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Shin-Yi Marzano

Research Molecular Biologist

 

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Shin-Yi Lee Marzano, Ph.D.
Research Molecular Biologist
Greenhouse Production Research Group
USDA-ARS Application Technology Research Unit
2801 W. Bancroft St., Mail Stop 604, 4271B Wolfe Hall
Toledo OH 43606
Office (419) 530-5053

I have been interested in beneficial microbes that are useful in managing diseases, whether in plant health or human health. I am motivated to study microbiomes and viromes because antimicrobial resistance is a substantial cause of death by infectious disease in the United States, and anti-fungicidal resistance is a big concern in agriculture. With a training in Environmental Microbiology, I am also interested in manipulating microbial pathways that can eliminate nutrient loss in runoff.

As part of my postdoc work, I surveyed the fungal virome in Sclerotinia sclerotiorum (white mold). The genome of S. sclerotiorum has been sequenced and is suitable as a model system from which the most diverse lineages of mycoviruses have been discovered. These mycoviruses include positive- and negative-stranded ssRNA, dsRNA viruses and a ssDNA virus capable of extracellular transmission. My current lab and the others have found that disruption mutants of S. sclerotiorum genes are reasonably easy to obtain. Therefore, as a continuation of a previous genome-wide investigation, my lab is dissecting the RNA silencing pathways of S. sclerotiorum, validating a short list of fungal genes targeted by small RNA-mediated degradation, either induced by mycovirus infection causing hypovirulence (reduced virulence) or by endogenous small RNAs. We approach this line of investigation by establishing reverse genetic systems to look at the effect of virus suppressor of gene silencing (VSR), the effect of different viral infections by synthetic biology, and aiming to optimize the viral systems to deliver transgenes to induce gene silencing (VIGS). Building on what we’ve learned in the past years, we are also interested in learning how secondary small RNAs are produced, and what biological significance they have in fungi.

Shin-Yi Marzano Google Scholar 

The Marzano Lab at USDA-ARS is interested in researching alternative disease control strategies applicable in both controlled environment agriculture and field crops.

1. Exploring RNAi-based management strategies to confer plant resistance to white mold infection
Growers lack effective genetic tools to manage losses caused by Sclerotinia sclerotiorum because of a lack of resistance to the pathogen in germplasms. This necessitates the identification of alternative sources of resistance for the disease. We have identified strong candidate genes in the Sclerotinia sclerotiorum RNA silencing pathway as the targets for the development of an RNAi-based pesticide. This study will develop methods for spray-induced gene silencing (SIGS) delivery of small RNAs or dsRNA to reduce the impact of Sclerotinia sclerotiorum on some of the dicots. Eventually, we will compare the effectiveness of SIGS on sunflower, edible snapbean, and dry beans for which transgenic approaches such as host-induced gene silencing are not feasible. The goal of this project is to develop molecular tools for SIGS control of white mold by three interrelated objectives: 1) Comparing dsRNA segments generated from different regions of Ago2 and their corresponding RNA secondary structures for SIGS; 2) Determining the effects of perturbing Ago2 homeostasis by a miRNA with varying base-pairing schemes; 3) Validating predicted cross-species miRNAs generated from a common mycoparasite that can target genes of members of the family Sclerotiniaceae simultaneously. The proposed work will allow us to better design SIGS for white mold control based on RNA secondary structure and secondary amplification of sRNA.

2. Developing gemycircularvirus-based pesticide for the control of Sclerotinia sclerotiorum
Sclerotinia sclerotiorum is a fungal pathogen that causes economically important diseases (e.g., white mold) in several crop species, many of which have not been adequately controlled by conventional technologies. Mycoviruses have been used successfully to reduce losses caused by some fungal plant pathogens. Uniquely, a group of mycovirus, gemycircularviruses, are stable, ubiquitous, and most importantly, infect fungi by extracellular transmission. For example, the prototype, Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1, can control S. sclerotiorum as a spray on leaves and has been shown to be field-effective. Unlike many well-studied mycoviruses, there is no need to rely on hyphal-fusion or intracellular transmission. The most well-studied mycovirus, Cryphonectria parasitica hypovirus 1, with an intracellular lifestyle, is not readily transmitted into most of the US strains of Cryphonectria parasitica, which has plagued the utility of mycoviruses overall. To overturn the generalized stigma and truly contribute to white mold control, the goal of this study is to determine the fungal host range of Soybean leaf-associated Gemygorvirus-1 (SlaGemV-1) that attenuates fungal virulence, and to develop novel strategies for the delivery of gemycircularvirus-based mycoviral fungicides. We have confirmed the infectivity of SlaGemV-1 on other evolutionarily related fungal pathogens of white mold, such as Botrytis cinerea and Monilinia fruticola, all belong to Sclerotiniaceae family, but does not infect distantly related fungal pathogens such as Fusarium oxysporum and Fusarium graminearum. We are currently developing ways to inoculate plants, including various dicots such as tomato, canola, sunflower, dry beans, lettuce, and basil.

 

Professional Expereince 
TT Assistant Professor (80% research, 20% teaching), 2016-2020. Biology and Microbiology (60%), Agronomy, Horticulture, and Plant Science (40%), South Dakota State University
Adjunct faculty, 2020-present, Plant Pathology, Ohio State University
Adjunct associate professor, 2020-present, Biological Sciences, University of Toledo

Educational Background
PhD, Crop Sciences, University of Illinois, Urbana-Champaign, USA
MSc, Environmental Engineering, University of Illinois, Urbana-Champaign, USA
MSc, Environmental Microbiology, Aberdeen University, UK
BSc, Environmental Health, National Taiwan University