Abstract:
We recently proposed the use of engineered irregularly shaped zinc oxide nanoparticles (ZnO NPs) coated with oleylamine (OAm), as photosynthetic biostimulants, to enhance crop yield. In the current research, we tested newly engineered rod-shaped ZnO nanorods (NRs) coated with oleylamine (ZnO@OAm NRs) regarding their in vivo behavior related to photosynthetic function and reactive oxygen species (ROS) generation in tomato (Lycopersicon esculentum Mill.) plants. ZnO@OAm NRs were produced via solvothermal synthesis. Their physicochemical assessment revealed a crystallite size of 15 nm, an organic coating of 8.7% w/w, a hydrodynamic diameter of 122 nm, and a ζ-potential of -4.8 mV. The chlorophyll content of tomato leaflets after a foliar spray with 15 mg L-1 ZnO@OAm NRs presented a hormetic response, with an increased content 30 min after the spray, which dropped to control levels 90 min after the spray. Simultaneously, 90 min after the spray, the efficiency of the oxygen-evolving complex (OEC) decreased significantly (p < 0.05) compared to control values, with a concomitant increase in ROS generation, a decrease in the maximum efficiency of PSII photochemistry (Fv/Fm), a decrease in the electron transport rate (ETR), and a decrease in the effective quantum yield of PSII photochemistry (ΦPSII), indicating reduced PSII efficiency. The decreased ETR and ΦPSII were due to the reduced efficiency of PSII reaction centers (Fv\'/Fm\'). There were no alterations in the excess excitation energy at PSII or the fraction of open PSII reaction centers (qp). We discovered that rod-shaped ZnO@OAm NRs reduced PSII photochemistry, in contrast to irregularly shaped ZnO@OAm NPs, which enhanced PSII efficiency. Thus, the shape and organic coating of the nanoparticles play a critical role in the mechanism of their action and their impact on crop yield when they are used in agriculture.
摘要:
我们最近提出使用工程不规则形状的氧化锌纳米颗粒(ZnONPs)涂覆油胺(OAm),作为光合生物刺激剂,以提高作物产量。在目前的研究中,我们测试了新设计的带有油胺(ZnO@OAmNRs)的棒状ZnO纳米棒(NRs),其体内行为与番茄(LycopersiconesculentumMill)中光合功能和活性氧(ROS)的产生有关。)植物。ZnO@OAmNRs是通过溶剂热合成生产的。他们的物理化学评估显示微晶尺寸为15纳米,8.7%w/w的有机涂层,流体动力学直径为122nm,ζ电位为-4.8mV。用15mgL-1ZnO@OAmNRs进行叶面喷雾后,番茄小叶的叶绿素含量呈角化反应,喷雾后30分钟含量增加,喷雾后90分钟降至对照水平。同时,喷雾后90分钟,与对照值相比,析氧复合物(OEC)的效率显着降低(p<0.05),随着ROS生成的增加,PSII光化学的最大效率(Fv/Fm)降低,电子传输速率(ETR)下降,PSII光化学的有效量子产率(ΦPSII)降低,表明PSII效率降低。ETR和ΦPSII的降低是由于PSII反应中心(Fv'/Fm')的效率降低。PSII处的过量激发能或开放PSII反应中心(qp)的分数没有变化。我们发现棒状ZnO@OAmNRs降低了PSII光化学,与不规则形状的ZnO@OAmNPs相反,这提高了PSII效率。因此,纳米粒子的形状和有机涂层在它们的作用机制以及它们在农业中使用时对作物产量的影响中起着至关重要的作用。