Molecular Mechanisms Of SA Signaling Pathway Proteins Involved In Plant Defense Biotic Stress In Arabidopsis Thaliana

Salicylic acid is an important signal molecule that is synthesized by plants during stress and is important for resistance to pathogens. Repeated treatment with salicylic acid (SA) analogs such as Benzothiadiazole carbothioic S-methyl ester (BTH) not only triggers defense responses, but also results in growth suppression. Therefore, BTH screen is an important assay to identify SA signaling pathway components. In this research we screen for BTH-insensitive mutants in both T-DNA insertion and EMS-mutagenized population via BTH screen assay. Trying to indicate Molecular mechanisms of SA signaling pathway proteins involved in plant defense biotic stress in Arabidopsis thaliana. And the main results are showed as follows:(1) Find the new function of WRKY54/WRKY70that regulate the plant defiance resistance. This mutant exhibits increased basal defense gene expression, yet it is compromised in basal defense. PR gene expression can’t be induced by BTH and NPR1protein can’t be accumulated in this mutant. These results predict that WRKY54/WRKY70may regulate the plant defense resistance through NPR1.(2) WRKY54/WRKY70mutated result in HR delayed. HR can’t be induced very quickly after pathogens infected. This indicate WRKY54/WRKY70plays an important role in regulate HR.(3) WRKY54/WRKY70mutated result in SAR blocked. Neither Chemical no biological can induce SAR in wrky54/wrky70mutant. This indicate WRKY54/WRKY70regulate SAR and plays an important role in regulate plant denfense.(4) Identified and cloned Arabidopsis thaliana defense related gene BIND1. TAIL PCR, followed by sequencing, revealed an insertion in a member of PFKB-like gene family. Cloned1742bp full-length genomic DNA and1032bp full length CDS. Subcellular localization of BIND1-GFP revealed that it is a cytosolic protein and could also be localized in the nucleus.(5) Find the function of BIND1in plant defense resistance. This gene is induced by BTH and the induction is almost completely dependent on NPR1. This mutant is deficient in defense gene expression, and show enhanced disease susceptibility to Pseudomonas. These results indicate BIND1infect plant defense and is a new regulator in SA signaling pathway.In this research we find a new regulator in SA signaling pathway and new function of WRKY54/WRKY70that regulate the plant defiance resistance. Based on these results, further clarify the molecular mechanism of plants SA signaling response to biotic stress. Laid the theoretical foundation of Molecular mechanisms of SA signaling pathway proteins involved in plant defense biotic stress.