Pollination in flowering plants is initiated by germination of pollen grains on stigmas followed by fast growth of pollen tubes representing highly energy-consuming processes. The symplastic isolation of pollen grains and tubes requires import of Suc available in the apoplast. We show that the functional coupling of Suc cleavage by invertases and uptake of the released hexoses by monosaccharide transporters are critical for pollination in tobacco (Nicotiana tabacum). Transcript profiling, in situ hybridization, and immunolocalization of extracellular invertases and two monosaccharide transporters in vitro and in vivo support the functional coupling in supplying carbohydrates for pollen germination and tube growth evidenced by spatiotemporally coordinated expression. Detection of vacuolar invertases in maternal tissues by these approaches revealed metabolic cross talk between male and female tissues and supported the requirement for carbohydrate supply in transmitting tissue during pollination. Tissue-specific expression of an invertase inhibitor and addition of the chemical invertase inhibitor miglitol strongly reduced extracellular invertase activity and impaired pollen germination. Measurements of (competitive) uptake of labeled sugars identified two import pathways for exogenously available Suc into the germinating pollen operating in parallel: direct Suc uptake and via the hexoses after cleavage by extracellular invertase. Reduction of extracellular invertase activity in pollen decreases Suc uptake and severely compromises pollen germination. We further demonstrate that Glc as sole carbon source is sufficient for pollen germination, whereas Suc is supporting tube growth, revealing an important regulatory role of both the invertase substrate and products contributing to a potential metabolic and signaling-based multilayer regulation of pollination by carbohydrates.

• MeSH
• 1-deoxynojirimycin analogy a deriváty   farmakologie   MeSH
• biologické modely MeSH
• hexosy metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• invertasa antagonisté a inhibitory   metabolismus   MeSH
• klíčení účinky léků   MeSH
• opylení účinky léků   MeSH
• proteiny přenášející monosacharidy genetika   metabolismus   MeSH
• pylová láčka účinky léků   enzymologie   růst a vývoj   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• reprodukovatelnost výsledků MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• sacharidy farmakologie   MeSH
• tabák enzymologie   genetika   metabolismus   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1-deoxynojirimycin MeSH
• hexosy MeSH
• inhibitory enzymů MeSH
• invertasa MeSH
• miglitol MeSH Prohlížeč
• proteiny přenášející monosacharidy MeSH
• rostlinné proteiny MeSH
• sacharidy MeSH

Plant-derived smoke stimulates seed germination in numerous plant species. Smoke also has a positive stimulatory effect on pollen germination and pollen tube growth. The range of plant families affected my smoke still needs to be established since the initial study was restricted to only three species from the Amaryllidaceae. The effects of smoke-water (SW) and the smoke-derived compounds, karrikinolide (KAR1 ) and trimethylbutenolide (TMB) on pollen growth characteristics were evaluated in seven different plant families. Smoke-water (1:1000 and 1:2000 v:v) combined with either Brewbaker and Kwack's (BWK) medium or sucrose and boric acid (SB) medium significantly improved pollen germination and pollen tube growth in Aloe maculata All., Kniphofia uvaria Oken, Lachenalia aloides (L.f.) Engl. var. aloides and Tulbaghia simmleri P. Beauv. Karrikinolide (10(-6) and 10(-7) m) treatment significantly improved pollen tube growth in A. maculata, K. uvaria, L. aloides and Nematanthus crassifolius (Schott) Wiehle compared to the controls. BWK or SB medium containing TMB (10(-3) m) produced significantly longer pollen tubes in A. maculata, K. uvaria and N. crassifolius. These results indicate that plant-derived smoke and the smoke-isolated compounds may stimulate pollen growth in a wide range of plant species.

• Klíčová slova
• Karrikinolide, pollen germination, pollen tube growth, smoke-water, trimethylbutenolide,
• MeSH
• furany farmakologie   MeSH
• gama-butyrolakton analogy a deriváty   farmakologie   MeSH
• kouř MeSH
• kultivační média MeSH
• liliovité účinky léků   MeSH
• pyl účinky léků   růst a vývoj   MeSH
• pylová láčka účinky léků   růst a vývoj   MeSH
• pyrany farmakologie   MeSH
• voda MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• butenolide MeSH Prohlížeč
• furany MeSH
• gama-butyrolakton MeSH
• karrikinolide MeSH Prohlížeč
• kouř MeSH
• kultivační média MeSH
• pyrany MeSH
• voda MeSH

Nitric oxide (NO) plays a key role in many physiological processes in plants, including pollen tube growth. Here, effects of NO on extracellular Ca(2+) flux and microfilaments during cell wall construction in Pinus bungeana pollen tubes were investigated. Extracellular Ca(2+) influx, the intracellular Ca(2+) gradient, patterns of actin organization, vesicle trafficking and cell wall deposition upon treatment with the NO donor S-nitroso-N-acetylpenicillamine (SNAP), the NO synthase (NOS) inhibitor N(omega)-nitro-L-arginine (L-NNA) or the NO scavenger 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) were analyzed. SNAP enhanced pollen tube growth in a dose-dependent manner, while L-NNA and cPTIO inhibited NO production and arrested pollen tube growth. Noninvasive detection and microinjection of a Ca(2+) indicator revealed that SNAP promoted extracellular Ca(2+) influx and increased the steepness of the tip-focused Ca(2+) gradient, while cPTIO and L-NNA had the opposite effect. Fluorescence labeling indicated that SNAP, cPTIO and L-NNA altered actin organization, which subsequently affected vesicle trafficking. Finally, the configuration and/or distribution of cell wall components such as pectins and callose were significantly altered in response to L-NNA. Fourier transform infrared (FTIR) microspectroscopy confirmed the changes in the chemical composition of walls. Our results indicate that NO affects the configuration and distribution of cell wall components in pollen tubes by altering extracellular Ca(2+) influx and F-actin organization.

• MeSH
• barvení a značení MeSH
• benzoáty farmakologie   MeSH
• biologické modely MeSH
• borovice účinky léků   metabolismus   MeSH
• buněčná stěna účinky léků   metabolismus   MeSH
• časové faktory MeSH
• extracelulární prostor účinky léků   metabolismus   MeSH
• glukany metabolismus   MeSH
• imidazoly farmakologie   MeSH
• intracelulární prostor účinky léků   metabolismus   MeSH
• klíčení účinky léků   MeSH
• kvartérní amoniové sloučeniny metabolismus   MeSH
• mikrofilamenta účinky léků   metabolismus   MeSH
• nitroarginin farmakologie   MeSH
• oxid dusnatý biosyntéza   farmakologie   MeSH
• pektiny metabolismus   MeSH
• polymerizace účinky léků   MeSH
• pylová láčka cytologie   účinky léků   růst a vývoj   metabolismus   MeSH
• pyridinové sloučeniny metabolismus   MeSH
• S-nitroso-N-acetylpenicilamin farmakologie   MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• vápník metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole MeSH Prohlížeč
• benzoáty MeSH
• callose MeSH Prohlížeč
• FM 4-64 MeSH Prohlížeč
• glukany MeSH
• imidazoly MeSH
• kvartérní amoniové sloučeniny MeSH
• nitroarginin MeSH
• oxid dusnatý MeSH
• pektiny MeSH
• pyridinové sloučeniny MeSH
• S-nitroso-N-acetylpenicilamin MeSH
• vápník MeSH