Chattha Muhammad Umer, Amjad Tahira, Khan Imran, Nawaz Muhammad, Ali Muqarrab, Chattha Muhammad Bilal, Ali Hayssam M, Ghareeb Rehab Y, Abdelsalam Nader R, Azmat Saira, Barbanti Lorenzo, Hassan Muhammad Umair
Department of Agronomy, University of Agriculture Faisalabad, Faisalabad, Pakistan.
Department of Agricultural Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, Pakistan.
Front Plant Sci. 2022 Sep 27;13:920570. doi: 10.3389/fpls.2022.920570. eCollection 2022.
Salinity stress (SS) is a challenging abiotic stress that limits crop growth and productivity. Sustainable and cost effective methods are needed to improve crop production and decrease the deleterious impacts of SS. Zinc (Zn) nano-particles (NPs) have emerged as an important approach to regulating plant tolerance against SS. However, the mechanisms of SS tolerance mediated by Zn-NPs are not fully explained. Thus, this study was performed to explore the role of Zn-NPs (seed priming and foliar spray) in reducing the deleterious impacts of SS on wheat plants. The study comprised different SS levels: control, 6 and 12 dS m, and different Zn-NPs treatments: control, seed priming (40 ppm), foliar spray (20 ppm), and their combination. Salinity stress markedly reduced plant growth, biomass, and grain yield. This was associated with enhanced electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (HO), sodium (Na), chloride (Cl) accumulation, reduced photosynthetic pigments, relative water contents (RWC), photosynthetic rate (Pn), transpiration rate (Tr), stomata conductance (Gs), water use efficiency (WUE), free amino acids (FAA), total soluble protein (TSP), indole acetic acid (IAA), gibberellic acid (GA), and nutrients (Ca, Mg, K, N, and P). However, the application of Zn-NPs significantly improved the yield of the wheat crop, which was associated with reduced abscisic acid (ABA), MDA, HO concentration, and EL, owing to improved antioxidant activities, and an increase in RWC, Pn, Tr, WUE, and the accumulation of osmoregulating compounds (proline, soluble sugars, TSP, and FAA) and hormones (GA and IAA). Furthermore, Zn-NPs contrasted the salinity-induced uptake of toxic ions (Na and Cl) and increased the uptake of Ca, K, Mg, N, and P. Additionally, Zn-NPs application substantially increased the wheat grain Zn bio-fortification. Our results support previous findings on the role of Zn-NPs in wheat growth, yield, and grain Zn bio-fortification, demonstrating that beneficial effects are obtained under normal as well as adverse conditions, thanks to improved physiological activity and the accumulation of useful compounds. This sets the premise for general use of Zn-NPs in wheat, to which aim more experimental evidence is intensively being sought. Further studies are needed at the genomic, transcriptomic, proteomic, and metabolomic level to better acknowledge the mechanisms of general physiological enhancement observed with Zn-NPs application.
盐胁迫(SS)是一种具有挑战性的非生物胁迫,它限制了作物的生长和生产力。需要可持续且具有成本效益的方法来提高作物产量并减少盐胁迫的有害影响。锌(Zn)纳米颗粒(NPs)已成为调节植物对盐胁迫耐受性的一种重要方法。然而,锌纳米颗粒介导的耐盐胁迫机制尚未得到充分解释。因此,本研究旨在探讨锌纳米颗粒(种子引发和叶面喷施)在减轻盐胁迫对小麦植株有害影响方面的作用。该研究包括不同的盐胁迫水平:对照、6和12 dS m,以及不同的锌纳米颗粒处理:对照、种子引发(40 ppm)、叶面喷施(20 ppm)及其组合。盐胁迫显著降低了植株生长、生物量和籽粒产量。这与电解质渗漏(EL)增加、丙二醛(MDA)、过氧化氢(HO)、钠(Na)、氯(Cl)积累、光合色素减少、相对含水量(RWC)、光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、水分利用效率(WUE)、游离氨基酸(FAA)、总可溶性蛋白(TSP)、吲哚乙酸(IAA)、赤霉素(GA)和养分(钙、镁、钾、氮和磷)有关。然而,锌纳米颗粒的应用显著提高了小麦作物的产量,这与脱落酸(ABA)、MDA、HO浓度和EL降低有关,这是由于抗氧化活性提高,以及RWC、Pn、Tr、WUE以及渗透调节化合物(脯氨酸、可溶性糖、TSP和FAA)和激素(GA和IAA)的积累增加。此外,锌纳米颗粒抑制了盐诱导的有毒离子(Na和Cl)的吸收,并增加了钙、钾、镁、氮和磷的吸收。此外,锌纳米颗粒的应用显著提高了小麦籽粒的锌生物强化作用。我们的结果支持了先前关于锌纳米颗粒在小麦生长、产量和籽粒锌生物强化方面作用的研究结果,表明由于生理活性的提高和有用化合物的积累,在正常和不利条件下都能获得有益效果。这为锌纳米颗粒在小麦中的普遍应用奠定了前提,为此正积极寻求更多的实验证据。需要在基因组、转录组、蛋白质组和代谢组水平上进行进一步研究,以更好地了解锌纳米颗粒应用所观察到的一般生理增强机制。