In the process of human practice, we have carried out scientific exchanges with many parties. Since our project involves Longjing Tea, Hangzhou's city card, we pay great attention to exchanges with relevant government departments and exchanges with scientific and technological experts during our research. We interviewed professors from Zhejiang University in many related fields at the beginning of experimental design, and obtained a lot of suggestions on experimental design, hardware design and feasibility from them, which helped us adjust the direction of the project in a timely manner. In the exchange with the government departments, we learned about the current status of tea garden pest control in Hangzhou and the relevant policies of biological control. The government's attitude towards our projects is also taken into account. Through extensive exchanges, we have obtained effective suggestions and general opinions from the community for our projects, and provided effective help for the design of our projects.

Longjing Villagers Committee

We interviewed Master Liu, a local plant protection expert in Longjing Village, who specializes in managing tea gardens. He told us that the general pest control mainly focuses on spraying pesticides and placing swatches, but swatches can only kill flying pests, and have no effect on pests such as tea inchworm and tea aphid. Pesticides are also restricted by the government. The list of pesticides that can be sprayed and the corresponding doses are listed by the tea department. Farmers must strictly abide by the regulations of the tea department. It is absolutely not allowed to spray other pesticides outside the list to ensure the absolute safety of tea quality. We asked about the local spending on pesticides. The pesticide fees for one acre of tea garden and the labor costs for pesticide spraying, excluding government and village subsidies, still require more than 1,000 farmers to invest, and the expenses will be even greater in summer. This huge labor cost makes local farmers distressed.

Soil and Solid Waste Division,
Ecological Environment Bureau, Yuhang District, Hangzhou City

At present, the soil and surface water pollution in some rural areas is relatively serious, and a large part of the reason comes from the fertilizers and pesticides used in the cultivated land. If we can reduce the use of pesticides and promote the rational use of chemical fertilizers by farmers, it will be of great help for the control of environmental pollution sources.

Law and Regulations Division ,
Environmental Protection Bureau, Hangzhou City   Researcher Chen

At present, there are no clear and detailed laws and regulations on biological products for environmental governance. Biological products only need to meet the regulations of the laboratory and pass the evaluation of professional institutions before they can be considered for use. For the government, the quality control of these products should be the responsibility of the upstream, so there is no need for specific policy restrictions.

Tea Research Institute ,
Chinese Academy of Agricultural Sciences   Researcher Zongxiu Luo

Tea aphid is a common pest in tea gardens. At present, measures to control tea aphid in tea gardens include spraying systemic pesticides or manually cutting off affected leaves. The use of synthetic biology to control pests is very promising, and no other team has explored this aspect so far. In addition, as a scientific research and government agency specializing in tea gardens, they believe that it is necessary to popularize popular science knowledge among farmers. Compared with the development of science and technology, farmers' thinking is still relatively backward. The development of synthetic biology is still in the growth stage. There are still many problems to be solved, and attention should be paid to the convenience and low cost of the product. In the experimental stage, you can go to the greenhouse for cultivating tea seedlings for research. There are many tea aphids growing in the environment of the greenhouse.

The harvest of the interview

Through interviews with the government, we learned that the pest control measures currently applied in the fields actually have their shortcomings, and our project can well complement these shortcomings. The advanced nature of synthetic biology determines that there will be a certain disconnect between us and farmers, and we will conduct specific popular science publicity for this. At present, the government has no specific policy restricting the application of our project. If the experiment successfully achieves the expected effect, we will contact the Tea Seedling Cultivation Center for further experiments.

Professor Liu Shusheng
Zhejiang University, Institute of Insect Sciences

Professor Liu Shusheng (Professor and Doctoral Supervisor of Zhejiang University) Professor Liu has a deep understanding of the effect of sex pheromones. In the conversation with Professor Liu, we learned that sex pheromones are not inter-species intercommunication, and different concentrations of nepetalol and nepetalactone have different effects on different species of tea aphids. The species of tea inchworms in Zhejiang are mixed. If the intraspecific variation is obvious, the applicability will be limited. Therefore, we hope to design switches in our chassis cells to achieve mixed secretion in specific concentration ratios.

Professor Mo Jianchu
Zhejiang University, Department of Plant Protection

As an insect expert, Professor Mo Jianchu told us that aphids alternate parthenogenesis and bisexual reproduction (spring and autumn). After entering parthenogenesis, the aphids insert their mouthparts (piercing-sucking) into the leaves and stop for a month or two, and then go to mate in the fall, which means that we can arrange our products in advance for a specific season to play a preventive role. He also told us that evasion may require sustained high concentrations, which requires our production and release to meet certain standards. Since the requirements for attracting natural enemies are not harsh, we can also attract natural enemies after meeting the conditions for avoiding them.

Professor Lou Yonggen
Professor and Doctoral Supervisor of Zhejiang University

Professor Lou Yonggen told us that cistrihexenol is not only released by tea trees when aphids come, but also released by other pests. To find aphids-specific substances, after searching the literature in the later period, we finally determined Benzyl alcohol was used as our test substance. At the same time, Professor Lou also told us that if a single ratio of sex pheromones is used to control pests, the ratio may change over time. In response to this, we used live yeast for production, and designed a detection feedback and release pathway to flexibly change the ratio of nepetalol and nepetalactone.

Professor Huang Jia
Zhejiang University, Chief Expert of Public Welfare Industry Research Project,
Post Scientist of Rice Industry Technology System

Professor Huang believes that nepetalactone is a component of catnip and is a repellant for most insects. Nepetalactone as an activator can stimulate the temperature-sensing ion channel of insects, so it can avoid many insects. Therefore, our choice of nepetalol and nepetalactone is correct, and our idea is also novel, but we need to pay attention to the release of nepetalactone. We were also inspired by our follow-up exchanges and discussions with other teams.

Professor Chen Xuexin
Zhejiang University, School of Agriculture and Biotechnology

Professor Chen Xuexin told us that the use of synthetic biology to control pests in the field is a very advanced way, which is definitely promising, but we need to pay attention to how to transmit the signal to the aphid pheromone produced by engineering yeast after sensing benzyl alcohol, This signal transduction route is not found in engineered yeast. Therefore, we designed the use of G protein-coupled receptors to conduct external stimuli.
At the same time, Professor Chen also proposed to be a carrier in terms of hardware design, as well as a releaser. To take into account the sun, wind and rain, can not affect the function. At the same time, it is necessary to prevent some birds from accidentally eating the engineered yeast. This provides great inspiration and help for our hardware design.

Professor Zhang Yan
Zhejiang University, medical school

Professor Zhang Yan is an expert in GPCR. He told us that the G protein in yeast is very special, and people can only recognize his unique G protein. Therefore, we chose to transfer the olfactory receptor HarmOR10 (which can specifically recognize benzyl alcohol) gene from Helicoverpa armigera into yeast.

The harvest of the interview

Through interviews with six biology professors, our team has gained a lot of experimental knowledge, which has clarified the feasibility of our project and the advanced nature of synthetic biology. We have obtained a lot of valuable suggestions on detection, construction of pathways and secretion, which laid the foundation for our subsequent construction of a complete experimental system.