Scientists "decode" genetic resources in high definition, Miscanthus

Scientists "decode" genetic resources "all-rounder" Miscanthus in high definition

Scientists high-definition "decoding" genetic resources "All-rounder" Miscanthus scientists "decoding" genetic resources "All-rounder" Miscanthus in high definition

Photo courtesy of Chen Cuixia, Miscanthus, Shandong Agricultural University Experimental Base

Shandong Agricultural University experimental base miscanthus Chen Cuixia courtesy ofShandong Agricultural University experimental base miscanthus Chen Cuixia courtesy

Miscanthus that grows in the wasteland is a tall weed, you may not have noticed them.

On May 6, "Nature-Plants" published online a chromosome-level reference genome map of the five-section mangosteen deciphered by the research group of Professor Chen Cuixia of the Agricultural College of Shandong Agricultural University.

Three high-level papers in half a year focusing on Miscanthus

Three high-level papers in half a year focusing on Miscanthus

From the publication of the genomes of Miscanthus and Nandi in "Nature-Communications" to the publication of the genomes of Miscanthus quinquefolia in "Nature-Plants", from the end of October 2020 to the present, within half a year, the sub-Journal of "Nature" successively published the research results of the genomes of three species of Miscanthus.

"The Miscanthus plants are the most promising bioenergy crops.

Not only that, it has a wide range of uses, which can consolidate soil and preserve water, improve soil, and improve the ecological environment; more importantly, it can be used as a renewable biomass raw material that can be converted into heat, electricity, liquid fuel, etc.

Chen Cuixia said that more than ten years ago, affected by the increase in oil prices, developed countries in Europe and the United States invested a lot of money in research on renewable energy, and lignocellulosic crops such as miscanthus and switchgrass became the research focus of scientists.

In fact, Miscanthus plants originated in Southeast Asia, and China is one of its important origins.

However, "Miscanthus plants are self-incompatible, their genomes are huge, and they are highly heterozygous.

"Today, when genomics is highly developed, revealing the genomic code of Miscanthus and analyzing its evolutionary process has important theoretical significance and application value for understanding its genetic basis, rapid and effective utilization, and creation of new germplasm.

 

Sorghum, Miscanthus, and sugar cane come from the same ancestor

Sorghum, Miscanthus, and sugar cane come from the same ancestor

In the process of species evolution, genome polyploidization is one of the most important ways of plant evolution and the production of new species.

Recent studies have found that there is a close relationship between the genomes of Miscanthus, Sorghum and Saccharum.

At present, the genomes of the wild species of sorghum and sugarcane have been deciphered, but Miscanthus has always lacked high-quality chromosome-level reference genomes.

Zhang Guobin, the first author of the paper and associate professor at Shandong Agricultural University, told China Science Daily that after more than ten years of research, they analyzed the high-depth sequencing data of the genome of the representative species of Miscanthus, and calculated its genome size to be 2462.

Taking into account the complexity of the Genome of Pentacarpus, they comprehensively used the second-generation, third-generation, and 10x Genomics sequencing methods, and attached them to the 19 chromosomes of Pentacarpus by Hi-C technology, using genetic maps and BioNano data successively.

The results showed that the five-section mango genome they assembled was a high-quality reference genome at the chromosome level.

Furthermore, Chen Cuixia's research team inferred the specific evolutionary relationship and time between the three species.

On the one hand, Miscanthus plants have undergone genome polyploidization and chromosomal rearrangement in the following 4 million years.
Among them, “we found that the chromosome 8 of the sorghum ancestral species fused with chromosomes 4 and 7, and found the centromere position of the new fusion chromosome.
” Zhang Guobin said, which explains the genus Miscanthus.
Why does the plant genome have 19 chromosomes instead of 20 chromosomes after a doubling?

On the one hand, Miscanthus plants have undergone genome polyploidization and chromosomal rearrangement in the following 4 million years.
Among them, “we found that the chromosome 8 of the sorghum ancestral species fused with chromosomes 4 and 7, and found the centromere position of the new fusion chromosome.
” Zhang Guobin said, which explains the genus Miscanthus.
Why does the plant genome have 19 chromosomes instead of 20 chromosomes after a doubling?

On the other hand, Saccharum plants maintain their basic chromosome number of 10 for about 3 million years, and then undergo a chromosome rearrangement to make 2n=16.
About 1 million years ago, the ancestor of the wild sugarcane species went through two consecutive genome-wide doublings, supplemented by a slight chromosomal rearrangement, and became the wild sugarcane species today (2n=8x=64).

 

Gene resource "all-rounder"

Gene resource "all-rounder"

Some experts believe that in addition to being an energy plant, the high resistance of Miscanthus may also bring abundant genetic resources to food crops that are also gramineous, such as rice and wheat.
Wujiemang is like a "all-rounder" of genetic resources.

"We have identified the CesA/Csl family genes of cellulose synthase in sorghum, sugarcane and Miscanthus.
" Chen Cuixia said that as energy plants, people mainly use Miscanthus lignocellulose.
Therefore, it is very important to study cellulose synthase.
necessary.

Identification of Cellulose Synthase Genes and Heat Map of Cellulose Synthase Members in Quinceanera, Sugarcane and Sorghum Photograph courtesy of Chen Cuixia

Identification of Cellulose Synthase Genes and Heat Map of Cellulose Synthase Members in Quinceanera, Sugarcane and Sorghum Photograph courtesy of Chen Cuixia

By comparing the five-node awns of different growth stages, they found that the expression level of cellulose synthase in the elongated stalk tissue is very high.
Compared with the expression levels of all genes in Miscanthus plants, most of the CesA and some Csl genes have the highest expression levels, which is consistent with the extremely high cellulose or hemicellulose content of Miscanthus plants.

For a long time, Chen Cuixia’s research group collected 75 germplasm resources of several representative species of Miscanthus, such as Miscanthus, Di, Nandi, and Miscanthus, and foreign hybrids such as Giant Miscanthus.
After re-sequencing the whole genome of them, It is found that there is a wide range of interspecific hybridization among Miscanthus plants.

"Miscanthus and sugarcane can cross successfully.
" Chen Cuixia said, because Miscanthus is self-incompatible, interspecific hybridization can be achieved within Miscanthus, and even cross-genus hybridization with closely related crops.
This provides theoretical support for breeding better Miscanthus, Sorghum or Sugarcane plant varieties through hybridization.

Chen Cuixia explained that sorghum, which belongs to the same subfamily of sugarcane as Miscanthus, is an important food crop in the world, while sugarcane is an important economic crop in the world.
The ability of Miscanthus to hybridize with it means that it is resistant to disease, drought, waterlogging, and salt-alkali.
The characteristic of tolerance to barrenness is likely to become a genetic resource for sorghum and sugarcane breeding, and may even provide a reference for rice, wheat and other food crops.

At present, they have carried out planting experiments in the saline-alkali land of the Yellow River Delta for nearly eight years.
A total of more than 20 acres of Miscanthus test materials were planted with good adaptability and excellent salt tolerance.
"This is of far-reaching significance to the fragile ecological restoration, soil improvement, development and utilization of saline-alkali land, and even food security and ecological security.
" Chen Cuixia said.

Related paper information: https://doi.
org/10.
1038/s41477-021-00908-y