Displaying all 11 publications

Abstract:
Sort:
  1. Variable expansin expression in Arabidopsis leads to different growth responses
    Goh HH, Sloan J, Malinowski R, Fleming A
    J Plant Physiol, 2014 Feb 15;171(3-4):329-39.
    PMID: 24144490 DOI: 10.1016/j.jplph.2013.09.009
    Expansins have long been implicated in the control of cell wall extensibility. However, despite ample evidence supporting a role for these proteins in the endogenous mechanism of plant growth, there are also examples in the literature where the outcome of altered expansin gene expression is difficult to reconcile with a simplistic causal linkage to growth promotion. To investigate this problem, we report on the analysis of transgenic Arabidopsis plants in which a heterologous cucumber expansin can be inducibly overexpressed. Our results indicate that the effects of expansin expression on growth depend on the degree of induction of expansin expression and the developmental pattern of organ growth. They support the role of expansin in directional cell expansion. They are also consistent with the idea that excess expansin might itself impede normal activities of cell wall modifications, culminating in both growth promotion and repression depending on the degree of expression.
    Matched MeSH terms: Hypocotyl/genetics; Hypocotyl/metabolism
  2. Fulltext Transcriptomic data of Arabidopsis hypocotyl overexpressing a heterologous CsEXPA1 gene
    Ilias IA, Airianah OB, Baharum SN, Goh HH
    Data Brief, 2017 Dec;15:320-323.
    PMID: 29214193 DOI: 10.1016/j.dib.2017.09.050
    Expansin increases cell wall extensibility to allow cell wall loosening and cell expansion even in the absence of hydrolytic activity. Previous studies showed that excessive overexpression of expansin gene resulted in defective growth (Goh et al., 2014; Rochange et al., 2001) [1,2] and altered cell wall chemical composition (Zenoni et al., 2011) [3]. However, the molecular mechanism on how the overexpression of non-enzymatic cell wall protein expansin can result in widespread effects on plant cell wall and organ growth remains unclear. We acquired transcriptomic data on previously reported transgenic Arabidopsis line (Goh et al., 2014) [1] to investigate the effects of overexpressing a heterologus cucumber expansin gene (CsEXPA1) on the global gene expression pattern during early and late phases of etiolated hypocotyl growth.
    Matched MeSH terms: Hypocotyl
  3. Transcriptome-wide effects of expansin gene manipulation in etiolated Arabidopsis seedling
    Ilias IA, Negishi K, Yasue K, Jomura N, Morohashi K, Baharum SN, et al.
    J Plant Res, 2019 Mar;132(2):159-172.
    PMID: 30341720 DOI: 10.1007/s10265-018-1067-0
    Expansin is a non-enzymatic protein which plays a pivotal role in cell wall loosening by inducing stress relaxation and extension in the plant cell wall. Previous studies on Arabidopsis, Petunia × hybrida, and tomato demonstrated that the suppression of expansin gene expression reduced plant growth but expansin overexpression does not necessarily promotes growth. In this study, both expansin gene suppression and overexpression in dark-grown transgenic Arabidopsis seedlings resulted in reduced hypocotyl length at late growth stages with a more pronounced effect for the overexpression. This defect in hypocotyl elongation raises questions about the molecular effect of expansin gene manipulation. RNA-seq analysis of the transcriptomic changes between day 3 and day 5 seedlings for both transgenic lines found numerous differentially expressed genes (DEGs) including transcription factors and hormone-related genes involved in different aspects of cell wall development. These DEGs imply that the observed hypocotyl growth retardation is a consequence of the concerted effect of regulatory factors and multiple cell-wall related genes, which are important for cell wall remodelling during rapid hypocotyl elongation. This is further supported by co-expression analysis through network-centric approach of differential network cluster analysis. This first transcriptome-wide study of expansin manipulation explains why the effect of expansin overexpression is greater than suppression and provides insights into the dynamic nature of molecular regulation during etiolation.
    Matched MeSH terms: Hypocotyl/growth & development*
  4. Fulltext Induction of hairy roots by various strains of Agrobacterium rhizogenes in different types of Capsicum species explants
    Md Setamam N, Jaafar Sidik N, Abdul Rahman Z, Che Mohd Zain CR
    BMC Res Notes, 2014 Jun 30;7:414.
    PMID: 24981787 DOI: 10.1186/1756-0500-7-414
    BACKGROUND: Capsicum annuum and Capsicum frutescens, also known as "chilies", belong to the Solanaceae family and have tremendous beneficial properties. The application of hairy root culture may become an alternative method for future development of these species by adding value, such as by increasing secondary metabolites and improving genetic and biochemical stability compared with normal Capsicum plants. Therefore, in this research, different types of explants of both species were infected with various Agrobacterium rhizogenes strains to provide more information about the morphology and induction efficiency of hairy roots. After 2 weeks of in vitro seed germination, young seedling explants were cut into three segments; the cotyledon, hypocotyl, and radical. Then, the explants were co-cultured with four isolated A. rhizogenes strains in Murashige & Skoog culture media (MS) containing decreasing carbenicillin disodium concentrations for one month.

    RESULTS: In this experiment, thick and short hairy roots were induced at all induction sites of C. annuum while thin, elongated hairy roots appeared mostly at wound sites of C. frutescens. Overall, the hairy root induction percentages of C. frutescens were higher compared with C. annuum. Hairy root initiation was observed earliest using radicles (1st week), followed by cotyledons (2nd week), and hypocotyls (3rd week). Cotyledon explants of both species had the highest induction frequency with all strains compared with the other explants types. Strains ATCC 13333 and ATCC 15834 were the most favourable for C. frutescens while ATCC 43056 and ATCC 43057 were the most favourable for C. annuum. The interactions between the different explants and strains showed significant differences with p-values < 0.0001 in both Capsicum species.

    CONCLUSIONS: Both Capsicum species were amenable to A. rhizogenes infection and hairy root induction is recommended for use as an alternative explants in future plant-based studies.

    Matched MeSH terms: Hypocotyl/growth & development; Hypocotyl/microbiology
  5. Fulltext Induction of Systemic Resistance in Cucumber by Hypovirulent Binucleate Rhizoctonia against Anthracnose Caused by Colletotrichum orbiculare
    Muslim A, Hyakumachi M, Kageyama K, Suwandi S
    Trop Life Sci Res, 2019 Jan;30(1):109-122.
    PMID: 30847036 DOI: 10.21315/tlsr2019.30.1.7
    Treatment with hypovirulent binucleate Rhizoctonia (HBNR) isolates induced systemic resistance against anthracnose infected by Colletotrichum orbiculare in cucumber, as there were no direct interaction between HBNR and C. orbiculare. This is because of the different distances between HBNR and C. orbiculare, where the root was treated with HBNR isolate and C. orbiculare was challenged and inoculated in leaves or first true leaves were treated with HBNR isolate and C. orbiculare was challenged and inoculated in second true leaves. The use of barley grain inocula and culture filtrates of HBNR significantly reduced the lesion diameter compared to the control (p = 0.05). The total lesion diameter reduction by applying barley grain inoculum of HBNR L2, W1, W7, and Rhv7 was 28%, 44%, 39%, and 40%, respectively. Similar results was also observed in treatment using culture filtrate, and the reduction of total lesion diameter by culture filtrate of HBNR L2, W1, W7, and Rhv7 was 45%, 46%, 42%, and 48%, respectively. When cucumber root was treated with culture filtrates of HBNR, the lignin was enhanced at the pathogen penetration, which is spread along the epidermis tissue of cucumber hypocotyls. Peroxidase activity in hypocotyls in the treated cucumber plant with culture filtrates of HBNR significantly increased before and after inoculation of pathogens as compared to the control. Significant enhancement was also observed in the fast-moving anodic peroxidase isozymes in the treated plants with culture filtrates of HBNR. The results showed the elicitor(s) contained in culture filtrates in HBNR. The lignin deposition as well as the peroxidase activity is an important step to prevent systemically immunised plants from pathogen infection.
    Matched MeSH terms: Hypocotyl
  6. Optimization of in vitro regeneration and Agrobacterium tumefaciens-mediated transformation with heat-resistant cDNA in Brassica oleracea subsp. italica cv. Green Marvel
    Ravanfar SA, Aziz MA, Saud HM, Abdullah JO
    Curr Genet, 2015 Nov;61(4):653-63.
    PMID: 25986972 DOI: 10.1007/s00294-015-0494-x
    An efficient system for shoot regeneration and Agrobacterium tumefaciens-mediated transformation of Brassica oleracea cv. Green Marvel cultivar is described. This study focuses on developing shoot regeneration from hypocotyl explants of broccoli cv. Green Marvel using thidiazuron (TDZ), zeatin, and kinetin, the optimization of factors affecting Agrobacterium-mediated transformation of the hypocotyl explants with heat-resistant cDNA, followed by the confirmation of transgenicity of the regenerants. High shoot regeneration was observed in 0.05-0.1 mg dm(-3) TDZ. TDZ at 0.1 mg dm(-3) produced among the highest percentage of shoot regeneration (96.67 %) and mean number of shoot formation (6.17). The highest percentage (13.33 %) and mean number (0.17) of putative transformant production were on hypocotyl explants subjected to preculture on shoot regeneration medium (SRM) with 200 µM acetosyringone. On optimization of bacterial density and inoculation time, the highest percentage and mean number of putative transformant production were on hypocotyl explants inoculated with a bacterial dilution of 1:5 for 30 min. Polymerase chain reaction (PCR) assay indicated a transformation efficiency of 8.33 %. The luciferase assay showed stable integration of the Arabidopsis thaliana HSP101 (AtHSP101) cDNA in the transgenic broccoli regenerants. Three out of five transgenic lines confirmed through PCR showed positive hybridization bands of the AtHSP101 cDNA through Southern blot analysis. The presence of AtHSP101 transcripts in the three transgenic broccoli lines indicated by reverse transcription-PCR (RT-PCR) confirmed the expression of the gene. In conclusion, an improved regeneration system has been established from hypocotyl explants of broccoli followed by successful transformation with AtHSP101 for resistance to high temperature.
    Matched MeSH terms: Hypocotyl/drug effects; Hypocotyl/genetics*; Hypocotyl/metabolism; Hypocotyl/microbiology
  7. Fulltext Development of Transgenic Papaya through Agrobacterium-Mediated Transformation
    Azad MA, Rabbani MG, Amin L, Sidik NM
    Int J Genomics, 2013;2013:235487.
    PMID: 24066284 DOI: 10.1155/2013/235487
    Transgenic papaya plants were regenerated from hypocotyls and immature zygotic embryo after cocultivation with Agrobacterium tumefaciens LBA-4404 carrying a binary plasmid vector system containing neomycin phosphotransferase (nptII) gene as the selectable marker and β-glucuronidase (GUS) as the reporter gene. The explants were co-cultivated with Agrobacterium tumefaciens on regeneration medium containing 500 mg/L carbenicillin + 200 mg/L cefotaxime for one week. The cocultivated explants were transferred into the final selection medium containing 500 mg/L carbenicillin + 200 mg/L cefotaxime + 50 mg/L kanamycin for callus induction as well as plant regeneration. The callus derived from the hypocotyls of Carica papaya cv. Shahi showed the highest positive GUS activities compared to Carica papaya cv. Ranchi. The transformed callus grew vigorously and formed embryos followed by transgenic plantlets successfully. The result of this study showed that the hypocotyls of C. papaya cv. Shahi and C. papaya cv. Ranchi are better explants for genetic transformation compared to immature embryos. The transformed C. papaya cv. Shahi also showed the maximum number of plant regeneration compared to that of C. papaya cv. Ranchi.
    Matched MeSH terms: Hypocotyl
  8. Reconstruction of the transcriptional regulatory network in arabidopsis thaliana aliphatic glucosinolate biosynthetic pathway
    Khalidah-Syahirah Ashari, Zeti-Azura Mohamed-Hussein, Muhammad-Redha Abdullah-Zawawi, Sarahani Harun
    Sains Malaysiana, 2018;47:2993-3002.
    Aliphatic glucosinolate is an important secondary metabolite responsible in plant defense mechanism and carcinogenic
    activity. It plays a crucial role in plant adaptation towards changes in the environment such as salinity and drought.
    However, in many plant genomes, there are thousands of genes encoding proteins still with putative functions and
    incomplete annotations. Therefore, the genome of Arabidopsis thaliana was selected to be investigated further to identify
    any putative genes that are potentially involved in the aliphatic glucosinolate biosynthesis pathway, most of its gene are
    with incomplete annotation. Known genes for aliphatic glucosinolates were retrieved from KEGG and AraCyc databases.
    Three co-expression databases i.e., ATTED-II, GeneMANIA and STRING were used to perform the co-expression network
    analysis. The integrated co-expression network was then being clustered, annotated and visualized using Cytoscape plugin,
    MCODE and ClueGO. Then, the regulatory network of A. thaliana from AtRegNet was mapped onto the co-expression
    network to build the transcriptional regulatory network. This study showed that a total of 506 genes were co-expressed
    with the 61 aliphatic glucosinolate biosynthesis genes. Five transcription factors have been predicted to be involved
    in the biosynthetic pathway of aliphatic glucosinolate, namely SEPALLATA 3 (SEP3), PHYTOCHROME INTERACTING FACTOR
    3-like 5 (AtbHLH15/PIL5), ELONGATED HYPOCOTYL 5 (HY5), AGAMOUS-like 15 (AGL15) and GLABRA 3 (GL3). Meanwhile,
    three other genes with high potential to be involved in the aliphatic glucosinolates biosynthetic pathway were identified,
    i.e., methylthioalkylmalate-like synthase 4 (MAML-4) and aspartate aminotransferase (ASP1 and ASP4). These findings
    can be used to complete the aliphatic glucosinolate biosynthetic pathway in A. thaliana and to update the information
    on the glucosinolate-related pathways in public metabolic databases.
    Matched MeSH terms: Hypocotyl
  9. Evaluation of the allelopathic potential of fifteen common Malaysian weeds
    Nurul Ain MB, Ismail BS, Nornasuha Y
    Sains Malaysiana, 2017;46:1413-1420.
    The use of allelopathy concept in weed management has received attentions to minimize extensively the reliance on herbicide applications on the agriculture industry in Malaysia. A laboratory study was conducted to evaluate the allelopathic potential of 15 Malaysian common weed species of different morphological characteristics (broadleaves, sedges and grasses). They were screened using the Sandwich method (from leaf litter leachate) and the Dish pack method (for testing the presence and content of volatile compounds in weeds). Among the 15 weed species tested, the leaf litter leachate of Centrosema pubescens was observed to be the most sensitive plant material inhibiting the growth of lettuce radicle (84%) and hypocotyl (55%) in the Sandwich bioassay compared to the control. This was followed by Asystasia gangentica (81%) and Cynodon dactylon (80%) inhibiting the lettuce radicle growth. In the Dish pack bioassay, Rhynchelytrum repens demonstrated maximum inhibition on the radicle and hypocotyl elongations by 44% and 29%, respectively, (over control) at 41 mm distance from the source well. Meanwhile, at the same distance, Cynodon dactylon was observed to have the least inhibitory effect on lettuce radicle growth by 12%. The results presented can be utilized as benchmark information for further research on the identification and isolation of allelochemicals for weed control strategies.
    Matched MeSH terms: Hypocotyl
  10. Chemical-Induced Inhibition of Blue Light-Mediated Seedling Development Caused by Disruption of Upstream Signal Transduction Involving Cryptochromes in Arabidopsis thaliana
    Ong WD, Okubo-Kurihara E, Kurihara Y, Shimada S, Makita Y, Kawashima M, et al.
    Plant Cell Physiol, 2017 01 01;58(1):95-105.
    PMID: 28011868 DOI: 10.1093/pcp/pcw181
    Plants have a remarkable ability to perceive and respond to various wavelengths of light and initiate regulation of different cascades of light signaling and molecular components. While the perception of red light and the mechanisms of its signaling involving phytochromes are largely known, knowledge of the mechanisms of blue light signaling is still limited. Chemical genetics involves the use of diverse small active or synthetic molecules to evaluate biological processes. By combining chemicals and analyzing the effects they have on plant morphology, we identified a chemical, 3-bromo-7-nitroindazole (3B7N), that promotes hypocotyl elongation of wild-type Arabidopsis only under continuous blue light. Further evaluation with loss-of-function mutants confirmed that 3B7N inhibits photomorphogenesis through cryptochrome-mediated light signaling. Microarray analysis demonstrated that the effect of 3B7N treatment on gene expression in cry1cry2 is considerably smaller than that in the wild type, indicating that 3B7N specifically interrupts cryptochrome function in the control of seedling development in a light-dependent manner. We demonstrated that 3B7N directly binds to CRY1 protein using an in vitro binding assay. These results suggest that 3B7N is a novel chemical that directly inhibits plant cryptochrome function by physical binding. The application of 3B7N can be used on other plants to study further the blue light mechanism and the genetic control of cryptochromes in the growth and development of plant species.
    Matched MeSH terms: Hypocotyl/genetics; Hypocotyl/metabolism
  11. Fulltext Effects of germination conditions on 5'-phosphodiesterase activity of selected seeds
    Pui, L.P., Abdulkarim, S.M., Ghazali, H.M.
    International Food Research Journal, 2012;19(4):1641-1648.
    MyJurnal
    5'-Phosphodiesterase (5'-PDE) is an enzyme that hydrolyses RNA to form 5'-inosine monophosphate (5'-IMP) and 5'-guanosine monophosphate (5'-GMP), which function as flavour enhancers. Selection of the best producer of 5'-PDE was made by determining the activity of the enzyme in six seeds that have been germinated, namely mung bean (Vigna radiate), soybean (Glycine max), adzuki/red bean (Vigna angularis L.), chick pea (Cicer arietinum), black eye pea (Vigna unguiculata) and petai (Parkia speciosa). Seeds that were not germinated acted as the control. In order to ensure there is no contamination from potential 5'-PDE-producing microorganisms during germination, microbial growth was reduced by using different surface sterilizing treatments where the seeds were soaked in 100 mL solution containing different concentrations of sodium hypochlorite (with or without 0.05% sodium azide) for 5 minutes before rinsing it five times with sterilized distilled water (total 500 mL). The seeds were observed every day for 3 days and the best surface sterilizing treatment was selected based on absence of mold growth and the effects on hypocotyl length. Sodium hypochlorite at 0.3% (v/v) concentration was able to inhibit mold growth in adzuki bean, soybean and chickpea. On the other hand, only 0.1% (v/v) sodium hypochlorite was needed to inhibit mold growth in black eye pea and petai, while mung bean required 0.05% (v/v) sodium hypochlorite to inhibit mold growth. Under these conditions, the growth of hypocotyl (hypocotyls length) was only slightly affected compared to the control. 5'-PDE was extracted from seeds that have been germinated for 24 hours and their control (ungerminated seeds) by homogenization in a blender with 400 mL of 50 mM acetate buffer, pH 4.5. After that, the homogenates were stirred for 30 min and the centrifuged at 9000 rpm for 15 min at 10°C. 5'-PDE activity was determined using thymidine 5'-monophosphate p-nitrophenyl ester as substrate at pH 7.0 and 55°C. The formation of nucleotide monophosphates, the products of reaction, was determined at 405 nm. As a strong presence of phosphomonoesterase (PME) will reduce the yield of nucleotide monophosphates as the enzyme hydrolyzes these products into nucleosides and orthophosphate, PME activity was also determined using p-nitrophenyl phosphate as the substrate at 60°C and pH 5.0. Thus, the seed with the highest 5'-PDE activity and a low PME activity can be selected. Germinated adzuki bean was found to have the highest 5'-PDE activity (0.59 µmol p-nitrophenol/min/mg protein) among the germinated seeds. A time-course study indicated that the level of 5'-PDE in adzuki bean increased with time of germination until 15 hours (0.69 µmol p-nitrophenol/min/mg protein), after which the acitivity decreased until it reached the basal level (0.44 µmol p-nitrophenol/min/mg protein) at 72 hours. On the other hand, PME in the bean was the highest at 9 h germination (0.98 µmol p-nitrophenol/min/mg protein). In general, controls have very low basal level of 5'-PDE activity (0.18- 0.42 µmol p-nitrophenol/min/mg protein).
    Matched MeSH terms: Hypocotyl
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links