Polyploid cells, which contain more than one set of chromosome pairs, are very common in nature. Polyploidy can provide cells with several potential benefits over their diploid counterparts, including an increase in cell size, contributing to organ growth and tissue homeostasis, and improving cellular robustness via increased tolerance to genomic stress and apoptotic signals. Here, we focus on why polyploidy in the cell occurs and which stress responses and molecular signals trigger cells to become polyploid. Moreover, we discuss its crucial roles in cell growth and tissue regeneration in the heart, liver, and other tissues.
Humans ; Liver ; Hepatocytes ; Cell Cycle ; Polyploidy ; Homeostasis

Lycophytes and seed plants constitute the typical vascular plants. Lycophytes have been thought to have no paleo-polyploidization although the event is known to be critical for the fast expansion of seed plants. Here, genomic analyses including the homologous gene dot plot analysis detected multiple paleo-polyploidization events, with one occurring approximately 13-15 million years ago (MYA) and another about 125-142 MYA, during the evolution of the genome of Selaginella moellendorffii, a model lycophyte. In addition, comparative analysis of reconstructed ancestral genomes of lycophytes and angiosperms suggested that lycophytes were affected by more paleo-polyploidization events than seed plants. Results from the present genomic analyses indicate that paleo-polyploidization has contributed to the successful establishment of both lineages-lycophytes and seed plants-of vascular plants.
Evolution, Molecular ; Genome, Plant ; Genomics ; Phylogeny ; Polyploidy ; Selaginellaceae/genetics*

OBJECTIVETo establish an effective protocol for plant generation and induce polyploidy of Morinda offcinalis.

METHODCallus was induced from immature embryo of M. officinalis and polyploidy was inducted by using colchicine treatment method. Chromosome was detected by flow cytometry.

RESULT AND CONCLUSIONThe highest induction rate of polyploidy was 18.40%, which was obtained with 500 mg x L(-1) colchicine treatment for 5 days. Roots of polyploid were bigger than diploid. Advantages of using immature embryo as explants are easy for sterilization, higher rate of callus induction and low degree dedifferentiation. The induced polyploidy of M. officinalis may have a value for spread of cultivation.

Chromosomes, Plant ; genetics ; Morinda ; genetics ; growth & development ; Polyploidy ; Tissue Culture Techniques ; methods

OBJECTIVETo determine the content of imperatorin in the tetraploidy radix angelicae dahuricae, and compare it with the original diplontic varites.

METHODThe chromatographic method was carried out on Nova-pak (4.6 mm x 200 mm, 5 microns) column with acetonitrile-water solution as a mobile phase. The flow rate was 1 ml.min-1. the detection wavelength was at 248 nm, and the column temperature was 25 degrees C.

RESULTThe eontent of was imperatorin in the tetraploidy radix 0.460% and 0.225% imperatorin in the diplontic species.

CONCLUSIONThe content of the mainly active constituent in the tetraploid is double to what it is in the original diplontic species.

Angelica ; chemistry ; genetics ; Furocoumarins ; analysis ; Plant Roots ; chemistry ; genetics ; Plants, Medicinal ; chemistry ; genetics ; Polyploidy

OBJECTIVETo acquire homozygous tetraploid germplasm of Rhodiola sachalinensis.

METHODPEG-mediated protoplast fusions were conducted using callus of Rh. sachalinensis as materials. Protoplast fusion products were embedded and cultured in low-density, low-melting-point agar and marked according to the protoplast size, and single-celled sister lines were established to acquire genetically homozygous tetraploid germplasm.

RESULTR(D) and R(M) of newborn daughter cells or protoplasm, metaphase cells or protoplasm were approximately in line with the formula R(D) = 0.793 7R(M). The change range in diameter of the diploid cells without fusion, two protoplasts fusion product were: 16.7 microm < or = R < 21.3 microm, 21.0 microm < or = R' < 26.8 microm respectively. There is an overlap between the two diameter ranges. The protoplast inoculation density of 1 x 10(4) cells x mL(-1) was appropriate when protoplasts were anchored by low-intensity, low-melting-point agar. Under the conditions of this density, plating efficiency was high and single cell origin of the sister lines microclones grew rapidly, and it was easy to mark the single cell microclones, and separate from each other to subculture. The chromosome counts results showed that chromosome numbers of diploid and tetraploid of single cell lines were 26 and 52, respectively. The result from flow cytometry assay showed that there is no presence of chimerism in single-cell regeneration plantlets.

CONCLUSIONThe results of this study provide a scientific basis for polyploid breeding of Rh. sachalinensis.

Cell Fusion ; methods ; Polyethylene Glycols ; pharmacology ; Polyploidy ; Protoplasts ; cytology ; drug effects ; Rhodiola ; cytology ; drug effects ; genetics

OBJECTIVEIn order to clarify the genetic background of Pinellia ternata germplasm resources in China, the chromosomal constitution and cytogeographical distribution of P. ternata were investigated in 27 different populations among 16 provinces and regions in China systematically.

METHODCytological and cytogeographical methods were used in the study.

RESULTP. ternata in China is a polyploid complex, which contains septuploid (2n = 7x = 91) , octoploid (2n = 8x = 104) , nonuploid (2n = 9x = 117) and decaploid (2n = 10x = 130). Meanwhile the aneuploid series (2n = 92, 103, 105, 115) of a minority of P. ternata were also found.

CONCLUSIONThe genetic differentiation and the phenomenon of ploidy miscellany commonly exist in the species of P. ternata in China, both for natural populations and cultivated populations. Toxicity and chemical components of different ploidy P. ternata should be clarified before the superior multiploid is selected for normalized plantation of the plant.

Aneuploidy ; China ; Chromosomes, Plant ; genetics ; Ecosystem ; Genetic Variation ; Pinellia ; genetics ; Plants, Medicinal ; genetics ; Polyploidy

An ancient genome duplication (PPP1) that predates divergence of the cereals has recently been recognized. We report here another potentially older large-scale duplication (PPP2) event that predates monocot-dicot divergence in the genome of rice (Oryza sativa L.), as inferred from the age distribution of pairs of duplicate genes based on recent genome data for rice. Our results suggest that paleopolyploidy was widespread and played an important role in the evolution of rice.
Biological Evolution ; Chromosome Mapping ; methods ; Evolution, Molecular ; Genetic Variation ; genetics ; Genome, Plant ; Oryza ; genetics ; Polyploidy

AIMTo investigate the chemical constituents of tetraploidy Banlangen (Isatis indigotica Fort.).

METHODSCompounds were separated by chromatography on silica gel. Their structures were determined by spectral analysis and chemical evidence.

RESULTSThree compounds were isolated. Their structures were identified as (E)-2-[(3'-indole) cyanomethylene]-3-indolinone (I), 2-(4-hydroxy-3-methoxyphenyl)-4-[(4-hydroxy-3-methoxy-phenyl)-methyl]-3- hydroxymethyl-tetrahydro-furan (II) and 2-methoxy-4-[tetrahydro-4-[(4-hydroxy-3-methoxy-phenyl)-methyl]-3- hydroxymethyl-2-furanyl] phenyl-1-O-beta-D-glucopyranoside (III).

CONCLUSIONCompound I is a new compound.

Indoles ; chemistry ; Isatis ; chemistry ; genetics ; Molecular Structure ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; genetics ; Polyploidy

Andrographis paniculata (Burm. f.) Nees (AP) is commonly used for the treatment of many infectious diseases and has been cultivated widely in Asian countries, and has been included in United States Pharmacopoeia as a dietary supplement, but the cultivars of A. paniculata are not abundant due to its self-pollinated. With the aims to enrich AP resources and provide materials for after breeding we explored the polyploidy induction. Different explants, colchicine concentration, and treatment time were tested. After identification by flow cytometry, eleven polyploid plants with different morphologic traits were obtained. The agronomic traits and andrographolide concentration of the polyploids were improved greatly. One of the polyploids (serial 3-7) was chosen for further study. The traits of the second and third generation polyploids (serial 3-7) were stable. Compared with the normal plants, the seeds (2nd generation) weight increased by 31%, and the andrographolide concentration of the leaves increased by 14% (2nd) and 28% (3rd). In conclusion, AP autopolyploids with different morphologic traits were established successfully for the first time, and the polyploids induction might be effective for crop improvement of AP.
Andrographis ; chemistry ; genetics ; growth & development ; Breeding ; Cell Culture Techniques ; Plant Extracts ; chemistry ; Polyploidy

OBJECTIVETo study the numbers of chromosome in Chinese herb Salvia miltiorrhiza from 7 provinces in China, and S. flava as well as S. evansiana from Yunnan province in China.

METHODThe young root was treated with the mixture of ice and water for 24 h, fixed with Carony's fixative for 6-12 h. After differentiating for 10-12 min with 1 mol x L(-1) hydrochloric acid at 60 'C and staining with carbol fuchsin,the section was observed under microscope.

RESULTChromosome numbers of S. miltiorrhiza and S.flava were 2n = 2x = 16. The numbers of S. evansiana were 2n = 4x = 32. The basic numbers of the chromosomes were x = 8. And tetraploids were observed in S. miltiorrhiza from Sichuan provices and Shandong provices.

CONCLUSIONThe basic number of the chromosomes are x = 8. The chromosome numbers of S. miltiorrhiza, S.flava and S. evansiana are 16,16 and 32 respectively. As the chromosomes are the small or micro-small ones, it is difficult to use them for karyotype.

Chromosomes, Plant ; genetics ; Diploidy ; Plant Roots ; genetics ; Plants, Medicinal ; genetics ; Polyploidy ; Salvia miltiorrhiza ; classification ; genetics ; Species Specificity