The genome sequencing of the amoeba plant and the study of new mechanisms for the formation of raw cell walls.

During the occurrence of the male matcher of the quilt plant, the haploid small spores undergo an asymmetrical fission division (PMI) to produce nutrient cells and reproductive cells, after which the reproductive cells undergo another symmetrical fissic division (PMII) to form two sperm cells.
is often regarded as an ideal developmental biology model, this simple system not only experiences the cell division, differentiation, cell fate decision and other important biological processes, but also involves a large number of pollen-specific gene expression control network.
the regulatory factors associated with cell cycle play a very important role in the development of the matching agent, while the molecular mechanism of the analysis of the cycle regulation of pollen cells is still subject to more research evidence.
recently, Yang Weicai of the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences made progress in controlling the molecular mechanism of the pollen cell cycle regulation.
study found that the mutation of the BICELLULAR POLLEN 1 (BICE1) gene slows down the DNA synthesis of reproductive cells, causing about 40% of the mutated pollen grains to stagnate in the two-cell stage, but the extension of the S phase of the reproductive cell does not affect the differentiation of their cells.
genetic and biochemical evidence suggests an interaction between BICE1 and MCM4 and MCM7, and abnormal two-cell pollen and abnormally concentrated chromosomes are also visible in BICE1 and MCM4 or MCM7 dual mutants.
the study showed that BICE1 played a role in DNA replication regulation through its interactions with MCM4 and MCM7.
the paper was recently published online in the new phyt magazine (DOI: 10.1111/nph.15610).
Yang Weicai Research Group Ph.D. Long Yanping and Ph.D. student Xie Dongjiang are the co-first authors of this article, and researcher Yang Weicai and associate researcher Shi Dongqiao are co-authors.
the research was supported by the National Natural Science Foundation of China and others.
plant institute Li Laixuan team found that many biological processes that regulate the formation of new secondary cell walls of pontoria are regulated by ubiquitinization, a translational modification involving the binding of SUMO (small ubiquitin-like modifier) to proteins.
January 18, 2019, the Chinese Academy of Sciences Shanghai Institute of Planting S. Li Laixuan team published on PLOS Genetics, "SUMO mar-on-LBD30 by SIZ1 regulates cell cell wall in formation Arabidops isthaliana", proposed a lbD30 pan-sensitization-mediated mechanism for the formation of the magenta-secondary cell wall formation.
plant cell walls provide structural support and regulate growth, all plant cells form primary cell walls, synthesized during cell expansion and differentiation, and specialized cell types can also deposit a secondary wall (SCW) on the inside of the primary cell wall after cell elongation is completed.
the main components of SCW are cellulose, non-cellulose polysaccharides and lignin.
these polymers are cross-linked, providing mechanical strength and hydrophobic properties for cell walls.
these characteristics are necessary for upright growth, long-distance transport of solute, selectivity of intra-root embryo nutrients and water transport, defense against pathogens, and the phenomenon of carcass espertin fragmentation, flower cracking and flower shedding 6.
researchers screened a amoeba T-DNA insertion mutant through a microscope to observe phenotypes that formed by SCW in the flower sequence.
two T-DNA insertion allels siz1-2 and siz1-3 impaired the atSIZ1 SUMO E3 connectiveae function and showed morphological characteristics.
compared with wild type, siz1 mutant plants are smaller and have shorter flower sequences.
to determine whether SIZ1 directly affects the formation of SCW, the researchers used an RNAi strategy to inhibit the expression of AtSIZ1 in cells that form secondary walls. The wood fiber cells of the
siz1-2 and siz1-3 showed significantly less wall thickness than wild type (wt) in the study of changes in SCW formation in siz1 mutants, and the researchers analyzed the chemical composition of their cell walls and tested the expression of SCW-related genes.
in the flower sequence, the stem of the siz1 plant reduced crystalline cellulose and lignin by more than 20 compared to wt.
in siz1 plants, non-cellulose polysaccharide is also significantly reduced.
in siz1 plants, the expression of SCW-forming genes is significantly inhibited.
these results show that AtSIZ1 is involved in regulating the transcription network formed by the control SCW.
in the study, the researchers looked at SCW defects in the SiZ1 mutant siennacin.
genetic and biochemical analysis showed that SCW defects were caused by the failure of LBD30 ubiquity mediated by SiZ1.
study reveals the mechanism by which ubiquitinization is used as a regulatory means in the formation of sCW of apoth.
found extensive variations in 1001 genomes and epigenomes of amoeba, an international team of scientists sequenced the whole and epigenomes of more than 1,000 amoeba plants, sampled from geographical locations.
collection of 1,001 genomes and 1,001 epigenomes not only sheds light on new aspects of its evolutionary history, but also provides a comprehensive species map of the interaction between genetic and epigenetic variations in this important model plant.
when next-generation sequencing occurs around 2007, genome sequencing can be sequenced relatively quickly and cheaply.
human geneticists have developed a project to sequence the genome 1000 cataloguing human genetic variation.
plant biologists were reluctant to show weakness and decided that "if our colleagues have a thousand genomes, then we have to have at least one thousand and one genome," said Detlef Weigel, director of the Max Planck Institute for Developmental Biology in Germany.
co-led the 1,001 Genome Project.
but sequencing the genome provides only a part of the story - the researchers further sequenced the transcription and methylation groups of these plants.
many of the problems with plant evolution and adaptation can be solved with new data. "It's a huge hypothesis generator, trying to understand what's going on in nature," explains Joey Kerr, an investigator at the Howard Hughes Institute of Medicine (HHMI) and the Gordon and Betty Moore Foundation (GBMF), a plant biologist at the Salk Institute who directs the 1,001 Epigenetics project.
"In the past, almost all of our genes in the lab have mutated, "
.
but here you are studying subtle and not-so-subtle genetic and epigenetic variations captured from the wild.
", therefore, it provides an opportunity for scientists interested in how wild plants adapt to climate change.
"The researchers will have the tools to study what kind of natural variation exists in the genes of interest," said Magnus Nordborg, director of the Gregor Mendel Institute in Austria, who co-led the 1001 Genome Project.
"ultimate goal is to move away from the reference genome and have a comprehensive understanding of all genetic variations - and everything associated with them.
" the two new studies, to be published july 14, 2016 in the journal Cell, show that about 25 percent of the genes in the genome exhibit diversity in methylation.
methylation, i.e. adding methyl to the DNA chain, is associated with the silence of the transposion factor (the "jump gene" in the genome).
"Methylation can also modify gene expression, for example by blocking transcription factors from landing gene promoters and activating them," said Carol Huang, a computational biologist at the Salk Institute who co-led the epigenome study.
researchers also found that the genome and the epigenome interact closely with each other.
"Some genes can control the epigenome in these different plants," Ecker explains.
" Taiji Kawakatsu, a phytobiologist at the Salk Institute who now works at the National Institute of Agricultural Biosciences in Japan, co-led the work, adding: "These genes may also play a role in producing cell-specific epigenome patterns and interspecies epigenome patterns."
dation of diversity."
although researchers have previously been looking for this link between the genome and the epigenome, the study is limited by smaller sample sizes. "There are 1,000 species, and we can measure how much we can measure the genetic variation to explain methylation variation," said Eriko Sasaki, a demographer at the Gregor Mendel Institute in Austria,
, who co-led epigenomic analysis. "it gives us a better quantitative understanding of the interaction between genetics and methylation variation,"
.
" They found another significant feature of the genes involved in immunity exhibiting more genetic and epigenetic variation than other categories of genes.
immune genes not only have small mutations, but also have "variable epithelial cell states, and are associated with large-scale structural resection and transposion factors," said Florian Jupe, a plant biologist at the Salk Institute who co-leader the genome project.
researchers also noted the correlation between genetic and epigenetic variation and climate and geographic location.
they are working to determine which genes and epigenetic markers allow specific species to thrive in specific environments.
plants are probably one of the best organisms to study adaptation: when plants are placed in a new environment, they have to adapt quickly because they have nowhere to go, explains HHMI investigator Joanne Chory, a plant biologist at the Salk Institute.
was not involved in the study. "I think plants are the only place where genotypes can be mapped to phenotypes and adaptability, "
.
it's hard for humans to do... If they can solve this problem in the plant world, it will make a huge contribution to understanding multicellular life in general," Chory said.
new data set will also be an inspiration to plant breeders, who usually focus on genetic markers to select genes of interest.
"Breeders may use epigenetic information just as they would use genetic information to select characteristics; the power of this approach can now be tested," Ecker said.
"In addition to the usefulness of individual genes, the idea that there are epigenetic variations that can be selected is something they should be aware of," he said.
Source: Network Integration.