Displaying publications 81 - 100 of 113 in total

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  1. Fulltext Differentiation of chromoplasts and other plastids in plants
    Sadali NM, Sowden RG, Ling Q, Jarvis RP
    Plant Cell Rep, 2019 Jul;38(7):803-818.
    PMID: 31079194 DOI: 10.1007/s00299-019-02420-2
    Plant cells are characterized by a unique group of interconvertible organelles called plastids, which are descended from prokaryotic endosymbionts. The most studied plastid type is the chloroplast, which carries out the ancestral plastid function of photosynthesis. During the course of evolution, plastid activities were increasingly integrated with cellular metabolism and functions, and plant developmental processes, and this led to the creation of new types of non-photosynthetic plastids. These include the chromoplast, a carotenoid-rich organelle typically found in flowers and fruits. Here, we provide an introduction to non-photosynthetic plastids, and then review the structures and functions of chromoplasts in detail. The role of chromoplast differentiation in fruit ripening in particular is explored, and the factors that govern plastid development are examined, including hormonal regulation, gene expression, and plastid protein import. In the latter process, nucleus-encoded preproteins must pass through two successive protein translocons in the outer and inner envelope membranes of the plastid; these are known as TOC and TIC (translocon at the outer/inner chloroplast envelope), respectively. The discovery of SP1 (suppressor of ppi1 locus1), which encodes a RING-type ubiquitin E3 ligase localized in the plastid outer envelope membrane, revealed that plastid protein import is regulated through the selective targeting of TOC complexes for degradation by the ubiquitin-proteasome system. This suggests the possibility of engineering plastid protein import in novel crop improvement strategies.
    Matched MeSH terms: Plant Proteins/genetics
  2. Differential expression of heat shock and floral regulatory genes in pseudocarpel initials of mantled female inflorescences from Elaeis guineensis Jacq
    Ooi SE, Sarpan N, Abdul Aziz N, Nuraziyan A, Ong-Abdullah M
    Plant Reprod, 2019 06;32(2):167-179.
    PMID: 30467592 DOI: 10.1007/s00497-018-0350-5
    KEY MESSAGE: Transcriptomes generated by laser capture microdissected abnormal staminodes revealed adoption of carpel programming during organ initiation with decreased expression of numerousHSPs,EgDEF1, EgGLO1but increasedLEAFYexpression. The abnormal mantled phenotype in oil palm involves a feminization of the male staminodes into pseudocarpels in pistillate inflorescences. Previous studies on oil palm flowering utilized entire inflorescences or spikelets, which comprised not only the male and female floral organs, but the surrounding tissues as well. Laser capture microdissection coupled with RNA sequencing was conducted to investigate the specific transcriptomes of male and female floral organs from normal and mantled female inflorescences. A higher number of differentially expressed genes (DEGs) were identified in abnormal versus normal male organs compared with abnormal versus normal female organs. In addition, the abnormal male organ transcriptome closely mimics the transcriptome of abnormal female organ. While the transcriptome of abnormal female organ was relatively similar to the normal female organ, a substantial amount of female DEGs encode HEAT SHOCK PROTEIN genes (HSPs). A similar high amount (20%) of male DEGs encode HSPs as well. As these genes exhibited decreased expression in abnormal floral organs, mantled floral organ development may be associated with lower stress indicators. Stamen identity genes EgDEF1 and EgGLO1 were the main floral regulatory genes with decreased expression in abnormal male organs or pseudocarpel initials. Expression of several floral transcription factors was elevated in pseudocarpel initials, notably LEAFY, FIL and DL orthologs, substantiating the carpel specification programming of abnormal staminodes. Specific transcriptomes thus obtained through this approach revealed a host of differentially regulated genes in pseudocarpel initials compared to normal male staminodes.
    Matched MeSH terms: Plant Proteins/genetics
  3. Fulltext DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium hybrid
    Khairul-Anuar MA, Mazumdar P, Othman RY, Harikrishna JA
    Ann Bot, 2022 Sep 26;130(4):579-594.
    PMID: 35980362 DOI: 10.1093/aob/mcac103
    BACKGROUND: Flower pigment and shape are determined by the coordinated expression of a set of structural genes during flower development. R2R3-MYB transcription factors are known regulators of structural gene expression. The current study focused on two members of this large family of transcription factors that were predicted to have roles in pigment biosynthesis and organ shape development in orchids.

    METHODS: Phylogenetic analysis was used to identify candidate Dendrobium catenatum R2R3-MYB (DcaMYB) sequences associated with pigment and cell shape development. Gene silencing of candidate DhMYBs in Dendrobium hybrid by direct application of dsRNA to developing flowers was followed by observation of gene expression level and flower phenotypes. Silencing of the structural gene chalcone synthase was used as a comparative control.

    KEY RESULTS: Ten candidate flower-associated DcaMYBs were identified. Flowers treated with dsRNA of DhMYB22 and DhMYB60 sequences were less pigmented and had relatively low expression of anthocyanin biosynthetic genes (F3'H and DFR), lower total anthocyanin concentration and markedly lower levels of cyanidin-3-glucoside and cyanidin-3-rutinoside. Petals of DhMYB22-treated flowers and sepals of DhMYB60-treated flowers showed the greatest colour difference relative to the same organs in untreated flowers. DhMYB22-treated flowers had relatively narrow and constricted lips, while DhMYB60-treated flowers had narrow and constricted sepals. No significant difference in shape was observed for DhCHS-treated or untreated flowers.

    CONCLUSIONS: Our results demonstrate that DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium. This is a first report of MYB regulation of floral organ shape in orchids.

    Matched MeSH terms: Plant Proteins/genetics
  4. DNA methylation changes in clonally propagated oil palm
    Sarpan N, Taranenko E, Ooi SE, Low EL, Espinoza A, Tatarinova TV, et al.
    Plant Cell Rep, 2020 Sep;39(9):1219-1233.
    PMID: 32591850 DOI: 10.1007/s00299-020-02561-9
    KEY MESSAGE: Several hypomethylated sites within the Karma region of EgDEF1 and hotspot regions in chromosomes 1, 2, 3, and 5 may be associated with mantling. One of the main challenges faced by the oil palm industry is fruit abnormalities, such as the "mantled" phenotype that can lead to reduced yields. This clonal abnormality is an epigenetic phenomenon and has been linked to the hypomethylation of a transposable element within the EgDEF1 gene. To understand the epigenome changes in clones, methylomes of clonal oil palms were compared to methylomes of seedling-derived oil palms. Whole-genome bisulfite sequencing data from seedlings, normal, and mantled clones were analyzed to determine and compare the context-specific DNA methylomes. In seedlings, coding and regulatory regions are generally hypomethylated while introns and repeats are extensively methylated. Genes with a low number of guanines and cytosines in the third position of codons (GC3-poor genes) were increasingly methylated towards their 3' region, while GC3-rich genes remain demethylated, similar to patterns in other eukaryotic species. Predicted promoter regions were generally hypomethylated in seedlings. In clones, CG, CHG, and CHH methylation levels generally decreased in functionally important regions, such as promoters, 5' UTRs, and coding regions. Although random regions were found to be hypomethylated in clonal genomes, hypomethylation of certain hotspot regions may be associated with the clonal mantling phenotype. Our findings, therefore, suggest other hypomethylated CHG sites within the Karma of EgDEF1 and hypomethylated hotspot regions in chromosomes 1, 2, 3 and 5, are associated with mantling.
    Matched MeSH terms: Plant Proteins/genetics
  5. Fulltext DNA methylation and expression of the EgDEF1 gene and neighboring retrotransposons in mantled somaclonal variants of oil palm
    Jaligot E, Hooi WY, Debladis E, Richaud F, Beulé T, Collin M, et al.
    PLoS One, 2014;9(3):e91896.
    PMID: 24638102 DOI: 10.1371/journal.pone.0091896
    The mantled floral phenotype of oil palm (Elaeis guineensis) affects somatic embryogenesis-derived individuals and is morphologically similar to mutants defective in the B-class MADS-box genes. This somaclonal variation has been previously demonstrated to be associated to a significant deficit in genome-wide DNA methylation. In order to elucidate the possible role of DNA methylation in the transcriptional regulation of EgDEF1, the APETALA3 ortholog of oil palm, we studied this epigenetic mark within the gene in parallel with transcript accumulation in both normal and mantled developing inflorescences. We also examined the methylation and expression of two neighboring retrotransposons that might interfere with EgDEF1 regulation. We show that the EgDEF1 gene is essentially unmethylated and that its methylation pattern does not change with the floral phenotype whereas expression is dramatically different, ruling out a direct implication of DNA methylation in the regulation of this gene. Also, we find that both the gypsy element inserted within an intron of the EgDEF1 gene and the copia element located upstream from the promoter are heavily methylated and show little or no expression. Interestingly, we identify a shorter, alternative transcript produced by EgDEF1 and characterize its accumulation with respect to its full-length counterpart. We demonstrate that, depending on the floral phenotype, the respective proportions of these two transcripts change differently during inflorescence development. We discuss the possible phenotypical consequences of this alternative splicing and the new questions it raises in the search for the molecular mechanisms underlying the mantled phenotype in the oil palm.
    Matched MeSH terms: Plant Proteins/genetics*
  6. Comparative genomics reveals differences in algal galactan biosynthesis and related pathways in early and late diverging red algae
    Ho CL
    Genomics, 2020 03;112(2):1536-1544.
    PMID: 31494197 DOI: 10.1016/j.ygeno.2019.09.002
    Red algae are a major source of marine sulfated galactans. In this study, orthologs and inparalogs from seven red algae were analyzed and compared with the aim to discover differences in algal galactan biosynthesis and related pathways of these algae. Red algal orthologs for putative carbohydrate sulfotransferases were found to be prevalent in Porphyridium purpureum, Florideophytes and Bangiophytes, while red algal orthologs for putative chondroitin sulfate synthases, sulfurylases, and porphyranases /carrageenases were found exclusively in Florideophytes and Bangiophytes. The acquirement of these genes could have happened after the divergence from Cyanidiales red algae. Cyanidiales red algae were found to have more number and types of putative sulfate permeases, suggesting that these genes could have been acquired in adaptation to the environmental stresses and biogeochemistry of respective habitats. The findings of this study shed lights on the evolution of different homeostasis mechanisms by the early and late diverging red algal orders.
    Matched MeSH terms: Plant Proteins/genetics
  7. Fulltext Comparative genomics of the nonlegume Parasponia reveals insights into evolution of nitrogen-fixing rhizobium symbioses
    van Velzen R, Holmer R, Bu F, Rutten L, van Zeijl A, Liu W, et al.
    Proc Natl Acad Sci U S A, 2018 May 15;115(20):E4700-E4709.
    PMID: 29717040 DOI: 10.1073/pnas.1721395115
    Nodules harboring nitrogen-fixing rhizobia are a well-known trait of legumes, but nodules also occur in other plant lineages, with rhizobia or the actinomycete Frankia as microsymbiont. It is generally assumed that nodulation evolved independently multiple times. However, molecular-genetic support for this hypothesis is lacking, as the genetic changes underlying nodule evolution remain elusive. We conducted genetic and comparative genomics studies by using Parasponia species (Cannabaceae), the only nonlegumes that can establish nitrogen-fixing nodules with rhizobium. Intergeneric crosses between Parasponia andersonii and its nonnodulating relative Trema tomentosa demonstrated that nodule organogenesis, but not intracellular infection, is a dominant genetic trait. Comparative transcriptomics of P. andersonii and the legume Medicago truncatula revealed utilization of at least 290 orthologous symbiosis genes in nodules. Among these are key genes that, in legumes, are essential for nodulation, including NODULE INCEPTION (NIN) and RHIZOBIUM-DIRECTED POLAR GROWTH (RPG). Comparative analysis of genomes from three Parasponia species and related nonnodulating plant species show evidence of parallel loss in nonnodulating species of putative orthologs of NIN, RPG, and NOD FACTOR PERCEPTION Parallel loss of these symbiosis genes indicates that these nonnodulating lineages lost the potential to nodulate. Taken together, our results challenge the view that nodulation evolved in parallel and raises the possibility that nodulation originated ∼100 Mya in a common ancestor of all nodulating plant species, but was subsequently lost in many descendant lineages. This will have profound implications for translational approaches aimed at engineering nitrogen-fixing nodules in crop plants.
    Matched MeSH terms: Plant Proteins/genetics*
  8. Cloning, expression, and characterization of recombinant Hev b 3, a Hevea brasiliensis protein associated with latex allergy in patients with spina bifida
    Wagner B, Krebitz M, Buck D, Niggemann B, Yeang HY, Han KH, et al.
    J Allergy Clin Immunol, 1999 Nov;104(5):1084-92.
    PMID: 10550757
    BACKGROUND: Two natural rubber latex proteins, Hev b 1 and Hev b 3, have been described in spina bifida (SB)-associated latex allergy.

    OBJECTIVE: The aim of this study was to clone and express Hev b 3 and to obtain the immunologic active and soluble recombinant allergen for diagnosis of SB-associated latex allergy.

    METHODS: A complementary DNA (cDNA) coding for Hev b 3 was amplified from RNA of fresh latex collected from Malaysian rubber trees (Hevea brasiliensis). PCR primers were designed according to sequences of internal peptide fragments of natural (n) Hev b 3. The 5'-end sequence was obtained by specific amplification of cDNA ends. The recombinant (r) Hev b 3 was produced in Escherichia coli as a 6xHis tagged protein. Immunoblotting and inhibition assays were performed to characterize the recombinant allergen.

    RESULTS: An Hev b 3 cDNA clone of 922 bp encoding a protein of 204 amino acid residues corresponding to a molecular weight of 22.3 kd was obtained. In immunoblots 29/35, latex-allergic patients with SB revealed IgE binding to rHev b 3, as did 4 of 15 of the latex-sensitized group. The presence of all IgE epitopes on rHev b 3 was shown by its ability to abolish all IgE binding to nHev b 3. Hev b 3 is related to Hev b 1 by a sequence identity of 47%. Cross-reactivity between these 2 latex allergens was illustrated by the large extent of inhibition of IgE binding to nHev b 1 by rHev b 3.

    CONCLUSION: rHev b 3 constitutes a suitable in vitro reagent for the diagnosis of latex allergy in patients with SB. The determination of the full sequence of Hev b 3 and the production of the recombinant allergen will allow the epitope mapping and improve diagnostic reagents for latex allergy.

    Matched MeSH terms: Plant Proteins/genetics
  9. Cloning, expression and characterization of sugarcane (Saccharum officinarum L.) transketolase
    Kalhori N, Nulit R, Go R
    Protein J, 2013 Oct;32(7):551-9.
    PMID: 24132392 DOI: 10.1007/s10930-013-9516-z
    Pentose phosphate pathway (PPP) composed of two functionally-connected phases, the oxidative and non-oxidative phase. Both phases catalysed by a series of enzymes. Transketolase is one of key enzymes of non-oxidative phase in which transfer two carbon units from fructose-6-phosphate to erythrose-4-phosphate and convert glyceraldehyde-3-phosphate to xylulose-5-phosphate. In plant, erythrose-4-phosphate enters the shikimate pathway which is produces many secondary metabolites such as aromatic amino acids, flavonoids, lignin. Although transketolase in plant system is important, study of this enzyme is still limited. Until to date, TKT genes had been isolated only from seven plants species, thus, the aim of present study to isolate, study the similarity and phylogeny of transketolase from sugarcane. Unlike bacteria, fungal and animal, PPP is complete in the cytosol and all enzymes are found cytosolic. However, in plant, the oxidative phase found localised in the cytosol but the sub localisation for non-oxidative phase might be restricted to plastid. Thus, this study was conducted to determine subcellular localization of sugarcane transketolase. The isolation of sugarcane TKT was done by reverse transcription polymerase chain reaction, followed by cloning into pJET1.2 vector and sequencing. This study has isolated 2,327 bp length of sugarcane TKT. The molecular phylogenetic tree analysis found that transketolase from sugarcane and Zea mays in one group. Classification analysis found that both plants showed closer relationship due to both plants in the same taxon i.e. family Poaceae. Target P 1.1 and Chloro P predicted that the compartmentation of sugarcane transketolase is localised in the chloroplast which is 85 amino acids are plant plastid target sequence. This led to conclusion that the PPP is incomplete in the cytosol of sugarcane. This study also found that the similarity sequence of sugarcane TKT closely related with the taxonomy plants.
    Matched MeSH terms: Plant Proteins/genetics
  10. Cloning of the Aegiceras corniculatum class I chitinase gene (AcCHI I) and the response of AcCHI I mRNA expression to cadmium stress
    Wang LY, Wang YS, Cheng H, Zhang JP, Yeok FS
    Ecotoxicology, 2015 Oct;24(7-8):1705-13.
    PMID: 26044931 DOI: 10.1007/s10646-015-1502-0
    Chitinases in terrestrial plants have been reported these are involved in heavy metal tolerance/detoxification. This is the first attempt to reveal chitinase gene (AcCHI I) and its function on metal detoxification in mangroves Aegiceras corniculatum. RT-PCR and RACE techniques were used to clone AcCHI I, while real-time quantitative PCR was employed to assess AcCHI I mRNA expressions in response to Cadmium (Cd). The deduced AcCHI I protein consists of 316 amino acids, including a signal peptide region, a chitin-binding domain (CBD) and a catalytic domain. Protein homology modeling was performed to identify potential features in AcCHI I. The CBD structure of AcCHI I might be critical for metal tolerance/homeostasis of the plant. Clear tissue-specific differences in AcCHI I expression were detected, with higher transcript levels detected in leaves. Results demonstrated that a short duration of Cd exposure (e.g., 3 days) promoted AcCHI I expression in roots. Upregulated expression was also detected in leaves under 10 mg/kg Cd concentration stress. The present study demonstrates that AcCHI I may play an important role in Cd tolerance/homeostasis in the plant. Further studies of the AcCHI I protein, gene overexpression, the promoter and upstream regulation will be necessary for clarifying the functions of AcCHI I.
    Matched MeSH terms: Plant Proteins/genetics*
  11. Cloning of nitric oxide associated 1 (NOA1) transcript from oil palm (Elaeis guineensis) and its expression during Ganoderma infection
    Kwan YM, Meon S, Ho CL, Wong MY
    J Plant Physiol, 2015 Feb 01;174:131-6.
    PMID: 25462975 DOI: 10.1016/j.jplph.2014.10.003
    Nitric oxide associated 1 (NOA1) protein is implicated in plant disease resistance and nitric oxide (NO) biosynthesis. A full-length cDNA encoding of NOA1 protein from oil palm (Elaeis guineensis) was isolated and designated as EgNOA1. Sequence analysis suggested that EgNOA1 was a circular permutated GTPase with high similarity to the bacterial YqeH protein of the YawG/YlqF family. The gene expression of EgNOA1 and NO production in oil palm root tissues treated with Ganoderma boninense, the causal agent of basal stem rot (BSR) disease were profiled to investigate the involvement of EgNOA1 during fungal infection and association with NO biosynthesis. Real-time PCR (qPCR) analysis revealed that the transcript abundance of EgNOA1 in root tissues was increased by G. boninense treatment. NO burst in Ganoderma-treated root tissue was detected using Griess reagent, in advance of the up-regulation of the EgNOA1 transcript. This indicates that NO production was independent of EgNOA1. However, the induced expression of EgNOA1 in Ganoderma-treated root tissues implies that it might be involved in plant defense responses against pathogen infection.
    Matched MeSH terms: Plant Proteins/genetics*
  12. Fulltext Characterizing haploinsufficiency of SHELL gene to improve fruit form prediction in introgressive hybrids of oil palm
    Teh CK, Muaz SD, Tangaya P, Fong PY, Ong AL, Mayes S, et al.
    Sci Rep, 2017 06 08;7(1):3118.
    PMID: 28596562 DOI: 10.1038/s41598-017-03225-7
    The fundamental trait in selective breeding of oil palm (Eleais guineensis Jacq.) is the shell thickness surrounding the kernel. The monogenic shell thickness is inversely correlated to mesocarp thickness, where the crude palm oil accumulates. Commercial thin-shelled tenera derived from thick-shelled dura × shell-less pisifera generally contain 30% higher oil per bunch. Two mutations, sh MPOB (M1) and sh AVROS (M2) in the SHELL gene - a type II MADS-box transcription factor mainly present in AVROS and Nigerian origins, were reported to be responsible for different fruit forms. In this study, we have tested 1,339 samples maintained in Sime Darby Plantation using both mutations. Five genotype-phenotype discrepancies and eight controls were then re-tested with all five reported mutations (sh AVROS , sh MPOB , sh MPOB2 , sh MPOB3 and sh MPOB4 ) within the same gene. The integration of genotypic data, pedigree records and shell formation model further explained the haploinsufficiency effect on the SHELL gene with different number of functional copies. Some rare mutations were also identified, suggesting a need to further confirm the existence of cis-compound mutations in the gene. With this, the prediction accuracy of fruit forms can be further improved, especially in introgressive hybrids of oil palm. Understanding causative variant segregation is extremely important, even for monogenic traits such as shell thickness in oil palm.
    Matched MeSH terms: Plant Proteins/genetics*
  13. Characterization of a KCS-like KASII from Jessenia bataua that elongates saturated and monounsaturated stearic acids in Arabidopsis thaliana
    Teh OK, Ramli US
    Mol Biotechnol, 2011 Jun;48(2):97-108.
    PMID: 21113689 DOI: 10.1007/s12033-010-9350-x
    As the world population grows, the demand for food increases. Although vegetable oils provide an affordable and rich source of energy, the supply of vegetable oils available for human consumption is limited by the "fuel vs food" debate. To increase the nutritional value of vegetable oil, metabolic engineering may be used to produce oil crops of desirable fatty acid composition. We have isolated and characterized β-ketoacyl ACP-synthase II (KASII) cDNA from a high-oleic acid palm, Jessenia bataua. Jessenia KASII (JbKASII) encodes a 488-amino acid polypeptide that possesses conserved domains that are necessary for condensing activities. When overexpressed in E. coli, recombinant His-tagged JbKASII was insoluble and non-functional. However, Arabidopsis plants expressing GFP-JbKASII fusions had elevated levels of arachidic acid (C20:0) and erucic acid (C22:1) at the expense of stearic acid (C18:0) and oleic acid (C18:1). Furthermore, JbKASII failed to complement the Arabidopsis KASII mutant, fab1-2. This suggests that the substrate specificity of JbKASII is similar to that of ketoacyl-CoA synthase (KCS), which preferentially elongates stearic and oleic acids, and not palmitic acid. Our results suggest that the KCS-like JbKASII may elongate C18:0 and C18:1 to yield C20:0 and C22:1, respectively. JbKASII may, therefore, be an interesting candidate gene for promoting the production of very long chain fatty acids in transgenic oil crops.
    Matched MeSH terms: Plant Proteins/genetics
  14. Characterization of Oil Palm Acyl-CoA-Binding Proteins and Correlation of Their Gene Expression with Oil Synthesis
    Amiruddin N, Chan PL, Azizi N, Morris PE, Chan KL, Ong PW, et al.
    Plant Cell Physiol, 2020 Apr 01;61(4):735-747.
    PMID: 31883014 DOI: 10.1093/pcp/pcz237
    Acyl-CoA-binding proteins (ACBPs) are involved in binding and trafficking acyl-CoA esters in eukaryotic cells. ACBPs contain a well-conserved acyl-CoA-binding domain. Their various functions have been characterized in the model plant Arabidopsis and, to a lesser extent, in rice. In this study, genome-wide detection and expression analysis of ACBPs were performed on Elaeis guineensis (oil palm), the most important oil crop in the world. Seven E. guineensis ACBPs were identified and classified into four groups according to their deduced amino acid domain organization. Phylogenetic analysis showed conservation of this family with other higher plants. All seven EgACBPs were expressed in most tissues while their differential expression suggests various functions in specific tissues. For example, EgACBP3 had high expression in inflorescences and stalks while EgACBP1 showed strong expression in leaves. Because of the importance of E. guineensis as an oil crop, expression of EgACBPs was specifically examined during fruit development. EgACBP3 showed high expression throughout mesocarp development, while EgACBP1 had enhanced expression during rapid oil synthesis. In endosperm, both EgACBP1 and EgACBP3 exhibited increased expression during seed development. These results provide important information for further investigations on the biological functions of EgACBPs in various tissues and, in particular, their roles in oil synthesis.
    Matched MeSH terms: Plant Proteins/genetics*
  15. Characterization of Eleusine indica with gene mutation or amplification in EPSPS to glyphosate
    Chen J, Jiang C, Huang H, Wei S, Huang Z, Wang H, et al.
    Pestic Biochem Physiol, 2017 Nov;143:201-206.
    PMID: 29183593 DOI: 10.1016/j.pestbp.2017.09.012
    The evolution of weed-resistant species threatens the sustainable use of glyphosate, which is the most important herbicide widely used in agriculture worldwide. Moreover, the high glyphosate resistance (>180-fold based on LD50) of Eleusine indica found in Malaysia, which carries a double mutation in its 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), made the control of this species more difficult. By contrast, the same species carrying the same double mutation in EPSPS (T102I+P106S) but found in China only shows a resistance level of not more than 14-fold based on GR50. The resistance level of this population is four times higher than that of the population carrying a single mutation (P106L). Although the members of this population survive under a high glyphosate dosage of 10,080gaeha-1, their growth was significantly inhibited by glyphosate under the recommend dose (840gaeha-1), where in the fresh weight was 85.4% of the control. EPSPS expression, relative copy number, and EPSPS activity in this population were similar to those of the susceptible population. In addition, the expression of two glutathione transferase (GST) genes (GST-U8 and GST-23) and the enzyme activity of the GST in this population did not significantly differ from those of the susceptible population. This finding is important in elucidating the resistance of the naturally evolved glyphosate-resistant (GR) weed species carrying a double mutation in EPSPS to glyphosate.
    Matched MeSH terms: Plant Proteins/genetics
  16. Fulltext Characterization of CRISPR Mutants Targeting Genes Modulating Pectin Degradation in Ripening Tomato
    Wang D, Samsulrizal NH, Yan C, Allcock NS, Craigon J, Blanco-Ulate B, et al.
    Plant Physiol, 2019 02;179(2):544-557.
    PMID: 30459263 DOI: 10.1104/pp.18.01187
    Tomato (Solanum lycopersicum) is a globally important crop with an economic value in the tens of billions of dollars, and a significant supplier of essential vitamins, minerals, and phytochemicals in the human diet. Shelf life is a key quality trait related to alterations in cuticle properties and remodeling of the fruit cell walls. Studies with transgenic tomato plants undertaken over the last 20 years have indicated that a range of pectin-degrading enzymes are involved in cell wall remodeling. These studies usually involved silencing of only a single gene and it has proved difficult to compare the effects of silencing these genes across the different experimental systems. Here we report the generation of CRISPR-based mutants in the ripening-related genes encoding the pectin-degrading enzymes pectate lyase (PL), polygalacturonase 2a (PG2a), and β-galactanase (TBG4). Comparison of the physiochemical properties of the fruits from a range of PL, PG2a, and TBG4 CRISPR lines demonstrated that only mutations in PL resulted in firmer fruits, although mutations in PG2a and TBG4 influenced fruit color and weight. Pectin localization, distribution, and solubility in the pericarp cells of the CRISPR mutant fruits were investigated using the monoclonal antibody probes LM19 to deesterified homogalacturonan, INRA-RU1 to rhamnogalacturonan I, LM5 to β-1,4-galactan, and LM6 to arabinan epitopes, respectively. The data indicate that PL, PG2a, and TBG4 act on separate cell wall domains and the importance of cellulose microfibril-associated pectin is reflected in its increased occurrence in the different mutant lines.
    Matched MeSH terms: Plant Proteins/genetics
  17. Fulltext Characterization and comparative sequence analysis of the DNA mismatch repair MSH2 and MSH7 genes from tomato
    Tam SM, Samipak S, Britt A, Chetelat RT
    Genetica, 2009 Dec;137(3):341-54.
    PMID: 19690966 DOI: 10.1007/s10709-009-9398-3
    DNA mismatch repair proteins play an essential role in maintaining genomic integrity during replication and genetic recombination. We successfully isolated a full length MSH2 and partial MSH7 cDNAs from tomato, based on sequence similarity between MutS and plant MSH homologues. Semi-quantitative RT-PCR reveals higher levels of mRNA expression of both genes in young leaves and floral buds. Genetic mapping placed MSH2 and MSH7 on chromosomes 6 and 7, respectively, and indicates that these genes exist as single copies in the tomato genome. Analysis of protein sequences and phylogeny of the plant MSH gene family show that these proteins are evolutionarily conserved, and follow the classical model of asymmetric protein evolution. Genetic manipulation of the expression of these MSH genes in tomato will provide a potentially useful tool for modifying genetic recombination and hybrid fertility between wide crosses.
    Matched MeSH terms: Plant Proteins/genetics*
  18. Cell-Free Expression of a Plant Membrane Protein BrPT2 From Boesenbergia Rotunda
    Liew YJM, Lee YK, Khalid N, Rahman NA, Tan BC
    Mol Biotechnol, 2021 Apr;63(4):316-326.
    PMID: 33565047 DOI: 10.1007/s12033-021-00304-z
    Prenylation of aromatic natural products by membrane-bound prenyltransferases (PTs) is an important biosynthesis step of many bioactive compounds. At present, only a few plant flavonoid-related PT genes have been functionally characterized, mainly due to the difficulties of expressing these membrane proteins. Rapid and effective methods to produce functional plant membrane proteins are thus indispensable. Here, we evaluated expression systems through cell-based and cell-free approaches to express Boesenbergia rotunda BrPT2 encoding a membrane-bound prenyltransferase. We attempted to express BrPT2 in Escherichia coli and tobacco plants but failed to detect this protein using the Western-blot technique, whereas an intact single band of 43 kDa was detected when BrPT2 was expressed using a cell-free protein synthesis system (PURE). Under in vitro enzymatic condition, the synthesized BrPT2 successfully catalyzed pinostrobin chalcone to pinostrobin. Molecular docking analysis showed that pinostrobin chalcone interacts with BrPT2 at two cavities: (1) the main binding site at the central cavity and (2) the allosteric binding site located away from the central cavity. Our findings suggest that cell-free protein synthesis could be an alternative for rapid production of valuable difficult-to-express membrane proteins.
    Matched MeSH terms: Plant Proteins/genetics
  19. Fulltext CaWRKY30 Positively Regulates Pepper Immunity by Targeting CaWRKY40 against Ralstonia solanacearum Inoculation through Modulating Defense-Related Genes
    Hussain A, Khan MI, Albaqami M, Mahpara S, Noorka IR, Ahmed MAA, et al.
    Int J Mol Sci, 2021 Nov 08;22(21).
    PMID: 34769521 DOI: 10.3390/ijms222112091
    The WRKY transcription factors (TFs) network is composed of WRKY TFs' subset, which performs a critical role in immunity regulation of plants. However, functions of WRKY TFs' network remain unclear, particularly in non-model plants such as pepper (Capsicum annuum L.). This study functionally characterized CaWRKY30-a member of group III Pepper WRKY protein-for immunity of pepper against Ralstonia solanacearum infection. The CaWRKY30 was detected in nucleus, and its transcriptional expression levels were significantly upregulated by R. solanacearum inoculation (RSI), and foliar application ethylene (ET), abscisic acid (ABA), and salicylic acid (SA). Virus induced gene silencing (VIGS) of CaWRKY30 amplified pepper's vulnerability to RSI. Additionally, the silencing of CaWRKY30 by VIGS compromised HR-like cell death triggered by RSI and downregulated defense-associated marker genes, like CaPR1, CaNPR1, CaDEF1, CaABR1, CaHIR1, and CaWRKY40. Conversely, transient over-expression of CaWRKY30 in pepper leaves instigated HR-like cell death and upregulated defense-related maker genes. Furthermore, transient over-expression of CaWRKY30 upregulated transcriptional levels of CaWRKY6, CaWRKY22, CaWRKY27, and CaWRKY40. On the other hand, transient over-expression of CaWRKY6, CaWRKY22, CaWRKY27, and CaWRKY40 upregulated transcriptional expression levels of CaWRKY30. The results recommend that newly characterized CaWRKY30 positively regulates pepper's immunity against Ralstonia attack, which is governed by synergistically mediated signaling by phytohormones like ET, ABA, and SA, and transcriptionally assimilating into WRKY TFs networks, consisting of CaWRKY6, CaWRKY22, CaWRKY27, and CaWRKY40. Collectively, our data will facilitate to explicate the underlying mechanism of crosstalk between pepper's immunity and response to RSI.
    Matched MeSH terms: Plant Proteins/genetics
  20. Fulltext CCoAOMT Down-Regulation Activates Anthocyanin Biosynthesis in Petunia
    Shaipulah NF, Muhlemann JK, Woodworth BD, Van Moerkercke A, Verdonk JC, Ramirez AA, et al.
    Plant Physiol, 2016 Feb;170(2):717-31.
    PMID: 26620524 DOI: 10.1104/pp.15.01646
    Anthocyanins and volatile phenylpropenes (isoeugenol and eugenol) in petunia (Petunia hybrida) flowers have the precursor 4-coumaryl coenzyme A (CoA) in common. These phenolics are produced at different stages during flower development. Anthocyanins are synthesized during early stages of flower development and sequestered in vacuoles during the lifespan of the flowers. The production of isoeugenol and eugenol starts when flowers open and peaks after anthesis. To elucidate additional biochemical steps toward (iso)eugenol production, we cloned and characterized a caffeoyl-coenzyme A O-methyltransferase (PhCCoAOMT1) from the petals of the fragrant petunia 'Mitchell'. Recombinant PhCCoAOMT1 indeed catalyzed the methylation of caffeoyl-CoA to produce feruloyl CoA. Silencing of PhCCoAOMT1 resulted in a reduction of eugenol production but not of isoeugenol. Unexpectedly, the transgenic plants had purple-colored leaves and pink flowers, despite the fact that cv Mitchell lacks the functional R2R3-MYB master regulator ANTHOCYANIN2 and has normally white flowers. Our results indicate that down-regulation of PhCCoAOMT1 activated the anthocyanin pathway through the R2R3-MYBs PURPLE HAZE (PHZ) and DEEP PURPLE, with predominantly petunidin accumulating. Feeding cv Mitchell flowers with caffeic acid induced PHZ expression, suggesting that the metabolic perturbation of the phenylpropanoid pathway underlies the activation of the anthocyanin pathway. Our results demonstrate a role for PhCCoAOMT1 in phenylpropene production and reveal a link between PhCCoAOMT1 and anthocyanin production.
    Matched MeSH terms: Plant Proteins/genetics
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