-
Categories
-
Pharmaceutical Intermediates
-
Active Pharmaceutical Ingredients
-
Food Additives
- Industrial Coatings
- Agrochemicals
- Dyes and Pigments
- Surfactant
- Flavors and Fragrances
- Chemical Reagents
- Catalyst and Auxiliary
- Natural Products
- Inorganic Chemistry
-
Organic Chemistry
-
Biochemical Engineering
- Analytical Chemistry
- Cosmetic Ingredient
-
Pharmaceutical Intermediates
Promotion
ECHEMI Mall
Wholesale
Weekly Price
Exhibition
News
-
Trade Service
"Our findings support the possibility of independent origin and parallel evolution of rice in Asia and Africa, as well as the hypothesis that rice genus may have originated in the paleocond period before and after continental drift. Explaining the latest findings, published June 7 in nature-newsletter, chen Lotte, a professor at the School of Life Sciences at South China Agricultural University, said.
" rice genus is widely distributed throughout Asia, Australia, Africa and the Americas. Chen Lottian said that the early theoretical hypothesis that the rice genus originated in the ancient continent and drifted around the world as the continent drifted, archaeological evidence also supports the possibility of this theory. Archaeological evidence suggests that continental drift occurred between 1 and 150 million years ago.
of rice genus is still controversial in academic circles. However, with the development of technology, the origin of rice genus based on wild rice genome sequencing results was approximately 15 million years ago, and there is a large time difference between the two theory.rice genus consists of 23 species, of which the cultivated rice is divided into asian cultivated rice (
) and African cultivated rice (
) two species (jointly known as "Asian-African rice"), the rest are wild rice species. Inter-sub-African rice hybrids have strong hybrid advantages, but intersubse reproductive isolation leads to low interstital infertility and strongness, which does not reflect the yield advantages of hybrids.Seatis the most important genetic seat that causes inter-Asian and African rice hybrid infertility, and its effect can lead to selective sterilization of female and male matching sons containing Asian rice-type allephic genes (
) in hybrids, resulting in severe allegratic biased inheritance (biased to African-type allephic genes
) in the offspring population. Therefore,
is a typical selfish gene base, which plays an important role in inter-species differentiation, but its molecular genetic mechanism has not been clear.
beginning of 2017, the Chen Lott team, in collaboration with the Liu Yaoguang task force, pioneered the cloning of
, a key gene in seat
(later named
). Then, in 2018, Japanese scientists cloned
another gene in the
. However, both genes are only some of the necessary factors for S1 hybrid infertility, and the
conditions that lead to the infertility of hybrids are unclear.
In a follow-up study, chen Lotte's team found through a series of gene knock-out and complementary experiments:
in addition to
-seat-controlled hybrid infertility,
also requires the participation of two other African rice allied gene constellations
specific genes
and
to occur (of which
is
).
further studies show that
's three chain-specific genes
and
work together to form a killer system that produces infertility signals in large and small spore mother cells. The infertility signal is transmitted to the matching son by subtracting to produce a lethal effect on the
genotype match, but the
-type matching son is normally bred because of the protective effect of
. Therefore, Chen Lottian's task force proposed
mechanism for interoperability of non-symmetrical genetics to mediat hybrid infertility.in order to
the origin and differentiation of the three genes S1 composite genetic seat, Chen Lottian's team analyzed the distribution of these three genes in different rice species. The results show that the ancient continental ancestral genotype
produced a variant genotype
(with an early termination code) through a single base mutation, which may have been fixed in the common wild rice (
) and Asian cultivated rice species that migrated to the plate distribution of the Asian continent through a genetic bottleneck during the period of the ancient continental division.
And the origin of the African rice
variant relates to the ancestral
base variation in the ancient continent and the insertion of new genes
and
on both sides of
, as well as the repeated recombination of these intermediate products to form functional variants into the wild ancestor species (such as
) of rice cultivated in Africa, and eventually fixed to the cultivation of rice in Africa.
In response to the time differences between the theory of the origin of the ancient continent and the theory of genomic molecular evolution, Chen Lotian believes that the time of origin of the rice genus inferred by genome sequencing results may be due to the fact that sequencing samples are limited to modern wild rice species (systems), and that it is not possible to obtain and determine the evolutionary but extinct ancient wild species (i.e., the result of incomplete genealogy) and not to rule out the consequences of long-distance migration.
"Our study provides molecular evidence for the origin of rice genus in ancient continental theology. Chen Lotian said that the research results systematically expounded the
molecular mechanism of intersubstitive infertility and its evolutionary origin route, which laid a theoretical and technical foundation for the subsequent break-up of intersubsomal hybrid reproductive isolation and the promotion of intersubstitian advantage utilization.
Liu Yaoguang, a member of the Chinese Academy of Sciences and a professor at South China Agricultural University, likened the study's revealed molecular rationale for Asian-African hybrid infertility to that of three bad guys, and then one of them was responsible for disinfecting and protecting the home where the three lived together, exhibiting the characteristics of a "selfish gene". In his opinion, the research is of great originality in theory and has great application value to accelerate the utilization of the advantages of rice far-off hybrids in China.
relevant paper information: