Modern plant diseases have a significant impact on crop production. The U.N. Food and Agriculture Organization estimates that up to 40% of global crop production is lost to plant pests and diseases each year[1]. This results in millions of people not having enough food to eat and seriously damages agriculture, which is the primary source of income for rural poor communities. Each year, plant diseases cost the global economy more than $220 billion, and invasive insects cost at least $70 billion. Therefore, managing plant diseases is crucial for ensuring food security and economic stability.

Through multiple consultation, article reading and experimental verification, our engineered bacteria can be used to enhance crop resistance to plant pathogenic fungi, and has the potential to be feasible solution for increasing crop yield. After investigated the opinions of the masses in Human Practice, to reduce the complexity of the process for farmers and enhance the practicality of the engineered bacteria, our Flora Sentinel is ultimately designed to be used in a manner similar to traditional pesticides.

In our project, we designed two independent strains to produce the action module pikm-1 and the helper module pikm-2, respectively. All engineered strains contain our biosafety module, self-amplifying module and TLS module.

In order to facilitate the use of users, we will produce Agrobacterium transient expression buffer, engineering bacteria wettable powder, surfactant matching use.

Figure 1: Product Composition of Flora Sentinel

First, the transient expression buffer powder can be used to resuscitate engineered strains when mixed with water. The buffer contains acetosyringone (AS), a phenolic compound that induces Agrobacterium T-DNA transfer, magnesium chloride (MgCl₂), MES monohydrate, and so on. They are used to regulate ionic strength and pH.

After recovery in a dark place for about 1 hour, the product can be diluted to a suitable concentration with water, and finally surfactant is added and sprayed on the liquid level using conventional pesticide equipment.

In addition, if we want to obtain better use effect, we can activate and amplify the engineered bacteria by professional staff using liquid medium. So that with fresh Agrobacterium, the activity of the bacteria can be significantly improved after magnesium chloride cleaning and transient expression buffer treatment. This method is suitable for large area, and professional spraying services can be provided by biological pesticide companies.

Figure 2: Product Preparation Method of Flora Sentinel

After spraying, engineering bacteria can enter mesophyll cells through wounds or stomas on the leaf surface under the action of surfactant, Related studies showed that Agrobacterium vectors effective transfection of 0.9-3.5% of leaf cells in the presence of a surfactant In most plants[2], the RNA we designed is transcribed, then move between plant tissues through TLS sequences. Long-time survival is achieved through self-amplifing sequences, so that the functional pikm immune module can be expressed in the whole plant under the specific recognition of nanoantibodies, which achieve prevention against upcoming pathogens.

Figure 3: Product Usage of Flora Sentinel

As a systemic delivery platform for disease resistance, it is theoretically possible to design nanobodies for different targets and achieve plant-specific disease resistance in a non-chemical pesticide and non-transgenic form. To this end, our service objects include but are not limited to the following categories:

Large Farms

For crops with large planting areas, high yield requirements, and relatively serious diseases, engineered bacterial strains combined with Advanced technologies such as precision agriculture can also be used to optimize resource use and increase yield.

Modern Planting Greenhouses

For high economic value crops that are susceptible to diseases, engineered bacterial strains combined with hydroponics or other soilless cultivation methods can ensure the quality of agricultural products.

Home Balconies or Gardens

For garden crops with high ornamental value, engineered strains can be used to keep plants healthy in combination with proper watering and fertilization.

Figure 4: Applicable Scenarios and Application Methods of Flora Sentinel

1 Customized Nanoantibodies for Pathogenic Bacteria

Our approach allows the design of customized resistance genes for specific pathogenic fungi. Given that different plant pathogenic fungi produce distinct effectors, and even different physiological races of the same strain can have unique effectors, we can design corresponding nanoantibodies based on these variations.

2 High Efficacy and Longevity

Our method exhibits high efficacy and longevity compared to RNA pesticides. We utilize Agrobacterium tumefaciens as a transporter, which facilitates easier entry into plant cells. Through the implementation of the Self-amplifying module and the TLS module, we enhance the persistence and range of action of our approach, qualifying plant for resistance throughout the susceptible period.

3 Safety for Animals, Plants, and the Environment

Our integrated biosafety module reduces the viability of engineered bacteria in the wild and limits horizontal gene transfer, thereby mitigating impact on environmental microbial communities. Moreover, compared to traditional chemical pesticides, The biodegradable nature of RNA reduces the risk of exposure to the environment.

4 Human Safety and Acceptability

Our method is safe and more acceptable to people compared to traditional transgenic technology. transient expression does not alter the genetic traits of plants but temporarily changes their physiological phenotype to enhance disease resistance.

(1) It may be affected by environmental factors and the effect is unstable. Agrobacterium has different physiological activities under different temperature and humidity conditions, so it cannot be used in all agricultural areas. In addition, the dosage and effect may be affected in different regions.

(2) Trade-off Between Yield and Resistance: There is often a trade-off between yield and disease resistance. Energy and resources that a plant could use to defend against diseases are instead used for growth and reproduction. Therefore, the use period and amount of engineered bacteria need to be strictly controlled.

(3) The design cycle of nanobody is long, so it is necessary to cooperate with other scientific research to establish a usable antibody platform, which still needs further research.