title: Silicon alleviates salt and drought stress of Glycyrrhiza uralensis seedling by altering antioxidant metabolism and osmotic adjustment.
abstract: This study was conducted to determine effect and mechanism of exogenous silicon (Si) on salt and drought tolerance of Glycyrrhiza uralensis seedling by focusing on the pathways of antioxidant defense and osmotic adjustment. Seedling growth, lipid peroxidation, antioxidant metabolism, osmolytes concentration and Si content of G. uralensis seedlings were analyzed under control, salt and drought stress [100 mM NaCl with 0, 10 and 20% of PEG-6000 (Polyethylene glycol-6000)] with or without 1 mM Si. Si addition markedly affected the G. uralensis growth in a combined dose of NaCl and PEG dependent manner. In brief, Si addition improved germination rate, germination index, seedling vitality index and biomass under control and NaCl; Si also increased radicle length under control, NaCl and NaCl-10% PEG, decreased radicle length, seedling vitality index and germination parameters under NaCl-20% PEG. The salt and drought stress-induced-oxidative stress was modulated by Si application. Generally, Si application increased catalase (CAT) activity under control and NaCl-10% PEG, ascorbate peroxidase (APX) activity under all treatments and glutathione (GSH) content under salt combined drought stress as compared with non-Si treatments, which resisted to the increase of superoxide radicals and hydrogen peroxide caused by salt and drought stress and further decreased membrane permeability and malondialdehyde (MDA) concentration. Si application also increased proline concentration under NaCl and NaCl-20% PEG, but decreased it under NaCl-10% PEG, indicating proline play an important role in G. uralensis seedling response to osmotic stress. In conclusion, Si could ameliorate adverse effects of salt and drought stress on G. uralensis likely by reducing oxidative stress and osmotic stress, and the oxidative stress was regulated through enhancing of antioxidants (mainly CAT, APX and GSH) and osmotic stress was regulated by proline.
authors.affiliation: College of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China.
authors.forename: Zhicai
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Yantai Institute of Forestry Science, Yantai, 264013, Shandong, China.
authors.forename: Lianhong
authors.initials: L
authors.lastname: Wang
authors.affiliation: Desertification Control Institute, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Laboratory Animal Center, Ningxia Medical University, Yinchuan, 750004, China.
authors.forename: Duoyong
authors.initials: D
authors.lastname: Lang
authors.affiliation: College of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China. zhang2013512@163.com.|Ningxia Engineering and Technology Research Center of Hui Medicine Modernization, Ningxia Collaborative Innovation Center of Hui Medicine, Laboratory of Hui Ethnic Medicine Modernization, Ministry of Education, Ningxia Medical University, Yinchuan, 750004, China. zhang2013512@163.com.
authors.forename: Xinhui
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000187:drug effects; D018533:Biomass; D002374:Catalase / Q000187:drug effects / Q000378:metabolism; D055864:Droughts; D018525:Germination / Q000187:drug effects; D005978:Glutathione / Q000187:drug effects; D029882:Glycyrrhiza uralensis / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D008954:Models, Biological; D009997:Osmotic Pressure / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D011092:Polyethylene Glycols / Q000494:pharmacology; D011392:Proline / Q000187:drug effects; D055049:Salt Tolerance / Q000187:drug effects; D036226:Seedlings / Q000187:drug effects* / Q000254:growth & development*; D012825:Silicon / Q000494:pharmacology*; D012965:Sodium Chloride / Q000378:metabolism*; D013312:Stress, Physiological; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D013481:Superoxides; C000595215:Polyethylene Glycol 6000; D011092:Polyethylene Glycols; D012965:Sodium Chloride; D008315:Malondialdehyde; D011392:Proline; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D002374:Catalase; D005978:Glutathione; D012825:Silicon
keywords: Antioxidant enzymes; Glycyrrhiza uralensis; Non-enzyme antioxidants; Osmotic adjustment; Reactive oxygen species; Salt and drought stress; Silicon