标签归档 上海夜网

Liu Xi is in the field, checking the rice varieties. The picture is provided by myself.

　　Where there is attack, there is defense. The war in the plant kingdom is the same as the war in human beings. Rice has accumulated rich combat experience in the evolution of hundreds of millions of years. How does it stimulate the immune system to start fighting? Who is the sentry in the face of the heavy pressure of rice blast fungus? How did they transmit military information to resist aggression after discovering the enemy’s situation? What tactics does rice use to fight?

　　After eight years of in-depth research, the team of Academician Wan Jianmin of Nanjing Agricultural University successfully cloned a new gene OsCNGC9 for regulating innate immunity of rice by methods of mutant identification, genetic analysis and gene mapping, revealing the molecular mechanism of the gene affecting rice blast resistance at seedling stage, discovering the inherent nature of rice relying on calcium channels to stimulate its own immune system to resist rice blast, and unveiling the mystery of rice war against rice blast. A few days ago, related research results were published online in the international authoritative academic journal Cell Research.

　　The beauty expert chose an ugly guy.

　　Liu Xi, an associate researcher at Nanjing Agricultural University, frowned when he saw brown necrotic spots on eight rice leaves, just like senile spots. As a breeding expert, he is in a beauty contest, and he likes the beautiful rice with "green stems and yellow seeds". These plants must be eliminated.

　　He didn’t expect that these eight diseased seedlings infected with rice blast, like those wild rice plants discovered by Yuan Longping, would become his most important scientific discovery at present, which opened a new milestone in the field of rice research.

　　It was a day in March, 2011, and he reviewed his more than 100,000 soldiers at Hainan Breeding Base — — More than 100,000 rice plants were heading at that time. Like a farmer, Liu Xi’s face is tanned. In order to speed up the breeding progress, like a migratory bird, he cultivates rice in Hainan in winter and Nanjing in summer.

　　Liu Xi planted more than 10 mu of rice in Hainan. There are too many rice materials, including 3,000 or 4,000 different kinds of breeding materials, and one material grows 40 seedlings. Every day, he has to observe, take photos and record in the field. He remembers the name, number and appearance of each rice plant, and he visits each rice plant at least four times a month.

　　These eight plants are nothing, and only a few varieties of three or four thousand rice seeds can be selected and propagated in the end.

　　A few days later, he saw these eight ugly guys again. "Age spots" are spreading, and their growth is also very poor, and they are a little short. He decided to wait a little longer to see.

　　A month later, although the "age spots" of these eight ugly guys continued to expand, they did not die, but they also bore fruit like other normal rice, although they were slightly thin.

　　What makes these eight rice plants look so ugly? Looking at the handsome companions next to the ugly guy, Liu Xi fell into deep thought and began to pay attention to them. When the harvest came, he harvested these eight ugly guys alone and took them back to Nanjing to continue planting.

　　Growing this generation in Nanjing, the ugly guy is not obvious. Liu Xi didn’t lose heart. It seems that this guy is a recessive gene control like a single eyelid. He decided to keep planting and see what the ugly guy was like.

　　It has been planted for two generations in a row. After continuous self-homozygosity, the ugly guy’s "ugly appearance" has finally been stably inherited, and features such as "senile plaque" have appeared continuously. Like the first generation, although ugly, they can all survive and breed offspring.

　　At the beginning of 2013, Liu Xi reported it to Academician Wan Jianmin as a new mutant material. Academician Wan Jianmin decided to start the research as a project.

　　Determining the identity of disease-resistant heroes by gene mapping

　　This project was given to Wang Jiachang, a 23-year-old young man, who was studying for a master’s degree at Nanjing Agricultural University. Professor Wang Yihua, the instructor, told him that it is no problem to graduate from this project, but what kind of discovery you can make depends on yourself.

　　Wang Jiachang didn’t expect this project to produce great results. His plan at that time was that as long as the doctor could graduate smoothly and find a good job.

　　After getting this special rice material, Wang Jiachang began to analyze it in detail by means of genetics and molecular biology.

　　Judging from the performance of field growth, the ugly guy began to become ugly after heading of rice — — When I was a child, ugly guys were not ugly, just like normal rice.

　　Through genetic analysis, Liu Xi found that 1/4 of the second generation of cross between ugly guy and normal companion had the phenotype of ugly guy. According to Mendel’s genetic law, it is a recessive gene that controls the ugliness of ugly guys, which is the same as Liu Xi’s previous guess.

　　Do genetic mapping first. Wang Jiachang and Liu Xi compared the ugly guy’s 12 chromosomes with normal varieties and screened them one by one to see which gene had a mutation.

　　Scientific research is very boring. There are more than 30,000 genes in rice. According to the house number of chromosome — — Molecular markers, finally found a different chromosome fragment on the ninth chromosome.

　　After getting this clip, the two began to go to the house to search for the hidden murderer who caused the ugly guy to be "ugly".

　　They used biochemical methods to analyze and found that a normal gene that turned out to be an ugly guy was seriously damaged and lost its function! According to the characteristics of this normal gene and the naming rules of biology, they gave this gene a name — — OsCNGC9 (A Jiu for short).

　　In organisms, the ion channel is like a city gate, which is guarded by a special person. All kinds of ions can go where they want to go through a special channel. They found that calcium ions prefer to walk the gate guarded by A Jiu.

　　Wang Jiachang is a little confused: What is the relationship between calcium ion, A Jiu and ugly guys’ "ugliness"? Which direction should we study? He began to consult all kinds of documents. In two years, he has been groping: what affects the fertility of rice? Or caused the aging of rice? It may also affect its plant height traits? What is the relationship between phenotypic traits such as "senile plaque", short stature and few offspring?

　　Two years later, several research directions of concern have not achieved good results, and Wang Jiachang is very anxious. In the second half of 2015, when he read the literature, he found that a large number of calcium ions would transmit defense information to cells during plant disease resistance, and calcium ions were recognized as the second messenger (the first messenger was plant hormone — — However, scientists in the field of plant disease resistance have always been curious about which channel the "communication soldier" calcium ion came in from.

　　The "senile plaque" on this ugly guy is the performance feature of many important immune genes. Did A Jiu affect the information transmission? Is it guarding the calcium channel?

　　Rice blast is a cancer of rice. The attacked rice suffered heavy casualties, ranging from 20% reduction in yield to no grain harvest. According to the data of the Ministry of Agriculture, in recent years, rice blast has caused more than 3 billion kilograms of food losses to China every year, and the annual loss of food in the world can feed 60 million people for one year.

　　When he put forward the research direction of rice blast, Academician Wan, the tutor, was very interested and gave him some suggestions to support him to continue his research. Combined with years of field observation, Liu Xi also supports this direction.

　　Wang Jiachang first analyzed whether A Jiu has resistance to rice blast. In order to avoid the influence of other factors such as "senile plaque" on the resistance analysis of rice blast, they chose to analyze the resistance of ugly guy who has not become ugly, and found that his disease resistance is very poor, his immunity is low, and A Jiu is closely related to calcium ions.

　　Heroic feats of disease-resistant heroes

　　What needs to be studied is: Is the "city gate" on duty in A Jiu a dedicated channel for calcium ions? To confirm this conclusion, electrophysiological experiments need to be carried out in animal cells. An interdisciplinary research problem is in front of them. Wang Jiachang has been studying plants and suddenly turned to the field of zoology, feeling blind.

　　At this time, the Institute of Plant Physiology and Ecology, Shanghai Institute of Life Sciences, Chinese Academy of Sciences, provided him with help to transform A Jiu into human embryonic kidney cells: if A Jiu is on duty for calcium channels, there will be obvious current formed by calcium ions after applying voltage inside and outside the cells.

　　As expected, when the voltage is applied to -200 mV, the current reaches -100 pA, which confirms that A Jiu is a dedicated channel for calcium ions.

　　In the process of plant disease resistance, does calcium also take this channel? After a series of physiological and biochemical experiments, it was found that because of A Jiu’s "sacrifice", no one opened the city gate, the calcium ion channel lost its function, and the calcium ion of the "communication soldier" could not enter the city to transmit military intelligence, which led to the lax defense in the city and no one took up the battle. The researchers found that other immune indexes of ugly guy were lower than those of normal rice. This shows that A Jiu is the "intelligence officer" who is on duty for the special military intelligence channel, and they give it a formal name — — Cyclic nucleotide ion channel 9.

　　At this time, another question appeared in their minds. The calcium ion of the "communication soldier" entered the city to transmit military intelligence. Who reported to the "intelligence officer" A Jiu to let the calcium ion of the "communication soldier" enter the city smoothly and set off an alarm to start the immune response? Through a series of biochemical experiments, they found another gene OsRLCK185 (referred to as "Awu") which regulates disease resistance. When "Awu" the sentry found the signal of foreign invasion, he quickly reported it to "intelligence officer" A Jiu, and A Jiu opened the "city gate" to allow "communication soldier" calcium ions to assemble in cells, so that the rice center started an immune response and enhanced rice disease resistance.

　　A battle process gradually formed in the minds of researchers. A Jiu, the "intelligence officer", played a vital role in the battle between rice and Magnaporthe grisea. Academician Wan Jianmin, the correspondent of the article, gave a vivid metaphor to the reporter. This series of processes is like an "offensive and defensive battle". Previously, researchers only saw the "communication soldiers" and knew little about how the previous "intelligence officers" and "sentries" played their roles.

　　This experiment has opened up a new research field, and discovered the calcium channel through the new gene, which is an immune signal transmission path from pathogen identification to calcium channel activation, and revealed the role of the new gene (OsCNGC9) in calcium ion elevation and rice disease resistance, providing important materials and theoretical basis for rice rice rice breeding against rice blast.

　　In order to study whether A Jiu, a hero of disease resistance, has the potential to improve rice blast resistance. The researchers used transgenic methods to verify it. A Jiu, a hero of disease resistance, was transferred to normal rice varieties to observe the change of disease resistance.

　　"In fact, it is to add more disease-resistant genes to rice cells, which is equivalent to adding several special military intelligence transmission channels." Wang Jiachang explained.

　　The next step is to continue the differentiation of cells containing new genes, cultivate rice seedlings, inoculate rice seedlings with Magnaporthe grisea and observe its growth and changes. The experiment was successful, and the new gene can significantly improve the disease resistance of rice, and the statistical analysis of the data is very significant.

　　Professor Ling Chiang, the assistant of Academician Wan Jianmin, said that this project is interdisciplinary and cross-platform, and has been supported by the Institute of Crop Science of Chinese Academy of Agricultural Sciences, the Institute of Plant Physiology and Ecology of Shanghai Institute of Life Sciences of Chinese Academy of Sciences, and the Institute of Genetics and Developmental Biology of Chinese Academy of Sciences.

　　The scientific community pays close attention to the research results of "calcium channel". Wan Jianmin believes that this achievement provides an important material and theoretical basis for rice blast resistance breeding.

　　Dr. Wang Jiachang, the co-first author of the article and Nanjing Agricultural University, told the reporter that he would continue to study the function of calcium channels in plants. "This project has changed my life plan." (China Youth Daily China Youth Network reporter Li Runwen correspondent Xu Tianying)

　　Xinhua News Agency, Beijing, September 19th(International observation) China can’t solve the "poison disaster" of the United States — — The abuse of fentanyl in the United States

　　Xinhua News Agency reporter Zhu Ruiqing Qiu Xia

　　US President Biden recently announced that more than 20 countries, including China, will be listed as "major drug transit countries or major illegal drug producers". In this regard, a spokesman for the Ministry of Foreign Affairs of China said a few days ago that the so-called determination by the US side is groundless and is a malicious smear. China firmly opposes this and has made solemn representations to the US side.

　　In recent years, drug abuse has surpassed gun violence and car accidents, and has become the main cause of accidental death in Americans. Among them, the abuse of opioid drugs such as fentanyl is the most serious. The United States accounts for only 5% of the world’s population, but it consumes 80% of the world’s opioids. It can be described as a black hole and chaotic source of global drug control, and it is a dominant "major drug demand country". The root of the problem of fentanyl abuse lies in domestic factors such as lax supervision of psychotropic drugs in the United States, collusion between government and business, and political polarization hindering the anti-drug process. However, American politicians try to shift contradictions to the outside world and "throw the pot" at China.

　　Forcing others to "take medicine" cannot cure their own "illness", as Al Jazeera said, "This is a disaster made by the United States itself".

　　This is the White House filmed in Washington, DC on January 20th. Xinhua News Agency reporter Liu Jie photo

　　Why are opioids rampant in the United States?

　　Fentanyl was synthesized in the 1960s, and it was the first fentanyl used in clinic. After it came out, it was quickly popularized and applied in the field of clinical anesthesia and pain treatment. It once became the main drug used in anesthesia surgery, and it was also the first choice for pain treatment, especially for postoperative analgesia. After fentanyl, a series of new analgesics such as sufentanil, alfentanil and remifentanil appeared in the fentanyl family. So far, fentanyl is still the main auxiliary drug of general anesthesia and widely used postoperative analgesic.

　　As a medicine, fentanyl can relieve pain for countless patients with its good effect. But in the United States, it has become a drug that harms society.

　　According to the data from the Centers for Disease Control and Prevention, fentanyl-based opioids are the main cause of overdose death in the United States. In the past ten years, the number of deaths caused by such drugs has increased by about three times. In 2021, this number surged to more than 80,000, more than 10 times the number of American soldiers killed in the wars in Iraq and Afghanistan.

　　In fact, there have been three waves of opioid abuse in American society, and fentanyl is only the "protagonist" of the third wave. The first wave of abuse began around 1991. At that time, some pharmaceutical companies invested a lot of money to support relevant experts and institutions, peddled the "theory of harmlessness of opioids", encouraged doctors to prescribe more prescriptions and pharmacies to vigorously promote them.

　　On November 10, 2022, in Washington, DC, an airplane flew over the American flag. Xinhua News Agency reporter Liu Jie photo

　　On the one hand, this practice has formed an "analgesic culture" in American society, and people are accustomed to using painkillers to treat diseases. On the other hand, it has led to a sharp increase in the prescription of opioids at that time and a rapid increase in the number of deaths caused by opioids. The most typical example is Oxycontin, a drug developed by Purdue Pharmaceutical Company in the United States at that time. From 1999 to 2017, a total of 200,000 Americans died from overdose related to Oxycontin and other prescription opioids. In the end, Purdue Pharmaceutical was sued.

　　The second wave of drug abuse began around 2010. At that time, prescription opioids became difficult to obtain, and people turned their attention to heroin — — A lower cost and more powerful opioid drug. According to the data of the US Centers for Disease Control and Prevention, the number of deaths caused by heroin overdose has increased rapidly since 2010. From 2010 to 2014, the death rate of heroin overdose among white Americans increased by 267%, African Americans by 213% and Latinos by 137%.

　　The third wave is the ongoing abuse of fentanyl. In recent years, fentanyl has become more and more popular among American drug addicts. According to data from the US Centers for Disease Control and Prevention, from August 2021 to August 2022, drug overdose claimed more than 100,000 lives, about two-thirds of which were caused by opioid drugs mainly fentanyl.

　　Looking back at the above three waves of abuse, it is not difficult to find that the addiction of abused drugs is stronger every time. And every wave of abuse paves the way for the next wave of more serious abuse, deepening America’s addiction to drugs again and again.

　　"It’s too late to put the devil in a bottle" and "the raging fire has broken through the fire line", which is how Anne Case, a professor at Princeton University, and angus deaton, a Nobel laureate in economics, described the problem of opium abuse in the United States in their book What’s wrong with America: Desperate Death and the Future of Capitalism. The book reads: "Opioid drugs have become an anesthetic for the public."

　　Pharmaceutical companies are deeply linked with politicians, so how to supervise them?

　　Under the pressure of public opinion, the US government has also taken actions to deal with drug abuse in the past few decades. For example, during the administration of former President Obama, he signed the 21st Century Cure Act, and spent $1 billion to deal with the abuse crisis of opioid prescription drugs used to treat moderate and severe pain. Trump took this issue as one of the priorities of the White House after taking office, and once listed the opioid crisis as a "national emergency"; Biden’s administration listed the problem of drug addiction as part of its "unity agenda", and listed the problem of mixing fentanyl with the non-opioid sedative toluene thiazide as the "latest threat" in the United States.

　　However, even so, why is drug abuse still banned in the United States? Why do addicts always find substitutes again and again? The fundamental reason is that American politicians, for their own interests and other reasons, always introduce anti-drug policies that treat the symptoms rather than the root causes, and are unwilling to implement drug supervision.

　　On the one hand, politicians get a lot of political contributions from pharmaceutical companies. In exchange, politicians need to "turn a blind eye" when formulating relevant drug control policies. As a result, the United States, as a big country of chemical raw materials in the world, has not yet managed fentanyl permanently.

　　According to a report in 2017 by the British newspaper The Guardian, over the past decade, pharmaceutical companies have invested nearly $2.5 billion in lobbying and funding US congressmen. About 90% of the U.S. House of Representatives and 97 of all 100 U.S. senators have received campaign donations from pharmaceutical companies, which seek to influence legislation on everything from the cost of drugs to the way new drugs are approved. In addition, in the American medical system, medical representatives play a great role. They encourage doctors to prescribe drugs by giving lectures and funding, which has caused many people to become addicted to drugs.

　　This is the capitol in Washington, DC, on January 19th. Xinhua News Agency (photo by Shen Ting)

　　Gao Jingzhu, a former assistant secretary of the US Department of Health and Human Services and a professor at Harvard University’s Chen Zengxi School of Public Health, pointed out that donations from opioid manufacturers to politicians continue to influence policy decisions. At the same time, retired officials from some government regulatory agencies often join the pharmaceutical industry, with almost no "cooling-off period". "This (drug abuse) crisis represents a multi-system regulatory failure."

　　On the other hand, political polarization hinders the drug control process. In view of the serious abuse of fentanyl in the United States, both parties in the United States admit that efforts need to be made to deal with this problem, but the two sides are "stumbling blocks" to each other and are unwilling to let the other side become the "hero" to solve this problem. Just in May this year, the Republican-controlled U.S. House of Representatives voted to consider the "Stop Trafficking in Fatal Fentanyl Act", and 133 members of the House of Representatives voted against it, 132 of whom were from the Democratic Party.

　　According to a report in Washington post, the US Congress didn’t pass a bill specifically for fentanyl until December 2017. However, it was nearly four years since legislators first received warnings about the dangers of this drug. "Congress has become incompetent and unable to meet the challenges of our time. Fentanyl is the latest example."

　　Treating internal diseases externally will only harm others and themselves.

　　Faced with the increasing abuse of fentanyl in the United States, the American government and politicians have done nothing in reducing domestic drug demand, strengthening the control of prescription drugs, and strengthening publicity and education on drug hazards. In response to the pressure of public opinion, they played "traditional skills" — — "Dumping the pot" abroad, and the main target of "dumping the pot" is China.

　　In recent years, the United States has repeatedly accused China of drug control, saying that "China imported a large amount of fentanyl into the United States" and "China chemicals flowed into Mexico to make fentanyl and then flowed into the United States", demanding that China "help crack down on the illegal trade of fentanyl". Recently, the United States frequently sued and sanctioned some enterprises in China and several citizens in China for allegedly producing and selling chemical precursors and related equipment involving fentanyl.

　　Some politicians in the United States always try to make China take the blame for the fentanyl problem and dress himself up as a "victim", but the American statement simply doesn’t hold water.

　　China has always held a "zero tolerance" attitude towards drugs, adopting the strictest control and the severest punishment. Fentanyl has never been abused on a scale outside the United States.

　　China is not only effective in drug control at home, but also always helps the international community, including the United States, to deal with the abuse of fentanyl in a humanitarian and responsible manner. In May 2019, China took the lead in arranging fentanyl substances in the whole world. According to the notification from the US Customs and Border Protection and other anti-drug law enforcement agencies, since September 2019, the US has not seized fentanyl from China.

　　China has also earnestly fulfilled its obligations under the 1988 Convention of the United Nations, and implemented an import and export licensing and international verification system for all listed chemicals, effectively preventing listed chemicals from flowing into the drug-making channels through international trade.

　　The United States sued and sanctioned China enterprises and citizens for allegedly producing and selling fentanyl-related chemical precursors and related equipment. However, these substances and equipment are non-listed chemicals and equipment and have a wide range of legal uses. According to international practice and common practice, it is the basic responsibility of the importing enterprise and the legal obligation of the importing government to ensure that the goods in international trade are not used for illegal purposes. The responsibilities that should be borne by the importer should not be imposed on the exporter.

　　With regard to the so-called fentanyl precursor flowing from China to Mexico, which was previously hyped by the US, the actual situation is that China has never received the relevant information from Mexico about "China precursor chemicals exported to Mexico for manufacturing drugs", and the US has never provided the factual basis for China chemicals flowing into Mexico to make fentanyl.

　　The above facts fully show that the relevant accusations made by the United States against China on the issue of fentanyl are unreasonable, and its purpose is to mislead the public and pass on the responsibility for its poor governance. As China’s Ministry of Foreign Affairs pointed out, "’s attempt to solve its concerns on drug control through pressure, coercion and illegal means is actually to treat internal diseases from outside, which will not work and will only harm others.".