About

Alejandra I. Huerta is an Assistant Professor in the Department of Entomology and Plant Pathology at NC State University. Her research employs both basic and applied approaches to study the biology underlying bacteria-plant and bacteria-microbiome interactions, with the long-term goal of understanding how plant pathogens infect their hosts and translating these findings into sustainable crop management strategies. Her lab investigates microbial interactions among plant-associated bacteria at molecular, cellular, organismal, and population levels, focusing on how these interactions affect plant responses, health, and crop yields. Specifically, her research encompasses the ecology, evolution, and population dynamics of plant-associated bacteria, including the study of niche specialization, competition, and effector-induced susceptibility as a trait for durable disease resistance. Dr. Huerta's work aims to develop tools and models to predict beneficial interactions within plant microbiomes, thereby improving plant resilience and yields in changing environments. She also contributes to teaching through courses such as PP501, PP502, and PP755, and actively engages in extension programs serving stakeholders, students, and junior scientists.

Research topics

• Biology
• Genetics
• Microbiology
• Horticulture
• Botany
• Computer Science
• Computational biology
• Data science
• Bioinformatics
• World Wide Web
• Ecology
• Environmental science
• Veterinary medicine
• Agronomy
• Environmental chemistry
• Chemistry
• Environmental engineering

Selected publications

• Table 2_Four decades of genomic stability and adaptive divergence in Xanthomonas phages: defining Duraznoxanthovirus arenicola and its evolutionary framework.docx

  Figshare · 2026-04-29

  datasetOpen accessSenior author

  Bacteriophages (phages) are abundant and ecologically significant, yet their diversity and roles in plant-associated ecosystems remain poorly understood, limiting their application in sustainable disease management. To address this gap, we characterized 15 phages infecting Xanthomonas arboricola pv. pruni, the causal agent of bacterial spot on peach, has been isolated for over four decades from North Carolina orchards. Comparative genomic and phylogenetic analyses revealed two temporally distinct clades with >95% nucleotide identity and 63 conserved core genes, forming a new genus and species, Duraznoxanthovirus arenicola. These findings challenge assumptions of pervasive genomic mosaicism, highlighting remarkable genomic stability alongside localized variability in accessory loci. Beyond genus-level characterization, our analyses support a broader taxonomic restructuring within the family Anamaviridae, introducing a new subfamily (Terravirinae) and two new genera (Duraznoxanthovirus and Ralstopathovirus). This work provides the a family-level framework for phages exclusively infecting plant-associated bacteria, offering evolutionary insights and a foundation for ecological studies and management strategies.

  PublisherDOI

• Table 4_Four decades of genomic stability and adaptive divergence in Xanthomonas phages: defining Duraznoxanthovirus arenicola and its evolutionary framework.xlsx

  Figshare · 2026-04-29

  datasetOpen accessSenior author

  Bacteriophages (phages) are abundant and ecologically significant, yet their diversity and roles in plant-associated ecosystems remain poorly understood, limiting their application in sustainable disease management. To address this gap, we characterized 15 phages infecting Xanthomonas arboricola pv. pruni, the causal agent of bacterial spot on peach, has been isolated for over four decades from North Carolina orchards. Comparative genomic and phylogenetic analyses revealed two temporally distinct clades with >95% nucleotide identity and 63 conserved core genes, forming a new genus and species, Duraznoxanthovirus arenicola. These findings challenge assumptions of pervasive genomic mosaicism, highlighting remarkable genomic stability alongside localized variability in accessory loci. Beyond genus-level characterization, our analyses support a broader taxonomic restructuring within the family Anamaviridae, introducing a new subfamily (Terravirinae) and two new genera (Duraznoxanthovirus and Ralstopathovirus). This work provides the a family-level framework for phages exclusively infecting plant-associated bacteria, offering evolutionary insights and a foundation for ecological studies and management strategies.

  PublisherDOI

• Table 3_Four decades of genomic stability and adaptive divergence in Xanthomonas phages: defining Duraznoxanthovirus arenicola and its evolutionary framework.xlsx

  Figshare · 2026-04-29

  datasetOpen accessSenior author

  Bacteriophages (phages) are abundant and ecologically significant, yet their diversity and roles in plant-associated ecosystems remain poorly understood, limiting their application in sustainable disease management. To address this gap, we characterized 15 phages infecting Xanthomonas arboricola pv. pruni, the causal agent of bacterial spot on peach, has been isolated for over four decades from North Carolina orchards. Comparative genomic and phylogenetic analyses revealed two temporally distinct clades with >95% nucleotide identity and 63 conserved core genes, forming a new genus and species, Duraznoxanthovirus arenicola. These findings challenge assumptions of pervasive genomic mosaicism, highlighting remarkable genomic stability alongside localized variability in accessory loci. Beyond genus-level characterization, our analyses support a broader taxonomic restructuring within the family Anamaviridae, introducing a new subfamily (Terravirinae) and two new genera (Duraznoxanthovirus and Ralstopathovirus). This work provides the a family-level framework for phages exclusively infecting plant-associated bacteria, offering evolutionary insights and a foundation for ecological studies and management strategies.

  PublisherDOI

• Four decades of genomic stability and adaptive divergence in Xanthomonas phages: defining Duraznoxanthovirus arenicola and its evolutionary framework

  Frontiers in Microbiology · 2026-04-29

  articleOpen accessSenior author

  Bacteriophages (phages) are abundant and ecologically significant, yet their diversity and roles in plant-associated ecosystems remain poorly understood, limiting their application in sustainable disease management. To address this gap, we characterized 15 phages infecting Xanthomonas arboricola pv. pruni , the causal agent of bacterial spot on peach, has been isolated for over four decades from North Carolina orchards. Comparative genomic and phylogenetic analyses revealed two temporally distinct clades with >95% nucleotide identity and 63 conserved core genes, forming a new genus and species, Duraznoxanthovirus arenicola . These findings challenge assumptions of pervasive genomic mosaicism, highlighting remarkable genomic stability alongside localized variability in accessory loci. Beyond genus-level characterization, our analyses support a broader taxonomic restructuring within the family Anamaviridae , introducing a new subfamily ( Terravirinae ) and two new genera ( Duraznoxanthovirus and Ralstopathovirus ). This work provides the a family-level framework for phages exclusively infecting plant-associated bacteria, offering evolutionary insights and a foundation for ecological studies and management strategies.

  PublisherDOI

• Table 1_Four decades of genomic stability and adaptive divergence in Xanthomonas phages: defining Duraznoxanthovirus arenicola and its evolutionary framework.docx

  Figshare · 2026-04-29

  datasetOpen accessSenior author

  Bacteriophages (phages) are abundant and ecologically significant, yet their diversity and roles in plant-associated ecosystems remain poorly understood, limiting their application in sustainable disease management. To address this gap, we characterized 15 phages infecting Xanthomonas arboricola pv. pruni, the causal agent of bacterial spot on peach, has been isolated for over four decades from North Carolina orchards. Comparative genomic and phylogenetic analyses revealed two temporally distinct clades with >95% nucleotide identity and 63 conserved core genes, forming a new genus and species, Duraznoxanthovirus arenicola. These findings challenge assumptions of pervasive genomic mosaicism, highlighting remarkable genomic stability alongside localized variability in accessory loci. Beyond genus-level characterization, our analyses support a broader taxonomic restructuring within the family Anamaviridae, introducing a new subfamily (Terravirinae) and two new genera (Duraznoxanthovirus and Ralstopathovirus). This work provides the a family-level framework for phages exclusively infecting plant-associated bacteria, offering evolutionary insights and a foundation for ecological studies and management strategies.

  PublisherDOI

• Transfer of Pseudomonas Syringae and Pseudomonas Savastanoi Pathovars to Pseudomonas Amygdali Based on Phenotypic and Genotypic Characterization with Improved Genomic Resources

  SSRN Electronic Journal · 2025-01-01

  preprintOpen accessSenior author
  PublisherDOI

• First Report of Bacterial Wilt on Southern Highbush Blueberries (<i>Vaccinium corymbosum</i>), Caused by <i>Ralstonia solanacearum</i>, in North Carolina

  Plant Disease · 2025-03-04

  articleOpen accessSenior author

  North Carolina is the seventh-largest producer of blueberries in the United States, with an estimated value of $104.6 million (USDA-NASS). In the Spring of 2024, a patch of approximately 50 contiguous southern highbush blueberries (SHB) (Vaccinium corymbosum cv. Rebel) exhibited dieback, leaf scorch, and wilt in one Bladen County, NC farm. Eleven woody stems were excised from different SHB bushes, surface sterilized, and cut into 5 cm pieces. Cut stems were then immersed in sterile deionized water (SDW) to test for bacterial streaming. A stream of fine, slimy strands of bacterial ooze exuded from all the stems. A plastic loop was used to streak 10 µl of the bacterial streaming supernatant onto Casamino Acid-Peptone-Glucose agar amended with Triphenyl Tetrazolium Chloride (Kelman 1954). After 48 hours of incubation at 28ºC, multiple white mucoid single colonies with a soft pink center, characteristic of Ralstonia solanacearum, were observed. Eleven isolates were randomly selected and stored in 30% glycerol at -80ºC. The 11 isolates were molecularly characterized as R. solanacearum phylotype II using Multiplex PCR (Fegan and Prior, 2005), where GMI1000, K60, CMR15, and PSI07 genomic DNA represent phylotype I, II, III, IV, respectively. None of the strains amplified the 357 bp band characteristic of the R. solanacearum Select Agent strains using the 630/631 primer pair (Fegan et al. 1998). Sequevar was determined by amplifying and sequencing the 750 bp region of the egl gene using ENDO-F/ENDO-R primers (Ji et al. 2007). The egl sequences were deposited to NCBI (GenBank accessions: PQ417932 to PQ417942) and compared to publicly available sequences. The egl sequence of the 11 isolates shared 100% (704/704 bp) and 99.7% (702/704 bp) identity with Sequevar 7 strains of R. solanacearum RF75 and K60, respectively (Cellier et al. 2023). This confirms the 11 isolates recovered from SHB bushes in NC are R. solanacearum, phylotype IIA, Sequevar 7 strains. Two isolates, AHR105 and AHR109, were randomly selected to perform Koch's postulates. Bacterial inoculum was prepared from 24 h cultures grown with shaking at 225 rpm at 28°C. Bacteria were pelleted and washed three times with SDW before resuspending in SDW to an O.D.600 of 0.2 (~ 2x108 CFU/ml). The roots of five six-month-old SHB ('cv. Rebel') were submerged in 500 ml of inoculum or water as a negative control, for 10 min at transplanting. Each experiment consisted of five plants per strain or water control and was repeated twice. All plants were incubated at 28°C, 80% relative humidity, and 8 h:16 h light-dark cycle in a growth chamber. The first symptoms appeared at four weeks post-inoculation, and by the sixth week, all AHR105 and AHR109 treated plants showed defoliation, dieback, and wilting. No symptoms were observed in the water-treated plants. Six weeks post-inoculation, all the plants were destructively sampled, and white mucoid single colonies with a soft pink center, similar in morphology to those initially inoculated, were recovered and confirmed to be AHR105 and AHR109 via PCR and sequencing; no bacteria were recovered from water-treated plants. R. solanacearum is known to cause wilting in tomato and tobacco-producing counties in NC but has not been previously reported on SHB in NC. The disease, however, was reported on blueberries in Florida and Georgia (Norman et al. 2017; Oliver et al. 2022). Accurate and timely detection of R. sol in SHB in NC is paramount for deploying specific and localized management tactics to safeguard NC SHB production.

  PublisherOA PDFDOI

• First Report of <i>Ralstonia pseudosolanacearum</i> Phylotype I Sequevar 14 Causing Bacterial Wilt on Tomato (<i>Solanum lycopersicum</i>) and Eggplant (<i>Solanum melongena</i>) in North Carolina, U.S.A.

  Plant Disease · 2025-03-04 · 5 citations

  articleOpen access

  Ralstonia solanacearum species complex (RSSC) consists of three species, including R. solanacearum, R. pseudosolanacearum, and R. syzygii. The K60-type strain of R. solanacearum was isolated from a wilted 'Marglobe' tomato in Raleigh, North Carolina (NC) in 1953 (Kelman 1954). It is classified as phylotype IIA, sequevar 7 (Prior and Fegan 2005). In July 2023, during a field visit in Eastern NC, patches of >50 eggplant (Solanum melongena cv. Pingtung Oriental) and tomato (Solanum lycopersicum cv. Saybrook) plants showing wilt symptoms were observed in a 1 ha field. Two plants from each host were collected from this site and tested positive for bacterial streaming in sterile deionized water for 2 min. One plant from each host was used for bacterial isolation by plating a 10 μl aliquot of the resulting bacterial streaming suspension on triphenyl tetrazolium chloride (TZC) medium (Kelman 1954) and incubated at 28°C for 48 hr. Multiple fluidal white colonies with a pink center and irregularly round morphology reminiscent of strains in the RSSC were observed on all plates. Only one colony from each plant host, NG-RL and EP-RL from tomato and eggplant, respectively, was selected for molecular characterization. Neither strain amplified the 357 bp band and was not R. solanacearum Select Agent (Opina et al. 1997). Genomic DNA from both NG-RL and EP-RL generated the 280 bp and 144 bp bands and confirmed as R. pseudosolanacearum phylotype I using the RSSC multiplex PCR (Fegan and Prior 2005). To determine sequevar, the primers Endo-F/Endo-R (Poussier et al. 2000; Fegan and Prior 2005) were used to sequence the partial endoglucanase (egl) gene from EP-RL and NG-RL (GenBank accessions: PQ554799 and PQ554800). These sequences were compared to publicly available egl sequences from GenBank and Cellier et al. (2023). A maximum likelihood phylogenetic tree showed that both NG-RL and EP-RL clustered with reference strains PSS81, MLI71-15, and Zo4 with 100% identity, confirming NG-RL and EP-RL are R. pseudosolanacearum phylotype I sequevar 14. To fulfill Koch's postulates, NG-RL and EP-RL inoculant was prepared from 48 h cultures grown on TZC plates at 28°C. Plates were flooded with sterile deionized water and then transferred to a falcon tube, adjusting O.D. 600 to 0.2 (~1×108 CFU/ml). The roots of six-week-old eggplants (cv. Black Beauty) and tomatoes (cv. Bonny Best) were wounded by running a scalpel through the soil 2 cm from the stem. This was repeated on six plants for both NG-RL and EP-RL. Mock-inoculated plants treated with sterile deionized water (SDW) served as controls. Plants incubated at 28°C in the greenhouse showed bacterial wilt symptoms nine days post-inoculation. R. pseudosolanacearum phylotype I sequevar 14 was confirmed from all bacteria-inoculated plants using the multiplex PCR and egl sequencing methods described above. No symptoms or bacteria were isolated from SDW mock-inoculated plants. There have been no prior reports of R. pseudosolanacearum phylotype I in North Carolina. To our knowledge, this is the first report on R. pseudosolanacearum phylotype I and the sequevar 14 in both tomato and eggplant in NC. This phylotype I is endemic to Asia and was first reported in the US in 2003 on pepper in Florida (Ji et al. 2006) and in 2015 on tomatoes in Louisiana (Jimenez Madrid et al. 2019). This finding highlights the need for a nationwide RSSC survey program, which can undoubtedly inform pathogen spread and management for crops in NC and beyond.

  PublisherOA PDFDOI

• Four Decades of Genomic Stability and Adaptive Divergence in <i>Xanthomonas arboricola</i> pv. <i>pruni</i> -Infecting Phages: Defining <i>Duraznoxanthovirus arenicola</i> and Its Evolutionary Framework

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-11-25

  preprintOpen accessSenior authorCorresponding

  Bacteriophages (phages) are abundant and ecologically significant, yet their diversity and roles in plant-associated ecosystems remain poorly understood, limiting their application in sustainable disease management. To address this gap, we characterized 15 phages infecting Xanthomonas arboricola pv. pruni , the causal agent of bacterial spot on peach, has been isolated for over four decades from North Carolina orchards. Comparative genomic and phylogenetic analyses revealed two temporally distinct clades with &gt;95% nucleotide identity and 63 conserved core genes, forming a new genus and species, Duraznoxanthovirus arenicola . These findings challenge assumptions of pervasive genomic mosaicism, highlighting remarkable genomic stability alongside localized variability in accessory loci. Beyond genus-level characterization, our analyses support a broader taxonomic restructuring within the family Anamaviridae , introducing a new subfamily ( Terravirinae ) and two new genera ( Duraznoxanthovirus and Ralstopathovirus ). This work provides the first family-level framework for phages exclusively infecting plant-associated bacteria, offering evolutionary insights and a foundation for ecological studies and management strategies.

  PublisherDOI

• High-Quality Complete Genomes of Three Phylotype IIA <i>Ralstonia solanacearum</i> Strains Isolated from Tomatoes in North Carolina

  PhytoFrontiers™ · 2025-05-28 · 1 citations

  articleOpen accessSenior author

  Ralstonia solanacearum ( R. sol) is a destructive bacterial plant pathogen and the causal agent of bacterial wilt in various crops, including tomatoes, blueberries, and eucalyptus. The type strain for this pathogen species is K60, isolated in North Carolina in 1953, and is one of two high-quality closed genomes for R. sol phylotype IIA strains in public databases. To enhance resources that support investigations into the genotypic diversity of R. sol in the United States, three complete, high-quality phylotype IIA R. sol genomes for strains isolated from tomatoes in North Carolina were generated using hybrid long- and short-read sequencing technologies. These new genomes have high and low CheckM scores for completeness and contamination, respectively, and provide valuable resources for studying R. sol evolution, epidemiology, and virulence, particularly in the context of U.S. pathogen populations. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

  PublisherDOI

Recent grants

• NSF Postdoctoral Fellowship in Biology FY 2015

  NSF · $138k · 2015–2017

Frequent coauthors

• Valérie Verdier

  Institut de Recherche pour le Développement

  9 shared

• Camille Piponiot

  7 shared

• Ying-Yu Liao

  North Carolina State University

  7 shared

• Jan E. Leach

  5 shared

• Francesca Baldassarre

  University of Salento

  4 shared

• Katherine M. D’Amico-Willman

  North Carolina State University

  4 shared

• Francesca Biondo

  University of Salento

  4 shared

• David F. Ritchie

  North Carolina State University

  4 shared

Education

• Ph.D., Entomology

  North Carolina State University

  2008

• M.S., Entomology

  North Carolina State University

  2003

• B.S., Entomology

  University of California, Davis

  2001

Awards & honors

• YEA: Advancing Equitable Agriscience Pathways (AEAP) through…
• Think and Seq: Rapid high-quality Long-read Sequencing of Ge…
• Harnessing Bacterial Competition Mechanisms Used By Endemic…
• Targeted On-Demand Disease Management Practices/Therapies (T…