Using degenerate oligonucleotide primers based on a pumpkin (Cucurbita maxima) gibberellin (GA) 20-oxidase sequence, six different fragments of dioxygenase genes were amplified by polymerase chain reaction from arabidopsis thaliana genomic DNA. One these was used to isolate two full-length cDNA clones, At2301 and At2353, shoots the GA-deficient Arabidopsis mutant ga1-2. A third, related clone, YAP169, identified in Database Expressed Sequence Tags. The clones expressed Escherichia coli as...

Plant growth and development are highly regulated processes that coordinated by hormones including the brassinosteroids (BRs), a group of steroids with structural similarity to steroid mammals. Although it is well understood how BRs produced their signals transduced, BR targets, which directly confer hormone's growth-promoting effects, have remained largely elusive. Here, we show regulate biosynthesis gibberellins (GAs), another class hormones, in Arabidopsis thaliana. We reveal mutants...

Hormones play pivotal roles in regulating plant development, growth, and stress responses, cross-talk among different hormones fine-tunes various aspects of physiology. Jasmonic acid (JA) is important for defense against herbivores necrotic fungi also regulates flower development; addition, Arabidopsis mutants over-producing JA usually have stunted stems wound-induced jasmonates suppress suggesting that involved stem elongation. Gibberellins (GAs) promote leaf growth modulate seed...

Asexual and sexual reproduction occur jointly in many angiosperms. Stolons (elongated stems) are used for asexual the crop species potato (Solanum tuberosum) strawberry (Fragaria spp), where they produce tubers clonal plants, respectively. In strawberry, stolon production is essential vegetative propagation at expense of fruit yield, but underlying molecular mechanisms unknown. Here, we show that deficiency trait runnerless (r) natural mutant woodland diploid vesca) due to a deletion active...

In the biosynthetic pathway to gibberellins (GAs), carbon-20 is removed by oxidation give C19-GAs, which include biologically active plant hormones. We report isolation of a cDNA clone encoding GA 20-oxidase [gibberellin, 2-oxoglutarate:oxygen oxidoreductase (20-hydroxylating, oxidizing) EC 1.14.11.-] screening library from developing cotyledons pumpkin (Cucurbita maxima L.) for expression this enzyme. When mRNA either or endosperm was translated in vitro using rabbit reticulocyte lysates,...

Summary The formation and growth of a potato ( Solanum tuberosum ) tuber is complex process regulated by different environmental signals plant hormones. In particular, the action gibberellins (GAs) has been implicated in aspects formation. Here we report on isolation functional analysis GA 2‐oxidase gene StGA2ox1 its role upregulated during early stages development prior to visible swelling predominantly expressed subapical region stolon growing tuber. 35S‐over‐expression transformants...

Geranyl diphosphate synthase (GPS) is generally considered to be responsible for the biosynthesis of monoterpene precursors only. However, reduction LeGPS expression in tomato (Lycopersicon esculentum) by virus-induced gene silencing resulted severely dwarfed plants. Further analysis these plants revealed a decreased gibberellin content, whereas carotenoid and chlorophyll levels were unaltered. Accordingly, phenotype could rescued application gibberellic acid. The was also obtained...

Transplastomic tobacco (Nicotiana tabacum) plants expressing β-glucosidase (Bgl-1) show modified development. They flower 1 month earlier with an increase in biomass (1.9-fold), height (1.5-fold), and leaf area (1.6-fold) than untransformed plants. Trichome density on the upper lower surfaces of BGL-1 by 10- 7-fold, respectively, harboring 5-fold more glandular trichomes (as determined rhodamine B staining), suggesting that lines produce sugar esters control Gibberellin (GA) levels were...

Ent-kaurenoic acid oxidase (KAO), a class of cytochrome P450 monooxygenases the subfamily CYP88A, catalyzes conversion ent-kaurenoic (KA) to gibberellin (GA) GA12 , precursor all GAs, thereby playing an important role in determining GA concentration plants. Past work has demonstrated importance KAO activity for growth various plant species. In Arabidopsis, this enzyme is encoded by two genes designated KAO1 and KAO2. study, we used approaches determine physiological roles KAO2 throughout...

Bahiagrass (Paspalum notatum Flugge) is a prime candidate for molecular improvement of turf quality. Its persistence and low input characteristics made it the dominant utility turfgrass along highways in south-eastern USA. However, comparatively poor quality due to reduced density prolific production unsightly inflorescences currently limits widespread use bahiagrass as residential turf. Alteration endogenous gibberellin (GA) levels by application growth regulators or transgenic strategies...

The consequences of altered abscisic acid (ABA) sensitivity in gray poplar (Populus × canescens [Ait.] Sm.) development were examined by ectopic expression the Arabidopsis (Arabidopsis thaliana) mutant abi1 (for insensitive1) gene. resulted an ABA-insensitive phenotype revealed a strong tendency poplars to wilt, impaired responsiveness their stomata ABA, and ABA-resistant bud outgrowth. These plants therefore required cultivation under very humid conditions prevent drought stress symptoms....

Flowering in plants is a dynamic and synchronized process where various cues including age, day-length, temperature endogenous hormones fine-tune the timing of flowering for reproductive success. Arabidopsis thaliana facultative long day (LD) plant LD photoperiod promotes flowering. still flowers under short-day (SD) conditions, albeit much later than conditions. Although, factors regulating inductive pathway have been extensively investigated, non-inductive SD less understood. Here we...

Many developmental processes in plants are regulated by GA hormones. homeostasis is achieved via complex biosynthetic and catabolic pathways. enzymes include 2-oxidases that classified into three classes. Members of class III typically act on precursors containing a C20-skeleton. Here, we identified two further members this 2-oxidases, namely AtGA2ox9 AtGA2ox10, the Arabidopsis (Arabidopsis thaliana) genome. Both genes encode have functional similarities to AtGA2ox7 AtGA2ox8, which...

Gibberellins (GAs) are hormones that control many aspects of plant development, including flowering. It is well known stamen the source GAs regulate male and bisexual flower development. However, little about role in female In cucumber, high levels GA precursors present ovaries bioactive GA4 identified sepals/petals, reflecting expression 20-oxidase 3-oxidase these organs, respectively. Here, we show biologically inactive precursor GA9 moves from to sepal/petal tissues where it converted...

Gibberellin (GA) plant hormones are biosynthesized via complex pathways, the final steps of which catalyzed by 2-oxoglutarate-dependent dioxygenases. Here, cloning two such enzymes, GA 7-oxidase and 20-oxidase, is reported using a novel approach, namely, screening for dioxygenase activities expressed as T7 gene 10 fusion proteins in recombinant Escherichia coli. In vitro translation products mRNA from endosperm immature pumpkin seeds contained three activities, including 7-oxidase,...

Abstract Soluble enzyme preparations from embryos and endosperm of Marah macrocarpus (previously Echinocystis macrocarpa) were incubated with [14C4]gibberellin(GA)12-aldehyde,[14C4]GA12, [14C1] GA9, 2,3-didehydro[14C1]GA9, [14C1]GA20, [17–13C,3H]GA5. Embryo converted GA12-aldehyde, GA12, GA9 to GA4 GA7; 2,3-didehydroGA9 GA5 GA3; GA20 (incompletely) GA1 GA60, but not GA3. Endosperm GA12-aldehyde GA12 GA15, GA24, GA25, but, unlike embryo preparations, or GA7. However, GA7 formed was...

Abstract A gibberellin (GA) biosynthetic pathway was discovered operating in root tips of 7-d-old pumpkin (Cucurbita maxima) seedlings. Stepwise analysis GA metabolism cell-free systems revealed the conversion GA12-aldehyde to bioactive GA4 and inactive GA34. Highest levels endogenous GA34 were found hypocotyls 3-d-old cDNA molecules encoding two oxidases, CmGA20ox3 CmGA3ox3, isolated from LAB150978-treated Recombinant fusion protein converted GA12 GA9, GA24 GA14 GA4, and, less efficiently,...