“In the fragrance of rice, it is said to be rich.” From the stamens quickly extended the shell, the flower medicine cracks, and the pollen falls on the stigma. The blooming process of rice Yinghua is usually completed in less than 30 minutes, but it has a decisive effect on rice production.
Regulating the flowering time of rice has always been a problem that breeders want to solve.
On March 13, “Nature -Communication” released the latest achievements of Shen Rongxin/Wang Haiyang team of South China Agricultural University online.The study taps the key regulatory factors of the flowering time of the rice -japonica rice, the transcription factor OSMYB8.
Rice bloom.Interviewee confession
The thesis reviewer believes that this research is an important breakthrough in the field of spending research. It is of great significance to solve the problem of not being killed in the japonica rice flower.Essence
The “hard bone” that has been troubled for a long time
Hybrid rice breeding is a great breakthrough in the history of agricultural breeding. The use of hybrid rice has made great contributions to global food security.Shen Rongxin, the author of the common communication and associate professor of South China Agricultural University, told the China Science Journal that the current hybrid rice in my country is mostly hybrids in rice dumplings. Due to the nearly genetic relationship of hybrids, its output potential mining has become the limit. One of the main reasons for the stagnation of rice in my country for the year.
“Daea rice and japonica rice are two obvious differentiation of two subspecies produced by Asian cultivated rice in the domestication process. The hybridization between sub -species has a strong hybrid advantage. It is expected that the output can be further increased by 15 ~ 30 from the current widely planted 籼/籼 hybrid rice.About or so. “Shen Rongxin said that when configured hybridization, pollen should leave the rice of the parent, and landed on the japonica rice stigma as the mother’s original to complete the pollination.
In the production of hybrid rice, only when the blooming time of the parents of the two parents meet can the hybrid seeds be efficiently produced.Therefore, flowering time is the key character to control the efficiency of rice hybridization.The efficiency of hybridization is an important factor that determines whether the hybrid combination can be widely used.
Interviewee confession
However, in most hybrid combinations, especially in the combination of tannins, the average blooming time of the mother -in -law and japonica rice is usually later than that of the parent’s rice rice, which means that it is not encountered when flowers.”This time difference has greatly reduced the pollution efficiency in the process of hybridization, resulting in low hybridization, high cost, and expensive hybrid seed prices, which seriously affects the use of strong hybrids between tadpoles.” Common communication authors of the paper.Wang Haiyang, a professor at South China Agricultural University.
The phenomenon of incompetence in rice parents is not a new discovery. In fact, in agricultural production practice, breeders have been paying attention to their parents’ time to meet the prerequisites for the production of hybrid production.
However, rice flowers are controlled by multi -gene control, and it is difficult to examine the sexual traits of flowers. It is easily affected by external environmental factors, and it is difficult to study in -depth research.Wang Haiyang told the “China Science News” that so far, the genes that have different different time of rice japonica rice flowers have not yet been cloned, and the genetic foundation and molecular mechanism of the difference between the time of rice japonica rice flowers are basically unclear.
It is on the basis of such a background and predecessors. In 2019, Wang Haiyang led by Liu Yaoguang, a professor of South China Agricultural University, an academician of the Chinese Academy of Engineering, Chen Lotian team and Zhuang Chuxiong team of South China Agricultural University, and successfully applied for the country.Natural Science Foundation Innovation Group Project.
With the strong support of the project, Shen Rongxin/Wang Haiyang’s team was allowed to “hard bones” and began to start the in -depth research of the cloning and breeding applications that did not encounter genes when pupae rice flowers.
Water absorption: find a breakthrough point
“In theory, a stigma requires only one grain to complete fertilization.” Heng Yueqin, an associate professor of the first author of the paper, said that the process of flowering pollination was affected by various internal and external factors.The flowers generally have only one flower pillar, but a large amount of pollen will be produced to ensure successful breeding.
The rice Yinghua generally blooms in the early morning and before the high temperature of the day, and can quickly respond to changes in temperature and change the flowering time.In the process of the hybridization of the japonica, as the paddy rice of the parent, if the flowering time is 1 hour earlier than the japonica rice as the mother, then when the mother is preparing to accept the pollen, the best pollination period of the parent’s book has been missed, thereby reducing the system to reduce the systemSpecies output.
Interviewee confession
However, from the opening to closed duration from opening to closed duration, it is difficult to investigate the flowering situation of multiple rice at one time.”It is difficult to cloned to flowers through traditional positive genetic genes.” Shen Rongxin said.
They found breakthroughs on the basis of predecessors’ research.
The Yinghua of rice is composed of a pair of plasma slices in the inside and outside of the inside and outside, and the pistils, and a pair of plasma located in the inside and outer pillar.Previous studies have found that before rice Yinghua was opened, the slurry was smaller, and the inside and outside hooks were together; and as the flowering time approached, the slurry gradually absorbed water and swollen, pushing the inside and outsideThe slurry is reduced, and the inside and outside will be closed again.
“The earlier when the water absorption and swelling reaches the maximum volume, the earlier the rice bloom.” Shen Rongxin said, so they focused on the key structure of the slices of the slices of rice flowers, as well asOne critical process.
However, the most difficult thing is the investigation of flower -like traits and the sampling of the slurry.
These two “arduous tasks” were handed over to the first author of the thesis and the doctoral student of South China Agricultural University.She first investigated the approximate time of the field materials in advance with visual inspection methods, and selected the appropriate ears of rice one afternoon in the afternoon of the day in advance.Until the day after the opening of Yinghua, the investigation was over.”This work requires multiple people to investigate together to ensure that it can be counted in a short time.” Gou Yajun said.
Sample samples also require multi -person cooperation.Cut the appropriate rice ears in the field and put it into the liquid nitrogen tank. After returning to the laboratory, the opening time of Yinghua is judged according to the birth location of Yinghua and the location of the flower medicine.
Provide new ideas for hybrid rice breeding
By analyzing the comparative analysis of the japonica rice slice transcription group of japonica rice with early flowering time and late flowering time, they eventually locked the key regulatory genes on the transcription factor OSMYB8.OsmyB8 has a low expression in the slurry of the day before flowering. As the flowering time is approaching the expression, the expression volume of the expression reaches its peak 1 hour before the flowering, and it is highly expressed in advance in the rice slurry.
According to Shen Rongxin, there is a natural mutation on the osoma -type OSMYB8 promoter that leads to a higher expression in OsMYB8 in rice slurry tablets, and then promotes the expression of downstream factor OSJAR1.OsMYB8-OSJAR1 molecular module By affecting the content of active jasmine in the slope, it promotes the opening of Yinghua. Earlier the flowers, eventually lead to the fact that the rice japonica rice flowers are not encountered.
In the next step, the team focuses on the cultivation of early flowers of japonica rice.
“Time to shorten the sprouts of rice japonica is of great significance for increasing the influence rate.” Shen Rongxin said that predecessor research found that if the splash time of japonica rice is spent 20 minutes in advance, it can significantly increase the production of hybridization.OsmyB8 is expected to be used to cultivate the japonica rice infertility system during early flowers and increase the production of japonica hybridization.You can also use genetic editing promoters to improve the expression level of japonica rice pro -genetic genes and create early flowering japonica rice germs.
In addition, with the warming of global climate, extreme high -temperature weather induced by climate change has become more and more serious in frequency, strength, and duration, which greatly threatens global agricultural production.
“Some varieties that are late in flowering time are easy to suffer from high temperature coercion, resulting in pollen infertility and decreased output.” Wang Haiyang said that cultivating early flowering rice varieties at high temperatures is an effective strategy to improve the high temperature resistance period of rice.
He believes that the high -expression rice -rice OSMYB8 and other genetic genes are imported into the japonica rice, or the OSMYB8 promoter in the japonica rice is edited into a cricket type through gene editing technology to increase the expression of osmyb8 in the japonica rice.In advance, the pollen childbirth caused by high temperature decreases.
This research not only reveals the inherent mechanism of rice flowers, but also provides new ideas and methods for future hybrid rice breeding.
Related thesis information: https://doi.org/10.1038/s41467-024-46579-z z