In order to love coming to China, Professor Yang used ＂biological doctors＂ to save abandoned mines.

Austin Battersea Stehelin, a Swiss professor at the School of Life Sciences, Sun Yat-sen University, and Xie Zhiping, an associate professor at the School of Life Sciences, Sun Yat-sen University, Yangcheng Evening News reporter Huang Yijun.　

Austin Battersea Stehelin was awarded the 2019 China Government Friendship Award (photo courtesy of the respondent).

　　On the afternoon of September 30th, the awarding ceremony of 2019 China Government Friendship Award was held in the Great Hall of the People. According to the news released by the Science and Technology Department of Guangdong Province, a total of seven foreign high-end experts were selected in Guangdong this time, and the number of selected experts was the highest in the past years. Among the seven experts, there is Christian Balthasar Staehelin, a full-time professor of Sun Yat-sen University, an academic leader of the State Key Laboratory of Pest Control and Resource Utilization, who is committed to studying plant genetic resources and genetic improvement.

　　Fourteen years ago, the Swiss Austin Battersea Stehelin and his wife Xie Zhiping from China traveled across the ocean to the School of Life Sciences of Sun Yat-sen University, bringing the international cutting-edge biological nitrogen fixation technology.

　　They provided more than 100 valuable rhizobia germplasm resources to China free of charge, uncovered the "language code" between these microorganisms and leguminous plants, created a "vanguard" of microorganisms and leguminous plants for soil remediation, and used green methods to make polluted mines return to green mountains.

　　Recently, the reporter interviewed the couple exclusively and listened to their stories about Professor Yang’s feelings in China.

　　A

　　Bring cutting-edge technology and valuable strains.

　　Nitrogen is one of the essential nutrients for plant growth. There is nearly 80% nitrogen in the atmosphere on the earth’s surface, but plants can’t absorb it directly from the air. At present, industrial chemical fertilizer is the most common nitrogen fixation method. However, only one-third of the nitrogen in chemical fertilizer can be absorbed by plants, and the remaining two-thirds remain in nature, causing problems such as soil hardening, water pollution, eutrophication of water bodies and increase of greenhouse gases.

　　Is there a more environmentally friendly way to make plants thrive? Austin Battersea Stehelin spent 30 years studying a group of microorganisms called rhizobia.

　　In China, this Swiss professor has a kind name — — "Old history". Walking into the plant room of the laboratory and picking up a Japanese lotus root, Lao Shi excitedly pointed to the tumors the size of rice grains between the plant roots in the culture solution and said, "Look, this is the nodule."

　　The mystery of plant growth lies in these small "rice grains".

　　When the right rhizobia meet the right plants, they can "talk" and coexist — — Rhizobia absorb nitrogen from the air and provide it to plants, and plants provide carbohydrates for rhizobia.

　　Once their "language code" is cracked, Lao Shi can accurately select rhizobia according to the needs of different plants and fix the nitrogen in the air on the roots of plants. Almost all of the nitrogen fixed by nodules will be absorbed by plants. In this way, no matter how harsh the environment is, as long as there is air, plants can thrive. This is the secret of biological nitrogen fixation.

　　It is not easy to find the right rhizobia. Lao Shi told reporters that in the current research, rhizobia can only interact with leguminous plants, and the bacteria that can successfully form nodules are even rarer. In China, this research is still very unpopular because of the high technical threshold and difficult strain screening.

　　In 2005, the old Shi Xuan and his wife Xie Zhiping, who are well-known in the international biological nitrogen fixation academic circles, both came to China to teach at Sun Yat-sen University. At the same time, he put his years of research efforts — — More than 100 rhizobia germplasm resources and effective technology for extracting nodulation factors were provided to China free of charge.

　　The broad-spectrum rhizobia 234 brought by him has been used as the "standard/control" bacteria for scientific research by many domestic research institutions, and the nodulation factor extracted has also been used as the "key" scientific research element for many scientific research institutions. He brought the latest scientific research ideas to China, which opened up a new prospect of nitrogen-fixing scientific research in China, and was recommended as the project leader of the National Key Basic Research Development Plan (973 Plan) (Molecular Mechanism of Nitrogen-fixing Nodules in Leguminosae Plants).

　　B

　　Couples work together to study soil pollution remediation.

　　Basic research is very boring. This bench has been used by Lao Shi for 30 years, and nearly half of the time has been spent in China.

　　"He likes doing scientific research and can sit still in the laboratory." Xie Zhiping, the wife of Lao Shi and an associate professor at the School of Life Sciences of Sun Yat-sen University, laughed.

　　The love story between Lao Shi and Xie Zhiping is romantic in the ordinary. Xie Zhiping is a native of Guangzhou. She studied in Guangdong Experimental Middle School in middle school and graduated from Sun Yat-sen University. She studied for a master’s degree and a doctor’s degree in university of basel, the oldest Swiss city, and got to know the old history. After graduating from Ph.D., Lao Shi went to the French National Academy of Sciences for postdoctoral research, and then returned to work at the University of Geneva.

　　In a foreign country, Xie Zhi often misses his hometown. She proposed that she wanted to return to China and her alma mater, Sun Yat-sen University. "Guangzhou is your home, that is my home, let’s go together!" Lao Shi said.

　　In 2005, "Professor Yang" really came. Xie Zhiping told reporters that at that time, there were very few western scientists introduced in China, and Lao Shi was the first full-time foreign professor introduced by Sun Yat-sen University.

　　Fourteen years ago, domestic scientific research conditions could not be compared with those in Europe at that time. At that time, Guangzhou University Town had just been completed, and the hot summer in Lingnan made it difficult for the old history who grew up in Europe to adapt. Air conditioning became his "life-saving straw".

　　Back in the lab, everything started from scratch. Mr. and Mrs. Lao Shi took the students to design their own molds for cultivating plants and build greenhouses.

　　"Before coming to China, many people told me that China was too far away. But in my research world, China’s laboratory is no different from foreign laboratories. " Lao Shi told reporters. With the support of Sun Yat-sen University, the laboratory gradually took shape, and an interdisciplinary research team including botany, microbiology, biochemistry and molecular biology was established. Lao Shi also instructed team members to publish more than 50 high-level papers in international academic journals.

　　"We like nature very much and hope to do something when we see that the environment is polluted." Lao Shi said.

　　To this end, the couple often take their students to collect soil samples in the wild, and go wherever they are "dirty". The reporter saw that there were polluted river sludge, extremely acidic polluted mineral soil, extremely salty sea sand and barren desert soil in the laboratory. They used these soils, added rhizobia, planted all kinds of leguminous plants, and explored the interaction between rhizobia and rice, corn and other crops to meet the needs of various soils and even sewage treatment.

　　C

　　Willing to contribute to environmental protection in China.

　　According to Lao Shi, every tiny nodule is a natural "garbage disposal plant" and "microbial hospital". Some rhizobia can absorb heavy metals in polluted soil; Some can fix nitrogen in nutrient-free soil to promote plant growth.

　　Three years ago, with the full support of Sun Yat-sen University and Kangtai Minsheng Environmental Science Research Institute, Lao Shi and his wife chose a 30-mu abandoned rare earth mining area in Ganzhou, Jiangxi Province to carry out soil remediation experiments. It was a devastated piece of rare earth tailings. Rare earth mining seriously damaged the original ecology of the mine, resulting in soil erosion, serious pollution of downstream rivers and lakes and groundwater, and deterioration of the ecological environment. The strong acid soaking in the process of rare earth mining almost made this land lose its vitality — — The soil desertification is serious and extremely barren, the ability of water and fertilizer conservation is poor, the organic matter and other soil essential elements are lacking, and the soil microbial diversity is seriously damaged.

　　"Almost no plants can grow in such bad soil." This is the first impression left by the field trip to the couple.

　　The local people tried to repair it. They used the most primitive "alien soil method". They transported good soil from other places to cover the polluted soil with a thickness of about 30 cm, and then planted plants. This method treats the symptoms rather than the root cause. After the restoration, the first batch of plants are planted and die soon, and then they are planted again, and so on. The cost of repairing an acre of land alone will cost tens of thousands of yuan.

　　Mr. and Mrs. Lao Shi did an experiment with biological nitrogen fixation: Stylosanthes leguminosa was planted here as a "pioneer" and supplemented with corresponding rhizobia to "cure the disease" for this soil. What is the actual effect? Three years later, Lao Shi went to see it again. Not only did Stylosanthes grow lush, but the pine trees originally planted here also survived, growing four or five meters high. "With the joint action of rhizobia and nitrogen-fixing plants, this soil has returned to health and other plants can grow well."

　　Now, Lao Shi and his team have chosen a new pilot and brought this "vanguard" to Dabaoshan Mine in Shaoguan, Guangdong Province, to pilot soil remediation. Xie Zhiping told reporters that they are still trying to purify sewage with rhizobia and leguminous plants in the laboratory. "Sewage is actually eutrophic. Leguminous plants with rhizobia can absorb nutrients and toxic molecules in sewage. Once the plants are pulled out, the water will be clearer."

　　Scientists have no borders, and scientific research never stops. Living in China for 14 years has turned Lao Shi from a foreigner who is afraid of heat into a "Guangzhou son-in-law" who can speak a few Cantonese. More and more, he found that his research is very useful for China, especially for environmental governance.

　　"The ultimate goal of scientific research is to serve the society." Lao Shi often warns students, "Do scientific research well, you can’t waste taxpayers’ money, you must give back to the society."

　　"We don’t want to just put knowledge in the laboratory. We have the responsibility and obligation to make some contributions to China and human society." He said.

　　After winning the Friendship Award this time, Lao Shi said: "It is a great honor to be awarded the Friendship Award of the China Municipal Government. I will continue to make efforts to contribute to the green mountains and green hills of China." (Yangcheng Evening News reporter Zhang Luyao)