| Title: | High basal defense gene expression determines sorghum resistance to the whorl-feeding insect southwestern corn borer |
| Author(s): | Cheng WN; Lei JX; Rooney WL; Liu TX; Zhu-Salzman K; |
| Address: | "Key Laboratory of Integrated Pest Management on Crops in Northwestern Loess Plateau, Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China. cwning@126.com" |
| ISSN/ISBN: | 1744-7917 (Electronic) 1672-9609 (Linking) |
| Abstract: | "Southwestern corn borer (SWCB, Diatraea grandiosella) and fall armyworm (FAW, Spodoptera frugiperda) are major pests of sorghum in the southern United States. Host plant resistance is a desirable means for reducing plant damage and yield losses from both insects. In this study, we evaluated 12 sorghum lines for whorl-stage resistance to leaf-feeding SWCB and FAW in greenhouse and laboratory bioassays. Differential plant responses were detected against the two insects. Among 12 lines tested, CM1821, Della and PI196583 were resistant to both insects, while BTx2752 was largely susceptible. Line R.09110 was resistant to SWCB, but susceptible to FAW, whereas Redbine-60 was susceptible to SWCB, but not to FAW. In addition, we quantified various chemical components in the plants and determined their association with insect resistance. Tannin and chlorophyll in leaves did not show any significant correlation with resistance to either insects, but contents of soluble protein in general were negatively correlated with resistance to both insects. Endogenous soluble sugar and dhurrin were only positively correlated with resistance to SWCB, but not with FAW resistance. To gain some molecular insight into resistance mechanism of sorghum to SWCB, we performed qPCR reactions for key genes encoding enzymes involved in dhurrin and jasmonic acid (JA) biosynthesis on selected resistant or susceptible lines. Although these genes were rapidly and strongly induced by insect feeding in all lines, the observed resistance is likely explained by higher constitutive dhurrin contents in some resistant lines and higher basal JA biosynthesis in others. Our results suggest that sorghum utilizes multiple strategies to defend itself against SWCB" |
| Keywords: | "Animals Cyclopentanes/metabolism Gene Expression Regulation, Plant/*physiology Genotype Herbivory/*physiology Larva/physiology Moths/*physiology Nitriles/metabolism Oxylipins/metabolism Sorghum/genetics/*metabolism Transcriptome United States Diatraea gra;" |
| Notes: | "MedlineCheng, Wei-Ning Lei, Jia-Xin Rooney, William L Liu, Tong-Xian Zhu-Salzman, Keyan eng Research Support, U.S. Gov't, Non-P.H.S. Australia 2013/08/21 Insect Sci. 2013 Jun; 20(3):307-17. doi: 10.1111/1744-7917.12002. Epub 2013 Jan 14" |
