The role of the cytoskeleton and dictyosome activity in the pulsatory growth of Nicotiana tabacum and Petunia hybrida pollen tubes
The role of the cytoskeleton and dictyosome activity in the pulsatory growth of Nicotiana tabacum and Petunia hybrida pollen tubes
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DOI：
10.1111/j.1438-8677.1996.tb00549.x
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发表时间：
1996-04-01
期刊：
影响因子：
--
通讯作者：
Cresti, M
中科院分区：
文献类型：
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作者：
Geitmann, A;Li, YQ;Cresti, M
普通烟草和矮牵牛的花粉管呈平行生长。持续数分钟的缓慢生长阶段被持续10-20秒的脉冲状延长所打断，生长速度增加高达24倍。用布雷菲德菌素A或莫能菌素抑制网质体活性并不导致抑制花粉的生长，但最终停止了花粉管的伸长。与此相反，用细胞松弛素D和秋水仙素抑制细胞骨架元素，导致花粉管放弃脉冲状伸长。得出的结论是，活性的dictyosomes不具有控制功能的机制中的生长，即使它是必要的花粉管伸长，因为细胞壁材料提供的分泌囊泡来自高尔基体。与此相反，细胞骨架元件，肌动蛋白和微管，似乎发挥了重要的调节作用，在脉冲状的延伸。此外，有人观察到，在实验过程中，几个花粉管爆裂后完成的脉冲状扩张，一方面表明，内部膨压是脉冲状扩张的驱动力。另一方面，破裂表明，在脉冲结束时，花粉管细胞壁相当弱，表明在这个时间点，它比缓慢生长期或脉冲开始时更薄或更不稳定。
Pollen tubes of Nicotiana tabacum and Petunia hybrida show pulsatory growth. Phases of slow growth lasting minutes are interrupted by pulse-like elongations lasting 10-20 seconds involving an increase of growth rate by up to 24-fold. Inhibition of dictyosome activity with brefeldin A or monensin did not result in an inhibition of pulsatory growth but eventually stopped pollen tube elongation. In contrast to this the inhibition of the cytoskeletal elements with cytochalasin D and colchicine caused the pollen tubes to abandon the pulse-like elongations. It was concluded that the activity of the dictyosomes does not have a controlling function in the mechanism of pulsatory growth, even though it is necessary for pollen tube elongation, since cell wall material is provided by secretory vesicles deriving from the Golgi apparatus. In contrast the cytoskeletal elements, actin and microtubules, seem to play an important regulatory role in the pulse-like elongations. In addition, it was observed that during the experiments several pollen tubes burst upon the completion of a pulse-like expansion, indicating on the one hand that the internal turgor is the driving force of the pulse-like expansions. On the other hand, the bursting shows that the pollen tube cell wall is rather weak at the end of a pulse, indicating that at this point of time it is either thinner or less stable than during the slow growth phase or at the beginning of a pulse.