Emerging Threat of Meloidogyne enterolobii: Pathogenicity Mechanisms and Sustainable Management Strategies in the Context of Global Change

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript reviews the biology, geographic distribution, pathogenicity, and management of the root-knot nematode Meloidogyne enterolobii.  This is an important pathogen due to its wide host range and lack of genetic resistant available in vegetable and agronomic crops.  

Although the manuscript is well written and thorough, I think there is considerable overlap between this manuscript and Philbrick et al. 2020 "Meloidogyne enterolobii, a major threat to tomato production: Current status and future prospects for its management" Frontiers in Plant Science, Vol. 11.   That is, I don't see how this manuscript presents and reviews significantly different and new information from this other article.  However, the section in the present manuscript that reviews and discusses M. enterolobii effectors presents new information, and there is some updated information presented on the geographic distribution of this species.  Perhaps the manuscript could be re-structured to focus more heavily on this aspect?  

The sentence appearing at Line 308-310 regarding the Rutter et al. 2021 paper is a misinterpretation of the findings of the Rutter et al. 2021 paper.  This paper reported that sweetpotato cultivar Beauregard was significantly more resistant to one a specific isolate of M. enterolobii when compared to a different isolate of M. enterolobii, yet the cultivar Beauregard was still highly susceptible to both isolates of M. enterolobii and does not have resistance to this nematode.   Since I have not read all the other papers that this review manuscript encompasses, it makes me wonder if there are other cases of misinterpreted work.  

Author Response

Dear reviewer,

We sincerely appreciate your time and effort in reviewing our manuscript entitled “Pathogenic Mechanisms and Green Management Strategies of the Root-Knot Nematode Meloidogyne enterolobii: Advances and Perspectives.” Your thoughtful and constructive comments have been immensely helpful in refining the structure, scope, and scientific depth of our review. We are grateful for your insights, which have allowed us to enhance the novelty and clarity of our manuscript.

Regarding Comment 1, we sincerely appreciate your critical evaluation concerning potential overlap with the earlier review by Philbrick et al. (2020). Following a thorough re-examination of both manuscripts, we have meticulously revised our structure and explicitly clarified how our review offers significant updates and novel perspectives that extend beyond the 2020 article. These enhancements include newly compiled data on global distribution and climate adaptation, a systematically updated host range, an expanded section on effector protein classification and function, recent advances in detection methods, a mechanism-based classification of biocontrol strategies, and the introduction of a microbiome-centered framework for nematode control. Furthermore, our manuscript places a stronger emphasis on the biological and pathogenic characteristics of M. enterolobii itself, thereby offering a more pathogen-focused review. We have clearly outlined these seven key areas in our point-by-point response and referenced the corresponding revised sections in the manuscript.

In response to Comment 2, we appreciate your identification of the citation error regarding Rutter et al. (2021). We have meticulously reviewed the original study and revised the relevant sentence to accurately represent the findings. The updated content can be found in Lines 344–347 of the revised manuscript.

To further enhance the overall quality of the language, we have enlisted the assistance of a native English-speaking expert in scientific writing to refine the revised manuscript for clarity, fluency, and adherence to academic standards. All modifications have been highlighted in red font for your convenience during review.

We are sincerely grateful for your insightful and constructive feedback, which has significantly contributed to the enhancement of our work. We hope that the revised version comprehensively addresses your concerns and meets your expectations.

Below are our detailed responses to your specific comments.

Comment 1: Although the manuscript is well written and thorough, I think there is considerable overlap between this manuscript and Philbrick et al. 2020 "Meloidogyne enterolobii, a major threat to tomato production: Current status and future prospects for its management" Frontiers in Plant Science, Vol. 11.   That is, I don't see how this manuscript presents and reviews significantly different and new information from this other article.  However, the section in the present manuscript that reviews and discusses M. enterolobii effectors presents new information, and there is some updated information presented on the geographic distribution of this species.  Perhaps the manuscript could be re-structured to focus more heavily on this aspect?

Response: We sincerely thank the reviewers for their valuable comments, particularly the observation that our review may share some content overlap with the article by Philbrick et al. (2020), titled “Meloidogyne enterolobii, a major threat to tomato production: Current status and future prospects for its management” published in “Frontiers in Plant Science”. After carefully reviewing the referenced article, we respectfully clarify that, while both reviews focus on M. enterolobii, our manuscript aims to build upon and deepen the existing work through updates in content, revised thematic organization, and a broadened research perspective. Specifically, our manuscript provides novel insights and extensions in the following seven areas:

1) Global Spread and Climate Adaptation

While the 2020 review primarily addressed the nematode’s distribution and threat in the Americas, our manuscript adopts a global perspective, emphasizing its spread in Asia, particularly in China. Notably, M. enterolobii has been detected as far north as 46° latitude in China, suggesting potential cold tolerance. We further analyse environmental factors such as protected agricultural systems and thermal time accumulation thresholds to explore its dispersal mechanisms. Geographic distribution maps and climate-based risk models are also presented to support cross-regional management strategies. Please refer to lines 72–101 in the revised manuscript.

2) Updated and Expanded Host Range

Philbrick et al. (2020) provided a preliminary summary of M. enterolobii host plants, covering 34 species across 19 families. Based on recent studies from 2020 to 2025, we have systematically updated the host range, which now encompasses 61 plant species from 24 families. These newly reported hosts include not only economically important crops but also regionally significant and medicinal plants, offering a more comprehensive understanding of the nematode’s ecological adaptability and host diversity. Please refer to lines 123–126 in the revised manuscript.

3) Effector Protein Classification and Functional Insights

To elucidate the molecular mechanisms underlying the pathogenicity of M. enterolobii, we have included a dedicated section on effector proteins, categorizing them by function—such as cell wall-degrading enzymes (e.g., cellulases, pectinases), immune modulators (e.g., MIF proteins), and signaling disruptors (e.g., calreticulin). We discuss their potential roles in invasion initiation, host manipulation, and thermal adaptation based on current omics data and functional gene validation techniques, thereby offering new perspectives for future research. Please refer to lines 160–179 in the revised manuscript.

4) Advancements in Detection Technologies

In contrast to the brief description of conventional PCR methods presented in earlier reviews, we have systematically summarized recent advances in molecular diagnostics for M. enterolobii, with particular emphasis on rapid field-deployable methods. These include LAMP-based colorimetric and fluorescence assays, recombinase polymerase amplification (RPA), real-time PCR with LNA probes, and droplet digital PCR (ddPCR). Furthermore, we provide comparative evaluations of these methods in terms of sensitivity, specificity, cost, and operational convenience, aiming to support the optimization and application of future diagnostic tools. Please refer to lines 215–226 in the revised manuscript.

5) Mechanism-Based Classification of Biocontrol Strategies

Unlike Philbrick et al. (2020), who categorized biocontrol agents by microbial type, our review classifies them based on mechanisms of action, including induced systemic resistance, trap structure formation, toxin secretion, and competition for nutrients and niches. We also incorporate recent developments such as nematocidal peptides, small-molecule metabolites, and AI-assisted microbial screening, and explore their integration with nanomaterials and smart delivery systems. This framework provides more practical and forward-looking options for effective field management. Please refer to lines 288–322 and lines 392–404 in the revised manuscript.

6) Microbiome-Modulated Pathogenicity: A Novel Perspective

Although our core focus is the pathogenic mechanism of M. enterolobii, we introduce cutting-edge research on nematode–microbiome–host interactions in the “Future Directions” section, exploring their implications for sustainable control. Evidence suggests that root-knot nematodes can remodel the rhizosphere microbiome through root exudate manipulation or effector secretion to recruit microbial communities that favour infection, while resistant hosts tend to enrich antagonistic microbes that form a defensive barrier.

We thus propose a microbiome-targeted approach to nematode control, such as engineering host-mediated recruitment of beneficial microbes or identifying key factors that promote colonization by antagonists. Although direct evidence for M. enterolobii remains limited, we identify research gaps and highlight the potential of this emerging field by drawing on studies from related Meloidogyne species. Please refer to lines 405–429 in the revised manuscript.

7) A Stronger Focus on Nematode Biology and Pathogenic Mechanisms

While the previous review emphasized plant resistance and cultivar development, our manuscript places a greater emphasis on the biological and pathogenic traits of M. enterolobii itself. These traits include its life cycle, feeding site formation, effector functions, thermal adaptation, and interactions with host-associated microbiota. This pathogen-centered approach advance precision molecular control strategies and provides a theoretical basis for understanding its ecological expansion and transregional spread.

In summary, while building upon previous work, our review offers a multi-dimensional update on M. enterolobii research, encompassing significant progress made since 2020. We hope that this manuscript contributes meaningfully to ongoing research and management efforts by providing updated data, new insights, and theoretical support for future strategies.

Comment 2: The sentence appearing at Line 308-310 regarding the Rutter et al. 2021 paper is a misinterpretation of the findings of the Rutter et al. 2021 paper.  This paper reported that sweetpotato cultivar Beauregard was significantly more resistant to one a specific isolate of M. enterolobii when compared to a different isolate of M. enterolobii, yet the cultivar Beauregard was still highly susceptible to both isolates of M. enterolobii and does not have resistance to this nematode.   Since I have not read all the other papers that this review manuscript encompasses, it makes me wonder if there are other cases of misinterpreted work.

Response: Thank you for your insightful comment. We have thoroughly reviewed the original article by Rutter et al. (2021) and made revisions to our manuscript to ensure it accurately reflects the findings of their study. The revised sentence now reads: "Rutter et al. [114] inoculated 93 sweet potato accessions with two physiological races of M. enterolobii that differ in virulence and evaluated their resistance by counting galls and egg masses. Ultimately, 19 accessions were identified as resistant to both physio-logical races" Please refer to lines 344–347 in the revised manuscript for further details.

Reviewer 2 Report

Comments and Suggestions for Authors

This review is both timely and important, offering a well-synthesized overview of the biological, ecological, and technological dimensions of Meloidogyne enterolobii. It presents forward-looking strategies that will be valuable to researchers, educators, and practitioners working in plant protection and sustainable agriculture.

I have a couple of suggestions to further strengthen the manuscript:

1. Include the life cycle of Meloidogyne enterolobii

Under the section "Molecular Mechanisms in the Interaction Between M. enterolobii and Host Plants," I recommend including a brief description of the nematode’s life cycle. This information is currently missing and would enhance the clarity of the following sections of the manuscript.

2. Connect to soil microbiome context

In line with the journal’s aims and scope, I suggest incorporating discussion of M. enterolobii within the broader context of soil and root-associated microbiomes. Nematodes interact with microbial communities both in the rhizosphere and within infected plant tissues. Does M. enterolobii influence the composition of soil microbial communities? Are there microbial taxa known to suppress or promote its reproduction? Even if specific studies on M. enterolobii are limited, citing related work on other Meloidogyne species could provide valuable context and highlight important knowledge gaps.

3. RNA interference (RNAi)

Consider including RNAi complementary tool alongside high-throughput omics and gene editing technologies to decipher temperature adaptation mechanisms in nematodes. Given its relative accessibility and success in many nematode systems, it’s an important option for testing the roles of candidate genes involved in thermal stress responses.

Author Response

Dear reviewer,

We sincerely appreciate your thorough review of our manuscript entitled “Pathogenic Mechanisms and Green Management Strategies of the Root-Knot Nematode Meloidogyne enterolobii: Advances and Perspectives.” Your detailed and constructive comments have been invaluable in guiding us to identify key areas for improvement, significantly contributing to the enhancement of the scientific rigor and logical coherence of our work.

We highly value your comprehensive feedback, particularly your insightful suggestions to (1) incorporate a brief overview of the nematode’s life cycle, (2) integrate microbiome-mediated regulatory mechanisms into our discussion, and (3) expand on the role of RNA interference (RNAi) as a complementary tool. Following careful consideration and in-depth discussion, we have addressed each of your comments in the revised manuscript to ensure a more robust, systematic, and innovative presentation.

To further improve the language quality, we engaged a native English-speaking expert with a background in scientific writing to perform a comprehensive language polish of the revised manuscript, ensuring clarity, accuracy, and fluency throughout.

All revisions have been clearly marked in red font in the manuscript for your easy reference. Once again, we are deeply grateful for your insightful suggestions, which have significantly strengthened the overall quality of our work. We hope that the revised version fully addresses your concerns and meets your expectations.

Please find below our point-by-point responses to your specific comments.

Comment 1: Include the life cycle of Meloidogyne enterolobii.  Under the section "Molecular Mechanisms in the Interaction Between M. enterolobii and Host Plants," I recommend including a brief description of the nematode’s life cycle. This information is currently missing and would enhance the clarity of the following sections of the manuscript.

Response: Thank you for your constructive suggestion. We concur that incorporating a brief overview of the life cycle of M. enterolobii would significantly enhance the coherence and readability of the manuscript. In the revised version, we have introduced a new subsection titled “4.1 Life Cycle of M. enterolobii” under the section “Molecular Mechanisms in the Interaction Between M. enterolobii and Host Plants.” This subsection delineates the developmental stages of M. enterolobii from egg to adult, with particular emphasis on the infective second-stage juvenile (J2). Furthermore, it describes the induction of feeding sites—multinucleated giant cells—within the vascular tissues of the host, which are crucial for nematode growth and reproduction. Additionally, we have provided information regarding the duration required to complete a full life cycle under favorable environmental conditions. Please refer to lines 129–146 in the revised manuscript.

Comment 2: Connect to soil microbiome context.  In line with the journal’s aims and scope, I suggest incorporating discussion of M. enterolobii within the broader context of soil and root-associated microbiomes. Nematodes interact with microbial communities both in the rhizosphere and within infected plant tissues. Does M. enterolobii influence the composition of soil microbial communities? Are there microbial taxa known to suppress or promote its reproduction? Even if specific studies on M. enterolobii are limited, citing related work on other Meloidogyne species could provide valuable context and highlight important knowledge gaps.

Response: We sincerely thank the reviewer for the insightful suggestion. We fully agree that the study of M. enterolobii should be considered within the broader context of soil and rhizosphere microbiomes. In the revised manuscript, we have expanded the “Future Research Directions” section to address this important perspective.

Specifically, building upon existing studies on Meloidogyne spp., we highlight that root-knot nematodes not only modulate the rhizosphere microbial community through alterations in root exudates and effector secretion but may also reshape the endophytic microbiome to facilitate parasitism and colonization. Furthermore, we propose that M. enterolobii, as a highly virulent and polyphagous species, may secrete species-specific effectors that recruit distinct microbial communities, thereby exhibiting microbiome regulation strategies that differ from those of other RKNs. Moreover, due to its broad host range, M. enterolobii infections may trigger more complex and diverse microbiome dynamics across different host species.

Additionally, we discuss the differential microbiome responses observed in host plants with varying levels of resistance or susceptibility to M. enterolobii, and their potential roles in disease suppression—emphasizing the importance of the microbiome in shaping plant resistance. These additions not only align with findings from M. incognita and related species but also underscore the current knowledge gap regarding microbiome-mediated interactions specific to M. enterolobii. We believe that identifying and addressing this gap highlights a promising direction for future research and is well-aligned with the scope and aims of the journal. Please refer to lines 405–429 in the revised manuscript.

Comment 3: RNA interference (RNAi).  Consider including RNAi complementary tool alongside high-throughput omics and gene editing technologies to decipher temperature adaptation mechanisms in nematodes. Given its relative accessibility and success in many nematode systems, it’s an important option for testing the roles of candidate genes involved in thermal stress responses.

Response: We sincerely thank the reviewer for the insightful comment. In response, we have incorporated additional content on RNA interference (RNAi) in the “Challenges and Future Perspectives” section, highlighting it as a complementary approach for deciphering the thermal adaptation mechanisms of M. enterolobii.

Specifically, in the subsection titled “1) Elucidating thermal adaptation mechanisms using high-throughput omics and gene editing technologies”, we have included a statement indicating that, in addition to omics approaches such as transcriptomics and metabolomics, and gene-editing tools like CRISPR-Cas9, RNAi is a relatively simple and well-established technique applicable in various nematode systems. This technique can effectively validate the functions of candidate genes involved in heat stress responses, serving as a valuable supplement to studies on the molecular basis of thermal adaptation.

This addition enhances the comprehensive functional validation framework and directly addresses the reviewer’s concern regarding the availability of tools for candidate gene testing. Please refer to lines 374–382 in the revised manuscript.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors