Strigolactones are a class of phytohormones with various functions in plant development, stress responses, and in the interaction with (micro)organisms in the rhizosphere. While their effects on vegetative development are well studied, little is known about their role in reproduction. We investigated the effects of genetic and chemical modification of strigolactone levels on the timing and intensity of flowering in tomato (Solanum lycopersicum L.) and the molecular mechanisms underlying such effects. Results showed that strigolactone levels in the shoot, whether endogenous or exogenous, correlate inversely with the time of anthesis and directly with the number of flowers and the transcript levels of the florigen-encoding gene SINGLE FLOWER TRUSS (SFT) in the leaves. Transcript quantifications coupled with metabolite analyses demonstrated that strigolactones promote flowering in tomato by inducing the activation of the microRNA319-LANCEOLATE module in leaves. This, in turn, decreases gibberellin content and increases the transcription of SFT. Several other floral markers and morpho-anatomical features of developmental progression are induced in the apical meristems upon treatment with strigolactones, affecting floral transition and, more markedly, flower development. Thus, strigolactones promote meristem maturation and flower development via the induction of SFT both before and after floral transition, and their effects are blocked in plants expressing a miR319-resistant version of LANCEOLATE. Our study positions strigolactones in the context of the flowering regulation network in a model crop species.

• Klíčová slova
• LANCEOLATE, flowering, miR319, strigolactones, tomato,
• MeSH
• gibereliny metabolismus   farmakologie   MeSH
• květy * účinky léků   růst a vývoj   metabolismus   genetika   MeSH
• laktony * metabolismus   farmakologie   MeSH
• listy rostlin metabolismus   účinky léků   MeSH
• mikro RNA * genetika   metabolismus   MeSH
• regulace genové exprese u rostlin * účinky léků   MeSH
• regulátory růstu rostlin metabolismus   farmakologie   MeSH
• rostlinné proteiny metabolismus   genetika   MeSH
• Solanum lycopersicum * genetika   růst a vývoj   metabolismus   účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• gibereliny MeSH
• laktony * MeSH
• mikro RNA * MeSH
• regulátory růstu rostlin MeSH
• rostlinné proteiny MeSH

• MeSH
• bakteriální proteiny * genetika   MeSH
• beta-laktamasy * genetika   analýza   MeSH
• laktony metabolismus   MeSH
• lidé MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice * metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• Názvy látek
• bakteriální proteiny * MeSH
• beta-laktamasy * MeSH
• carbapenemase MeSH Prohlížeč
• laktony MeSH

Maize (Zea mays) is a major staple crop in Africa, where its yield and the livelihood of millions are compromised by the parasitic witchweed Striga. Germination of Striga is induced by strigolactones exuded from maize roots into the rhizosphere. In a maize germplasm collection, we identified two strigolactones, zealactol and zealactonoic acid, which stimulate less Striga germination than the major maize strigolactone, zealactone. We then showed that a single cytochrome P450, ZmCYP706C37, catalyzes a series of oxidative steps in the maize-strigolactone biosynthetic pathway. Reduction in activity of this enzyme and two others involved in the pathway, ZmMAX1b and ZmCLAMT1, can change strigolactone composition and reduce Striga germination and infection. These results offer prospects for breeding Striga-resistant maize.

• MeSH
• klíčení MeSH
• kukuřice setá * genetika   metabolismus   MeSH
• laktony * metabolismus   MeSH
• šlechtění rostlin MeSH
• Striga * růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• GR24 strigolactone MeSH Prohlížeč
• laktony * MeSH

Nitrogen (N) and phosphorus (P) are among the most important macronutrients for plant growth and development, and the most widely used as fertilizers. Understanding how plants sense and respond to N and P deficiency is essential to optimize and reduce the use of chemical fertilizers. Strigolactones (SLs) are phytohormones acting as modulators and sensors of plant responses to P deficiency. In the present work, we assess the potential role of SLs in N starvation and in the N-P signalling interplay. Physiological, transcriptional and metabolic responses were analysed in wild-type and SL-deficient tomato plants grown under different P and N regimes, and in plants treated with a short-term pulse of the synthetic SL analogue 2'-epi-GR24. The results evidence that plants prioritize N over P status by affecting SL biosynthesis. We also show that SLs modulate the expression of key regulatory genes of phosphate and nitrate signalling pathways, including the N-P integrators PHO2 and NIGT1/HHO. The results support a key role for SLs as sensors during early plant responses to both N and phosphate starvation and mediating the N-P signalling interplay, indicating that SLs are involved in more physiological processes than so far proposed.

• Klíčová slova
• nitrate starvation, nutrient deficiency, phosphate starvation, tomato,
• MeSH
• dusík fyziologie   MeSH
• fosfor fyziologie   MeSH
• heterocyklické sloučeniny tricyklické metabolismus   MeSH
• laktony metabolismus   MeSH
• signální transdukce * MeSH
• Solanum lycopersicum fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dusík MeSH
• fosfor MeSH
• GR24 strigolactone MeSH Prohlížeč
• heterocyklické sloučeniny tricyklické MeSH
• laktony MeSH

Belowground interactions of plants with other organisms in the rhizosphere rely on extensive small-molecule communication. Chemical signals released from host plant roots ensure the development of beneficial arbuscular mycorrhizal (AM) fungi which in turn modulate host plant growth and stress tolerance. However, parasitic plants have adopted the capacity to sense the same signaling molecules and to trigger their own seed germination in the immediate vicinity of host roots. The contribution of AM fungi and parasitic plants to the regulation of phytohormone levels in host plant roots and root exudates remains largely obscure. Here, we studied the hormonome in the model system comprising tobacco as a host plant, Phelipanche spp. as a holoparasitic plant, and the AM fungus Rhizophagus irregularis. Co-cultivation of tobacco with broomrape and AM fungi alone or in combination led to characteristic changes in the levels of endogenous and exuded abscisic acid, indole-3-acetic acid, cytokinins, salicylic acid, and orobanchol-type strigolactones. The hormonal content in exudates of broomrape-infested mycorrhizal roots resembled that in exudates of infested non-mycorrhizal roots and differed from that observed in exudates of non-infested mycorrhizal roots. Moreover, we observed a significant reduction in AM colonization of infested tobacco plants, pointing to a dominant role of the holoparasite within the tripartite system.

• Klíčová slova
• mycorrhizal fungi, parasitic plants, plant hormones, rhizosphere, root exudates, small-molecule communication, strigolactones,
• MeSH
• chromatografie kapalinová MeSH
• cytokininy metabolismus   MeSH
• heterocyklické sloučeniny tricyklické metabolismus   MeSH
• hmotnostní spektrometrie MeSH
• houby fyziologie   MeSH
• interakce hostitele a patogenu MeSH
• kořeny rostlin metabolismus   mikrobiologie   MeSH
• kyselina abscisová metabolismus   MeSH
• kyselina salicylová metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• laktony metabolismus   MeSH
• mykorhiza fyziologie   MeSH
• Orobanche růst a vývoj   mikrobiologie   MeSH
• tabák růst a vývoj   mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytokininy MeSH
• GR24 strigolactone MeSH Prohlížeč
• heterocyklické sloučeniny tricyklické MeSH
• indoleacetic acid MeSH Prohlížeč
• kyselina abscisová MeSH
• kyselina salicylová MeSH
• kyseliny indoloctové MeSH
• laktony MeSH

Structural knowledge of biological macromolecules is essential for understanding their function and for modifying that function by engineering. Protein crystallography is a powerful method for elucidating molecular structures of proteins, but it is essential that the investigator has a basic knowledge of good practices and of the major pitfalls in the technique. Here we describe issues specific for the case of structural studies of strigolactone (SL) receptor structure and function, and in particular the difficulties associated with capturing complexes of SL receptors with the SL hormone ligand in the crystal.

• Klíčová slova
• Crystallization, Ligand binding, Macromolecular crystallography, Strigolactone, Strigolactone receptors,
• MeSH
• heterocyklické sloučeniny tricyklické metabolismus   MeSH
• konformace proteinů MeSH
• krystalografie rentgenová MeSH
• laktony metabolismus   MeSH
• ligandy MeSH
• molekulární modely MeSH
• receptory buněčného povrchu genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• signální transdukce MeSH
• vazba proteinů MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• GR24 strigolactone MeSH Prohlížeč
• heterocyklické sloučeniny tricyklické MeSH
• laktony MeSH
• ligandy MeSH
• receptory buněčného povrchu MeSH
• rostlinné proteiny MeSH

Directional transport of the phytohormone auxin is a versatile, plant-specific mechanism regulating many aspects of plant development. The recently identified plant hormones, strigolactones (SLs), are implicated in many plant traits; among others, they modify the phenotypic output of PIN-FORMED (PIN) auxin transporters for fine-tuning of growth and developmental responses. Here, we show in pea and Arabidopsis that SLs target processes dependent on the canalization of auxin flow, which involves auxin feedback on PIN subcellular distribution. D14 receptor- and MAX2 F-box-mediated SL signaling inhibits the formation of auxin-conducting channels after wounding or from artificial auxin sources, during vasculature de novo formation and regeneration. At the cellular level, SLs interfere with auxin effects on PIN polar targeting, constitutive PIN trafficking as well as clathrin-mediated endocytosis. Our results identify a non-transcriptional mechanism of SL action, uncoupling auxin feedback on PIN polarity and trafficking, thereby regulating vascular tissue formation and regeneration.

• MeSH
• Arabidopsis genetika   metabolismus   MeSH
• heterocyklické sloučeniny tricyklické metabolismus   MeSH
• hrách setý genetika   metabolismus   MeSH
• kyseliny indoloctové metabolismus   MeSH
• laktony metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin genetika   fyziologie   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• GR24 strigolactone MeSH Prohlížeč
• heterocyklické sloučeniny tricyklické MeSH
• kyseliny indoloctové MeSH
• laktony MeSH
• proteiny huseníčku MeSH
• regulátory růstu rostlin MeSH

miR156 is a conserved microRNA whose role and induction mechanisms under stress are poorly known. Strigolactones are phytohormones needed in shoots for drought acclimation. They promote stomatal closure ABA-dependently and independently; however, downstream effectors for the former have not been identified. Linkage between miR156 and strigolactones under stress has not been reported. We compared ABA accumulation and sensitivity as well as performances of wt and miR156-overexpressing (miR156-oe) tomato plants during drought. We also quantified miR156 levels in wt, strigolactone-depleted and strigolactone-treated plants, exposed to drought stress. Under irrigated conditions, miR156 overexpression and strigolactone treatment led to lower stomatal conductance and higher ABA sensitivity. Exogenous strigolactones were sufficient for miR156 accumulation in leaves, while endogenous strigolactones were required for miR156 induction by drought. The "after-effect" of drought, by which stomata do not completely re-open after rewatering, was enhanced by both strigolactones and miR156. The transcript profiles of several miR156 targets were altered in strigolactone-depleted plants. Our results show that strigolactones act as a molecular link between drought and miR156 in tomato, and identify miR156 as a mediator of ABA-dependent effect of strigolactones on the after-effect of drought on stomata. Thus, we provide insights into both strigolactone and miR156 action on stomata.

• Klíčová slova
• Solanum lycopersicum, abscisic acid (ABA), after-effect of drought, hormone signalling, osmotic stress, stomata, stress-responsive microRNA,
• MeSH
• dehydratace MeSH
• heterocyklické sloučeniny tricyklické metabolismus   MeSH
• kyselina abscisová metabolismus   MeSH
• laktony metabolismus   MeSH
• mikro RNA metabolismus   fyziologie   MeSH
• průduchy rostlin fyziologie   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• RNA rostlin metabolismus   fyziologie   MeSH
• Solanum lycopersicum metabolismus   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• GR24 strigolactone MeSH Prohlížeč
• heterocyklické sloučeniny tricyklické MeSH
• kyselina abscisová MeSH
• laktony MeSH
• mikro RNA MeSH
• Mirn156 microRNA, Arabidopsis MeSH Prohlížeč
• regulátory růstu rostlin MeSH
• RNA rostlin MeSH

During arbuscular mycorrhizal symbiosis, colonization of the root is modulated in response to the physiological status of the plant, with regulation occurring locally and systemically. Here, we identify differentially expressed genes encoding CLAVATA3/ESR-related (CLE) peptides that negatively regulate colonization levels by modulating root strigolactone content. CLE function requires a receptor-like kinase, SUNN; thus, a CLE-SUNN-strigolactone feedback loop is one avenue through which the plant modulates colonization levels.

• MeSH
• Glomeromycota fyziologie   MeSH
• kořeny rostlin metabolismus   mikrobiologie   MeSH
• laktony metabolismus   MeSH
• Medicago truncatula metabolismus   mikrobiologie   MeSH
• mykorhiza fyziologie   MeSH
• rostlinné geny * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• laktony MeSH

The luxS gene is responsible for the synthesis of AI-2 (autoinducer-2), a signaling molecule that participates in quorum sensing regulation in a large number of bacteria. In this work, we investigated which phenotypes are regulated by luxS gene in Serratia proteamaculans 94, psychrotrophic strain isolated from spoiled refrigerated meat. AI-2 was identified in S. proteamaculans 94, and the luxS gene involved in its synthesis was cloned and sequenced. A mutant with the inactivated luxS gene was constructed. Inactivation of the luxS gene was shown to lead to the absence of AI-2 synthesis, chitinolytic activity, swimming motility, suppression of the growth of fungal plant pathogens Rhizoctonia solani and Helminthosporium sativum by volatile compounds emitted by S. proteamaculans 94 strain, and to a decrease of extracellular proteolytic activity. The knockout of the luxS gene did not affect synthesis of N-acyl-homoserine lactones, lipolytic, and hemolytic activities of S. proteamaculans 94.

• MeSH
• bakteriální proteiny genetika   MeSH
• biofilmy růst a vývoj   MeSH
• fenotyp MeSH
• homoserin analogy a deriváty   metabolismus   MeSH
• laktony metabolismus   MeSH
• lyasy štěpící vazby C-S genetika   MeSH
• maso mikrobiologie   MeSH
• mikrobiální interakce MeSH
• quorum sensing genetika   MeSH
• regulace genové exprese u bakterií MeSH
• Serratia genetika   metabolismus   MeSH
• těkavé organické sloučeniny analýza   MeSH
• umlčování genů * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• homoserin MeSH
• laktony MeSH
• LuxS protein, Bacteria MeSH Prohlížeč
• lyasy štěpící vazby C-S MeSH
• N-octanoylhomoserine lactone MeSH Prohlížeč
• těkavé organické sloučeniny MeSH