Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


osu1357158502.pdf (6.42 MB)

ETD Abstract Container

Abstract Header

Identification and Characterization of In-planta Expressed Secreted Effector Proteins from Magnaporthe oryzae

Songkumarn, Pattavipha
http://rave.ohiolink.edu/etdc/view?acc_num=osu1357158502

Abstract Details

2013, Doctor of Philosophy, Ohio State University, Plant Pathology.
Rice blast disease, caused by the fungus Magnaporthe oryzae, is one of the most serious diseases of rice. Interactions between rice and M. oryzae involve the recognition of cellular components and the exchange of complex molecular signals from both partners. How these interactions occur in rice is still elusive. Previously, we employed gene expression profiling, including robust-long serial analysis of gene expression (RL-SAGE), massively parallel signature sequencing (MPSS), and sequencing by synthesis (SBS), to examine transcriptome profiles of infected rice leaves. A total of 6,413 in-planta expressed fungal genes, including 851 genes encoding putative effector proteins, were identified. To elucidate the molecular basis of interactions between rice and M. oryzae upon infection, we combined the results from gene expression profiling with high throughput gene cloning, and rapid protoplast transient expression assay for large-scale identification of M. oryzae effector proteins that induce cell death in rice plants. In total, seven M. oryzae proteins were found to induce cell death in rice protoplasts and six of them were found to induce cell death in the non-host plant, Nicotiana benthamiana. However, this cell death only occurred when the proteins contained the signal peptide for secretion to the extracellular space. Although these seven M. oryzae effectors are diverse in their sequence and structure, the physiological basis of cell death induced by most of these effectors is similar. Among all identified effectors, three effectors, i.e., MGG_05232, MGG_08370, MGG_08409, contain carbohydrate-binding modules (CBMs). To elucidate the pathogenesis function of the three CBM-containing effectors, we generated transgenic M. oryzae strains that carried out gene replacement and gene overexpression. Among the three of them, the MGG_08409 effector containing cellulose binding domain showed pathogenic function in rice. In addition, MGG_08409 binds to cellulose, the component of plant cell wall, and has glucanase activity against cellulose substrate. This study demonstrates that our integrative genomic approach is effective for the identification of in-planta expressed cell death-inducing effector from M. oryzae, which may play important role facilitating colonization and fungal growth during infection. Characterization of these fungal effector proteins will provide new insights into the molecular basis of the rice and M. oryzae interactions.
Guo-Liang Wang, PhD (Advisor)
Pierluigi (Enrico) Bonello, PhD (Committee Member)
Thomas K. Mitchell, PhD (Committee Member)
David M. Mackey, PhD (Committee Member)
Plant Pathology
Magnaporthe oryzae; effectors; CBMs

Recommended Citations

Citations

  • Songkumarn, P. (2013). Identification and Characterization of In-planta Expressed Secreted Effector Proteins from Magnaporthe oryzae [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1357158502

    APA Style (7th edition)

  • Songkumarn, Pattavipha. Identification and Characterization of In-planta Expressed Secreted Effector Proteins from Magnaporthe oryzae. 2013. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1357158502.

    MLA Style (8th edition)

  • Songkumarn, Pattavipha. "Identification and Characterization of In-planta Expressed Secreted Effector Proteins from Magnaporthe oryzae." Doctoral dissertation, Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1357158502

    Chicago Manual of Style (17th edition)

osu1357158502
2,228
© 2013, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.