【作者】 李文娟； 何萍； 金继运；

【Author】 Li Wen-juan~(1,2),He Ping~(2,*),Jin Ji-yun~2 (1 Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China;2 Key Laboratory of Plant Nutrition and Nutrient Cycling,Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

【机构】 中国农业科学院农业环境与可持续发展研究所； 中国农业科学院农业资源与农业区划研究所农业部植物营养与养分循环重点开放实验室；

【摘要】 采用砂培实验,比较人工接种禾谷镰刀菌(Fusarium graminearum)后,不同钾处理对玉米幼根中糖含量及糖代谢关键酶活性和基因表达的影响,揭示钾素对作物抗病过程中糖类物质代谢的影响及其与玉米抗性的关系。结果表明,不施钾处理中,与对照未接菌处理相比,接菌后玉米幼根中蔗糖和葡萄糖含量均显著降低,且蔗糖的下降速率高于葡萄糖的下降速率。随着病原菌入侵时间的延长,不施钾处理葡萄糖与蔗糖比值显著升高,接菌8d后,缺钾幼根葡萄糖与蔗糖的比值是充足供钾幼根的近10倍。此外,钾素有利于病原菌入侵后,幼根中蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)活性提高,ss和sps基因表达量增加。而缺钾处理中,ss基因的表达量几乎没有发生变化,sps基因的表达量在接菌后6d才有所增加。说明在病原菌入侵后,钾素可以通过调节受侵染组织糖代谢相关酶的活性,保持受侵染部位糖含量及其组成的稳定,增强抗病能力。更多还原

【Abstract】 The effects of potassium on sucrose and glucose content,sugar metabolism related enzyme activity and the expression of their genes in maize root infected with Fusarium graminearum were studied under sand-culture experiment.The results showed that under K stress,pathogen infection led to significant decrease of sucrose and glucose contents.And the sucrose content declined more quickly than that of glucose.With the process of infection,the ratio of glucose to sucrose increased in no potassium applied treatment;8 days after infection,the ratio was 10 times higher in K deficient roots than in K adequate roots.Besides,the gene expression and activity of sucrose phosphate synthase(SPS) and sucrose synthase(SS) were induced by pathogen infection in potassium treated maize root. Pathogen induced higher activity of SPS in potassium addition treatment,but decreased SPS activity in K deficient root.In -K treatment,sps gene expressed in 6 days after inoculation,and no change of ss expression was observed in K-stressed root.This study demonstrated that K could enhance maize resistance to stalk rot by regulating sugar metabolism related enzyme to maintain the optimal sugar metabolism in infected position,in order to enhance the resistance to stalk rot.更多还原