of ATHB25. Simultaneous knockdown of ATHB25, ATHB22, and ATHB31 expression decreases seed longevity, as does loss of ATHB25 and ATHB22 function in a double mutant line. Seeds from wild-type plants treated with GA and from a quintuple DELLA mutant (with constitutive GA signaling) are more tolerant to aging, providing additional evidence for a role of GA in seed longevity. A correlation was observed in several genotypes between seed longevity and mucilage formation at the seed surface, suggesting that GA may act by reinforcing the seed coat. This mechanism was supported by the observation of a maternal effect in reciprocal crosses between the wild type and the athb25-1D mutant.

show abstract

Gibberellin biosynthesis and its regulation

Cited by 702 publications

References 203 publications

TheFragaria vescaHomolog of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 Represses Flowering and Promotes Vegetative Growth

TheFragaria vescaHomolog of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 Represses Flowering and Promotes Vegetative Growth

DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

ARABIDOPSIS THALIANA HOMEOBOX25 Uncovers a Role for Gibberellins in Seed Longevity

Contact Info

Product

Resources

About