The effects of low energy nitrogen ion implantation on lily (Lilium davidii Duch.) pollen germination and the distribution of the actin cytoskeleton during pollen germination have been studied. Preliminary results sho...The effects of low energy nitrogen ion implantation on lily (Lilium davidii Duch.) pollen germination and the distribution of the actin cytoskeleton during pollen germination have been studied. Preliminary results showed that the ratio of pollen germination increased from (16.0±1.6)% to (27.0±2.1)% when implanted with nitrogen ions by 100 keV and a dose of 1013 ions/cm2. Further experiments were performed by staining the actin filaments in pollen with rhodamine-phalloidin and detected by using laser confocol microscopy. After hydration for 10 h, the actin filaments in ion implanted pollen grains tended to form thick bundles oriented in parallel or ring shape at the germinal furrow, indicating that the effect of nitrogen ion implantation on the germination of pollen might be mediated by reorganization of the actin cytoskeleton.展开更多
Dear Editor, As an essential element for pollen tube tip growth, actJn cytoskeleton has been a focus for decades. Recently, both rapid-freeze and room-temperature fixation have revealed the presence of a subapical co...Dear Editor, As an essential element for pollen tube tip growth, actJn cytoskeleton has been a focus for decades. Recently, both rapid-freeze and room-temperature fixation have revealed the presence of a subapical cortical F-actin （actin fringe） as a consistent feature of lily pollen tubes （Lovy-Wheeler et al., 2005）. The actin fringe consists of a palisade of short longitudinally oriented actin cables that start about 1-5~m behind the extreme apex and extend basally for an additional 5-10pm （Lovy-Wheeler et al., 2005）. MeanwhJJe, observations in live cells using Lifeact-mEGFP, an actin probe consisting of the first 17 amino acids from the budding yeast ABP-140 fused to GFP, which does not affect the dynamics of actin, compellingly support the presence of a cortical actin fringe in lilv pollen tubes ~Vidali et al.. 2009~.展开更多
The assembly of microtubules is essential for physiological functions of microtubules. Addition of microtubule-stabilizing reagents or microtubule 'seeds' is usually necessary for plant tubulin assembly in vit...The assembly of microtubules is essential for physiological functions of microtubules. Addition of microtubule-stabilizing reagents or microtubule 'seeds' is usually necessary for plant tubulin assembly in vitro, which hinders the investigation of plant microtubule dynamics. In the present note, highly purified plant tubulins have been obtained from lily pollen, a non-microtubule-stabilizing reagent or microtubule 'seed' system for plant tubulin assembly has been established and the analysis of plant tubulin assembly performed. Experiment results showed that purified tubulin polymerized in vitro, and a typical microtubule structure was observed with electron microscopy. The kinetics curve of tubulin assembly exhibited typical 'parabola'. The presence of taxol significantly altered the character of plant tubulin assembly, including that abnormal microtubules were assembled and the critical concentration for plant tubulin assembly was decreased exceedingly from 3 mg/mL in the absence of taxol to 0.043 mg/展开更多
Maize pollen actin has been labeled with Oregon Green 488 iodoacetamide. A yield of 3 mg fluorescent actin analogue has been obtained from 10 mg of maize pollen actin, which is 99% in purity and the dye/protein ratio ...Maize pollen actin has been labeled with Oregon Green 488 iodoacetamide. A yield of 3 mg fluorescent actin analogue has been obtained from 10 mg of maize pollen actin, which is 99% in purity and the dye/protein ratio is 72%. In the presence of Mg2+ and K+, the fluorescent actin analogue polymerized into filaments in vitro. Green fluorescent filaments were observed when the fluorescent actin was introduced into living plant cells by microinjection, indicating that the fluorescent actin analogue functions similarly to the native actin.展开更多
The actin cytoskeleton constituted of globular actin(G-actin)is a ubiquitous component of eukary- otic cells and plays crucial roles in diverse physiologi- cal processes in plant cells,such as cytoplasmic streaming,or...The actin cytoskeleton constituted of globular actin(G-actin)is a ubiquitous component of eukary- otic cells and plays crucial roles in diverse physiologi- cal processes in plant cells,such as cytoplasmic streaming,organelle and nucleus positioning,cell morphogenesis,cell division,tip growth,etc.In re-展开更多
文摘The effects of low energy nitrogen ion implantation on lily (Lilium davidii Duch.) pollen germination and the distribution of the actin cytoskeleton during pollen germination have been studied. Preliminary results showed that the ratio of pollen germination increased from (16.0±1.6)% to (27.0±2.1)% when implanted with nitrogen ions by 100 keV and a dose of 1013 ions/cm2. Further experiments were performed by staining the actin filaments in pollen with rhodamine-phalloidin and detected by using laser confocol microscopy. After hydration for 10 h, the actin filaments in ion implanted pollen grains tended to form thick bundles oriented in parallel or ring shape at the germinal furrow, indicating that the effect of nitrogen ion implantation on the germination of pollen might be mediated by reorganization of the actin cytoskeleton.
文摘Dear Editor, As an essential element for pollen tube tip growth, actJn cytoskeleton has been a focus for decades. Recently, both rapid-freeze and room-temperature fixation have revealed the presence of a subapical cortical F-actin （actin fringe） as a consistent feature of lily pollen tubes （Lovy-Wheeler et al., 2005）. The actin fringe consists of a palisade of short longitudinally oriented actin cables that start about 1-5~m behind the extreme apex and extend basally for an additional 5-10pm （Lovy-Wheeler et al., 2005）. MeanwhJJe, observations in live cells using Lifeact-mEGFP, an actin probe consisting of the first 17 amino acids from the budding yeast ABP-140 fused to GFP, which does not affect the dynamics of actin, compellingly support the presence of a cortical actin fringe in lilv pollen tubes ~Vidali et al.. 2009~.
文摘The assembly of microtubules is essential for physiological functions of microtubules. Addition of microtubule-stabilizing reagents or microtubule 'seeds' is usually necessary for plant tubulin assembly in vitro, which hinders the investigation of plant microtubule dynamics. In the present note, highly purified plant tubulins have been obtained from lily pollen, a non-microtubule-stabilizing reagent or microtubule 'seed' system for plant tubulin assembly has been established and the analysis of plant tubulin assembly performed. Experiment results showed that purified tubulin polymerized in vitro, and a typical microtubule structure was observed with electron microscopy. The kinetics curve of tubulin assembly exhibited typical 'parabola'. The presence of taxol significantly altered the character of plant tubulin assembly, including that abnormal microtubules were assembled and the critical concentration for plant tubulin assembly was decreased exceedingly from 3 mg/mL in the absence of taxol to 0.043 mg/
文摘Maize pollen actin has been labeled with Oregon Green 488 iodoacetamide. A yield of 3 mg fluorescent actin analogue has been obtained from 10 mg of maize pollen actin, which is 99% in purity and the dye/protein ratio is 72%. In the presence of Mg2+ and K+, the fluorescent actin analogue polymerized into filaments in vitro. Green fluorescent filaments were observed when the fluorescent actin was introduced into living plant cells by microinjection, indicating that the fluorescent actin analogue functions similarly to the native actin.
文摘The actin cytoskeleton constituted of globular actin(G-actin)is a ubiquitous component of eukary- otic cells and plays crucial roles in diverse physiologi- cal processes in plant cells,such as cytoplasmic streaming,organelle and nucleus positioning,cell morphogenesis,cell division,tip growth,etc.In re-
