Human Practices

Overview

Peach gummosis is a significant disease affecting the health of peach trees, primarily caused by fungal infections or environmental stress. It leads to bark cracking and the exudation of gummy substances, severely weakening the trees and even causing death. Current control methods rely on chemical agents and agricultural management, but issues such as drug resistance and environmental pollution persist, leaving a lack of efficient and eco-friendly solutions. During our iGEM journey, we aim to develop an effective biopesticide to address peach tree gummosis. We strive to consider multiple factors to ensure that our biopesticide is user-friendly, accessible, cost-effective to produce, and aligned with public expectations. Our team consists of environmentally conscious members who actively engage in diverse integrated human practices (HP) to gather feedback and insights on various aspects of the project. This approach allows us to refine our biopesticide design and create a sustainable solution.

1. Commercial Value Analysis

This part was written by Jinyao Chu and Yixiang Sun with AI assistant.

Analyzing the project's commercial value is a prerequisite step that ensures our work aligns with practical needs and market relevance, rather than being purely theoretical.

RNA-based biopesticides

Driven by the triple factors of growing global crop resistance to pesticides, tightening national policies on pesticide residue supervision, and escalating health demands of consumers, RNA interference (RNAi) pesticides, leveraging their technical advantages of 'highly effective pest control + no residue', are reshaping the landscape of the pesticide market. Currently, nanocoating technology has matured, so supply chain risks no longer require prioritized consideration. Meanwhile, the market differentiation between organic and conventional fruits and vegetables, combined with the rigid constraints of policies, not only highlights the urgent demand for RNA pesticides but also provides precise policy anchors for their commercialization path.

  1. Policy drive: Rigid demand gap arising from upgraded pesticide residue supervision.

    2. At the national level, a full-chain pesticide residue supervision system covering 'production control - circulation testing - punishment for violations' has been established. Traditional planting models and pesticide products are now facing systemic compliance pressures, and RNA pesticides have emerged as the optimal solution to meet policy requirements.

  2. Cost and competition: Differentiated pricing and cost reduction logic under policy guidance

    3. National pesticide residue policies have not only increased the compliance costs of traditional pesticides but also provided policy endorsement for the pricing of RNA pesticides, endowing them with greater competitive advantages in the price stratification of fruits and vegetables.

    • Cost side: Conversion of policy compliance costs into technological substitution dividends.
    • Terminal pricing: Policy endorsement strengthens the rationality of 'Safety Premium'.
  3. Consumption and channel drive: Policy credibility empowers value transmission

    4. The authority of national pesticide residue policies serves as a natural trust endorsement for the market education of RNA pesticides, which can significantly reduce the cognitive costs on the consumer side and the promotion difficulties on the channel side.

    • Consumer side: Policy testing standards establish trust anchors.
    • Channel Side: Policy compliance demands activate promotion incentives.
  4. Risk response: Policy tools address market acceptance challenges.

    5. By aligning with pesticide residue supervision policies, the market risks of RNA pesticides can be transformed into policy adaptation advantages, accurately resolving three core challenges:

    • Farmer side: Replacing technical persuasion with policy compliance benefits
    • Consumer side: Building intuitive cognition through policy scenarios.
    • Channel partner side: Reducing promotion costs through policy collaboration.
  5. Future Outlook: Full-scenario penetration in the fruit and vegetable sector driven by policy dividends.

    6. The continuous upgrading of national pesticide residue supervision will become a core catalyst for the rapid substitution of RNA pesticides. In the short term (1-2 years), the focus can be placed on areas with the strictest policy supervision: prioritizing coverage of leafy vegetables (such as spinach and rape) that are frequently sampled during circulation, and export-oriented fruits (such as citrus and apples). Relying on the selling point of 'compliance to avoid risks', a penetration rate of 10%-15% can be achieved. In the medium term (3-5 years), as organic certification standards become more stringent, RNA pesticides will replace inefficient prevention and control methods in traditional organic farming, promoting the large-scale production of 'quasi-organic fruits and vegetables' such as berries and melons/eggplants, with the market scale exceeding 2 billion US dollars. In the long term, RNA pesticides are expected to become the core technical carrier for the national 'pesticide reduction campaign' and 'agricultural product quality and safety improvement project', driving the proportion of 'residue-free fruits and vegetables' to exceed 40%. Driven by both policies and the market, they will establish a core position in the green transformation of agriculture.

Chitinase Extraction from Peach Leaves
1. Core Principle and Commercial Value
Core Principle

The extraction of chitinase from peach tree leaves relies on the enzyme's natural chitin-degrading activity:

  • Chitin is a key component of cell walls in plant pathogenic fungi (e.g., peach brown rot pathogen (Monilinia fructicola), peach leaf curl pathogen (Taphrina deformans)) and exoskeletons of some agricultural pests.
  • Peach leaf chitinase specifically hydrolyzes β-1,4 glycosidic bonds in chitin, destroying the structural integrity of pathogens/pests, thereby inhibiting growth/reproduction or killing them to control plant diseases and pests.
Commercial Value
  1. Natural and Green Advantage: Plant-derived enzyme, degradable in nature without toxic residues, meets green biopesticide market demand and avoids chemical pesticide pollution.
  2. Fruit Tree Targeting: Highly effective against peach-specific diseases (brown rot, leaf curl) and pests; fills the gap for targeted peach orchard biocontrol products.
  3. By-Product Utilization: Peach tree leaves (agricultural by-products from pruning) reduce raw material costs, with obvious advantages over microbial fermentation (no need for culture media/fermentation equipment).
  4. Extended Scenarios: Applicable to fruit fresh-keeping (inhibit fungal growth during storage), feed additives (improve livestock digestion), and biological fertilizers (enhance soil fertility).
2. Competitive Advantages vs. Microbial Fermentation

Compared with mainstream microbial fermentation for chitinase production, peach leaf extraction has 3 core advantages:

  1. Lower Cost and Simpler Process
    • Microbial fermentation requires professional workshops, fermentation tanks, complex culture media, and strict condition control (high early investment).
    • Peach leaves (low-cost agricultural by-products) only need crushing, buffer extraction, centrifugation, and purification—no high-pressure equipment, short process flow.
  2. Higher Safety and Market Acceptance
    • Microbial fermentation risks residual by-products (pathogen metabolites) or heavy metal pollution from media.
    • Peach leaf chitinase is a natural plant component; high purity after purification, aligns with "natural, safe" concepts (ideal for high-end/organic fruit planting).
  3. Stronger Targeting for Peach Orchards
    • Microbial chitinase has broad-spectrum activity but lacks adaptability to peach-specific pathogens.
    • Peach leaf chitinase evolves with peach trees to resist local pests, adapting to peach orchard environments (temperature, humidity) and degrading peach pathogens (e.g., Monilinia fructicola) more efficiently.

Additional Advantage: Environmental sustainability—reduces agricultural waste (avoids leaf incineration/stacking pollution), conforms to "circular agriculture" policies, and easily obtains subsidies.

3. Technical Process and Key Commercialization Links
Main Technical Process (6 Core Steps)
  1. Raw Material Pretreatment: Select fresh/dried leaves (high enzyme activity, e.g., spring young leaves), clean, low-temperature dry (40-50°C), crush into 40-60 mesh powder.
  2. Enzyme Extraction: Mix leaf powder with phosphate buffer (pH 6.0-7.0) at 1:10-1:20 solid-liquid ratio; extract 2-4 hours at 20-25°C with gentle stirring.
  3. Crude Enzyme Separation: Centrifuge at 8000-10000 rpm for 15-20 minutes; collect supernatant (crude enzyme); leaf residue reused as organic fertilizer.
  4. Enzyme Purification:
    • Primary: Ammonium sulfate precipitation (40%-60% saturation) or ultrafiltration (20-30 kDa membrane) to get semi-pure enzyme.
    • Secondary: Ion exchange/gel filtration chromatography (for high-purity needs, e.g., fresh-keeping/feed additives).
  5. Enzyme Activity Detection: Use DNS or colloidal chitin plate method; only products with ≥500 U/g (international unit) enter next step.
  6. Formulation Processing: Process into liquid (add stabilizers/surfactants) or solid (spray-dried powder) based on application scenarios.
Key Technical Links Affecting Commercialization
  1. Extraction Rate and Activity Retention: Optimize buffer type/solid-liquid ratio; add protectants (glycerol, EDTA) to avoid enzyme inactivation during drying/extraction.
  2. Purification Simplification and Cost Control: Develop low-cost technologies (replace chromatography with cheap ultrafiltration membranes; optimize ammonium sulfate usage) for large-scale production.
  3. Product Stability: Develop stabilizers (trehalose, sodium alginate) and microencapsulation technology to extend shelf life (≥6 months at room temperature) and resist field conditions (high temperature, rain).
4. Commercialization Cycle and Key Influencing Factors
Typical Cycle: 18-24 Months

Shorter than microbial fermentation chitinase (24-36 months). Stage division:

  1. Laboratory Research (3-4 months): Optimize pretreatment/extraction/purification; determine parameters; conduct preliminary efficacy tests.
  2. Pilot Scale-Up (4-5 months): Build small pilot line (50-100 kg/day crude enzyme); verify process stability; adjust parameters.
  3. Field Verification and Formulation Optimization (5-6 months): Conduct orchard efficacy tests; optimize formulations; complete safety evaluation (non-target organisms like bees/earthworms).
  4. Industrial Line and Registration (6-9 months): Build industrial line (500-1000 tons/year); apply for certifications (biopesticide registration, organic certification); build supply chain.
Key Factors Affecting Cycle
  1. Raw Material Supply Stability: Peach leaves are seasonal (spring/summer peak). Delays occur if no annual supply system (e.g., low-temperature storage centers) is established (prolongs cycle by 3-6 months).
  2. Efficacy Verification and Registration Speed: Field tests depend on peach growth cycles (1-2 disease periods/year); missed periods require waiting. Incomplete registration materials cause review delays.
  3. Scale-Up Technology Maturity: Laboratory processes (small centrifuges) cannot directly apply to industry (large continuous centrifuges). Unresolved technical issues (uneven mixing, low ultrafiltration efficiency) prolong cycle by 2-4 months.
5. Cost Analysis and Competitive Advantages
Cost Composition
  1. R&D Cost: 800,000-1.2 million yuan (laboratory equipment: 150k-200k; pilot line: 300k-400k; field tests: 200k-300k; registration: 150k-200k). 30%-40% lower than microbial chitinase (1.5-2 million yuan, requires strain screening/fermentation optimization).
  2. Application Cost: After mass production (1000 tons/year), unit cost of finished product (≥500 U/g) is 80-120 yuan/kg. Peach orchard dosage: 200-300 g/ha (diluted 500-800x); application cost: 16-36 yuan/ha.
Cost Advantage Comparison
  • vs. Conventional Chemical Pesticides:
    • Chemical pesticides (carbendazim, thiophanate-methyl): 20-50 yuan/ha per application, but require 3-5 applications/year (annual cost: 60-250 yuan/ha).
    • Peach leaf chitinase: 1-2 applications/year (annual cost: 16-72 yuan/ha) — 60%-70% cost advantage. No hidden costs (environmental governance, food safety testing) of chemicals.
  • vs. Microbial Chitinase:
    • Microbial chitinase unit cost: 150-200 yuan/kg; application cost: 30-60 yuan/ha.
    • Peach leaf chitinase: 40%-70% lower application cost. More stable raw material supply (agricultural by-products) vs. microbial fermentation (affected by glucose/yeast extract price fluctuations).
6. Environmental Benefits and Commercialization Solutions
Environmental Benefits
  1. Zero Pollution and No Residue: Plant-derived protein, fully degraded into amino acids/small carbohydrates in 15-20 days. Solves soil compaction, water eutrophication, and food residue from chemicals.
  2. Agricultural Waste Recycling: A 10,000-mu peach orchard produces 500-800 tons of leaves/year. Extracting chitinase reduces incineration (air pollution) and stacking (rot pollution); leaf residue reused as organic fertilizer (forms "peach leaf → chitinase → fertilizer" cycle).
  3. Biodiversity Protection: Only acts on chitin-containing pests/pathogens; no toxicity to bees, earthworms, or birds. Avoids beneficial organism killing by broad-spectrum chemicals.
Commercialization Challenges and Solutions
Challenges Solutions
Seasonal raw material supply: Large quantities only in spring/summer; off-season leaves have low enzyme activity. 1. Establish low-temperature drying/storage centers to ensure annual supply.
2. Develop multi-raw material technology: Expand to Rosaceae leaves (apple, pear) with similar chitinase properties.
Low market awareness: Farmers prefer mature chemical pesticides; low recognition of new plant-derived enzymes. 1. Set up demonstration orchards in core peach-producing areas (cooperate with agricultural departments) to show efficacy/cost advantages.
2. Launch cost-sharing policies to reduce farmer trial costs.

2. Spark: Get Inspiration

This part was written by Ye Zhu with AI assistant.

In 2025, through face-to-face interactions with other participating teams, we held in-depth discussions, acquired valuable hands-on experience, and significantly broadened our understanding and perspective on the applications of synthetic biology.

Communication With ZJU-China 2025
    First visit to ZJU-China's laboratory

    On May 10 2025, we visited ZJU-China's laboratory and decided to collaborate on human practices part.

    Deeper communication with ZJU-China 2025

    On July 26 2025, ten members of our team visited ZJU-China at Zhejiang University's Zijingang Campus for an exchange activity. Since some of our members had already visited their laboratory back in May, this time we went directly to the conference room to listen to their presentation on this year's project, 'LumaManta.' They began by explaining the origin and meaning of the project name, then elaborated on their project design and progress from the perspectives of DryLab, WetLab, and Human Practices. Through their detailed sharing—from topic selection to implementation—we sensed their passion for biology and iGEM, as well as the unity and perseverance of the ZJU-China team. Beneath it all, of course, were their interesting personalities and their hearts dedicated to iGEM. We aim to learn from their outstanding qualities and apply them to our own project.  

    After the presentation, we moved on to a Q&A session. Our team members actively asked questions, and their responses were thorough and detailed. This exchange not only allowed us to make new friends but also helped resolve some of our doubts. It inspired new designs and ideas for the future development of our project.

    We have also provided our feedback on their project, and these audio recordings are available on their Bilibili channel.

Met More iGEMers In CCiC

From August 6-8 2025, we attended the China Regional iGEMer Conference (CCiC) in Zhongguancun, Beijing. During the conference, we listened to presentations from other teams about their projects, encountered many fascinating initiatives, and gained insights into their experimental progress. Through these exchanges, we reflected on how to improve our own project. We learned from their approaches and formats in Human Practices (HP) to refine our own HP efforts. In the poster session, we engaged in in-depth discussions with various schools, exchanged gifts, and addressed challenges by posing questions to one another, helping to resolve issues we couldn't tackle alone. It is said that the format of CCiC closely resembles that of the iGEM Jamboree, which provided us with valuable preparation for attending the Jamboree in Paris, helping to alleviate some of our nerves. By participating in CCiC, we learned about more projects, connected with more iGEMers, and met more friends passionate about biology. Additionally, the conference resolved some of our doubts and provided us with more and better ideas for the future development of our project.

The posters we encountered at CCiC 2025 inspired us greatly.

3. Stakeholders

Concerning the specific prevention and control of peach gummosis, we talked to local farmers, with whom we also consulted about their willingness to participate in our new pesticide trials in the future. Here is the survey to understand peach growers' views and needs regarding peach cultivation and the use of biopesticides.

Feedback from Peach Growers

Regarding RNA-based biopesticides, we interviewed China's first high-tech enterprise specializing in this area.

Q&A with Professor Xueming Tang (CEO of Silicon Gene) on the Application, Competitive Advantages, Commercialization of RNA Biopesticides
Q: What are your views on the core principles and advantages of RNA-based biopesticides in plant disease control?
Q: What are your views on the core principles and advantages of RNA-based biopesticides in plant disease control?
Q: What are your views on the core principles and advantages of RNA-based biopesticides in plant disease control?
Q: Currently, international giants (such as Bayer and Syngenta) are also venturing into RNA pesticides. What are the core competitive advantages of Silicon Gene?
Q: What is the primary mechanism of Silicon Gene's RNA pesticides?
Q: What are the R&D and application costs of Silicon Gene's RNA pesticides? Do they offer advantages over conventional pesticides on the market?
Q: What are the environmental benefits of Silicon Gene's pesticides?
Q: What challenges has the company faced during R&D?

For the Fenghua honey peach industry, we had an interview with the director of Fenghua Honey Peach Research Institute to better understand existing control methods, factors influencing peach tree gummosis, and the disease resistance of different peach tree varieties, we interviewed the director of the Fenghua Honey Peach Research Institute. She answered our questions in clear and accessible language, deepening our understanding of these key aspects.

An Interview with Miaojin Chen (Director of Fenghua Honey Peach Research Institute)
Q: Peach gum is said to have medicinal effects. What's your opinion on this?
Q: Have we developed any related products?
Q: Among the main Fenghua honey peach varieties, which one shows stronger resistance to gummosis? What's the relationship between this resistance and the variety's genetic or physiological characteristics?
Q: What's the typical lifespan of these peach trees?
Q: Has the research institute made any new discoveries regarding the causes of peach gummosis?
Q: Has the research institute made any new discoveries regarding the causes of peach gummosis?
Q: Has the research institute made any new discoveries regarding the causes of peach gummosis?
Q: Do we use any agents to prevent and control gummosis?
Q: Does peach gummosis affect fruit quality? Is there any related research?
Q: Does gummosis affect yield? Can it cause entire branches to stop bearing fruit?
Q: Are there any green prevention and control methods?
Q: Are there any professional detection technologies?

4. Our Opinions

Classmates' Views on our project
Fenghua Peach Industry Value
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Honey peach is one of Fenghua's specialties. If this project succeeds, it will further increase peach yields, expand exports, boost local economic development, enhance reputation, and attract tourists from other regions.
Student's View
Significance of Gummosis Research
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After participating in Fenghua peach gummosis intervention research, I deeply realized that technology is not cold but warm assistance. It helps peach farmers increase income while indirectly promoting people's awareness integration.
Student's View
Reasons to Support the Project
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I strongly support this project as it positively impacts peach tree lifespan and yield. This increases both production and farmers' income, effectively driving regional economic development.
Student's View
Gummosis Control and Environmental Protection
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Controlling peach gummosis teaches us that common plant diseases can be solved. Biological pesticides cause less environmental damage than traditional ones, embodying the new green development concept.
Student's View
Synthetic Biology and Daily Life
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"Synthetic biology" and "peach gummosis" - never thought these profound terms would enter my life. It turns out technology is comprehensively changing daily life, and knowledge can truly be applied in practice.
Student's View
Impact on Farmers and Hometown
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This project will increase farmers' harvests and income, stimulating production enthusiasm. Treating peach trees and extending their lifespan helps Fenghua, "the hometown of honey peaches," achieve further development. Even high school students can improve life with small actions.
Student's View
Perseverance of Fenghua High Team
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Peach blossoms bring harvest joy, but gummosis causes distress. Fenghua High School's iGEM team conducts research year after year, delving into genetic levels and pooling team strength to overcome challenges.
Student's View
Deep Significance of Research
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This research is highly significant. Through it, I learned about "peach gummosis" for the first time and realized that even with advanced technology, many agricultural issues remain unsolved. Technology is never cold; there's warmth behind it.
Student's View

Summary

As a high school team, our humanistic practices for peach gummosis biopesticide R&D acted as a 'bridge'. It took us beyond textbooks and labs, gathered insights from all sides, and guided the project toward being easy to use, accessible, affordable, and long-lasting.

We exchanged with other iGEM teams:

  • In May, we visited ZJU-China's lab.
  • In July, their 'LumaManta' project sharing taught us how to coordinate dry/wet experiments and run humanistic practices.
  • In August, CCiC gave us poster design and presentation tips, easing our pressure for the Grand Jamboree.

Talks with peach farmers were most rewarding. They wanted both 'convenient' and 'cost-effective' pesticides.

We have also consulted some experts:

  • Professor Tang (Silicon Gene) clarified RNA pesticide stabilization and cost-cutting challenges, highlighting farmers' purchasing power.
  • Director Chen (Fenghua Honey Peach Institute) noted local gummosis ties to varieties and old methods, stressing R&D must fit local needs.

Our classmates' feedback also made us realize the need for science popularization and highlighted overlooked details like biopesticide storage conditions.

Above all, these practices shattered the 'scientific research myth'. We learned research is not just 'paper talk'. Advices from all sides clarified the project direction, advanced our goals: to find out solutions that help farmers and boost our hometown's peach industry.