Wang Lei: The magic weapon to adapt to the environment -biological clock

The universe is everything, ever -changing, but in the end, it does not leave its "clock"!

Wang Lei

Researcher at the Institute of Botany of the Chinese Academy of Sciences

The homeland that we live in the survival ~ Earth, every day, is rotating 24 hours a day. In addition to the rotation of the earth, it also revolves around the sun.

In the ancient book "Zhou Yi" in our country, there is a sentence called "the heavens and the earth are achieved four times", that is, the change of heaven and earth has led to the formation of our four seasons.

Faced with the day and night of light and temperature caused by the rotation and revolving of the earth, and seasonal changes, we humans have various survival (methods), such as "the sunrise is made, the sunset is at the sunset", and So how to deal with this environment of day and night or seasonal changes?

During the day, you will find soybeans or peanuts. Its leaves are completely open. At night, soybean leaves will hang down, and the leaves of peanuts will be completely closed, like the current national botanical garden in Hehuan Trees, it is at night, the leaves will be completely closed, indicating that the plant will also "make the sunrise and the sunset."

If we look at this single time in this plant, you may not see the form of its movement, but a delayed photography technology, you can see the movement of the plant.

Just like a fan, but this fan is twenty -four hours a day, so it is very slow.

Some people may have such a question: there is light during the day, no light at night, is the movement of the plant being driven by light?

In fact, as early as 1729, French astronomer, noticing that he was not a botanist, and a astronomer De Ma Lang observed the stars in the night sky with an astronomical sticks, he found that the mimosa around him was at night. The leaves are closed, and the day the next day is opened. He thought at the time, is this an inherent rhythm of a plant or really affected by light? Just like what we think now.

He did a very simple experiment and put Mimosa into a black box. However, the next morning, when he looked at this mimosa, he found that the leaves were still open, that is, Mimosa, Mimosa The opening of the leaves is not driven by light, but has its inner rhythm.

In fact, this inner rhythm movement, Darwin proposed that the movement of plants was powerful in 1880.

Everyone knows that Darwin is the founder of evolution theory, and he proposes the idea of ​​evolutionary theory of "things competing for heaven and the survival of the fittest."

In 1880, he and his son Francis Darwin wrote the book "The Power of Movement in Plants". In this book, the movement of plants is attributed to two categories. One is to move sex. For example, plants will grow towards light and grow towards water. This is called sexual sport. Calling Nastic Movement, like the rhythm of day and night, is a kind of emotional movement he classified.

He proposed the survival of the fittest, and he was thinking, why did the plants do this kind of exercise?

Everyone knows that exercise fitness is consumed by energy, as well as plants. It needs to open the leaves and close the leaves, and it also consumes energy. Then this kind of exercise must have its meaning.

From the perspective of evolution, what does it mean? Later, he proposed a hypothesis that the reason why the plants would have the rhythm driven by this biological clock to drive were actually to resist the invasion of pests at night and reduce the stage of pest activities;

On the other hand, everyone may also be able to get it. When its leaves are low, water can be kept better.

So from these two aspects, it is worth it for the energy consumption of this plant, so this is a meaning of its evolution.

We don't know if it is senior or not, but I dare to say that it is more complicated. Because it is different from people, we have an unfavorable environment, such as low temperature or high temperature outside, we can hide, but the plant can not move, it must stand there Can't retreat. Then it should cope with this environment, it should be a more complicated system to maintain its inner steady state. I think this may give us a human enlightenment, that is, when dealing with the external environment, it may be complicated. Sometimes the system is more stable.

Plants have a more complicated biological clock system, such as vegetables, after you harvest it, this biological clock can still be maintained. Under the conditions of our experiments, even if you separate its cells, It can still maintain the vibration of the biological clock in vitro for nearly a week.

For more than a hundred years, everyone did not know what the inner mechanism was in it. Until 1995, after entering the era of molecular biology, everyone can be in fruit flies, including other models of biological biological biology Inside, let's analyze something to control the biological clock, what genes are controlled, and how these genes are composed of.

The three American scientists used fruit flies as model creatures, and they identified the key components of the biological clock, and built them into a feedback ring of translation translation of the biological clock. In fact, in the same era, the research of plants has also entered a quantitative era.

Steve Cay is in the field of biological clock research, and it can be said that it has done a milestone work.

He uses the coding gene of the fluorescent enzyme of fireflies to drive the report gene as a biological clock, and he can quantitatively study the cycle, amplitude and effectiveness of the biological clock. Although it is very simple to use, the article is published on the cover of "Science". Everyone knows what this significance is, so this is a milestone job.

After more than two decades of research, everyone has clearly knew that the plant creature clock has three basic architectures. The first large plate is the input of light and temperature signals in the environment, and the other is the central shock.

The central shockr is a feedback ring of transcription and translation composed of genes and protein. By expressing and controlling downstream genes, it presented rhythmicness in time dimension, thereby regulating various behaviors of plants.

This is the existing, and the central shocks of the plants that have been simplified at present, like a complex system of an integrated circuit board, is a model of a relatively simple central shock that we can summarize at present.

In this shock model, each component is a transcription factor, which can regulate the expression of hundreds of downstream and even thousands of genes, so you can imagine it. Each component is in the body of the life machine body. An important port, it can regulate many behaviors of downstream, so that they show the rhythmic nature of day and night.

In this model creature, there are about one -third of the expression of genes that we already know at present, and the time dimension is regulated by the biological clock, so we can see that the elongation of cells is extended, and the elongation of cells is extended. The motion of the leaves, and even the dynamic dynamics of the day of chloroplasses, and the opening and closing of the pores. The pores are channels for water and gas in and out of the plant. In the flowering time season, it is also regulated by the biological clock.

In fact, there is far more than. We may sometimes have such a shallow impression. I planted a watermelon yesterday. Why didn't I look at it a day? It seemed like I grew up? That's right, believe your intuition, confident, you are right.

You can see that watermelon quickly expands quickly at night and expands quickly at night. During the day, its growth almost stopped, just like we blowing balloons, so its growth shows this obvious rhythm of day and night.

Not only the growth and development of plants have been regulated by plant biological clocks, but also the biological clock is also a defensive weapon that plants respond to pests. The reason why we say that the biological clock is a magic weapon for plants to adapt to the environment, it is manifested in all aspects.

Researchers at the University of Rice in the United States have done a very simple experiment. Two types of insects and plants are treated. One is to let the worm during the day, and the plants are during the day; the other is to let the worm during the day. Essence

These two treatments are called synchronous treatment. Synchronous treatment is that you are also during the day during the day. Non -synchronized treatment is that when the plant is during the day, the bug is at night, that is, the darkness does not understand the night during the day.

What are the consequences in this case?

You can see that the left side is synchronized, and the right is non -synchronized. On the first day of the beginning, you may not see any difference, but soon this difference is very obvious. You can see When synchronizing, the worm will quickly eat the leaves of the vegetables.

They also proposed that if vegetables want to keep fresh or transport long -distance transportation, give it a certain amount of light and dark treatment, so that it can maintain a strong biological clock, which is very meaningful to preservation of vegetables. question.

Why can it deal with pests? In fact, there are scientific principles. They measured one of the metabolites in them, called glucosate, and found that this weapon against pests showed obvious rhythm of day and night in the day.

In the daytime, the expression is high, so the bug does not like to eat it, and the expression is low at night. At this time, the bug will take advantage of it, so you can see that the biological clock is also a defensive weapon for the pest.

We may find that science is very interesting, but in fact science is not only interesting, science is still useful.

We look at the beans. Sometimes I think the soybeans in the north are very good. If you take it back to the south, you will find how it is? It will soon bloom, and there will be no high yield.

Chinese scientists have done a very prominent work in terms of soybeans, and they have found that soybeans native to the Huanghuaihai area of ​​my country have been in the process of entering north and south. , And then adapt to the local light cycle, to give it the best proportion of nutritional growth and reproductive growth, and provide us with high -quality products;

At the same time, in the rice, like flowering time, we are called the "dumping period" and the number of divisions. It has also been regulated by the biological clock, and even the efficient use of nitrogen.

After returning from the United States in 2013, I was thinking about a question. Can I want to do some ground -to -ground work? In fact, before I went to the United States in 2006, during my PhD, I had been doing a job of regulating the development of rice, and then I had some technical reserves in rice. At this time, I wonder if I can do some salt resistance? Some people may ask why the problem of salt resistance is to be regulated. In fact, this problem not only has its theoretical significance, but also has very specific practical needs.

This is a status quo of soil salt and staining the world. You can see that the saltization of our Chinese soil is more serious worldwide. In China, all of our farmers of rice are about 20%of the land. The invasion of saline -alkali is a problem in our real production.

my country ’s saline -alkali land is mainly divided into four large areas: Northwest Salviac Area, Northeast Salone Alkali Area, Binhai Salian Alkali Area and North China Salone Alkali Area.

Especially in the salt -alkali area of ​​the Northeast, everyone knows that the rice in the Northeast is delicious, and it also has some problems of salt alkali.

We think, can we give a solution to our time biology from the perspective of the biological clock, because it grows on the saline -alkali land, it can actually complete its entire fertility cycle, then its output will be Very low, this is also a very unfavorable problem for the safety of our country's food.

At this time, we started to use (in fact in 2013, there was a technology that was born, everyone knows now, it is very hot, it is called gene editing technology) gene editing technology, which can quickly obtain related functions in plants. The lack of mutant body, then we basically make a common lack of the components of all corresponding rice biological clocks.

What we just started to be disappointed is that many genes have nothing to do with the stress of rice. It has nothing to do with you before and after processing.

However, science always prefer some diligent people. In the process of doing so, we discover that one of the gene mutations is very sensitive to salt stress once this function is gone. It will almost be overwhelmed by the whole army, so why does this phenomenon cause this phenomenon?

We conducted further research from the mechanism. We found that there is an coding gene in the root of the sodium ion channel. The main function of this gene is absorbed from the soil into the root.基因功能缺失了以后，它这个门就关不上了，它就不停地从土壤里头吸，导致了钠离子不停地积累，从而导致了离子的毒害，还有活性氧的产生，从而导致The apoptosis of cells, that is, we finally saw that the plants would die.

This shows that at the time dimension, the opening and passing of the ion channel is very critical for the salt resistance of rice.

However, this gene is unfortunate that it does not have many functions in the dumping period, that is, it has a particularly special function in salt tolerance. In fact, when salt damage, it will often lead to delay in the dumping period. This delay in the dumping period is actually very bad in production. If it rushed to autumn and the weather becomes cold, sometimes the grouting may not be so timely.

Can we get some materials, can we get it better with salt resistance and adjustment period?

We are lucky to get a mutation of genes. After this mutation, it can show a phenotype that is very patient with salt stress. You can see it and compare it. It can still live well.

What's more interesting is that this mutant is tall and large, and the dumping period is relatively advanced. Then such materials will be very useful for us. It can be used as a key target for future design and breeding. Essence

In addition to such a development and the effect of a stress, we also want to know why it has such a function.

We find that it is the same as the one just now. It also affects the expression of ion transport protein, but unlike the one just now, it is to reduce the expression of these genes, that is, the transfer section of these ion channels, encoding the ion channels These genes, which are lowered up and down at the level of transcription. After the lowering, the sodium ions can be rejected. If it is not sucked in, naturally it can make plants live better.

On the one hand, we regulate the pumping period of rice, on the other hand, regulating salt tolerance, and analyzing such a mechanism. It is also published in the international "Plant Cell & Environmentttt" magazine. One of the five outstanding academic papers.

In addition to this phenomenon we see, in fact, in fact, saline -alkali stress is not isolated. Sometimes, while salt coercion, it will be accompanied by drought coercion. Can it find a gene? What about biological stress?

Then we were fortunate to find one of the biological clock genes. After the mutation of this biological clock gene, it was not only sensitive to salt, but also very sensitive to drought penetration, which means that it allows rice to endure the necessary factors of these coercion. Such a gene may also have its martial arts in the future design and breeding.

With the above interpretation of these genes, coupled with the rapid development of our Chinese plant biology in the past two decades, we already have good knowledge, and we may form a joint force to treat our germination for our germsMake rapid design and breeding and improve.Changing, never leave its "clock".

From the perspective of our time biology, we use the components of our biological clock and other tasks to advance together to strive for our breeding and improvement. Thank you.

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