title: Damage to Trichothecium roseum caused by sodium silicate is independent from pH.
abstract: Trichothecium roseum is one of the most important postharvest pathogens in arid and semiarid regions. Sodium silicate (NaSi) and environmental pH have significant inhibitory effects on fungal growth. However, no study has addressed the relationship of NaSi and pH in combination and the effects on T. roseum. In this work, we showed that spore germination, germ tube elongation, and mycelial growth of T. roseum were significantly inhibited by various NaSi concentrations, which had corresponding increasing pHs. Furthermore, these NaSi solutions showed a much greater impact than did pH treatments alone. The pathogenicity of NaSi-treated conidia on a model assay (conidia-inoculated apple fruit) was dramatically reduced, whereas no changes of pathogenicity were evident for the corresponding pH (various sodium hydroxide (NaOH) solutions) treatments. Fluorescent microscopy, using propidium iodide staining, showed damage of the plasma membranes of T. roseum conidia treated with both NaSi and NaOH, although the damage was more severe with NaSi. Leakage of proteins and sugars was significantly higher in NaSi-treated and NaOH-treated conidia than in untreated controls. In addition, serious damage was observed in the conidia exposed to NaSi for longer periods of time. Ultrastructural observations showed that treatment with either NaSi or NaOH caused a plasmolysis state and disorganized organelles. Taken together the results show that NaSi has inhibitory effects on T. roseum and that the inherent higher pH of NaSi solutions of higher concentrations simply acts as an enhancer of the inhibitory effects of NaSi.
authors.affiliation: a College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.|b College of Grassland Sciences and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.
authors.forename: Li-li
authors.initials: LL
authors.lastname: Niu
authors.affiliation: a College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Bi
authors.affiliation: a College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.
authors.forename: Xiao-dong
authors.initials: XD
authors.lastname: Bai
authors.affiliation: a College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.
authors.forename: Sheng-gui
authors.initials: SG
authors.lastname: Zhang
authors.affiliation: a College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.
authors.forename: Hua-li
authors.initials: HL
authors.lastname: Xue
authors.affiliation: a College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.
authors.forename: Yong-cai
authors.initials: YC
authors.lastname: Li
authors.affiliation: a College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: c Department of Biology, California State University, Fresno, CA 93711, USA.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Calderón-Urrea
mesh_terms: D005638:Fruit / Q000382:microbiology; D005656:Fungal Proteins / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D027845:Malus / Q000382:microbiology; D003904:Mitosporic Fungi / Q000187:drug effects* / Q000254:growth & development; D017640:Silicates / Q000494:pharmacology*; D012972:Sodium Hydroxide / Q000494:pharmacology; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D005656:Fungal Proteins; D017640:Silicates; D012972:Sodium Hydroxide; C005691:sodium silicate
keywords: conidia ultrastructure; inhibition; pathogenicity; pathogénicité; silicate de sodium; sodium silicate; ultrastructure des conidies