INTRODUCTION
Introduction The "Strategic Framework for Global Food Security and Nutrition" indicates that food security is an increasing concern, with green agriculture becoming an important development direction. However, the long-term abuse of chemical pesticides has led to intensified ecological crises, reduced control efficacy, and threatens groundwater safety through bioaccumulation [1-3]. Cherry tomatoes, as an important economic crop, are native to the Andes Mountains in South America and were introduced to China in the 17th century. The global planting area is approximately 1 million hectares, with the Netherlands, the United States, and China being the major producers. In China, provinces and regions like Guangdong, Guangxi, and Hainan have a planting area of about 150,000 hectares, which is continuously expanding. Among these, Lingshui Cherry Tomato from Lingshui, Hainan, is a National Geographical Indication product (with an output value of 2 billion CNY in 2018), and Dianbai, Guangdong, plants over 60,000 mu annually (output value nearly 2 billion CNY), making them core production areas. This crop combines taste and nutrition: its vitamin content is 1.7 times that of ordinary tomatoes (rich in VC, VE). VC enhances immunity and promotes collagen synthesis, while VE acts as a potent antioxidant protecting cells. It also contains glutathione (promotes growth and development), lycopene (antioxidant, protects cardiovascular health), as well as sugars, organic acids, minerals, etc. It is easily digestible and absorbent and has good processing adaptability.
PROBLEM
1. Threat of Bacterial Diseases Plant bacterial diseases cause a 10%-30% reduction in global crop yield, resulting in economic losses exceeding hundreds of billions of USD [4]. A typical disease such as tomato bacterial wilt is caused by Ralstonia solanacearum. This Gram-negative bacterium has the following characteristics: Distribution: Tropical, subtropical, and some temperate regions Hosts: Infects over 200 species across 54 families (e.g., tomato/potato/tobacco) Pathogenic mechanism: Enters via roots → colonizes xylem → blocks vascular bundles → plant wilting Core weapon: Type III Secretion System (T3SS) secretes effectors, inhibiting plant immunity [5]
2. Bottlenecks in Green Control Traditional chemical agents (e.g., streptomycin) easily cause ecological pollution and drug resistance. Although biological control solutions exist (e.g., using Beauveria bassiana against tobacco bacterial wilt), control effectiveness is unsatisfactory due to the complex pathogenesis of the pathogen and limited research on plant disease resistance genes.
3. Application Challenges of Erucamide The discovery of the plant-derived disease resistance compound erucamide offers a breakthrough for green control. As a secondary metabolite of Brassicaceae plants, this plant-derived compound (Brassicaceae secondary metabolite) has a dual control mechanism: Targeted inhibition: Binds to the T3SS key protein HrcC, blocking effector protein delivery [6] Immune activation: Triggers salicylic acid (SA)/jasmonic acid (JA) pathways to enhance systemic resistance [7]Advantages: Environmentally friendly (degradation period 3-7 days / residue <0.01 ppm), low cost (mu cost a few CNY), high stability [8]. Disadvantages: Natural extraction is limited by extremely low content (0.1%-0.3% of seed dry weight) and seasonal constraints, making large-scale application difficult [9].
Our solution
Utilize synthetic biology techniques to engineer Escherichia coli chassis cells, constructing engineered bacteria with "pathogen detection - targeted synthesis - ecological adaptation" functions to achieve high-efficiency synthesis of erucamide:
1. Synthesis Pathway (Glucose → Erucamide) Carbon metabolism change: Glucose → Acetyl-CoA (PtsG) Erucic acid synthesis: Acetyl-CoA → Fatty acid → Erucic acid (FabH) Amidation: Erucic acid → Erucamide (GlnA) Secretion and release: Output product via extracellular secretion



2. Technical Value Pioneers a microbial heterologous synthesis system for plant-derived disease resistance compounds Establishes a full-chain technology encompassing "natural product analysis - pathway reconstruction - module integration" [10] Promotes the transition of disease control from chemical intervention to biological intelligent regulation
3. Application Prospects Short-term benefits: Focus on application in cherry tomato production areas (Lingshui, Hainan / Dianbai, Guangdong), specifically targeting bacterial wilt control, reducing pesticide use, ensuring yield and quality, and unlocking potential output value. Low cost (mu input a few CNY) accelerates the adoption of green technology. Technology replication: Engineer multiple microbial chassis to build a library of plant-derived disease resistance compounds Field extension: Provide a paradigm for controlling bacterial diseases in food crops like rice and wheat Industrial transformation: Optimize the environmental adaptability of engineered bacteria, promoting agriculture towards an "ecologically friendly, efficient, and sustainable" development model This technology reconstructs the biosynthetic pathway of erucamide through synthetic biology, breaking through the bottlenecks of natural extraction and providing a breakthrough solution for green control. Its large-scale application will reconcile the contradiction between food security and ecological balance, holding strategic significance for global agricultural sustainable development.
References

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