Tian Zhixi: Douzhi is soaring, saline -alkali land in the scent of beancurd

Author:CC forum Time:2022.09.23

Taoists, natural laws, all things are followed here, as well as beans; Scientific exploration is not only the development law of nature, but also the persistence of forever in constant setbacks.

Tian Zhixi

Researcher at the Institute of Genetics and Development Biology, Chinese Academy of Sciences

2021 Science Exploration Award winner

I am Tian Zhixi from the Institute of Genetics and Development of the Chinese Academy of Sciences. Today I want to share with you the story of "Douzhi", and it is also our thinking and exploration of the dilemma of the soybean crisis.

Speaking of soybeans, I think everyone is no stranger. We often say that soybean oil, tofu, bamboo, soy milk, and edamame may be the food that many friends like, but maybe some friends are not very clear. Ingredients, that is, the plant protein in animal feed is mainly from soybeans.

It is precisely because of the various uses of soybeans that my country needs to consume a lot of soybeans each year and how much soybean is consumed?

This is a statistics of my country's domestic soybeans and imported soybeans since 1995. Everyone can see that my country ’s demand for soybeans has gradually risen and relied more on imports. At present, we have 80%to 85%of them depend on imports, that is, there is a big contradiction in the supply and demand of soybeans in my country, which seriously affects my country's food safety.

During my Ph.D., I mainly studied the quality of rice cooking, that is, the rice is delicious or not. What is it determined? In 2011, I returned to the Institute of Heredity Development of the Chinese Academy of Sciences and established my own laboratory. What research will be carried out in the future?

It is precisely to see this demand for soybeans in my country, so we position the goals of the laboratory on the research of soybeans, thinking about contributing to the rise of Chinese soybeans with a high fighting spirit.

It is not enough to report the heart and this enthusiasm of the country and this enthusiasm. We need to find the root cause of the problem.

After analysis, we realized that the reason for the soybean crisis in China is that there are many population in my country, less cultivated land, and grain production cannot meet demand. In this case, we need to import part of the food to meet the gaps of our food.

This is the changes in the production of rice, wheat, corn, and soybean in my country since 1961. From this set of numbers, you can see very clearly that rice, wheat and corn have been greatly improved in the past sixty years. It can be said that it has been turned 2 to 3 times, or even more Improved, but there is no substantive leap. Why is this?

Because in the past sixty years, rice, wheat and corn have undergone a breeding innovation, that is, dwarfed and dense. The innovation of this breeding has greatly improved the production of the yield, and it has achieved what we often say -the green revolution. Why does soybeans lack this green revolution?

The output of crops that we often say actually refers to the number of seeds in the unit area.

From this picture, it can be seen very clearly that the raw parts of the soybean seeds are obviously different from the other three main grain crops. Because of rice and wheat, its seeds are mainly born at the top. The impact of the yield is not great; the seeds of corn are mainly born in the middle, but its ears are relatively small. You can see that there are only 1 to 2, so the reduction of plant height has little effect on its yield; but soybeans are different. Seeing its seeds born in each part of the plant from top to bottom, if the plant height is reduced, it has a great impact on its production. In this case, it is difficult to achieve the green revolution of soybeans through reducing plant heights and through dense planting.

This requires us to break through the existing breeding thinking model and breeding methods to comprehensively improve the different traits of soybeans in order to achieve the purpose of achieving the green revolution of soybeans.

Let's review the process of breeding technology innovation. So far, our breeding technology has gone through three important innovations and is exploring the fourth time -that is, design breeding.

In the past three breeding methods, artificial domestication options are the most primitive breeding model, which has a long period of cycle; and traditional hybrid breeding has great blindness, and its efficiency is relatively low. Molecular breeding is mainly for minority traits for minority traits. Improvement. Although these three breeding technical models have contributed to the increase in soybean production, it is difficult to achieve qualitative breakthroughs in a short time. Different design and breeding can be designed according to the goals to achieve comprehensive orientation improvement of different properties. This is what we just said just now, soybean green revolution. In other words, design breeding brings us a hint of hope, which may help us quickly realize the green revolution of soybeans.

How to carry out design breeding? In fact, it is relatively clear in mind. Give different excellent traits together to form a super soybean.

How to gather it together? For example, high -yield, high -quality, and high resistance. We know that the traits are determined by genes. If we first find these genes that control different properties, and then the genes that control the excellent traits, through the means of molecule, or through hybrid means, form a super superficial means Soy.

For example, we want to create a super car with different types of different types and excellent performance in the future. What do we have to do at this time? Find parts that can build this super car. Our cars can be divided into different types. Each car has its advantages and its disadvantages. Only by finding a more comprehensive hardware store can we assemble our future super cars.

This problem also exists for soybean design and breeding. Because soybeans are also divided into different types, including wild soybeans, farm, and cultivation varieties. They have different forms, and each of them has their own advantages and disadvantages because they have their own unique genome.

If we use the genome of a certain type of soybean as a template to further upgrade and transform, it is difficult to achieve the purpose of the green revolution. Therefore, we must build an integrated genome that includes genome information that includes different types of soybeans in order to achieve the design of the future super soybean.

In fact, scientists have previously proposed a concept called Pan -based. We choose a different individual that can represent this species, then assemble each individual's genome, and then compare the same points and different points of different individuals, and then through certain means Integration forms a standard comprehensive genome.

How to assemble? This is a challenge. The easiest way is to use iteration methods.

From a certain genome as the starting point, and then the sequences that are different in order are connected in order, forming a linear genome. However, everyone can also clearly see that it has great defects, because with different individuals as a starting point, the genomes built are different, although this is a standard genome from this species. So it is difficult for us to cross this defect. Is there a better way to solve this problem?

Utilizing the theory, you can solve it well, because it can record the location of the mutant and the information of the mutant alone, and transform the original line -type, one -dimensional genome into a two -dimensional two -dimensional of this graphic The genome can solve this problem perfectly.

This is theoretically solving the bottleneck of our traditional genome perfectly. Can it be achieved? In fact, we have never done it in plants, and we want to try to make the graphic structure genome of soybeans.

When he discussed this idea with our students at that time, he felt very stressful because no one had done it before, but he was very excited at the same time. The same reason, no one had never done it.

It was driven by this excitement and interest, we carried out research day and day after day. Fortunately, after two years of hard work, we successfully completed this work and published in the "Cell" magazine, and then It was also rated as one of the "Top Ten Scientific Progress in China's Agricultural Agriculture" in 2021.

Everyone will ask, what are the advantages of this graphic structure genome and traditional genome? We know that the current soybeans are basically yellow, but its ancestors are actually black, but how do you gradually change from black to yellow? Through the research of the pan -based group of our graphics structure, the changes in its genome structure clearly showed the changes in the color of the soybean seed skin;

Another example is that some of the soybeans are actually dim and some are more shiny. We all like this kind of shiny, one is because of our senses, and the second is because its oil content is relatively high. But what are the internal reasons? Through our graphic structure pan -based pan -based group comparison, everyone can see that it is because this shiny soybean has a gene. In fact, this analysis is difficult to achieve in the previous genome.

It is driven by this genome that we and our collaborators have cloned some important agronomic tradition regulatory genes, including output quality, chlorophyll degradation, light cycle -related, anti -inverse related, and also related, also also That is to say, we have found those components that come to assemble super cars. Can we assemble our super car in the next step?

In fact, it is not that simple, and there is another challenge, which is a problem for the best individual and coordinated improvement. Or take super cars as an example. We find parts. If their models do not match, is it that we cannot assemble it? Second, even if this type matching, the performance is not matched, its engine is super strong, but its tires and chassis cannot be supported. Is there a certain problem to launch it? In fact, there are the same problem in the plant, because there is a very strong interaction between its genetic genes. Its interaction makes it a synergy or an antagonism between the traits, which is a antagonistic, which is this that is. Need to balance in breeding.

Just now that we clone a gene that controls the size of the seeds, that is, the gene -related genes. In our in -depth research, it not only controls the size of the seeds, but also controls the quality. , Increase the oil content, but the protein decreases. This is why our wild soybeans are relatively small, but its protein is relatively high and the oil content is relatively low. Now the cultivation of soybeans is larger. It, but the protein decreases;

We all know that there are some fluff on soybeans, some have more fluff, some fluffy, and even some fluff. What is the use of fluff? Through our research, we found that it has a certain correlation with the drought resistance of soybeans. For example, if there is more fluff, it will not resist drought. Is it better to find those varieties with less fluff in our breeding, because it is more resistant to drought;

In our research, it is also found that it is also related to another characteristic, that is, insect -resistant, with less fluff, it does not resist insect -resistant, and the fluff is more insect -resistant.

Therefore, in the breeding, we need to find a balance point, so that the fluff is to a more suitable degree, which is not only drought and insect -resistant. Therefore, the real breeding must be a coordinated improvement of different traits, and "the yin and yang are in place, the shape is perfect".

But how can we let us design it ourselves and achieve this "yin and yang, perfect"? This requires finding its real internal regulation network, that is, the relationship between the genes of the plant and the relationship between the traits.

It is for this problem that we have studied the 84 characteristics of soybeans, and then found their regulatory network. This network can clearly explain the relationship between traits. In other words, some genes control different traits at the same time, and some genes control a trait separately, so that different traits have positive correlation or negative correlation.

How to use this network? Let me give you another example. For example, we just want to regulate a one -character character. At this time, we need to control the trait only, and the special gene is selected, so that this trait only improves this trait. But if we want to change different traits at the same time, at this time we need to choose the genes that control different traits at the same time. But there is also an exception. If these two traits are antagonistic, under the action of this gene, this gene cannot be selected at this time, and you have to choose those two traits and those who improve them respectively. Gene. Therefore, this network provides us with a very good theory and foundation.

Based on this theory, we carried out research on soy molecular design and breeding, and then obtained some varieties.

I just introduced it to you that the yield of soybeans and the protein content of soybeans are generally antagonistic, that is, negatively related, but how to improve protein and the output can increase?也就是在刚才我提到的网络的这种理论支持下，我们对一些基因进行的这种选择，利用杂交对基因型进行选择，在这种情况下，利用了两个亲本，本来蛋白含量并It is not high, and then choose the genes through a step -by -step hybridization. You can see that our output has also increased, the protein content has also been increased, and it was approved by the national audit last year.

Through soybean design and breeding, we have obtained some varieties with increased yield, but everyone can also imagine that there is still a lot of distance from the green revolution I just mentioned, because our goal is that the future output can double. This road is relatively long. I believe that with our in -depth understanding of this trait, it will be able to achieve it.

But can the crisis of soybeans be achieved by relying on this soybean green revolution? Because we just said that our self -sufficiency rate is only 15-20%. If our output can double, it is only a 30 ~ 40%. Is there any other way to further alleviate the crisis of our soybeans?

The problem of our soybeans is that the production is low, and the second is our arable land insufficient.

In addition to 1.8 billion existing cultivated land, my country also has more than 100 million acres of saline -alkali land. It can be seen that it is distributed in different areas of our country, because the salt alkali is too high, and the existing cultivation of these crops cannot grow. But it also gives us an inspiration. If we can choose some soybeans that can grow on this saline -alkali land, can we also meet some of our soybeans?

It was with this idea that we carried out some research, just in the entrance of the Yellow River in Dongying, Shandong, a place with more saline and alkali land. This is the first time we took a photo of Dongying, Shandong. You can see that at that time we also lamented that this place was particularly beautiful, and it also gave us unlimited reveries, unlimited hope, and then brought the seeds of hope for hope. Sowing to the ground, everyone is waiting for autumn to harvest. But everyone can see that in the first year of this scene, when we autumn, we arrived in the ground, very, very frustrated, because it was almost all over the army. As we continue to observe in depth, let us be very excited because we see a few plants that can really survive, because when the army is overwhelming, it can survive Alkali.

But there is also a problem. You can see that it is very short and the output is very low. How can it further increase its output? We wondered if it was in cultivation technology, and we could further innovate. After continuous experiments, I found some methods.

The first, for example, membrane covering technology, can see that the membrane is compared with non -membranes, which can obviously improve the ability to resist saline and alkali;

In addition, there are targeted microorganisms, which microorganisms can improve its saline -alkali ability.

Through continuous research, we have made a little progress. In the case of natural rain, we rely on natural rain, and we have screened about 8,000 materials on this place. The portion is relatively anti -saline, and there are 18 parts of them.

In 2021, two of them demonstrated 30 acres of demonstrations, and then reached a real collection, reaching 260 kg/mu. Everyone may not be particularly familiar with this number, because the average yield of the existing cultivated land of soybeans in my country is only about 130 kg/mu in the country.

Of course, it has indeed given us some hope. We also see that the future salt -resistant soybeans will definitely be successful.

But there are still many challenges. The first is to adapt. Because the saline -alkali land is not only salt -alkali, it also needs to have drought, flood, high temperature, and low temperature during different cultivation management periods. These coercion conditions;

The second one requires collaboration, collaboration is the collaboration and research of different technologies. Because it is also saline -alkali land, its conditions are relatively harsh, and it gives you a very short window for farming. In the past, we mainly rely on artificially. Everyone can also see that after the rain, we must rely on people to drain water, and then cultivate the planting. If we plant hundreds of thousands of acres or millions of acres in the future, we cannot rely on people anymore, we need this kind of fertilizer mechanical cultivation, and the collaboration of plant protection to achieve this true standardized cultivation model;

The third one I think is more important is harmony. Saline -alkali land is a treasure house we developed in the future, but at the same time, it is also an important part of natural ecology. How to make agricultural production and ecological protection develop harmoniously in the future, I think this is something we need to consider and need attention.

You can also see that my country ’s demand for soybeans, or our crisis, is still very long, but we will continue to work hard to strive to solve the crisis of soybeans as soon as possible. Finally, I used a poem to end my speech today.

The night gave me black eyes