Current Projects

Overview

Our lab uses plant-parasitic nematodes and their host plants as model organisms to explore the fundamental aspects of host-parasite interactions. In addition to basic research, we are committed to practical applications, particularly those addressing the agricultural challenges posed by nematodes in California.

Research Areas

Evolution of Host-Parasite Relationships in Nematodes

A key focus of our research is understanding the evolution of host-parasite relationships, especially the complex interactions between nematodes and their host plants. These parasites present unique challenges, particularly in how they meet their nutritional needs. We aim to uncover how nematode nutrition and metabolism are regulated across different species, shedding light on the strategies these parasites use to thrive within their hosts.

For instance, our recent work has explored the role of vitamin B5 in nematode parasitism. Vitamin B5 is essential for producing coenzyme A, a molecule critical for various metabolic processes. We discovered that nematodes manipulate the production and availability of vitamin B5 in their host plants to support their growth and reproduction. This finding not only highlights a novel aspect of host-parasite interaction but also suggests new ways to target nematode metabolism as a potential strategy for controlling these parasites.

In this context, we are also interested in nematode-produced peptides that mimic plant peptides. These peptides are a fascinating example of convergent evolution, where parasitic nematodes have evolved molecules that closely resemble plant peptides that promote root growth. This mimicry not only helps establish parasitism but also raises important questions about the evolutionary pressures and mechanisms behind such advanced adaptations. Understanding these processes could lead to new strategies for disrupting nematode infections.

How Do Nematodes Overcome Plant Resistance?

Another major research area is understanding how nematodes bypass the resistance mechanisms of host plants. Some crops have been bred to resist nematodes, providing crucial tools for managing these pests in agriculture. These resistances have been developed through traditional breeding methods, incorporating genes from wild plant relatives.

A well-known example is the Mi-1 resistance gene in tomatoes, which has been effective against the most damaging species of root-knot nematodes. However, widespread use of Mi-1 has led to the emergence of nematode populations that can overcome this resistance, posing a significant challenge to sustainable crop production. This situation raises critical questions about the genetic factors and evolutionary processes that allow nematodes to break these defenses. Our research seeks to identify these factors, offering insights essential for developing new strategies to maintain durable resistance in crops.

Developing Functional Genomics Tools for Parasitic Nematodes

Parasitic nematodes are valuable model organisms for studying various aspects of biology, including parasitism and reproduction. Their complex interactions with host plants and diverse reproductive strategies make them ideal for exploring fundamental biological processes. Among these nematodes, Meloidogyne hapla, a northern root-knot nematode, stands out because it can reproduce both sexually and asexually. This dual strategy provides a rich system for investigating the genetic mechanisms that drive these processes, offering insights into both evolutionary biology and functional genomics.

However, progress in this research has been slowed by the lack of genetic transformation tools for these nematodes. This limitation hampers detailed studies of gene function and regulation. To overcome this challenge, we are developing comprehensive genomic resources for M. hapla while also creating new tools for genetic manipulation. These efforts aim to enable deeper studies of nematode biology, ultimately contributing to innovative strategies for managing these pests and enhancing our understanding of broader biological principles.

Sustainable Solutions for Nematode Management

With increasing restrictions on chemical fumigants and a lack of effective alternatives, the need for sustainable methods to manage root-knot nematodes has grown, particularly in economically important vegetables and nuts. Our lab is focused on developing both biological control and biotechnological approaches to address this challenge. One key area of research is understanding how soil microbes interact with root-knot nematodes and identifying specific microbes that can serve as biological control agents. This research aims to develop eco-friendly methods that effectively reduce nematode populations in crops like tomatoes and walnuts.

In addition to biocontrol strategies, we are pioneering biotechnological solutions, such as CRISPR and host-induced RNA interference (RNAi), to target nematodes at the molecular level. These efforts are conducted in collaboration with commodity boards and growers’ organizations, ensuring that the solutions are tailored to the specific needs of the agricultural industry. By focusing on high-value crops like tomatoes and walnuts, our research seeks to provide sustainable, long-term solutions for managing nematode-related challenges in these critical agricultural sectors.