Scientists discover gene that increases yields in corn and rice

According to reports, in the early morning of March 25th, Beijing time, Science magazine published online the joint research results of the China Agricultural University team and the Huazhong Agricultural University team. A key gene found in both corn and rice was discovered. Experiments show that by editing and improving this gene, it is expected that the yield of corn and rice can be increased by about 10% and 8% respectively.

The two-in-one gene is useful for the yield of corn and rice, but wheat is missing. It can be said that this discovery is good news for all mankind. It is well deserved to be published in Science!

Today let’s talk about what this article is about.

In fact, the title briefly introduces it: Convergent selection of a WD40 protein that enhances grain yield in maize and rice

That is, we found a gene that can increase yield in maize and rice, and systematically analyzed the convergent selection of maize and rice at both the single gene and whole genome levels.

Let me introduce this article to you.

01. Food is the first necessity of the people, and the seeds of food are the first

I remember there was a question on the Internet a few days ago: If the whole world suddenly blocks us, can we be self-sufficient in food?

In fact, although people usually don’t pay attention to food issues, I believe that many people have experienced or seen from the news the food shortage problem that may be caused by the ban since the epidemic in recent years. Compared with lack of money and electricity, famine is the real restriction of life. This is only a temporary isolation, and there is no food crisis overall. However, if there is a national food shortage, then it will not be a short-term problem, just like the problem faced by mankind in the movie "Interstellar" is the food problem.

Therefore, the food crisis is actually an invisible but always hanging sword. The three major staple foods, corn, rice and wheat, are the world's most important food and are also important for maintaining human groups. For example, the introduction of corn and potatoes successfully stabilized my country's GDP at more than 100 million.

How to increase their production can be said to be related to the survival of mankind. After all, whether it is directly used as food or indirectly as livestock feed, it is very important.

02. Coincidence or inevitability? Corn and rice

As the world's three major staple foods, wheat was domesticated by the people of West Asia, rice was domesticated by the Chinese people, and corn was domesticated by the Americans.

It can be said that they are distributed in Eurasia and the Americas. Their ancestors are different, and their shapes and growths vary greatly. However, the great ancestors still worked hard to domesticate them. This has gone through a long period of improvement and artificial selection. So, is there a common choice among them? Is it "unintentional"?

This time, a joint team from China Agricultural University and Huazhong Agricultural University came together to interpret this issue. How did they do it?

03. Which gene determines the number of rows of corn?

First, they made a very "special" corn, which was a special 6-row corn made from wild corn. Question here: Do you know whether the number of rows of common corn is odd or even?

The purpose is to find the key gene that controls the number of rows in corn. But this is not easy, so let me explain it briefly. Many trait genes can be roughly divided into two categories.

One is the gene for qualitative traits, which simply means determining traits and generally conform to the 0/1 rule, for example, a boy is a boy and a girl is a girl. The other is the gene for quantitative traits, which simply means determining quantity and are often continuous, for example, height, which can range from a few dozen centimeters to more than two meters.

In actual research, the former is easier, after all, it is easier to determine whether something is present or not. But the latter is much more difficult, because the quantity is continuous, and it is difficult to find a significant trait gene. Therefore, have you noticed that to this day, we still haven't found an IQ gene or a height gene? This is the problem. (Of course, it is not absolute. Some height genes have been found through dwarfism, but not all.) Corn yield also conforms to this rule and is a quantitative trait.

The creative approach of the research team this time was to first create a special 6-row corn, which is significantly different from the common dozens of rows of corn and thus easier to study.

Next, I will describe my major: bioinformatics. They test the genome and then look for candidate genes.

As a result, I actually found it, which is quite lucky. I have done similar research before, but my efforts were basically in vain because it is very difficult to locate the key gene.

The answer is: KRN2.

This gene can directly regulate the number of rows of corn ears.

This gene has undergone a lot of selection, especially the part from –800 to –100 bp.

Next, they used experiments to verify the KRN2 gene:

This study found that KRN2 and another gene DUF1644 can work synergistically.

Okay, that’s it, corn is solved.

04. What about the rice yield?

Now that we have solved the problem of corn, what about other crops? For example, rice.

Why did you think of rice? Actually, there is some basis for association. Rice and corn have the following similarities:

Loss of seed dispersal: For comparison, imagine how dandelions disperse their seeds, and how corn seeds stay on the cob when they mature.

Reduced seed dormancy: Everyone imagines that rice can grow three seasons a year, almost without sleep. However, many seeds must be dormant.

The number of grains increases during the evolutionary process: This is the easiest to understand. As the number of grains increases, the natural yield increases.

Because of this, the two seem to have a tendency to converge, so they may be converging in evolution.

So, the next step is to find similar genes. This is simple. We just need to find homologous genes, that is, the ones with similar ancestors (just think about it, genes are from 0 to many).

We actually found it. KRN2 in corn does have a homologous gene in rice, called OsKRN2.

Look, it is the following

The two have great similarities (homology) and are very close in evolutionary relationship.

The next step is verification.

Needless to say, this gene really has an effect on rice and is related to rice yield control.

05. Conclusion

Well, at this point, the article is basically over.

Take a look at the picture:

The study found important genes that control the yield of corn and rice. The gene for corn is KRN2, and the gene for rice is OsKRN2. These two genes are homologous genes.

It seems that our ancestors had the same idea in the domestication process. The Chinese and American people, separated by the Pacific Ocean, finally selected rice and corn in a similar genetic way, cattle.

Genetics have also proven that these genes have undergone similar selection processes in corn and rice.

It shows that great minds think alike. The Chinese and American people have found similar ideas.

And these two genes can indeed determine the yield.

The author did some gene editing and the results are as follows

After gene editing, the number of corn ear rows increased and the yield increased by 10%; the yield of rice increased by 8%.

As for this research, this gene is a gene with major intellectual property rights in my country. In the future, it can be used to improve rice and corn and increase yields. It can be said that it will also be a very important contribution to solving my country's food security problem in the future.

Finally, after reading this article, I really feel that agriculture is not easy. The three rural issues are important issues in my country, but they have always been difficult. For example, the corn and rice yield genes of two top agricultural schools, Zhongnong and Huanong, took three generations and 18 years to finally make a splash. During this period, many masters and doctoral students were left with nothing.

I hope the country and society can be warmer to those working in agriculture.