植物膜转运的模型预测、实验验证及生理学影响-自主发布-资讯-生物在线

植物膜转运的模型预测、实验验证及生理学影响

作者:旭月(北京)科技有限公司 2010-03-03T00:00 (访问量:4708)

细胞膜是控制细胞振荡的中心,细胞的振荡在植物界中十分普遍。例如质膜电位的周期性变化、液泡电位及电流的波动、质外体的浓度变化、胞内pH及Ca2+的波动、不同细胞类型质膜跨膜离子流振荡等。然而,目前除了大致了解膜和离子流直接或间接参与振荡过程,研究人员对这种振荡的生理学功能仍然知之甚少。

Shabala等研究人员应用反馈受控振荡模型提出了许多设想:(1)振荡周期强烈依赖于质子泵活性;(2)质子泵活性受抑制时,振荡停止;(3)H+和K+流之间存在方向性的转变;(4)细胞膜上有对外界温度和离子浓度变化感受的“窗口”,对外界不同的变化细胞表现为不同的振荡模式;(5)振荡特性与细胞大小紧密相关等。他们使用“非损伤微测技术”直接测定了不同环境条件下植物根、叶片及真菌细胞跨膜的H+、K+、Ca2+O2的振荡规律。通过对模型预测及实验测定数据的比较,用实验成功地证实了之前设想的正确性。

此项研究结合模型预测及实验数据,根据植物对盐、温度、渗透、低氧及pH胁迫的适应性反应,对振荡的生理学功能作了较为清晰的阐述。这个模型可以指导筛选抗盐、抗涝等方面的育种工作。

点击查看大图
图注:
上图:玉米根部O2流的振荡变化作为O2利用情况的指标。A:不同氧气浓度下O2流的振荡规律;B:O2流振荡对外界氧气的依赖性。

关键词适应(Adaptation);离子流(Ion flux);膜(Membrane)
参考文献:Shabala S et al. . J. Exp. Bot. .2006, 57: 171-184.
全文下载http://www.xuyue.net/xylt/viewthread.php 转载请注明出处

------------------------------------------------------------------

Oscillations in plant membrane transport model predictions, experimental validation, and physiological implications

Abstract

Although oscillations in membrane-transport activity are ubiquitous in plants, the ionic mechanisms of ultradian oscillations in plant cells remain largely unknown, despite much phenomenological data. The physiological role of such oscillations is also the subject of much speculation. Over the last decade, much experimental evidence showing oscillations in net ion fluxes across the plasma membrane of plant cells has been accumulated using the non-invasive MIFE technique. In this study, a recently proposed feedback-controlled oscillatory model was used. The model adequately describes the observed ion flux oscillations within the minute range of periods and predicts: (i) strong dependence of the period of oscillations on the rate constants for the H+ pump; (ii) a substantial phase shift between oscillations in net H+ and K+ fluxes; (iii) cessation of oscillations when H+ pump activity is suppressed; (iv) the existence of some ‘window’ of external temperatures and ionic concentrations, where nondamped oscillations are observed: outside this range, even small changes in external parameters lead to progressive damping and aperiodic behaviour; (v) frequency encoding of environmental information by oscillatory patterns; and (vi) strong dependence of oscillatory characteristics on cell size. All these predictions were successfully confirmed by direct experimental observations, when net ion fluxes were measured from root and leaf tissues of various plant species, or from single cells. Because oscillatory behaviour is inherent in feedback control systems having phase shifts, it is argued from this model that suitable conditions will allow oscillations in any cell or tissue. The possible physiological role of such oscillations is discussed in the context of plant adaptive responses to salinity, temperature,osmotic, hypoxia, and pH stresses.

旭月(北京)科技有限公司 商家主页

地 址: 海淀区苏州街49-3号盈智大厦601室

联系人:

电 话: 010-82622628;010-62656315;010-62523549

传 真: 010-82622629(传真/直拨电话)

Email:china@youngerusa.cn

相关咨询

【成果回顾】MP万建民院士:无损"电生理"Ca2+流作为膜通道功能核心验证手段 为揭示CNGC9通道调控水稻低温响应机制提供证据 (2021-09-17T11:33 浏览数:8801)

S Shabala、陈仲华:叶肉细胞排Cl-排K+速率可用于预测温室和大田水稻生殖期的耐盐能力 (2021-09-17T11:16 浏览数:8364)

New Phytol于彦春/武丽敏:NMT发现KAR酶失活致热激后叶肉吸Ca失调为KAR酶通过调节胁迫信号赋予水稻耐热性提供证据 (2021-09-14T15:51 浏览数:9805)

【成果回顾】种康院士:NMT发现冷胁迫下CIPK7点突变水稻根吸Ca2+​增强 为CIPKs调控水稻耐寒机制的研究提供关键证据 (2021-09-14T15:46 浏览数:9565)

山农学者:种子吸Ca2+速率可作为种子活力快速评价指标 (2021-09-10T15:13 浏览数:11033)

【成果回顾】MP谢旗:NMT发现VPS23A促盐胁迫下根排Na+为ESCRT组分增强SOS模块功能维持拟南芥耐盐提供证据 (2021-09-10T14:57 浏览数:7388)

Crop J南农张阿英:NMT发现CBL5促盐胁迫下根排Na+为CBLs通过调节Na+稳态促谷子耐盐提供直接证据 (2021-09-10T14:33 浏览数:8270)

北林:NMT发现NO促Pb吸收并诱导Ca2+流紊乱 为NO增强Pb毒性的机制研究提供证据 (2021-09-03T16:18 浏览数:8645)

【成果回顾】西北研究院:NMT发现FAD3通过亚麻酸调节Ca2+信号增强烟草对多重胁迫的耐受性 (2021-09-03T15:59 浏览数:7661)

中国林科院张华新、杨秀艳:NMT发现白刺通过维持叶肉排Na+保K+能力及H+泵活性来适应盐胁迫 (2021-08-31T16:01 浏览数:8857)

ADVERTISEMENT