tailieunhanh - báo cáo khoa học: " Ectopic expression of MdSPDS1 in sweet orange (Citrus sinensis Osbeck) reduces canker susceptibility: involvement of H2O2 production and transcriptional alteration"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Ectopic expression of MdSPDS1 in sweet orange (Citrus sinensis Osbeck) reduces canker susceptibility: involvement of H2O2 production and transcriptional alteration | Fu et al. BMC Plant Biology 2011 11 55 http 1471-2229 11 55 BMC Plant Biology RESEARCH ARTICLE Open Access Ectopic expression of MdSPDS1 in sweet orange Citrus sinensis Osbeck reduces canker susceptibility involvement of H2O2 production and transcriptional alteration Xing-Zheng Fu1 2 Chuan-Wu Chen1 2 Yin Wang1 2 Ji-Hong Liu1 2 and Takaya Moriguchi3 Abstract Background Enormous work has shown that polyamines are involved in a variety of physiological processes but information is scarce on the potential of modifying disease response through genetic transformation of a polyamine biosynthetic gene. Results In the present work an apple spermidine synthase gene MdSPDSl was introduced into sweet orange Citrus sinensis Osbeck Anliucheng via Agrobacterium-mediated transformation of embryogenic calluses. Two transgenic lines TG4 and TG9 varied in the transgene expression and cellular endogenous polyamine contents. Pinprick inoculation demonstrated that the transgenic lines were less susceptible to Xanthomonas axonopodis pv. citri Xac the causal agent of citrus canker than the wild type plants WT . In addition our data showed that upon Xac attack TG9 had significantly higher free spermine Spm and polyamine oxidase PAO activity when compared with the WT concurrent with an apparent hypersensitive response and the accumulation of more H2O2. Pretreatment of TG9 leaves with guazatine acetate an inhibitor of PAO repressed PAO activity and reduced H2O2 accumulation leading to more conspicuous disease symptoms than the controls when both were challenged with Xac. Moreover mRNA levels of most of the defense-related genes involved in synthesis of pathogenesis-related protein and jasmonic acid were upregulated in TG9 than in the WT regardless of Xac infection. Conclusion Our results demonstrated that overexpression of the MdSPDS1 gene prominently lowered the sensitivity of the transgenic plants to canker. This may be at least partially correlated with the .