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1.
bioRxiv ; 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38617336

ABSTRACT

Formation of biomolecular condensates can be driven by weak multivalent interactions and emergent polymerization. However, the mechanism of polymerization-mediated condensate formation is less studied. We found lateral root cap cell (LRC)-specific SUPPRESSOR OF RPS4-RLD1 (SRFR1) condensates fine-tune primary root development. Polymerization of the SRFR1 N-terminal domain is required for both LRC condensate formation and optimal root growth. Surprisingly, the first intrinsically disordered region (IDR1) of SRFR1 can be functionally substituted by a specific group of intrinsically disordered proteins known as dehydrins. This finding facilitated the identification of functional segments in the IDR1 of SRFR1, a generalizable strategy to decode unknown IDRs. With this functional information we further improved root growth by modifying the SRFR1 condensation module, providing a strategy to improve plant growth and resilience.

2.
Microb Cell Fact ; 22(1): 220, 2023 Oct 26.
Article in English | MEDLINE | ID: mdl-37880695

ABSTRACT

BACKGROUND: Normally, a salt amount greater than 3.5% (w/v) is defined as hypersaline. Large amounts of hypersaline wastewater containing organic pollutants need to be treated before it can be discharged into the environment. The most critical aspect of the biological treatment of saline wastewater is the inhibitory/toxic effect exerted on bacterial metabolism by high salt concentrations. Although efforts have been dedicated to improving the performance through the use of salt-tolerant or halophilic bacteria, the diversities of the strains and the range of substrate spectrum remain limited, especially in chlorophenol wastewater treatment. RESULTS: In this study, a salt-tolerant chlorophenol-degrading strain was generated from Rhodococcus rhodochrous DSM6263, an original aniline degrader, by adaptive laboratory evolution. The evolved strain R. rhodochrous CP-8 could tolerant 8% NaCl with 4-chlorophenol degradation capacity. The synonymous mutation in phosphodiesterase of strain CP-8 may retard the hydrolysis of cyclic adenosine monophosphate (cAMP), which is a key factor reported in the osmoregulation. The experimentally verified up-regulation of intracellular cAMP level in the evolved strain CP-8 contributes to the improvement of growth phenotype under high osmotic condition. Additionally, a point mutant of the catechol 1,2-dioxygenase, CatAN211S, was revealed to show the 1.9-fold increment on activity, which the mechanism was well explained by molecular docking analysis. CONCLUSIONS: This study developed one chlorophenol-degrading strain with extraordinary capacity of salt tolerance, which showed great application potential in hypersaline chlorophenol wastewater treatment. The synonymous mutation in phosphodiesterase resulted in the change of intracellular cAMP concentration and then increase the osmotic tolerance in the evolved strain. The catechol 1,2-dioxygenase mutant with improved activity also facilitated chlorophenol removal since it is the key enzyme in the degradation pathway.


Subject(s)
Chlorophenols , Dioxygenases , Rhodococcus , Catechol 1,2-Dioxygenase/metabolism , Wastewater , Biodegradation, Environmental , Molecular Docking Simulation , Rhodococcus/metabolism , Chlorophenols/chemistry , Chlorophenols/metabolism , Phosphoric Diester Hydrolases/metabolism
3.
Plant Biotechnol J ; 21(3): 536-548, 2023 03.
Article in English | MEDLINE | ID: mdl-36403232

ABSTRACT

Increase in grain yield is always a major objective of wheat genetic improvement. The SQUAMOSA promoter-binding protein-like (SPL) genes, coding for a small family of diverse plant-specific transcription factors, represent important targets for improving grain yield and other major agronomic traits in rice. The function of the SPL genes in wheat remains to be investigated in this respect. In this study, we identified 56 wheat orthologues of rice SPL genes belonging to 19 homoeologous groups. Like in rice, nine orthologous TaSPL genes harbour the microRNA156 recognition elements (MRE) in their last exons except for TaSPL13, which harbour the MRE in its 3'-untranslated region (3'UTR). We modified the MRE of TaSPL13 using CRISPR-Cas9 and generated 12 mutations in the three homoeologous genes. As expected, the MRE mutations led to an approximately two-fold increase in the TaSPL13 mutant transcripts. The phenotypic evaluation showed that the MRE mutations in TaSPL13 resulted in a decrease in flowering time, tiller number, and plant height, and a concomitantly increase in grain size and number. The results show that the TaSPL13 mutants exhibit a combination of different phenotypes observed in Arabidopsis AtSPL3/4/5 mutants and rice OsSPL13/14/16 mutants and hold great potential in improving wheat yield by simultaneously increasing grain size and number and by refining plant architecture. The novel TaSPL13 mutations generated can be utilized in wheat breeding programmes to improve these agronomic traits.


Subject(s)
Plant Breeding , Triticum , Triticum/genetics , Mutation , Phenotype , Promoter Regions, Genetic , Edible Grain/genetics
5.
Plant Biotechnol J ; 17(8): 1623-1635, 2019 08.
Article in English | MEDLINE | ID: mdl-30706614

ABSTRACT

CRISPR/Cas9 has been widely used for genome editing in many organisms, including important crops like wheat. Despite the tractability in designing CRISPR/Cas9, efficacy in the application of this powerful genome editing tool also depends on DNA delivery methods. In wheat, the biolistics based transformation is the most used method for delivery of the CRISPR/Cas9 complex. Due to the high frequency of gene silencing associated with co-transferred plasmid backbone and low edit rate in wheat, a large T0 transgenic plant population are required for recovery of desired mutations, which poses a bottleneck for many genome editing projects. Here, we report an Agrobacterium-delivered CRISPR/Cas9 system in wheat, which includes a wheat codon optimized Cas9 driven by a maize ubiquitin gene promoter and a guide RNA cassette driven by wheat U6 promoters in a single binary vector. Using this CRISPR/Cas9 system, we have developed 68 edit mutants for four grain-regulatory genes, TaCKX2-1, TaGLW7, TaGW2, and TaGW8, in T0 , T1 , and T2 generation plants at an average edit rate of 10% without detecting off-target mutations in the most Cas9-active plants. Homozygous mutations can be recovered from a large population in a single generation. Different from most plant species, deletions over 10 bp are the dominant mutation types in wheat. Plants homozygous of 1160-bp deletion in TaCKX2-D1 significantly increased grain number per spikelet. In conclusion, our Agrobacterium-delivered CRISPR/Cas9 system provides an alternative option for wheat genome editing, which requires a small number of transformation events because CRISPR/Cas9 remains active for novel mutations through generations.


Subject(s)
CRISPR-Cas Systems , Gene Editing , Triticum/genetics , Agrobacterium , Genome, Plant , Plants, Genetically Modified , Promoter Regions, Genetic , RNA, Guide, Kinetoplastida/genetics , Sequence Deletion
6.
Mol Ecol Resour ; 18(6): 1427-1443, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30086204

ABSTRACT

Tragopogon (Asteraceae) is an excellent natural system for studies of recent polyploidy. Development of an efficient CRISPR/Cas9-based genome editing platform in Tragopogon will facilitate novel studies of the genetic consequences of polyploidy. Here, we report our initial results of developing CRISPR/Cas9 in Tragopogon. We have established a feasible tissue culture and transformation protocol for Tragopogon. Through protoplast transient assays, use of the TragCRISPR system (i.e. the CRISPR/Cas9 system adapted for Tragopogon) was capable of introducing site-specific mutations in Tragopogon protoplasts. Agrobacterium-mediated transformation with Cas9-sgRNA constructs targeting the phytoene desaturase gene (TraPDS) was implemented in this model polyploid system. Sequencing of PCR amplicons from the target regions indicated simultaneous mutations of two alleles and four alleles of TraPDS in albino shoots from Tragopogon porrifolius (2x) and Tragopogon mirus (4x), respectively. The average proportions of successfully transformed calli with the albino phenotype were 87% and 78% in the diploid and polyploid, respectively. This appears to be the first demonstration of CRISPR/Cas9-based genome editing in any naturally formed neopolyploid system. Although a more efficient tissue culture system should be developed in Tragopogon, application of a robust CRISPR/Cas9 system will permit unique studies of biased fractionation, the gene-balance hypothesis and cytonuclear interactions in polyploids. In addition, the CRISPR/Cas9 platform enables investigations of those genes involved in phenotypic changes in polyploids and will also facilitate novel functional biology studies in Asteraceae. Our workflow provides a guide for applying CRISPR/Cas9 to other nongenetic model plant systems.


Subject(s)
Gene Editing/methods , Polyploidy , Tragopogon/genetics , Agrobacterium/genetics , CRISPR-Associated Protein 9/metabolism , Cell Culture Techniques , Clustered Regularly Interspaced Short Palindromic Repeats , Mutagenesis, Site-Directed , Protoplasts , Transformation, Genetic
7.
Plant Biotechnol J ; 16(2): 381-393, 2018 02.
Article in English | MEDLINE | ID: mdl-28640964

ABSTRACT

The CRISPR/Cas9 system has become a powerful tool for targeted mutagenesis. Switchgrass (Panicum virgatum L.) is a high yielding perennial grass species that has been designated as a model biomass crop by the U.S. Department of Energy. The self-infertility and high ploidy level make it difficult to study gene function or improve germplasm. To overcome these constraints, we explored the feasibility of using CRISPR/Cas9 for targeted mutagenesis in a tetraploid cultivar 'Alamo' switchgrass. We first developed a transient assay by which a non-functional green-fluorescent protein gene containing a 1-bp frameshift insertion in its 5' coding region was successfully mutated by a Cas9/sgRNA complex resulting in its restored function. Agrobacterium-mediated stable transformation of embryogenic calli derived from mature caryopses averaged a 3.0% transformation efficiency targeting the genes of teosinte branched 1(tb1)a and b and phosphoglycerate mutase (PGM). With a single construct containing two sgRNAs targeting different regions of tb1a and tb1b genes, primary transformants (T0) containing CRISPR/Cas9-induced mutations were obtained at frequencies of 95.5% (tb1a) and 11% (tb1b), respectively, with T0 mutants exhibiting increased tiller production. Meanwhile, a mutation frequency of 13.7% was obtained for the PGM gene with a CRISPR/Cas9 construct containing a single sgRNA. Among the PGM T0 mutants, six are heterozygous and one is homozygous for a 1-bp deletion in the target region with no apparent phenotypical alterations. We show that CRISPR/Cas9 system can generate targeted mutagenesis effectively and obtain targeted homozygous mutants in T0 generation in switchgrass, circumventing the need of inbreeding.


Subject(s)
CRISPR-Cas Systems/genetics , Genome, Plant/genetics , Panicum/genetics , Gene Editing , Mutagenesis/genetics , Tetraploidy
8.
BMC Genomics ; 17(1): 789, 2016 10 10.
Article in English | MEDLINE | ID: mdl-27724902

ABSTRACT

BACKGROUND: Lycoris aurea is a medicine-valuable and ornamental herb widely distributed in China. Former studied have showed that methyl jasmonate (MJ) treatment could increase the content of glanthamine-a worldwide medicine for symptomatic treatment of Alzheimer's disease in genus Lycoris plants. To explore the possible role of miRNAs in the regulation of jasmonic acid signaling pathway and uncover their potential correlations, we investigated the expression profiles of small RNAs (sRNAs) and their targets in Lycoris aurea, with MJ treatment by using next-generation deep sequencing. RESULTS: A total of 365 miRNAs were identified, comprising 342 known miRNAs (representing 60 miRNA families) and 23 novel miRNAs. Among them, 143 known and 11 novel miRNAs were expressed differently under MJ treatment. Quantitative real-time PCR of eight selected miRNAs validated the expression pattern of these loci in response to MJ treatment. In addition, degradome sequencing analysis showed that 32 target genes were validated to be targeted by the 49 miRNAs, respectively. Gene function and pathway analyses showed that these targets such as auxin response factors (ARFs), squamosa promoter-binding like (SPL) proteins, basic helix-loop-helix (bHLH) proteins, and ubiquitin-conjugating enzyme E2 are involved in different plant processes, indicating miRNAs mediated regulation might play important roles in L. aurea response to MJ treatment. Furthermore, several L. aurea miRNAs associated with their target genes that might be involved in Amaryllidaceae alkloids biosynthehsis were also analyzed. CONCLUSIONS: A number of miRNAs with diverse expression patterns, and complex relationships between expression of miRNAs and targets were identified. This study represents the first transcriptome-based analysis of miRNAs in Lycoris and will contribute to understanding the potential roles of miRNAs involved in regulation of MJ response.


Subject(s)
Acetates/pharmacology , Cyclopentanes/pharmacology , Gene Expression Regulation, Plant/drug effects , Lycoris/drug effects , Lycoris/genetics , MicroRNAs/genetics , Oxylipins/pharmacology , Plant Growth Regulators/pharmacology , RNA, Plant , Cluster Analysis , Computational Biology , Evolution, Molecular , Gene Expression Profiling , High-Throughput Nucleotide Sequencing , Reproducibility of Results , Transcriptome
9.
J Integr Plant Biol ; 58(5): 475-91, 2016 May.
Article in English | MEDLINE | ID: mdl-26172438

ABSTRACT

Limited information is available for soybean root traits and their plasticity under drought stress. To date, no studies have focused on examining diverse soybean germplasm for regulation of shoot and root response under water limited conditions across varying soil types. In this study, 17 genetically diverse soybean germplasm lines were selected to study root response to water limited conditions in clay (trial 1) and sandy soil (trial 2) in two target environments. Physiological data on shoot traits was measured at multiple crop stages ranging from early vegetative to pod filling. The phenotypic root traits, and biomass accumulation data are collected at pod filling stage. In trial 1, the number of lateral roots and forks were positively correlated with plot yield under water limitation and in trial 2, lateral root thickness was positively correlated with the hill plot yield. Plant Introduction (PI) 578477A and 088444 were found to have higher later root number and forks in clay soil with higher yield under water limitation. In sandy soil, PI458020 was found to have a thicker lateral root system and higher yield under water limitation. The genotypes identified in this study could be used to enhance drought tolerance of elite soybean cultivars through improved root traits specific to target environments.


Subject(s)
Glycine max/growth & development , Seeds/growth & development , Water , Biomass , Humidity , Missouri , Phenotype , Phylogeny , Plant Leaves/physiology , Plant Roots/physiology , Plant Shoots/physiology , Quantitative Trait, Heritable , Soil , Stress, Physiological
10.
J Biotechnol ; 216: 98-9, 2015 Dec 20.
Article in English | MEDLINE | ID: mdl-26467717

ABSTRACT

Thermophilic Geobacillus thermoglucosidasius could ferment a wide range of substrates with low nutrient requirements for growth. Here, the first released the complete genome sequence of G. thermoglucosidasius DSM2542 may facilitate the design of rational strategies for further strain improvements and provide information for exploring industrially interesting enzymes with thermotolerant properties.


Subject(s)
Biotechnology , Genome, Bacterial , Geobacillus/genetics , Industrial Microbiology , Base Sequence
11.
PLoS One ; 10(10): e0140524, 2015.
Article in English | MEDLINE | ID: mdl-26468648

ABSTRACT

KEY MESSAGE: W3 is essential for ß-diketone biosynthesis but suppresses its hydroxylation. Loss-of-function mutation w3 significantly increased cuticle permeability in terms of water loss and chlorophyll efflux.


Subject(s)
Genes, Plant , Nitriles/metabolism , Quantitative Trait Loci , Sulfones/metabolism , Triticum/genetics , Triticum/metabolism , Waxes/metabolism , Chromosome Mapping , Gene Expression Regulation, Plant , Mutation , Permeability , Phenotype , Transcription, Genetic , Waxes/chemistry
12.
Theor Appl Genet ; 128(4): 745-55, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25656150

ABSTRACT

KEY MESSAGE: This work laid the foundation for cloning of shattering gene Br2 and provided first line of evidence that two major Aegilops tauschii lineages are differentiated by an inversion polymorphism. Chromosome inversions often accompany population differentiation and capture local adaptation during speciation. Aegilops tauschii, the D-genome donor species of hexaploid wheat, consists of two genetically isolated lineages, L1 and L2, but little is known about the genetic mechanisms underlying the population differentiation in this diploid species. During fine mapping of the shattering gene Br2 using a large F2 population derived from a cross between TA1604 (an L1 accession) and AL8/78 (an L2 accession), we found contrasting patterns of crossover distribution in the Br2 interval and neighboring regions despite the high local gene synteny with Brachypodium distachyon and rice. Br2 was localized in a 0.08-cM interval, and 13 marker loci formed a block, where single-crossovers were completely suppressed, but double-crossovers were enriched with a recombination rate of ~11 cM/Mb. In contrast, in a neighboring region no double-crossover was recovered, but single-crossover rate reached 24 cM/Mb, which is much higher than the genome-wide average. This result suggests a putative inversion polymorphism between the parental lines in the Br2 region. Genotyping using the markers from the Br2 region divided a collection of 55 randomly sampled A. tauschii accessions into two major groups, and they are largely genetically isolated. The two groups correspond to the L1 and L2 lineages based on their geographic distribution patterns. This provides first evidence that inversions may underlie the evolution of A. tauschii lineages. The presence of inter-lineage inversions may complicate map-based cloning in A. tauschii and transfer of useful traits to wheat.


Subject(s)
Chromosome Inversion , Chromosome Mapping , Chromosomes, Plant , Poaceae/genetics , Cloning, Molecular , Evolution, Molecular , Genetic Linkage , Genetic Markers , Genetics, Population , Genome, Plant , Genotype , Haplotypes , Oryza/genetics , Phylogeny , Recombination, Genetic , Sequence Analysis, DNA , Triticum/genetics
13.
New Phytol ; 204(3): 704-714, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25059383

ABSTRACT

Polyploid wheats comprise four species: Triticum turgidum (AABB genomes) and T. aestivum (AABBDD) in the Emmer lineage, and T. timopheevii (AAGG) and T. zhukovskyi (AAGGA(m) A(m) ) in the Timopheevi lineage. Genetic relationships between chloroplast genomes were studied to trace the evolutionary history of the species. Twenty-five chloroplast genomes were sequenced, and 1127 plant accessions were genotyped, representing 13 Triticum and Aegilops species. The A. speltoides (SS genome) diverged before the divergence of T. urartu (AA), A. tauschii (DD) and the Aegilops species of the Sitopsis section. Aegilops speltoides forms a monophyletic clade with the polyploid Emmer and Timopheevi wheats, which originated within the last 0.7 and 0.4 Myr, respectively. The geographic distribution of chloroplast haplotypes of the wild tetraploid wheats and A. speltoides illustrates the possible geographic origin of the Emmer lineage in the southern Levant and the Timopheevi lineage in northern Iraq. Aegilops speltoides is the closest relative of the diploid donor of the chloroplast (cytoplasm), as well as the B and G genomes to Timopheevi and Emmer lineages. Chloroplast haplotypes were often shared by species or subspecies within major lineages and between the lineages, indicating the contribution of introgression to the evolution and domestication of polyploid wheats.


Subject(s)
Biological Evolution , Chloroplasts/genetics , Polyploidy , Triticum/genetics , Genetic Variation , Genome, Plant , Genotype
14.
Plant Sci ; 214: 113-20, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24268169

ABSTRACT

Dehydrins (DHNs) are late embryonic abundant proteins characterized by the dehydrin domains that are involved in plant abiotic stress tolerance. In this study, fifty-four wheat DHN unigenes were identified in the expressed sequence tags database. These genes encode seven types of dehydrins (KS, SK3, YSK2, Y2SK2, Kn, Y2SK3, and YSK3) and separate in 32 homologous clusters. The gene amplification differed among the dehydrin types, and members of the YSK2- and Kn-type DHNs are more numerous in wheat than in other cereals. The relative expression of all of these DHN clusters was analyzed using an in silico method in seven tissue types (i.e. normal growing shoots, roots, and reproductive tissues; developing and germinating seeds; drought- and cold-stressed shoots) as well as semi-quantitative reverse transcription polymerase chain reaction in seedling leaves and roots treated by dehydration, cold, and salt, respectively. The role of the ABA pathway in wheat DHN expression regulation was analyzed. Transcripts of certain types of DHNs accumulated specifically according to tissue type and treatment, which suggests their differentiated roles in wheat abiotic stress tolerance.


Subject(s)
Gene Expression Profiling , Multigene Family , Plant Proteins/genetics , Triticum/genetics , Abscisic Acid/pharmacology , Cold Temperature , Droughts , Expressed Sequence Tags , Flowers/genetics , Flowers/growth & development , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Plant/drug effects , Genetic Variation , Phylogeny , Plant Growth Regulators/pharmacology , Plant Leaves/genetics , Plant Leaves/growth & development , Plant Proteins/classification , Plant Roots/genetics , Plant Roots/growth & development , Plant Shoots/genetics , Plant Shoots/growth & development , Reverse Transcriptase Polymerase Chain Reaction , Seedlings/genetics , Seedlings/growth & development , Seeds/genetics , Seeds/growth & development , Sodium Chloride/pharmacology , Triticum/growth & development
15.
Theor Appl Genet ; 126(8): 2123-39, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23689745

ABSTRACT

Understanding the genetics underlying yield formation of wheat is important for increasing wheat yield potential in breeding programs. Nanda2419 was a widely used cultivar for wheat production and breeding in China. In this study, we evaluated yield components and a few yield-related traits of a recombinant inbred line (RIL) population created by crossing Nanda2419 with the indigenous cultivar Wangshuibai in three to four trials at different geographical locations. Negative and positive correlations were found among some of these evaluated traits. Five traits had over 50 % trial-wide broad sense heritability. Using a framework marker map of the genome constructed with this population, quantitative trait loci (QTL) were identified for all traits, and epistatic loci were identified for seven of them. Our results confirmed some of the previously reported QTLs in wheat and identified several new ones, including QSn.nau-6D for effective tillers, QGn.nau-4B.2 for kernel number, QGw.nau-4D for kernel weight, QPh.nau-4B.2 and QPh.nau-4A for plant height, and QFlw.nau-5A.1 for flag leaf width. In the investigated population, Nanda2419 contributed all QTLs associated with higher kernel weight, higher leaf chlorophyll content, and a major QTL associated with wider flag leaf. Seven chromosome regions were related to more than one trait. Four QTL clusters contributed positively to breeding goal-based trait improvement through the Nanda2419 alleles and were detected in trials set in different ecological regions. The findings of this study are relevant to the molecular improvement of wheat yield and to the goal of screening cultivars for better breeding parents.


Subject(s)
Inbreeding/methods , Triticum/genetics , China , Chromosome Mapping , Chromosomes, Plant/genetics , Crops, Agricultural/genetics , Crosses, Genetic , Phenotype , Quantitative Trait Loci/genetics
16.
Theor Appl Genet ; 126(5): 1189-200, 2013 May.
Article in English | MEDLINE | ID: mdl-23381806

ABSTRACT

Non-additive allelic interactions underlie over dominant and under dominant inheritance, which explain positive and negative heterosis. These heteroses are often observed in the aboveground traits, but rarely reported in root. We identified a very short root (VSR) phenotype in the F1 hybrid between the common wheat (Triticum aestivum L.) landrace Chinese Spring and synthetic wheat accession TA4152-71. When germinated in tap water, primary roots of the parental lines reached ~15 cm 10 days after germination, but those of the F1 hybrid were ~3 cm long. Selfing populations segregated at a 1 (long-root) to 1 (short-root) ratio, indicating that VSR is controlled by a non-additive interaction between two alleles in a single gene locus, designated as Vsr1. Genome mapping localized the Vsr1 locus in a 3.8-cM interval delimited by markers XWL954 and XWL2506 on chromosome arm 5DL. When planted in vermiculite with supplemental fertilizer, the F1 hybrid had normal root growth, virtually identical to the parental lines, but the advanced backcrossing populations segregated for VSR, indicating that the F1 VSR expression was suppressed by interactions between other genes in the parental background and the vermiculite conditions. Preliminary physiological analyses showed that the VSR suppression is independent of light status but related to potassium homeostasis. Phenotyping additional hybrids between common wheat and synthetics revealed a high VSR frequency and their segregation data suggested more Vsr loci involved. Because the VSR plants can be regularly maintained and readily phenotyped at the early developmental stage, it provides a model for studies of non-additive interactions in wheat.


Subject(s)
Chromosomes, Plant/genetics , Genes, Plant , Hybrid Vigor/genetics , Plant Roots/genetics , Triticum/genetics , Crosses, Genetic , Gene-Environment Interaction , Germination , Phenotype , Plant Roots/growth & development , Triticum/growth & development
17.
PLoS One ; 8(1): e54129, 2013.
Article in English | MEDLINE | ID: mdl-23349804

ABSTRACT

Cuticular wax composition greatly impacts plant responses to dehydration. Two parallel pathways exist in Triticeae for manipulating wax composition: the acyl elongation, reduction, and decarbonylation pathway that is active at the vegetative stage and yields primary alcohols and alkanes, and the ß-diketone pathway that predominates at the reproductive stage and synthesizes ß-diketones. Variation in glaucousness during the reproductive stage of wheat is mainly controlled by the wax production genes, W1 and W2, and wax inhibitor genes, Iw1 and Iw2. Little is known about the metabolic and physiological effects of the genetic interactions among these genes and their roles in shifting wax composition during plant development. We characterized the effect of W1, W2, Iw1, and Iw2 and analyzed their interaction using a set of six near-isogenic lines (NILs) by metabolic, molecular and physiological approaches. Loss of functional alleles of both W genes or the presence of either Iw gene depletes ß-diketones and results in the nonglaucous phenotype. Elimination of ß-diketones is compensated for by an increase in aldehydes and primary alcohols in the Iw NILs. Accordingly, transcription of CER4-6, which encodes an alcohol-forming fatty acyl-CoA reductase, was elevated 120-fold in iw1Iw2. CER4-6 was transcribed at much higher levels in seedlings than in adult plants, and showed little difference between the glaucous and nonglaucous NILs, suggesting that Iw2 counteracts the developmental repression of CER4-6 at the reproductive stage. While W1 and W2 redundantly function in ß-diketone biosynthesis, a combination of both functional alleles led to the ß-diketone hydroxylation. Consistent with this, transcription of MAH1-9, which encodes a mid-chain alkane hydroxylase, increased seven-fold only in W1W2. In parallel with the hydroxyl-ß-diketone production patterns, glaucousness was intensified and cuticle permeability was reduced significantly in W1W2 compared to the other NILs. This suggests that both W1 and W2 are required for enhancing drought tolerance.


Subject(s)
Ketones/metabolism , Plant Epidermis/metabolism , Plant Proteins/metabolism , Triticum/metabolism , Waxes/metabolism , Adaptation, Physiological/genetics , Biosynthetic Pathways/genetics , Droughts , Epistasis, Genetic , Gas Chromatography-Mass Spectrometry , Gene Expression Profiling , Gene Expression Regulation, Plant , Microscopy, Electron, Scanning , Permeability , Plant Epidermis/genetics , Plant Epidermis/ultrastructure , Plant Leaves/genetics , Plant Leaves/metabolism , Plant Leaves/ultrastructure , Plant Proteins/genetics , Polymorphism, Single Nucleotide , Reverse Transcriptase Polymerase Chain Reaction , Triticum/genetics , Waxes/chemistry
18.
J Bacteriol ; 194(22): 6304-5, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23105052

ABSTRACT

Pseudomonas aeruginosa DQ8, which was isolated from the crude oil polluted soil in the Daqing oilfield of China, can efficiently degrade diesel, crude oil, n-alkanes, and polycyclic aromatic hydrocarbons (PAHs). Here, we present a 6.8-Mb assembly of its genome sequence. We have annotated 23 coding sequences (CDSs) responsible for catabolism of n-alkanes and PAHs.


Subject(s)
Alkanes/metabolism , Genome, Bacterial , Polycyclic Aromatic Hydrocarbons/metabolism , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/genetics , Gene Expression Regulation, Bacterial , Molecular Sequence Data
19.
J Biomed Mater Res A ; 100(7): 1761-9, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22488929

ABSTRACT

Digital flexor tendon repair poses a significant challenge for hand surgeons. Currently, extrasynovial tendon grafts are frequently used in clinical settings to bridge flexor tendon defects. However, the healing process is always accompanied by postoperative adhesion. This is mostly due to the fact that no synovial membrane covers the extrasynovial tendon surface, in contrast to the intrasynovial tendon. In this study, we present an efficient method of developing a functional synovial biomembrane on the surface of the extrasynovial tendon. Synoviocytes were isolated from the knee joint of a Japanese white rabbit. After being infected with lentivirus, the over-expression of synoviolin in these synoviocytes was confirmed by semi-quantitative RT-PCR and western blotting. Cellular proliferation and increased hyaluronic acid secretion were confirmed in the synoviolin over-expressing synoviocytes by MTT-based method, cell cycle assays and ELISA. Furthermore, the synoviolin over-expressing synoviocytes were co-cultured with extrasynovial tendons that were harvested from the hind leg of rabbits. After being co-cultured in vitro for 3 and 7 days, these infected synoviocytes were found to accelerate the formation of a biomembrane on the tendon surface compared to the control group. More importantly, Alcian blue staining confirmed the ability of this cultured biomembrane to produce specific matrices containing acidic carboxyl mucopolysaccharides (mainly hyaluronic acid). All these results demonstrate that the over-expression of synoviolin stimulates the proliferation and HA secretion of synoviocytes and facilitates the formation of a functional synovial biomembrane.


Subject(s)
Cell Membrane , Synovial Membrane , Ubiquitin-Protein Ligases/metabolism , Animals , Base Sequence , Coculture Techniques , DNA Primers , Enzyme-Linked Immunosorbent Assay , Hyaluronic Acid/metabolism , Lentivirus/genetics , Microscopy, Electron, Scanning , Rabbits , Reverse Transcriptase Polymerase Chain Reaction , Synovial Membrane/metabolism , Tendons/surgery , Tumor Suppressor Protein p53/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitination
20.
PLoS One ; 6(11): e27166, 2011.
Article in English | MEDLINE | ID: mdl-22087259

ABSTRACT

BACKGROUND: The major hindrance to multidetector CT imaging of the left extraperitoneal space (LES), and the detailed spatial relationships to its related spaces, is that there is no obvious density difference between them. Traditional gross anatomy and thick-slice sectional anatomy imagery are also insufficient to show the anatomic features of this narrow space in three-dimensions (3D). To overcome these obstacles, we used a new method to visualize the anatomic features of the LES and its spatial associations with related spaces, in random sections and in 3D. METHODS: In conjunction with Mimics® and Amira® software, we used thin-slice cross-sectional images of the upper abdomen, retrieved from the Chinese and American Visible Human dataset and the Chinese Virtual Human dataset, to display anatomic features of the LES and spatial relationships of the LES to its related spaces, especially the gastric bare area. The anatomic location of the LES was presented on 3D sections reconstructed from CVH2 images and CT images. PRINCIPAL FINDINGS: What calls for special attention of our results is the LES consists of the left sub-diaphragmatic fat space and gastric bare area. The appearance of the fat pad at the cardiac notch contributes to converting the shape of the anteroexternal surface of the LES from triangular to trapezoidal. Moreover, the LES is adjacent to the lesser omentum and the hepatic bare area in the anterointernal and right rear direction, respectively. CONCLUSION: The LES and its related spaces were imaged in 3D using visualization technique for the first time. This technique is a promising new method for exploring detailed communication relationships among other abdominal spaces, and will promote research on the dynamic extension of abdominal diseases, such as acute pancreatitis and intra-abdominal carcinomatosis.


Subject(s)
Imaging, Three-Dimensional/methods , Peritoneal Cavity/anatomy & histology , Visible Human Projects , Abdominal Cavity/anatomy & histology , China , Humans , Omentum , Software , United States
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