Arabidopsis Thaliana Resistance Is Enhanced By Touching Trichomes

Plants employ the complex defense systems to accommodate biotic stress.The system divides into the physical and the chemical defense.The physical defense includes the surface wax layer,hard shell,spine,epidermis and other special structures evolved by plants to directly against the invasion of pests and pathogen.Plants utilize secondary metabolites,chemical compounds and volatile organic compounds to play chemical defense.Trichome plays an important role as the first line defense between plant leaf and the environment.There are many kinds of trichomes on the plant leaves,such as needle,hooked,flat,umbrella-shaped and anchor shaped.Arabidopsis thaliana trichome has been used as a model on studying cell cycle,cell polarity and cell differentiation.Trichome structure usually affects its function.However,the function of trichome structure is few reported.Previous studies have found that the morphology of the Arabidopsis trichome bottom is similar to nipple.Deformation and stress concentration occurred at the bottom of trichome when it suffered external mechanical stimulating.It has been shown that mechanical disturbing trichome can cause Ca²⁺change and pH value increase in the skirt cells.Changes in Ca²⁺concentration and pH value are the early signals of the priming defense.In this study,transcriptome sequencing was used to analyze gene transcription levels in Arabidopsis leaf after mechanical touching trichomes.The content of defense-related compounds were detected.Arabidopsis resistance to Botrytis cinereal and beet armyworm were tested after touching trichomes.Our results provide a reference to understand other plants non-glandular trichome function,and new perspectives and ideas for plant resistance to biotic stress.The main results were as follows:1.Transcriptome sequencing results show that the transcription level of genes related to defense is significantly increase after touching trichomes.2.DAB staining results show that hydrogen peroxide is produced in Arabidopsis,soybean and corn trichomes after touching.Touching trichomes increase the anthocyanin content of Arabidopsis leaves and enable callose to accumulate surroundings cells.3.AtPDF1.2 and AtMYB51 are induced to express in trichome and surroundings cells after touching trichomes.4.Touching trichomes inhibites Botrytis cinerea T4 infection in Arabidopsis and Soybean mosaic virus SC-8 infection in soybean,also enhances the resistance of Arabidopsis to beet armyworm.