Domestication and plant genotype determine the impact of a generalist plant pathogen
Contributed by Ash Zemenick @mtn_ash & Nicole Soltis @nic0lise
Agriculture, Agroecosystem, Bisexual, Disease ecology, Ecology, Experimental, Fundamental research, Fungi, Genetics, Lab, LGBTQIA+, Molecular biology, North America, Plants, Quantitative genetics, Terrestrial, Woman
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Nicole E. Soltis, Susanna Atwell, Gongjun Shi, Rachel Fordyce, Raoni Gwinner, Dihan Gao, Aysha Shafi, and Daniel J. Kliebensteina. 2019. Interactions of Tomato and Botrytis cinerea Genetic Diversity: Parsing the Contributions of Host Differentiation, Domestication, and Pathogen Variation. The Plant Cell 31: 502-519. link
Slide 1: Researcher’s Background
Nicole Soltis is a plant biologist who studies the genetics of plant disease. She is also passionate about science communication and evidence-based policy. She was a cofounder of Sacramento’s Science Distilled and is currently a Science Fellow at California Council on Science and Technology (CCST).
PB: Why did you become a biologist?
NS: I always treasured time in nature and was fascinated by the living things around me. I wanted to understand those living things- how did they become what they are now? What were their lives like?
PB: What is your favorite part about your job?
NS: In my current job, I get to work with lots of motivated, talented people from diverse backgrounds.
PB: What obstacles have you overcome to get where you are?
NS: I experienced lots of anxiety in school that often made it hard for me to focus or to complete projects on time. A strong support team of friends, plus working on my mental and physical health, helped me overcome those challenges and get all the way through a PhD.
PB: What advice do you have for aspiring biologists?
NS: Follow your passion to the type of questions you like to study most. You’ll learn plenty of practical, valuable skills along the way, and you’ll enjoy the work more!
PB: Do you feel that any dimension of your identity is invisible or under-represented/marginalized in STEM?
NS: My sexuality is generally invisible in the workplace.
Slide 2: Research Overview
Take home message of study
In this study, Dr. Nicole Solitis sought to understand how the impact of a generalist plant pathogen on tomato plants might vary depending on the pathogen genotype, plant genotype, and whether or not the plant was domesticated (crop) or wild. To do this, she infected domesticated and wild tomato plants with a genetically diverse population of the fungus Botrytus cinerea. She found that infection by B. cinerea (measured by the size of lesions formed by the fungus on a leaf) depended on plant genotype and the pathogen’s genotype. On average, lesions were larger on domesticated tomatoes compared to wild tomatoes.
Figure 1 from Soltis et al. 2019 shows leaves of cultivated and wild tomatoes that were experimentally infected with Botrytis cinerea, a fungus that infects many types of plant species (it is considered to be a generalist plant pathogen). The caption from the figure reads, “Individual tomato leaflets of 6 S. lycopersicum (cultivated tomato) genotypes and 6 S. pimpinellifolium genotypes are in randomized rows, and spore droplets of individual B. cinerea isolates are in randomized columns. Digital images were collected 72 h after inoculation. Randomized leaflets were infected with single droplets of spore suspensions from 40 randomized B. cinerea isolates, and digital images were taken 72 h after inoculation.”
Slide 3: Key Research Points
Figure 3 from Soltis et al. 2019 shows the area on tomato leaves covered by lesions of the pathogen B. cinerea (y-axis) is different for wild and domesticated tomatoes (x-axis). The particular combination of the plant and fungus genotype impact how large of a lesion will grow, but on average, domesticated tomatoes infected with B. cinerea develop larger lesions than wild tomato species.
The caption from the paper reads, “The violin plots show the mean virulence of each B. cinerea isolate on the
tomato genotypes, grouped as wild or domesticated germplasm. The domestication effect on lesion size is significant (ANOVA, P = 0.0006; Table 1). The interaction plot between the two violin plots connects the average lesion size of a single B. cinerea isolate between the wild and domesticated germplasm.”
Understanding how to protect crops from fungal pathogens is an important aspect of farm management and therefore is an important area of agricultural research. Typically, when a pathogen is devastating crop yield, researchers look to wild relatives to find genes that might help the crop fight off the disease (resistance genes) which can be like looking for a needle in the haystack because crops can have many wild relatives. This study suggests that we may be able to streamline the process of developing pathogen-resistant crops by looking for resistance genes.