121 research outputs found
Expression and Trafficking of the Îł Subunit of Na,K-ATPase in Hypertonically Challenged IMCD3 Cells
The γ subunit (FXYD2) of Na,K-ATPase is an important regulator of the sodium pump. In this investigation we have analysed the trafficking of γ to the plasma membrane in cultures of inner medullary collecting duct cells (IMCD3) following acute hypertonic challenge and brefeldin A (BFA) treatment. Following hypertonic challenging for 24 hr immunofluorescence labeling revealed initial co-localization of the γ subunit and 58K Golgi protein in the cytoplasm, but no co-localization of α1 and Golgi protein. Exposure of the challenged cells to BFA prevented the subsequent incorporation of γ into the basolateral plasma membrane. The γ subunit instead remained in cytoplasmic vesicles while cell proliferation and cell viability decreased simultaneously. Following removal of BFA from the hypertonic medium the IMCD3 cells recovered with distinct expression of γ in the basolateral membrane. The α1 subunit was only marginally influenced by BFA. The results demonstrate that the γ subunit trafficks to the plasma membrane via the Golgi apparatus, despite the absence of a signal sequence. The results also suggest that the γ and α subunits do not traffic together to the plasma membrane, and that the γ and α subunit have different turnover rates during these experimental conditions
Immunolocalization of Antifreeze Proteins in Winter Rye Leaves, Crowns, and Roots by Tissue Printing
Effects of a dicamba/MCPA/mecoprop herbicide mixture on the leaves of a barley variety
vokKirjasto Aj-KDikamba/MCPA/mekoproppi-herbisidiseoksen vaikutukset Ohran lehtee
Effects of a dicamba/MCPA/mecoprop herbicide mixture on the leaves of a barley variety
Plants of a barley cultivar Pomo were sprayed at 2-node stage with a herbicide mixture, âMepro Specialâ, containing dicamba, MCPA and mecoprop, and the plants were grown at two different temperatures. 15°C and 23° C. The effects of the herbicide on the morphology and anatomy were studied by light and electron microscopes and the effects on the chlorophyll content of leaves were studied at various intervals after the spraying. First sign of damage in the morphology of plants grown both at 23° C and 15°C were observable 10-12 days after the spraying but those in the ultrastructure as soon as 1 day after the treatment. The cells of the vascular bundle sheath were most sensitive while the mesophyll cells were unchanged during the total observation period of 12 days at 15°C. At a higher temperature injuries of various stages were observable also in the mesophyll 6 days after the treatment. The clearest alterations became visible in the chloroplasts. They swelled to spherical in shape, the intergrana and later also grana lamellae formed vesicles by dilating, later they broke down, and ultimately the plastid envelope disintegrated. The amount of starch and chlorophyll decreased, whereas the number and size of osmiophilic plastoglobuli increased significantly. The mitochondria swelled, the cristae frequently disappeared and the outer membrane of the envelope distended largely. The nucleus was best capable of resisting the toxic effects of the herbicide. The tonoplast and plasmalemma were broken down a short time before the final disintegration of the cell structures. High temperature obviously reinforced the toxic effects of the herbicide mixture
Dikamba/MCPA/mekoproppi-herbisidiseoksen vaikutukset ohran lehteen
Plants of a barley cultivar Pomo were sprayed at 2-node stage with a herbicide mixture, âMepro Specialâ, containing dicamba, MCPA and mecoprop, and the plants were grown at two different temperatures. 15°C and 23° C. The effects of the herbicide on the morphology and anatomy were studied by light and electron microscopes and the effects on the chlorophyll content of leaves were studied at various intervals after the spraying. First sign of damage in the morphology of plants grown both at 23° C and 15°C were observable 10-12 days after the spraying but those in the ultrastructure as soon as 1 day after the treatment. The cells of the vascular bundle sheath were most sensitive while the mesophyll cells were unchanged during the total observation period of 12 days at 15°C. At a higher temperature injuries of various stages were observable also in the mesophyll 6 days after the treatment. The clearest alterations became visible in the chloroplasts. They swelled to spherical in shape, the intergrana and later also grana lamellae formed vesicles by dilating, later they broke down, and ultimately the plastid envelope disintegrated. The amount of starch and chlorophyll decreased, whereas the number and size of osmiophilic plastoglobuli increased significantly. The mitochondria swelled, the cristae frequently disappeared and the outer membrane of the envelope distended largely. The nucleus was best capable of resisting the toxic effects of the herbicide. The tonoplast and plasmalemma were broken down a short time before the final disintegration of the cell structures. High temperature obviously reinforced the toxic effects of the herbicide mixture.Ohran Pomo-lajikkeen 2-solmuasteella olevia yksilöitĂ€ ruiskutettiin kotimaisella 'Mepro Special'-rikkakasvihĂ€vitteellĂ€, joka sisĂ€ltÀÀ dikambaa, MCPA:ta ja mekoproppia. KĂ€siteltyjĂ€ ja kontrollikasveja kasvatettiin tĂ€mĂ€n jĂ€lkeen 15°C tai 23° C:ssa pitkĂ€n pĂ€ivĂ€n olosuhteissa pimeĂ€jakson lĂ€mpötilan ollessa 10°C. LehdistĂ€ otettiin nĂ€ytteitĂ€ valo- ja elektronimikroskopiaa varten sekĂ€ klorofyllimÀÀrityksiin eri aikoina 12 pĂ€ivĂ€n kuluessa. Kasvien morfologiassa nĂ€htiin ensimmĂ€iset merkit herbisidin haittavaikutuksista lehtien kellastumisena molemmissa lĂ€mpötiloissa vasta 10â12 pĂ€ivÀÀ ruiskuttamisen jĂ€lkeen. Hienorakenteessa sensijaan nĂ€kyi muutoksia johtojĂ€nnetupensoluissa selvĂ€sti jo 1 pĂ€ivĂ€n kuluttua. Mesofyllin solut pysyivĂ€t lĂ€hes muuttumattomina 15°C:ssa koko havaintojentekoajan, mutta 23° C:ssa vaurioita alkoi esiintyĂ€ selvĂ€sti 6 pĂ€ivĂ€n kuluttua. Organelleista herkimpiĂ€ olivat kloroplastit, joiden muoto aluksi muuttui pyöreĂ€ksi. Ensin paisuivat intergranatylakoidit ja sitten granatylakoidit muodostaen pieniĂ€ rakkuloita. Osmiofiilisten plastoglobuloitten mÀÀrĂ€ ja koko kasvoi huomattavasti. MyöhempiĂ€ vaurioitumisen merkkejĂ€ olivat lamellien ja kloroplastikelmun sekĂ€ tonoplastin rikkoontuminen. Myös mitokondriot turposivat, ja kristat saattoivat hĂ€vitĂ€ kokonaan. Usein kelmun ulompikalvo irtosi sisĂ€kalvosta venyen pussimaisesti. Plasmalemman rikkoonnuttua solun kaikki rakenteet hajosivat. TĂ€rkkelyksen mÀÀrĂ€ssĂ€ todettiin huomattava nousu 15°C:ssa kasvaneissa kasveissa 3 t kĂ€sittelyn jĂ€lkeen, mutta 1 pv kĂ€sittelystĂ€ sekĂ€ tĂ€rkkelyksen ettĂ€ klorofyllin mÀÀrĂ€ alkoivat laskea. Korkea lĂ€mpötila lisĂ€si selvĂ€sti myrkkyvaikutuksia, mikĂ€ nĂ€kyi rakenteiden muutoksinakin. RiittĂ€vĂ€stĂ€ kastelusta huolimatta voitiin todeta, ettĂ€ 6 pv 23° C:ssa kasvaneissa kontrollikasveissa alkoi esiintyĂ€ yleisiĂ€ solun vanhenemiseen liittyviĂ€ muutoksia, osoittaen Pomo-lajikkeen kĂ€rsivĂ€n aineenvaihdunnan eri tasoilla
Ultrastructural Changes Arising from Freezing of Leaf Blade Cells of Cold Acclimated Rye (Secale cereale)
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