Research Institute on Terrestrial Ecosystems, National Research Council, via Moruzzi 1, I-56124, Pisa, Italy.
Department of Agriculture, Food and Environment, University of Pisa, via Mariscoglio 34, I-56124, Pisa, Italy.
Plant Physiol Biochem. 2022 Apr 1;176:9-20. doi: 10.1016/j.plaphy.2022.02.009. Epub 2022 Feb 12.
Nickel-induced changes in photosynthetic activity were investigated in three Ni-hyperaccumulating Odontarrhena species with increasing Ni tolerance and accumulation capacity, O. muralis, O. moravensis, and O. chalcidica. Plantlets were grown in hydroponics at increasing NiSO concentrations (0, 0.25, and 1 mM) for one week, and the effects of Ni on growth, metal accumulation, photosynthesis, and nitrogen (N) allocation to components of the photosynthetic apparatus were analysed. Nickel treatments in O. chalcidica, and O. moravensis to a lesser extent, increased not only the photochemical efficiency of photosystem II (PSII) and the CO assimilation rate, but also CO diffusion from the atmosphere to the carboxylation sites. These two species displayed a specific increase and/or rearrangement of the photosynthetic pigments and a higher leaf N allocation to the photosynthetic components in the presence of the metal. Odontarrhena muralis displayed a decrease in photosynthetic performance at the lowest Ni concentration due to a combination of both stomatal and non-stomatal limitations. Our data represent the first complete investigation of the effects of Ni on the photosynthetic machinery in Ni hyperaccumulating plants. Our findings clearly indicate a stimulatory, hormetic-like, effect of the metal on both biophysics and biochemistry of photosynthesis in the species with the highest hyperaccumulation capacity.
研究了三种镍超积累 Odontarrhena 物种的光合作用活性在镍诱导下的变化，这三种物种的镍耐受性和积累能力逐渐增强，分别为 O. muralis、O. moravensis 和 O. chalcidica。将幼苗在水培中于不同浓度的 NiSO₄（0、0.25 和 1 mM）下培养一周，分析了镍对生长、金属积累、光合作用和氮（N）分配到光合装置组件的影响。镍处理增加了 O. chalcidica 和 O. moravensis 中的光系统 II（PSII）的光化学效率和 CO 同化率，在一定程度上增加了 CO 从大气到羧化部位的扩散。这两个物种在金属存在的情况下，显示出特定的增加和/或排列的光合色素和更高的叶片 N 分配到光合组件。O. muralis 在最低镍浓度下显示出光合性能下降，这是由于气孔和非气孔限制的共同作用。我们的数据代表了对镍超积累植物中光合作用机制受镍影响的首次全面研究。我们的发现清楚地表明，金属对具有最高超积累能力的物种的光合作用的生物物理和生物化学具有刺激、激素样的影响。
