Institute of Global Innovation Research



Institute of Global Innovation Research



Online Seminar【GIR Open Seminar】Dr. Richard S. Nelson / Oklahoma State University・Dr. Masayoshi Hashimoto / Tokyo University

Date 2020.12.17 (10 : 00 - 12:00)
Venue Zoom
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※On-line Seminar via Zoom and Google Classroom.
Registration is required for the Zoom meeting. Please contact Assoc. Prof. Sasaki (e-mail:

<Program 1>

Dr. Richard S. Nelson
Adjunct Professor
Department of Entomology & Plant Pathology, Oklahoma State University

Retired Professor & Research Administrator
Noble Research Institute, LLC

"Host-plant virus protein interactions: Characterizations and knowledge-based considerations for agricultural application"

Virus components interact with host components during plant infections. Researchers have and continue to focus on identifying these host components. Identification of interacting components leads to studies aimed at understanding the function of the interaction. These interactions often benefit or inhibit the infection process. A list of some viruses and the virus-host component interactions known for them will be presented. I will then focus on a few of the interactions that my laboratory and a collaborative laboratory have identified and begun to characterize for function. These include disparate host proteins functioning in a wide variety of host activities that have been “pulled” into the physiology of the virus. An example interaction is of plant Qa-SNARE protein, SYP23 (syntaxin of plants 23), with the 126 kDa protein of Tobacco mosaic virus (TMV). SYP2 family members are associated with vesicle fusions with the vacuolar membrane in the plant while the 126 kDa protein is associated with virus accumulation and spread. The interaction of SYP proteins with the 126 kDa protein and the influence of this interaction on virus accumulation and spread will be described in relationship to previous findings showing the importance of the vacuole for TMV accumulation. Other host proteins to be discussed include the ATP-synthase γ-subunit, a nuclear-encoded chloroplast protein, and Chloroplast Unusual Positioning Protein 1 (CHUP1), associated with chloroplast movement in response to changes in light intensity, that interact with proteins from TMV and Cauliflower mosaic virus, respectively. The presentation will end with updated thoughts on how to use information from these studies for practical benefit in agriculture.

<Program 2>

Dr. Masayoshi Hashimoto
Assistant Professor
Laboratory of Crop Ecology and Morphology, Graduate School of Agricultural and Life Sciences, University of Tokyo

"Plant root-associated microbiota and plant iron nutrition"

In nature, roots of healthy plants are densely colonized by a subset of microbes mainly derived from the surrounding soil biota. The potential beneficial services from the root-associated microbiota are a subject of extensive research interest for developing sustainable agriculture. Iron (Fe), an essential micronutrient for plant growth, easily become unavailable for plants by precipitating in soils at high pH conditions, and thereby about one third of soils on the earth surface is estimated to be iron-deficient. Under iron-deficient conditions, plants activate the molecular machinery for iron mobilization and uptake including root-secreted plant secondary metabolites, coumarins, which reduce and chelate Fe3+ from soil to root in model plant Arabidopsis thaliana. We recently found evidences supporting the beneficial services from root microbiota in the context of plant iron nutrition that is dependent on plant-derived coumarins. Disruption of coumarin pathway alters the microbiota and impairs plant growth in iron-limiting soil. Root microbiota reconstitution experiment suggested that plant growth performance improved by the synthetic microbial community under iron-limiting condition is dependent on plant iron import and secretion of the coumarin fraxetin. This beneficial trait is also found in a number of single bacterial strains across the core taxonomic lineages of the root microbiota. Transcriptomic and elemental analyses further supported that microbiota and coumarins interact to promote growth by relieving plant iron starvation response. These results show that root-secreted coumarins enhance plant performance under iron-deficient condition by eliciting microbe-assisted iron nutrition. We propose that the bacterial root microbiota, stimulated by secreted coumarins, is an integral mediator of plant adaptation to iron-limiting soils.

Language English
Intended for Registration is required.
Co-Organized by Institute of Global Innovation Research, "Life Science" Sasaki Team
Excellent Leader Development for Super Smart Society by New Industry Creation and Diversity
Contact Institute of Global Innovation Research, Institute of Agriculture,
Assoc. Prof. Nobumitsu Sasaki
e-mail: chaki (at)


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