title: Effects of slag-based silicon fertilizer on rice growth and brown-spot resistance.
abstract: It is well documented that slag-based silicon fertilizers have beneficial effects on the growth and disease resistance of rice. However, their effects vary greatly with sources of slag and are closely related to availability of silicon (Si) in these materials. To date, few researches have been done to compare the differences in plant performance and disease resistance between different slag-based silicon fertilizers applied at the same rate of plant-available Si. In the present study both steel and iron slags were chosen to investigate their effects on rice growth and disease resistance under greenhouse conditions. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the effects of slags on ultrastructural changes in leaves of rice naturally infected by Bipolaris oryaze, the causal agent of brown spot. The results showed that both slag-based Si fertilizers tested significantly increased rice growth and yield, but decreased brown spot incidence, with steel slag showing a stronger effect than iron slag. The results of SEM analysis showed that application of slags led to more pronounced cell silicification in rice leaves, more silica cells, and more pronounced and larger papilla as well. The results of TEM analysis showed that mesophyll cells of slag-untreated rice leaf were disorganized, with colonization of the fungus (Bipolaris oryzae), including chloroplast degradation and cell wall alterations. The application of slag maintained mesophyll cells relatively intact and increased the thickness of silicon layer. It can be concluded that applying slag-based fertilizer to Si-deficient paddy soil is necessary for improving both rice productivity and brown spot resistance. The immobile silicon deposited in host cell walls and papillae sites is the first physical barrier for fungal penetration, while the soluble Si in the cytoplasm enhances physiological or induced resistance to fungal colonization.
authors.affiliation: Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Ning
authors.affiliation: Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Alin
authors.initials: A
authors.lastname: Song
authors.affiliation: Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Fenliang
authors.initials: F
authors.lastname: Fan
authors.affiliation: Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Li
authors.affiliation: Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China; Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Liang
mesh_terms: D002473:Cell Wall / Q000187:drug effects / Q000382:microbiology; D002736:Chloroplasts / Q000187:drug effects / Q000382:microbiology; D003593:Cytoplasm / Q000187:drug effects / Q000382:microbiology; D060467:Disease Resistance / Q000187:drug effects*; D005308:Fertilizers; D005658:Fungi / Q000187:drug effects; D007501:Iron / Q000494:pharmacology; D058503:Mesophyll Cells / Q000187:drug effects / Q000382:microbiology; D009181:Mycoses / Q000382:microbiology / Q000517:prevention & control*; D012275:Oryza / Q000187:drug effects* / Q000254:growth & development* / Q000382:microbiology; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D018515:Plant Leaves / Q000254:growth & development / Q000382:microbiology; D012825:Silicon / Q000494:pharmacology*; D012822:Silicon Dioxide / Q000494:pharmacology; D012987:Soil; D013232:Steel / Q000494:pharmacology
chemical_list: D005308:Fertilizers; D012987:Soil; D013232:Steel; D012822:Silicon Dioxide; D007501:Iron; D012825:Silicon