Project description:rs11-03_agro transcriptomic comparison of tumoric tissues induced by different c58 agrobacterium lines What are the functions and the regulatory pathways of the bacterial quorum-sensing system in the context of Agrobacterium/Arabidopsis interactions?
Project description:This research focuses on the design, manufacturing and validation of a new Agrobacterium tumefaciens C58 whole-genome tiling microarray platform for novel RNA transcript discovery. A whole-genome tiling microarray allows both annotated genes as well as previously unknown RNA transcripts to be detected and quantified at once. The Agrobacterium tumefaciens C58 genome is re-acquired with next-generation sequencing and then used to design the tilinlg microarray with the thermodynamic analysis program Picky. Validations are performed by subjecting Agrobacterium tumefaciens C58 under various growth conditions and then using the tling microarrays to verify expected gene expression patterns.
Project description:Agrobacterium tumefaciens is a special plant pathogen causing crown gall disease. This pathogen is well known for the technology Agrobacterium-mediated transformation. As a pathogen, Agrobacterium triggers plant immunity, and this affects transformation. But the signaling components and pathways in plant immunity to Agrobacterium remain elusive. We demonstrate two Arabidopsis MAPKKs MKK4/MKK5 and their downstream MAPKs MPK3/MPK6 play a major role in both Agrobacterium-triggered immunity and Agrobacterium-mediated transformation. Agrobacteria induce MPK3/MPK6 activity and plant defense responsive genes expression in a very early stage. This process is dependent on MKK4/MKK5 function. Loss of function of MKK4 and MKK5 or their downstream MPK3 and MPK6 abolishes plant immunity to agrobacteria, and increases the transformation frequency, while activation of MKK4 and MKK5 enhances the plant immunity and represses the transformation. Global transcriptome indicates agrobacteria induce various plant defense pathways, including ROS production, ethylene and SA-mediated defense responses, and MKK4/MKK5 is essential for these pathways induction. Activation of MKK4 and MKK5 promotes ROS production and cell death in agrobacteria infection process. Ethylene and SA act bypass of MKK4/MKK5 signaling to regulate transformation. Based on these results, we propose MKK4/5-MPK3/6 cascade is an essential signaling pathway to regulate Agrobacterium-mediated transformation by modulating Agrobacterium-triggered plant immunity.
