人为TiO2纳米颗粒的广泛可用性有助于它们渗透到环境中并促进与植物的相互作用。它们改变植物生长并改变其营养状况。特别是,代谢过程受到影响。在这项工作中,研究了纳米TiO2对豌豆(PisumsativumL.)光合作用效率的影响。应用具有三个Ti水平(10;50和100mgL-1)的水培培养。在所有浓度下,纳米颗粒都渗透到植物组织中,并通过单颗粒ICP-MS/MS方法进行检测。纳米颗粒改变了CO2同化速率和气体交换参数(即蒸腾作用,气孔导度,气孔下CO2浓度)。最明显的影响是观察到的Ti50mgL-1培养,其中光合作用效率,蒸腾作用和气孔导度增加了14.69%,4.58%和8.92%,分别。他们进一步证实了高的最大核酮糖1,5-双磷酸羧化率(27.40%的增加),电子输运速率最大(增加21.51%),CO2补偿点最低(减少45.19%)。此外,铜的浓度,Mn,Zn,Fe,Mg,Ca,对K和P进行了检查,观察到直接参与光合作用的元素的变化最明显(Cu,Zn,Mn,和Fe)。根中的铜浓度,Ti50mgL-1培养的茎和叶比对照低33.15%,38.28%和10.76%,分别。类似处理和器官中的锌含量降低了30.24%,26.69%和13.35%。叶片中的Mn和Fe含量分别增加了72.22%和50.32%,分别。我们的结果表明,豌豆中抑制水分吸收的植物防御机制已被刺激光合作用的纳米颗粒TiO2的光催化活性所克服。与大量的气孔导度相反,蒸腾作用减少了,因为叶绿体中已经消耗了异常部分的水流,并且无法释放到大气中。
Wide availability of anthropogenic TiO2 nanoparticles facilitates their penetration into environment and prompts interactions with plants. They alter plants growth and change their nutritional status. In particular, metabolic processes are affected. In this work the effect of nanometric TiO2 on
photosynthesis efficiency in green pea (Pisum sativum L.) was studied. Hydroponic cultivations with three Ti levels (10; 50 and 100 mg L-1) were applied. At all concentrations nanoparticles penetrated into plant tissues and were detected by the single particle ICP-MS/MS method. Nanoparticles altered the CO2 assimilation rate and gas exchange parameters (i.e. transpiration, stomatal conductance, sub-stomatal CO2 concentration). The most pronounced effects were observed for Ti 50 mg L-1 cultivation where
photosynthesis efficiency, transpiration and stomatal conductance were increased by 14.69%, 4.58% and 8.92%, respectively. They were further confirmed by high maximum ribulose 1,5-bisphosphate carboxylation rate (27.40% increase), maximum electron transport rate (21.51% increase) and the lowest CO2 compensation point (45.19% decrease). Furthermore, concentrations of Cu, Mn, Zn, Fe, Mg, Ca, K and P were examined with the most pronounced changes observed for elements directly involved in
photosynthesis (Cu, Zn, Mn, and Fe). The Cu concentrations in roots, stems and leaves for Ti 50 mg L-1 cultivation were below the control by 33.15%, 38.28% and 10.76%, respectively. The Zn content in analogous treatment and organs decreased by 30.24%, 26.69% and 13.35%. The Mn and Fe levels in leaves were increased by 72.22% and 50.32%, respectively. Our results indicated that plant defence mechanisms which restrain the water uptake have been overcome in pea by photocatalytic activity of nanoparticulate TiO2 which stimulated
photosynthesis. On the contrary to the substantial stomatal conductance, the transpiration has been reduced because exceptional part of water flow was already consumed in chloroplasts and could not have been freed to the atmosphere.