Ayyaz Ahsan, Fang Rouyi, Ma Junyi, Hannan Fakhir, Huang Qian, Athar Habib-Ur-Rehman, Sun Yongqi, Javed Muhammad, Ali Shafaqat, Zhou Weijun, Farooq Muhammad Ahsan
Institute of Crop Science, Ministry of Agriculture and Rural Affairs Key Laboratory of Spectroscopy Sensing, Zhejiang University, Hangzhou 310058, China.
Institute of Botany, Bahauddin Zakariya University, Multan 60800, Pakistan.
NanoImpact. 2022 Oct;28:100423. doi: 10.1016/j.impact.2022.100423. Epub 2022 Sep 7.
Foliar-application of nano-particles enhanced the foliar nutrient status and crop growth and yield. It is hypothesized that being second messenger molecule, supplementation of Ca via calcium nanoparticles (Ca-NPs) can trigger various signaling pathways of physiological processes which can lead to alleviate the adverse effects of drought stress on the growth of canola (Brassica napus L.). Nano-enabled foliar-application could be an ideal strategy for advancing agricultural productivity. The present study explored the role of calcium nanoparticles (Ca-NPs) in alleviating drought stress in hydroponic Brassica napus (B. napus) plants. The foliar applied Ca-NPs were spherically shaped with an average size of 86 nm. Foliar application of 100 mg L Ca-NPs enhanced biomass of canola plants and considered as optimal dose. Ca-NPs at 100 mg L has a greater favorable impact on mesophyll ultrastructure, PSI and PSII efficacy, gas exchange parameters, chlorophyll content, and mineral absorption. The Ca-NPs treatment increased NPQ and Y(NPQ) under drought condition, indicating a higher PSII protective response to stressed conditions with better heat dissipation as a photoprotective component of NPQ. Ca-NPs application also reduced oxidative stress damage as measured by a reduction in reactive oxygen species (ROS) generation in terms of hydrogen peroxide and malondialdehyde (HO and MDA). Furthermore, Ca-NPs induced drought tolerance response corresponded to an increased in key antioxidative defense enzymes (SOD, POD, CAT, APX), as well as non-enzymatic components (protease, lipoxygenase, proline, total soluble protein contents, endogenous hormonal biosynthesis), and secondary metabolite expression in B. napus plants. Taken together, the results of this study offer new insights into the physiological and molecular mechanisms by which B. napus responds to Ca-NPs exposure.
纳米颗粒的叶面喷施提高了叶片营养状况以及作物生长和产量。据推测，作为第二信使分子，通过钙纳米颗粒（Ca-NPs）补充钙可以触发生理过程的各种信号通路，从而减轻干旱胁迫对油菜（Brassica napus L.）生长的不利影响。纳米叶面喷施可能是提高农业生产力的理想策略。本研究探讨了钙纳米颗粒（Ca-NPs）在缓解水培油菜（B. napus）植株干旱胁迫中的作用。叶面喷施的Ca-NPs呈球形，平均粒径为86 nm。叶面喷施100 mg L Ca-NPs可提高油菜植株的生物量，被认为是最佳剂量。100 mg L的Ca-NPs对叶肉超微结构、PSI和PSII效率、气体交换参数、叶绿素含量和矿物质吸收有更大的有利影响。Ca-NPs处理在干旱条件下增加了NPQ和Y(NPQ)，表明PSII对胁迫条件有更高的保护反应，作为NPQ的光保护成分具有更好的散热能力。Ca-NPs的应用还减少了氧化应激损伤，这通过过氧化氢和丙二醛（H₂O₂和MDA）形式的活性氧（ROS）生成减少来衡量。此外，Ca-NPs诱导的耐旱反应对应于油菜植株中关键抗氧化防御酶（SOD、POD、CAT、APX）以及非酶成分（蛋白酶、脂氧合酶、脯氨酸、总可溶性蛋白含量、内源激素生物合成）和次生代谢物表达的增加。综上所述，本研究结果为油菜对Ca-NPs暴露的生理和分子机制提供了新的见解。
