Biotechnology, the art of tinkering with nature, is thousands of years old. The Asians who grew the rice as food did it too. Genetic research has now shown that the first Asian rice farmers mainly chose plants with a special gene, even if they did not know this themselves. This goes against the view that the most important changes in the rice plant are due to the so-called Green Revolution of the last century.
History is not just a matter of understanding what your country used to look like and who was once important. No, it also has to do with putting yourself in the spirit of your ancestors. What was their day like and what did they do to survive? And how could they establish a kingdom, empire or even a dynasty?
The oldest book in the world
Japanese biologist Makoto Matsuoka wanted to answer that question for his Asian ancestors. Ten thousand years ago, they managed to grow rice and ramp up production to immense piles. But how did they manage that?
Matsuoka did not look for the answer in paper history books or archaeological excavations, but deciphered part of the oldest 'history book' in the world:DNA.
Small plant, thick grains
Not that people knew anything about DNA ten thousand years ago. Still, without realizing it, Matsuoka's distant cousins in mainland China discovered a particular gene, known today as SD1. By crossing rice plants, the first rice farmers changed the SD1 gene. As a result, rice production went up considerably, the biologist writes in the journal PNAS .
The changes in the gene kept the stem of the plant short, giving the plant more energy to grow other things, such as edible grains of rice. Matsuoka draws this conclusion after an extensive DNA comparison between ordinary Asian rice, Japanese rice and wild rice.
That ten thousand years ago rice production already depended on SD1, is surprising. Modern biotechnologists have always thought that changes in SD1 are relatively new. In fact, everyone assumed that the gene was heavily modified during the Green Revolution, some fifty years ago. At that time, modern biotechnologists discovered new ways to rapidly change the DNA of plants, for example through new crossings and radioactive radiation.
New or ancient?
At first, Matsuoka was also unsure whether SD1 was changed thousands of years ago, or recently. To see whether the changes on SD1 were enforced before or after the Green Revolution, Matsuoka deliberately chose rice varieties for his research that are considered "old-fashioned" today:the primordial varieties that the Green Revolution could not reach. They most resemble the rice varieties from ten thousand years ago.
The biologist was pleasantly surprised with what he saw. SD1 was also found to be different from wild rice in these primordial varieties. And just as interesting:the changes on SD1 also appeared to differ between the primordial varieties, indicating that Asian rice farmers in the distant past independently made their rice plants smaller while increasing the grain size.
What the first growers thought of
In fact, it seems that Matsuoka's ancestors were particularly focused on the SD1 gene. In many respects, the DNA of the primordial varieties is very similar to that of wild rice, except for the part containing the SD1 gene. This means that when people first started growing rice, they sometimes crossed it – consciously or not – with wild rice.