Integrated Human Practices

Overview

Fig.1 the Overview of integrated human practice

Extreme catastrophic climates, such as drought and frost, not only become a major barrier to agricultural development but also bring enormous threats to global food security. According to statistics, we realized that this seems to be the global climate catastrophe rather than the exception these years. Famers tell us that many economic agricultural products, such as tea and navel orange, have suffer the negative effects of drought and frost in the past three years.

After the human practice survey in the tea garden and orchard, we learned that global climate change has triggered frequent extreme weather events. Unfortunately, the existing approach cannot protect the tea and navel orange trees from the damage of drought and frost, which encouraged us to develop a new method based on synthetic biology tools. We have further learned more about the actual situation in the planting process from human practices, which guided us to choose and produce water-retention and antifreeze material, design hardware, and. Beyond that, the discussion with Prof. Lyu and Wang give us more advice on the design of the biosafety part. These human practices activities make our experimental program closer to the complete project and actual working environment.

At last, we conducted feedback interviews with farmers, government agencies, the public, and enterprises, respectively. First, we feedback on the improved hardware to the farmer to collect the information of usage experience. Second, the damage reports of sudden drought and frost disasters on economic crops were feedback to the government agencies, which can contribute against drought and frost disasters through collaboration with government agencies. Third, the damage information was also feedback to the public to not only raise their awareness of environmental protection but also increase their understanding of the power of synthetic biology. Lastly, we feedback on the research results to the enterprise to search for cooperation, laying the foundation for applying our research results to solve the damage caused by drought and frost as soon as possible.

2.Emergency

2020, the iGEM team at Xiamen University (XMU-China) focused on the detection and degradation of pesticide residue (glyphosate) which remains in tea leaves and soil, respectively (please see project of 2020 XMU-China for details). After the iGEM competition in 2020, we continued to have that very close link with the tea grower in Wuyishan. At the end of 2022, they got in contact again with our team not for glyphosate but for another much more serious problem, a sudden drought.

Gannan navel orange, a Chinese national protected geographic indication product, comes from the south of Jiangxi province. At the end of 2022, the orchardist tells us that they also suffered heavy economic losses from the catastrophic climate change of sudden drought and frost.

In March 2023, the average precipitation of Qingdao City, a seashore city, was 4.3 mm, which was 75.4% lower than that in the same month in the previous year. Spring is the time for all plants to grow, while the sudden drought prevents the seeds' germination. Many individual farmers suffered heavy economic losses.

Fig.2 Tea plantation workers were watering the dry tea trees (left) and the orchards were suffering from frost (right)

3. Background

After that, we investigated damage from drought and frost, two natural disasters caused by extreme climate. Global warming triggers frequent extreme climate phenomena, such as drought and frost, which not only become a major barrier to agricultural development but also bring enormous threats to global food security. According to statistics, the drought area has reached 63% in the United States in 2022, resulting in economic losses of $ 22.2 billion. Beyond that, the economic loss and area caused by low temperature and frost damage reached up to $1.73 billion and 870.7 thousand hectares in China last year (please see Description for details).

We realized that this seems to be the global climate catastrophe rather than the exception these years. Accordingly, our members went to Wuyishan and Xinfeng to investigate the economic losses and solutions of drought and frost.

After the survey in Wuyishan, we learned that the temperature is uniform and the climate is mild, which is suitable for the growth of tea trees. Unfortunately, the sudden drought lasted for more than 6 months in 2022, which triggered the reduced tea production by more than 33% in Wuyishan. The tea tree is mainly planted on the mountainside and summit. The soil layer is thin and the water evaporates quickly. A continuous dry climate would lead the drought easily. Drought will not only slow down the growth of tea trees but also lead to leaf atrophy, yellow, and fall off, harming the number and quality of buds (the main source of tea). Worst of all, the continuous drought not only affected the quality of tea seriously but also caused the death of many tea trees.

In 2022, artificial irrigate tools, such as water pipes and water wheels, were employed by tea farmers to cope with the sudden drought. However, these traditional means are just a drop in the bucket when face to a long-term drought. According to incomplete statistics, the cost of artificial irrigate is as high as ¥70,000 to ¥100,000 yuan for a tea garden during the drought season. Unfortunately, their effort cannot protect the tea trees from the drought absolutely, not only tea production and quality reduction but also death is inevitable. Mrs. Wu, a farmer in the tea garden, told us that "each tea tree contains the special flavor accumulated over a long period from Wuyishan mountain, which was irrecoverable in 3-5 years from the drought damage".

Fig.3 Members of XMU-China investigated tea plantations in Wuyishan

4.2 Orchard in Xinfeng

Gannan navel orange, a Chinese national protected geographic indication product, originates from the south of Jiangxi province, whose annual output reaches up to 1.5 million tons. The climate of Ganzhou is mild with plenty of light and rainfall, which make it the largest navel orange-producing area and planting area in China and the world, respectively. Xinfeng, a county located in the south of Ganzhou, is the birthplace of navel orange which owns the largest navel orange planting area in Gannan city. However, due to the abnormal climate change in recent years, the local navel orange planting industry has suffered huge losses from frost, drought, and other disasters.

Drought often occurs from July to September in Xinfeng, which is the fast growth period for the navel orange fruit. Once the lack of water, the fruit will grow slowly and atrophic, which will seriously affect the production and quality. To give sufficient water to the fruit trees, 100 acres of fruit trees need 60 tons of water every day. Similar to that of tea trees, artificial irrigate tools, such as water pipe, was employed to water the fruit trees, which won't work during the long-term drought. Drought will harm fruit production and quality and even death of the fruit trees.

Frost often occurs from December to January in Xinfeng, which causes the underground and surface parts of fruit trees to freeze over, bark cracking. The navel orange trees have poor cold resistance ability, the damage to growth and even death would happen when temperature drops to 0 to -3 °C and -3 to -7 °C, respectively. To protect fruit trees from frost damage, farmers generally burn straw to produce smoke and cover the trees with thermal insulation film. However, incineration will produce a lot of toxic and harmful gases, causing environmental pollution and safety problems (fire disasters). It will cost a large workload and money to cover the thermal insulation film.

Fig.4 Members of XMU-China investigated orchards in Xinfeng

4.3 Conclusion

After a survey and references investigation, we learn that global climate change triggers frequent extreme weather events. It was inconceivable to us that drought and frost occur frequently in the cities of southern China, which is warm and humid. Many economic agricultural products, such as tea and navel orange, suffer the negative effects of drought and frost. Unfortunately, the existing approach cannot protect the tea and navel orange trees from drought absolutely, not only production and quality reduction but also the death of the trees is inevitable. So, on the one hand, we need to develop engineered strains to produce biocompatible water-retention material to slow down water evaporation. On the other hand, we need to develop engineered strains to produce antifreeze material that can protect trees from frost.

After the survey, we know that the main cause of drought is the deficiency of the water retention ability of soil. Similarly, water freezing in the soil triggers damage to roots when it comes to frost. Unfortunately, reliance on the current approach will not resolve underlying problems. Thus, we decided to engineer bacteria and combine them with software and hardware equipment to protect agriculture from drought and frost. On one hand, we tried to design engineered strains to produce materials with water retention properties (please see Design for details). based on synthetic biology. On the other hand, we try to construct engineered bacteria to express antifreeze materials based on synthetic biology which can lower the freezing point of water and inhibit the growth of small ice crystals, preventing further damage to roots from ice crystals (please see Design for details).

However, we also faced many intractable problems when turning the design into a practical solution. Thus, we consulted some professors, technicians, and farmers about our project for some advice, which could offer us some design guidance.

Fig.5 Members of XMU-China discussed project design each other

5.2 For drought

How to choose the material with water-retention properties?

Huang Qiang, is a scientist in the School of Environmental Science and Engineering, Jiageng College at Xiamen University. After reading the reference, we knew that he had made efforts to improve the water retention performance, in which sugar cane waste and high-efficiency bacteria were used as a soil amendment to guard against moisture loss. This inspired us to express a material with a strong water retention ability and environmental compatibility, preventing moisture loss around the plant root.

After further literature research and material screening, the crosslinked product of bacterial cellulose and hyaluronic acid, which exhibit excellent water retention performance, was selected as water-retentive material. However, there are many forms of crosslinks product, the spherical one is easier to preserve. So, we began to design the gene circuit to express the bacterial cellulose and hyaluronic acid, respectively. After collection, the crosslinking agent can be added to produce water-retention material.

5.3 For frost

How to choose the material with antifreeze properties?

Before we begin to design the gene circuit to express the antifreeze material, we need to select one that is suitable for orchardists. So, we interviewed Chunsheng Li, an agronomist, to harvest a deep insight into the planting process of navel oranges. Mr. Li told us that frost may cause irreversible damage to the roots and branches of fruit trees. "It is of great significance if your material helps fruit trees to resist the cold at -1 to -2 °C” Mr. Li put forward his expectations for our project. He also believes that a way without digging and laying in the actual process can save a lot of manpower and money. From this interview, we think the antifreeze protein will be a perfect choice to help fruit trees against the cold.

Fig.6 Members of XMU-China were talking with Mr. Li

5.4 Conclusion

Through brainstorming, we decided to develop a new way to present the damage from the sudden drought and frost disasters through synthetic biology, which may reduce their impact on the yield and quality of economic crops (such as tea and navel orange). During the discussion with agricultural experts, they put forward some suggestions for us in the selection of water-retention materials and antifreeze materials. We have learned more about the actual situation in the planting process from the interview, which guided us to determine the final idea.

How to produce and apply the water-retention material?

How to produce water-retention material? How can we let the water-retention material be located in a suitable position in the soil? With these questions in mind, we visited a navel orange farmer and a tea farmer. Mr. Luo is a navel orange farmer in Xinfeng whose orchard is closer to an irrigation water source than others, while he is also suffering from drought. Mr. Luo took us on a grand tour of an advanced sprinkler irrigation system in his orchard, which integrated irrigation with fertilizer equipment. So, we had an idea to design hardware to produce and collect spherical crosslinks products, which could enter the soil (please see Hardware for details).

Fig.7 Members of XMU-China were talking with Mr. Luo

How to apply the water-retention material to the tea blade?

Mr. Wu is a tea farmer in Wuyishan, and we carried out a communication on the water-retention material with him. Mr. Wu told us that navel oranges have thick skin to prevent water evaporation as much as possible. Unlike navel orange, the leaf bud is the most important part of tea, which is the most vulnerable part to drought. So, they need to protect the roots, buds, and leaves of tea. They wish to spray water-retention material on the surface of the leaves in liquid form, just like putting moisturizing cream. This gives us a new perspective, although literature indicates that spherical crosslinking has better water retention performance, the water-retention material forms a colloidal solution in water that is more suitable for application on the surface of tea leaves. If the colloidal crosslinks product is the most appropriate solution, we can greatly simplify the design of the hardware, which may better meet the needs of farmers.

6.2 For frost

When and how to start the production of antifreeze proteins?

After we designed the gene circuit to express antifreeze proteins, a problem presented when and how to regulate the production of antifreeze proteins. In the interview process, Mr. Luo told us that we don't have enough time to start the production of antifreeze proteins over a large area when the frost is on the way. AFPs are a protein, we certainly don't want to produce it too early because it would be degraded and lose its activity. So, we were inspired to develop a temperature control system that responded to low temperatures to regulate the expression of AFPs, which also requires a more elaborate design (please see Design for details).

Would engineered bacteria be washed away by irrigation water or rainwater?

In the interview process, Mr. Luo also told us that rain increases as they enter autumn and winter. So, he wondered whether engineered bacteria would be washed away by irrigation water or rainwater. It is a practical problem that could happen with a high probability and will be overlooked in the laboratory. To avoid irrigation water or rainwater washing away our engineered bacteria, we plan to make them bind to the surface of crop roots and blades. After investigation, we found that the surface of most crop roots and blades contains cellulose. Thus, we try to display a cellulose-binding module (CBM), a class of proteins with cellulose-binding function to the surface of engineered bacteria (please see Design for details).

6.3 For bio-safety

How to conduct human practice following bioethics

To ensure that our communication with ordinary farmers is in line with the ethical requirements, we have had an in-depth face-to-face discussion with Lyu Jianwei, a teacher from Xiamen University, on biosafety ethics. Professor Lyu Jianwei's were interests in biotechnology law and ethics, biotechnology governance, and biotechnology intellectual property rights. Professor Lyu gave us a lot of advice to ensure that our project is accepted by the public and conforms to safety ethics. He told us that we must keep the public informed, which is also the most important rule throughout our HP activities. The discussion made us realize that we must always be responsible for the world, which is not only the responsibility of a scientific researcher but also involves many legal and regulatory issues.

Fig.8 Members of XMU-China were talking with Professor Lu Jianwei

How to protect the environment from the potential threat of our engineered strains?

Biosafety design is necessary to protect the environment from the potential threat of our engineered strains. The proposed implement environment of the project this year is soil (please see Proposed Implement for details). Therefore, we must not only consider the suicide gene circuit to keep engineered strains from escaping the working environment but also design the module to prevent gene exchange between engineered strains and other bacteria in the soil. Thus, we designed a toxin-bactericidal system and a toxin-antitoxin system (please see Safety for details).

We interviewed with Professor Wang Dai to discuss the biosafety problem in our design. "As a Gram-negative bacterium, E. coli can easily exchange genes with other strains species." Professor Wang Dai told us that the design of the toxin-antitoxin system may not be able to fully achieve our purpose of preventing horizontal gene transfer (HGT). He suggests that we can set toxin genes in a location close to the plasmid antibiotic site, which can improve the efficiency of preventing HGT.

In fact, the best choice is that transfer all our genes to the genome of the chassis. However, this is a grand project, and it is difficult for us to complete in the limited time of the 2023 season. But to achieve our goal, we will continue our efforts in the future work.

Fig.9 Members of XMU-China were talking with Professor Dai Wang

6.4 Conclusion

In the implementation process of the project, we further communicate with farmers to make the experimental program closer to the actual working environment. They raised many questions about our project. How to produce materials and apply them against frost and drought damage? How to apply them to different parts of the crop? How to avoid biosafety issues? Based on communication, we optimize the experimental program continuously according to the actual situation.

We went to the tea garden again to collect information from the farmers about the usage experience of the hardware in a real environment. "What should I do if I can't connect to the network?" Because these farmers are not proficient in using the internet, they have raised concerns. So, we have further upgraded the hardware, which can connect to the network by itself. We even equipped the hardware with an Internet of Things card, which makes the hardware more stable.

After upgrading the hardware design constantly, we got good feedback from farmers. " The drought alerts are particularly well designed, and if we have this in the field, we will not worry about the watering every day." Mr. Lyu said so. Of course, hardware design is the key step for the application of our project, we will continue to improve the hardware so that it can better meet the needs of farmers.

Fig.10 Members of XMU-China test hardware in a tea plantation

7.2 Collaborate with government agencies

As the government department in charge of hydrological monitoring and water conservancy dispatching, the Xiamen Municipal Water Resources Bureau can not only predict the occurrence of drought through indicators such as rainfall, climate early warning system, reservoir level and evaporation, but also build sound water conservancy projects to ease water resource dispatching during drought. The Wuyishan Meteorological Bureau has taken some measures to prevent and cope with drought and frost damage, such as establishing meteorological observation stations, installing automatic measuring and reporting systems, issuing early warning information, and providing technical guidance. We visited the Meteorological Bureau and the Water Resources Bureau to introduce them to the impact of sudden drought and frost disasters on tea and navel oranges. We further describe the loss of cash crops from drought and frost disasters and the limitations of mainly targeted treatment measures. Finally, we show them that we attempt to construct the engineered strains to synthesize water-retention and antifreeze materials based on synthetic biological methods to reduce the economic losses caused by sudden drought and frost disasters. Our human practice activities and solutions provided have been recognized by government departments, who have high hopes for our research results. Finally, we hope to bridge the gap between farmers and governments, through which to contribute against drought and frost disasters by collaborating with government agencies.

Fig.11 Members of XMU-China were communicating with government staff

7.3 Raise public awareness of environmental protection and synthetic biology

We conducted a face-to-face communication with the public at the Xiamen Science and Technology Museum, by which to let the public understand the negative impact of extreme climate disasters on agricultural production using shocking images. We call on the public to pay attention to climate change in their daily activities and make their contributions to protecting the environment and saving water. In this activity, we not only introduced the development and application of synthetic biology to the public but also described XMU-China's attempts to alleviate the impact of sudden drought and frost on agricultural production through synthetic biology this year. A series of small games are designed to stimulate children's interest in synthetic biology and increase the public's understanding of synthetic biology. Hereby, call on everyone to join hands to create a better living environment in the future.

Fig.12 Members of XMU-China introduced the project at the Xiamen Science and Technology Museum

7.4 Raise enterprise concern of synthetic biology technology

Once the project is complete, we try to understand the gap between our research and the industry. At the same time, it also allows more companies to pay attention to the excellent performance of synthetic biotechnology in solving practical problems. Therefore, we contacted the excellent biological agent enterprise in China, Sanju Biology, and conducted in-depth communications. During the communications, we introduced our projects and discussed the questions related to the development, production, and marketing of bioproducts. The staff of Sanju Biology highly praised our research results but also pointed out that there is still a big gap from industrialization. For example, the form of the product. Solid products are more convenient to sell, transport, and use, while liquid products can better maintain the activity of bacterial metabolites. Thus, we learned about the gap between industrial production and laboratory scale, and companies will be more concerned about the powerful tool of synthetic biology. Finally, we also reached an initial intention to cooperate with the staff of Sanju Biology, laying the foundation for applying our research results to solve the damage caused by drought and frost as soon as possible.

Fig.13 Members of XMU-China were communicating with enterprise technicians

7.5 Conclusion

In this process, we conducted interviews with the farmers, government agencies, the public, and enterprises, respectively. First, we feedback on the improved hardware to the farmer to collect the information of usage experience. Second, the damage reports of sudden drought and frost disasters on economic crops were feedback to the government agencies, which can contribute against drought and frost disasters through collaboration with government agencies. Third, the damage information was also feedback to the public to not only raise their awareness of environmental protection but also increase their understanding of the power of synthetic biology. Lastly, we feedback on the research results to the enterprise to search for cooperation, laying the foundation for applying our research results to solve the damage caused by drought and frost as soon as possible.

We hope that through our integrated human practice, more people from different roles (farmer, government agencies, public, and enterprise) can pay attention to the damage caused by drought and frost, and more people can devote themselves to this field to solve this problem.