Nanoceria seed priming enhanced salt tolerance in rapeseed through modulating ROS homeostasis and α-amylase activities

• Published in: Journal of nanobiotechnology Vol. 19; no. 1; pp. 276 - 19
• Main Authors: Khan, Mohammad Nauman, Li, Yanhui, Khan, Zaid, Chen, Linlin, Liu, Jiahao, Hu, Jin, Wu, Honghong, Li, Zhaohu
• Format: Journal Article
• Language: English
• Published: England BioMed Central 16.09.2021; BMC
• Subjects: alpha-Amylases - metabolism; Amylases; Antioxidants; Brassica; Brassica napus; Brassica napus - drug effects; Brassica napus - metabolism; Cerium; Cerium - chemistry; Cerium oxides; Crop production; Damage tolerance; Enzymes; Experiments; Gene expression; Germination; Homeostasis; Hydrogen peroxide; Hygroscopic water; Imbibition; Localization; Metabolism; Metabolites; Metal Nanoparticles - chemistry; Metal Nanoparticles - toxicity; Na+/K+ ratio; Nanoceria; Nanomaterials; Nanoparticles; Nanotechnology; Plant Roots - drug effects; Plant Roots - metabolism; Plant stress; Plant tolerance; Polyacrylic acid; Potassium - chemistry; Potassium - metabolism; Priming; Rape plants; Rapeseed; Reactive Oxygen Species - metabolism; ROS homeostasis; Salinity; Salinity tolerance; Salt stress; Salt tolerance; Seed priming; Seeds; Seeds - drug effects; Seeds - enzymology; Seeds - metabolism; Sodium - chemistry; Sodium - metabolism; Sodium chloride; Sodium Chloride - pharmacology; Superoxide Dismutase - metabolism; Transmission electron microscopy; α-Amylase; α-amylase activity; Nanoceria; Na+/K+ ratio; Salt stress; α-amylase activity; ROS homeostasis; Seed priming
• DOI: 10.1186/s12951-021-01026-9
• ISSN: 1477-3155

Salinity is a big threat to agriculture by limiting crop production. Nanopriming (seed priming with nanomaterials) is an emerged approach to improve plant stress tolerance; however, our knowledge about the underlying mechanisms is limited. Herein, we used cerium oxide nanoparticles (nanoceria) to prime rapeseeds and investigated the possible mechanisms behind nanoceria improved rapeseed salt tolerance. We synthesized and characterized polyacrylic acid coated nanoceria (PNC, 8.5 ± 0.2 nm, -43.3 ± 6.3 mV) and monitored its distribution in different tissues of the seed during the imbibition period (1, 3, 8 h priming). Our results showed that compared with the no nanoparticle control, PNC nanopriming improved germination rate (12%) and biomass (41%) in rapeseeds (Brassica napus) under salt stress (200 mM NaCl). During the priming hours, PNC were located mostly in the seed coat, nevertheless the intensity of PNC in cotyledon and radicle was increased alongside with the increase of priming hours. During the priming hours, the amount of the absorbed water (52%, 14%, 12% increase at 1, 3, 8 h priming, respectively) and the activities of α-amylase were significantly higher (175%, 309%, 295% increase at 1, 3, 8 h priming, respectively) in PNC treatment than the control. PNC primed rapeseeds showed significantly lower content of MDA, H O , and O in both shoot and root than the control under salt stress. Also, under salt stress, PNC nanopriming enabled significantly higher K retention (29%) and significantly lower Na accumulation (18.5%) and Na /K ratio (37%) than the control. Our results suggested that besides the more absorbed water and higher α-amylase activities, PNC nanopriming improves salt tolerance in rapeseeds through alleviating oxidative damage and maintaining Na /K ratio. It adds more knowledge regarding the mechanisms underlying nanopriming improved plant salt tolerance.