Alejandra Huerta

The National Juntos Consortium (NJC) and STEM AP is a transformational, interdisciplinary, collaborative project that will prepare Latinx youth to become the next generation of leaders and workforce in STEM and Agriscience. Led by NCSU, STEM AP will improve STEM participation, persistence, and career readiness among Latinx youth in North Carolina and Washington. The project draws from culturally responsive pedagogy, behavioral science theory, and evidence-based practice, and will establish a replicable, scalable program that improves Latinx youth representation in post-secondary STEM education programs and advances DEIA work within the LGU Extension System. The project objectives include: 1. Increase opportunities for Latinx youth to engage in STEM education and workforce activities; 2. Enhance the skills and capacities of Latinx youth to engage with STEM APP learning and career opportunities; and 3. Increase the motivation of STEM APP youth to engage in STEM-related learning and career opportunities. 4. Develop the National Juntos Consortium to support the scalability and sustainability of Juntos and Juntos STEM AP. Through this innovative approach, combining 4-H Thriving Model, positive youth development, and the behavior change process as defined within the COM-B framework, the project will increase Latinx youth STEM identity (i.e. seeing themselves as successful in a STEM career pathway) and the likelihood to pursue and be successful in a STEM (agricultural sciences) career. The project will also launch the National Juntos Consortium, a first-of-its-kind collaborative Extension initiative with representation in all national regions focused on diversity, equity, inclusion, and access.

Project is in support of PSI. Drs. Huerta, Baltzegar, and Gold are pleased to submit this internal pre-proposal to NC State in support of their commitment and desire to write and submit a full-length proposal to the USDA-NIFA Equipment Grant Program, where they will lead a team of 26 other faculty requesting funds to acquire a Whole Genome Sequel IIe System sequencer from PabBio. The PacBio Sequel IIe is the current state-of-the-art technology for high-quality sequencing of genomes, transcriptomes, and epigenomes. If successful, this would be the first Sequel IIe in the University and possibly the state. The PacBio Sequel IIe system (product code 101-986-400) is priced at $525,000.00; The on-site system training (product code 100-125- 100) is $12,500; and the necessary uninterrupted power supply (UPS) (product code 100-609-000) is $7,000. The total for the instrument, installation and training for the instrument is $544,500.00. This sum is well above the funding limit for the USDA-NIFA EGP. However, Dr. Huerta has been in conversation with Dr. Nicole Newell, Sequencing Application Specialist at PacBio, to negotiate a 10% discount on the above listed sale price to bring the price down to $490,050 (see quote attached and letter of support from PacBio???s willingness to collaborate with us to make this grant and purchase a reality).

Soilborne bacterial pathogens place major constraints on small and large agricultural production systems. Three destructive bacterial pathogens that negatively impact maximum attainable yield are: Ralstonia, Pectobacterium and Dickeya spp. All can survive for extended periods of time away from a susceptible host and can inhabit different microclimates and soil types. Ralstonia spp. cause bacterial wilt on over 200 different plant species including tomato, potato, and plantains [1, 2]. It is estimated that on potato alone Ralstonia can cause $1 billion dollar in losses per year. Pectobacterium and Dickeya spp. are two genera of related broad-host-range entero-bacterial pathogens that infect plant tissue, fruit, and seed during the growing season and are also postharvest pathogens. Together Pectobacterium and Dickeya spp. can cause soft rot on over 50% of all angiosperm plant orders [1]. Traditional tactics to manage bacterial pathogens have relied on copper-based agrochemicals that impact soil health and deployment of genetically resistant host plants[3, 4]. Unfortunately, pathogen evolution and a changing climate make some of these tactics ineffective or impossible to implement. The challenge that I have decided to accept as a scientist is to apply multiomic approaches, improved biotechnological tools, and precision agriculture techniques to develop sustainable field/crop/region specific on-farm practices that protect beneficial microbes to support health soils but eradicate the pathogenic agents of choice. This technology will empower farmers to become effective stewards of their land and together we can build stronger healthier soils that produce nutritious food that is accessible to all.

Seedborne bacterial diseases are a problem for true seed and crop productions worldwide. If not detected and timely managed, they can cause significant economic losses on important agronomic crops. Seedborne Pseudomonas syringae strains infect both true seed and fresh food crops of cucurbit, chard, and beet (CCB), limiting production nationwide and impacting international trade. Infested seed is the primary source of inoculum and responsible for the long-distance movement of bacterial pathogens across borders or the introduction of diseases into new geographic areas. Thus, improved and effective seed treatment therapies that detect and decrease or eradicate pathogenic Pseudomonas syringae bacterial population from true seed and food crops are imperative. Bacteriophage, a virus that parasitizes and can lyse a bacterium, have been shown to be a viable control strategy for diseases caused by plant pathogenic bacteria. Similarly, it has been proposed that riboflavin photochemical treatment may inactivate pathogenic microorganisms in seed and plant tissue as it does in blood and plasma. We hypothesized that novel biological (bacteriophage) and chemical (riboflavin) seed and crop treatments will be effective at managing seedborne bacterial pathogens. Over the course of the proposed project, which has two research objectives, we will gain breadth and depth of knowledge on phage detection, diversity, genetics and biology. We will also explore the efficacy of bacteriophage and riboflavin photochemical treatment for eliminating seed borne bacterial pathogens.

Ralstonia solanacearum is the causal agent of bacterial wilt, one of the most devastating bacterial diseases of many plants. Among the more than 200 plant species susceptible to R. solanacearum, there are high-value crops such as tobacco, tomato, banana, and potato. K60, a warm-temperate R. solanacearum strain from North Carolina, strongly outcompetes a cold-tolerant highland strain R3bv2, a select agent in the US. This competitive fitness is correlated to the production and secretion of strain-specific growth inhibitors, identified as Rhs-toxins. Preliminary bioinformatic analyses on 27 strains of the pathogen revealed that the majority of R. solanacearum strains encode at least three or more Rhs-toxins. Coincidently, K60 has the largest number of predicted rhs-genes at 14, previously thought to be 30 due to poor sequencing depth. However, little is known about the genomic profiles of R. solanacearum strains endemic to the US. Thus, much less about the Rhs- gene repertoires in strains of the R. solanacearum species complex. The proposed research will endeavor to generate a R. solanacearum bacterial collection from endemic strains isolated from hosts, soils, weeds in the US. More importantly, representatives of the genotypic and phenotypic diversity in the nation will be whole genome sequenced. Profiling rhs-gene repertoires and complete genome of R. solanacearum across its endemic range is critical for: 1) pathogen surveillance; 2) developing breeding strategies to enhance disease resistance; 3) identify robust and effective diagnostic markers; and 4) novel tool to manage the destructive bacterial disease of many plants.

This project will investigate the application of lime to raise soil pH to be inhibitory to bacterial wilt of tomato and improve production of tomato on otherwise un-farmable land.

This project will address the biology, ecology and diversity of bacteria phage in different agricultural setting.

North Carolina State University will develop integrated management strategies for bacterial soft rot in sweetpotato postharvest by determining which bacterial pathogens are causing disease, identifying effective products for chemical control that are acceptable for organic and export markets, and providing information on diagnostics and cultural management to stakeholders to through web-based resources, grower meetings, and field days.

Common approaches to manage Ral, Xan, Pse and Cmm include host resistance (genetics), chemical spray treatments, biological agents and cultural practices. However, repeated use of these interventions can cause plant pathogenic bacteria to develop resistance, thus reversing disease management tactics. Profiling the genetic diversity of plant pathogenic bacterial populations in North Carolina is important for: 1) Pathogen surveillance; 2) breeding strategies to enhance disease resistance; and 3) robust and effective diagnostic markers for bacterial pathogens. The objective of the proposed work is to profile the diversity of Ral, Xan, Pse and Cmm in tomato production field in North Carolina.