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The oil palm EgPAL1 gene promoter and its regulatory region were functional as a promoter in the heterologous system of Arabidopsis according to the cis-acting elements present in that region. The promoter was developmentally regulated, vascular tissue specific and responsive to water stress agents. Phenylalanine ammonia lyase (PAL, EC 4.3.1.24) is the key enzyme of the phenylpropanoid pathway which plays important roles in plant development and adaptation. To date, there is no report on the study of PAL from oil palm (Elaeis guineensis), an economically important oil crop. In this study, the 5′ regulatory sequence of a highly divergent oil palm PAL gene (EgPAL1) was isolated and fused with GUS in Arabidopsis to create two transgenic plants carrying the minimal promoter with (2302 bp) and without its regulatory elements (139 bp). The regulatory sequence contained cis-acting elements known to be important for plant development and stress response including the AC-II element for lignin biosynthesis and several stress responsive elements. The promoter and its regulatory region were fully functional in Arabidopsis. Its activities were characterised by two common fundamental features of PAL which are responsive to plant internal developmental programme and external factors. The promoter was developmentally regulated in certain organs; highly active in young organs but less active or inactive in mature organs. The presence of the AC elements and global activity of the EgPAL1 promoter in all organs resembled the property of lignin-related genes. The existence of the MBS element and enhancement of the promoter activity by PEG reflected the behaviour of drought-responsive genes. Our findings provide a platform for evaluating oil palm gene promoters in the heterologous system of Arabidopsis and give insights into the activities of EgPAL1 promoter in oil palm.

Seaweeds survive in marine waters with high sulfate concentration compared to those living at freshwater habitats. The cell wall polymer of Gracilaria spp. which supplies more than 50% of the world agar is heavily sulfated. Since sulfation reduces the agar quality, it is interesting to investigate the effects of sulfate deprivation on the sulfate contents of seaweed and agar, as well as the metabolic pathways of these seaweeds. In this study, two agarophytes G. changii and G. salicornia were treated under sulfate deprivation for 5 days. The sulfate contents in the seaweed/agar were generally lower in sulfate-deprivated samples compared to those in the controls, but the differences were only statistically significant for seaweed sample of G. changii and agar sample of G. salicornia. RNA sequencing (RNA-Seq) of sulfate-deprivated and untreated seaweed samples revealed 1,292 and 3,439 differentially expressed genes (DEGs; ≥1.5-fold) in sulfate-deprivated G. changii and G. salicornia, respectively, compared to their respective controls. Among the annotated DEGs were genes involved in putative agar biosynthesis, sulfur metabolism, metabolism of sulfur-containing amino acids, carbon metabolism and oxidative stress. These findings shed light on the sulfate deprivation responses in agarophytes and help to identify candidate genes involved in agar biosynthesis.

The purpose of this study was to evaluate the effectiveness of using RNA interference in down regulating the expression of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Eksotika papaya. One-month old embryogenic calli were separately transformed with Agrobacterium strain LBA 4404 harbouring the three different RNAi pOpOff2 constructs bearing the 1-aminocyclopropane-1-carboxylic acid oxidase gene. A total of 176 putative transformed lines were produced from 15,000 calli transformed, selected, then regenerated on medium supplemented with kanamycin. Integration and expression of the targeted gene in putatively transformed lines were verified by PCR and real-time RT-PCR. Confined field evaluation of a total of 31 putative transgenic lines planted showed a knockdown expression of the targeted ACO1 and ACO2 genes in 13 lines, which required more than 8 days to achieve the full yellow colour (Index 6). Fruits harvested from lines pRNAiACO2 L2-9 and pRNAiACO1 L2 exhibited about 20 and 14 days extended post-harvest shelf life to reach Index 6, respectively. The total soluble solids contents of the fruits ranged from 11 to 14° Brix, a range similar to fruits from non-transformed, wild type seed-derived plants.

The supply of agar as an important gelling and thickening agent in various industrial applications depends heavily on harvesting of natural seaweed resources and seaweed farming. To facilitate the selection of good seaweed source with higher agar yield and stronger gel strength, accurate and rapid screening method using molecular markers is necessary to replace the tedious, laborious and time-consuming conventional method which involves agar extraction and gel analysis. In this study, we characterized the expression of a number of algal transcripts and proteins from an agar producing seaweed, Gracilaria changii with the aim to identify potential markers for agar yield and gel strength. In total, 15 candidate transcripts that are directly or indirectly related to putative agar biosynthetic pathway were identified based on literature search. The transcript abundance of 4 and 11 of these candidates were found to be significantly (P

Aims: This studywas carried out to investigate the metal tolerance levels of Melastoma malabathricumLinn. plantlets. Study Design:The metal tolerance levels of M. malabathricumL. were examined using an in vitroapproach. The ability of the plant to survive in tissue culture medium containing aluminium (Al), copper (Cu) and cobalt (Co) were assessed. Place and Duration ofStudy:The study was carried out in the Plant Culture Lab oratory

Agar is a jelly-like biopolymer synthesized by many red seaweeds as their major cell wall component. Due to its excellent rheological properties, it has been exploited commercially for applications in food, cosmetic, pharmaceutical, biomedical and biotechnology industries. Despite its multiple uses, the biosynthesis of this phycocolloid is not fully understood. The current knowledge on agar biosynthesis is inferred from plant biochemistry and putative pathways for ulvan and alginate biosynthesis in green and brown seaweeds, respectively. In this review, the gaps in our current knowledge on agar biosynthetic pathway are discussed, focusing on the biosynthesis of agar precursors, elongation of agar polysaccharide chain and side chain modification. The development of molecular markers for the screening of desired seaweeds for industrial exploitation is also discussed.

Vanda Mimi Palmer (VMP), an orchid hybrid of Vanda tesselata and Vanda Tan Chay Yan is a highly scented tropical orchid which blooms all year round. Previous studies revealed that VMP produces a variety of isoprenoid volatiles during daylight. Isoprenoids are well known to contribute significantly to the scent of most fragrant plants. They are a large group of secondary metabolites which may possess valuable characteristics such as flavor, fragrance and toxicity and are produced via two pathways, the mevalonate (MVA) pathway or/and the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway. In this study, a sesquiterpene synthase gene denoted VMPSTS, previously isolated from a floral cDNA library of VMP was cloned and expressed in Lactococcus lactis to characterize the functionality of the protein. L. lactis, a food grade bacterium which utilizes the mevalonate pathway for isoprenoid production was found to be a suitable host for the characterization of plant terpene synthases. Through recombinant expression of VMPSTS, it was revealed that VMPSTS produced multiple sesquiterpenes and germacrene D dominates its profile.

Melastoma malabathricum Linn. is a shrub that belongs to the family Melastomataceae and a common herbal plant used in folk medicines to treat inflamed wounds. This study was carried out with the aim to evaluate the inhibitory activities of different concentrations of the M. malabathricum Linn. flower and fruit crude extracts against a variety of microorganisms. The inhibitory effects of both extracts were tested against the microorganisms using the disc diffusion method. The lowest concentrations of the extracts producing inhibition zones against the test microorganisms were used to determine their Minimum Inhibitory Concentrations (MICs) and Minimum Microbicidal Concentrations (MMCs). Both crude extracts showed strong inhibitory activities against Gram-positive bacteria. The range of MIC values for the crude flower and fruit extracts on all the bacteria tested were 12.5 to 100.0 mg/ml. Overall, Gram-positive bacteria were more susceptible to the crude extracts compared to Gram-negative species, potentiating a possible use of the extracts to inhibit or kill potential pathogens.

A comprehensive study on the orchid diversity in Penang Hill, Penang, Malaysia was conducted from 2004 to 2008 with the objective to evaluate the presence of orchid species listed by Curtis (J Strait Br R Asiat Soc 25:67–173, 1894) after more than 100 years. A total of 85 species were identified during this study, of which 52 are epiphytic or lithophytic and 33 are terrestrial orchids. This study identified 57 species or 64.8% were the same as those recorded by Curtis (1894), and 78 species or 66.1% of Turner’s (Gardens’ Bull Singap 47(2):599–620, 1995) checklist of 118 species for the state of Penang including 18 species which were not recorded by Curtis (1894) and the current study but are actually collected from Penang Hill. A comparison table of the current findings against Curtis (1894) and Turner (1995) is provided which shows only 56 species were the same in all three studies. The preferred account for comparison was Curtis’ (1894) list as his report was specifically for the areas around Penang Island especially Penang Hill, Georgetown and Ayer Itam areas. Our study reveals that about 50% of Curtis’ collection localities have been converted to residential areas and agricultural land, and this probably explains the decreasing numbers of species found in the current study especially for the terrestrial species as epiphytic species have better adaptation capabilities towards environmental changes. Seven species were identified as new records to Penang Hill as they were not recorded by Curtis (1894). None of the three species recorded as endemic to Penang by Turner (1995) was recollected during the current study, of which only Zeuxine rupestris was in Curtis’ (1894) list. Overall, we concluded that Penang hill harbours at least 136 species of orchids of which 78 species or 57.4% were recollected in this study. This also indicates that this area is still suitable for orchid growth even though it is surrounded by rapid development and mass conversion of forested land into fruit orchards and residential area. The designation of Penang Hill as a Permanent Forest Reserve would better guarantee the survival of some orchid species unless human interventions and climatic changes occur.

The aims of this study were to isolate and characterize putative fragrance-related cDNAs from the floral cDNA library of Vanda Mimi Palmer, an orchid hybrid that has won several international awards for its sweet fragrance. A total of 1,000,000 pfu were screened by hybridizing cDNA library plaques with fully open flower cDNA probe of Vanda Mimi Palmer representing all mRNAs expressed during daytime. The clones that gave positive signals were in vivo excised and PCR-amplified inserts were subjected to reverse-Northern analysis by hybridizing with cDNA probes of fully open flower of Vanda Mimi Palmer (fragrant orchid) and its bud or fully open flower of Vanda Tan Chay Yan (non-fragrant orchid) separately. The clones up-regulated in fully open flower stage of Vanda Mimi Palmer compared to its bud stage or fully open flower of Vanda Tan Chay Yan were sequenced. Sequence analyses showed the presence of eight putative fragrance-related cDNAs of which two were putative Vanda Mimi Palmer 4-(cytidine 5′-diphospho)-2-C-methyl-d-erythritol kinase (VMPCMEK) and Vanda Mimi Palmer cytochrome P450 protein (VMPCyP450). These two transcripts were selected for full-length cDNA isolation and expression analysis by real-time RT-PCR. The VMPCMEK transcript encodes a polypeptide of 400 amino acid residues, while the VMPCyP450 encodes 538 amino acid residues. Relative expression analysis of VMPCMEK and VMPCyP450 transcripts by real-time RT-PCR showed up-regulated expressions in floral tissues compared to vegetative tissues, and both were found to be developmentally regulated.

A subtracted cDNA library of open flower was constructed using the suppression subtractive hybridization (SSH) technique, to identify fragrance-related transcripts of Vanda Mimi Palmer. In total, 107 transcripts up-regulated during blooming were identified and sequenced. Only 33 clones (4 singletons and 29 contigs) showed similarities to known sequences in the public database. Of these, thirty-two clones were transcripts encoding fragrance-related enzymes including sesquiterpene synthase, (±)-germacrene D synthase, tyrosine decarboxylase and putative acyltransferase. Two fragrance-related transcripts, VMPAAT encoding a putative alcohol acyltransferase and VMPSTS encoding a sesquiterpene synthase, were subjected to full-length cDNA isolation and characterization. The full length cDNA of VMPAAT has a 1343 bp open reading frame (ORF) of 448 amino acid residues whereas VMPSTS is predicted to encode a polypeptide of 561 amino acid residues with 1682 bp ORF. VMPAAT and VMPSTS show high homologies with plant alcohol acyltransferase and terpene synthase, respectively. Real time RT-PCR indicated that both transcripts were expressed preferentially in floral tissues, with high levels in blooming and full bloom flowers. VMPAAT and VMPSTS transcripts were expressed in a rhythmic pattern. The results presented in this study will be potentially useful in providing additional insights into the fragrance-related pathways of Orchidaceae members, which until today is still limited.

Vanda Mimi Palmer (VMP) is a highly sought as fragrant-orchid hybrid in Malaysia. It is economically important in cosmetic and beauty industries and also a famous potted ornamental plant. To date, no work on fragrance-related genes of vandaceous orchids has been reported from other research groups although the analysis of floral fragrance or volatiles have been extensively studied. An expressed sequence tag (EST) resource was developed for VMP principally to mine any potential fragrance-related expressed sequence tag-simple sequence repeat (EST-SSR) for future development as markers in the identification of fragrant vandaceous orchids endemic to Malaysia. Clustering, annotation and assembling of the ESTs identified 1,196 unigenes which defined 966 singletons and 230 contigs. The VMP dbEST was functionally classified by gene ontology (GO) into three groups: molecular functions (51.2%), cellular components (16.4%) and biological processes (24.6%) while the remaining 7.8% showed no hits with GO identifier. A total of 112 EST-SSR (9.4%) was mined on which at least five units of di-, tri-, tetra-, penta-, or hexa-nucleotide repeats were predicted. The di-nucleotide motif repeats appeared to be the most frequent repeats among the detected SSRs with the AT/TA types as the most abundant among the dimerics, while AAG/TTC, AGA/TCT-type were the most frequent trimerics. The mined EST-SSR is believed to be useful in the development of EST-SSR markers that is applicable in the screening and characterization of fragrance-related transcripts in closely related species.

Vanda Mimi Palmer is a fragrant-orchid of which has won several international awards for its fragrance emission characteristic. A partial sequence encoding putative phenylacetaldehyde synthase (VMPPAAS) transcript which might be involved in the fragrance biosynthesis of this orchid was previously identified in the floral Expressed Sequence Tags (ESTs) of this orchid. The aims of this study were to isolate full-length cDNA of VMPPAAS and followed by molecular characterization. The full-length cDNA was isolated by SMART RACE PCR amplification while the expression analysis was carried out using real-time RT-PCR for different tissues, different flower developmental stages and different time points in a 24 h cycle. The VMPPAAS transcript encodes for a polypeptide of 508 amino acid residues consisting of 1524 bp Open Reading Frame (ORF) flanked by 92 bp of 5' Untranslated Region (UTR) and 93 bp of 3' UTR including a poly-A tail. It has a conserved motif for pyridoxal phosphate attachment site and a VHVDAAY motif, which are also shared by other plant decarboxylase proteins such as tyrosine decarboxylases, tryptophan decarboxylases and phenylacetaldehyde synthase. Expression analysis of VMPPAAS transcript by real-time RT-PCR showed an up-regulated expression in floral tissues especially in sepal and petal and down-regulated in vegetative tissues. The expression was shown to be developmentally regulated in the flower life-cycle as well as temporally regulated in a 24 h cycle.

To date, a total of 288 species from 96 genera were identified from the limestone areas in Perlis and Padawan-Bau, Sarawak, of which many of these are restricted to limestone habitat and either endemic to Perlis or to Sarawak. Knowledge and data obtained from the field observation over the past 8 years leads us to report that at least 15 species endemic to limestone has become rare in the wild in Perlis, Bau and Padawan Sarawak. This was mainly attributed by: i) lack of emphasis by the government on understanding and protecting biodiversity in this kind of habitat; ii) lack of scientists willing to do research in dangerous and disaster prone limestone habitat; and iii) lack of knowledge and awareness among local communities on the importance of conserving and utilizing their natural resources in a sustainable manner.

A 1-deoxy- d -xylulose 5-phosphate reductoisomerase ( DXR ) transcript was successfully isolated from the floral cDNA library of Vanda Mimi Palmer ( VMPDXR ). The full-length cDNA of clone VMPDXR was predicted to encode a polypeptide of 473 amino acid residues with 15 bp of 5′ UTR and 230 bp of 3′ UTR including a poly-A tail. VMPDXR was predicted to have a molecular mass of 51.4 kD and a p I value of 6.04. It has two conserved domains, an N-terminal NADPH binding site (GSTGSIG) and an N-terminal proline-rich region (PPPPAWPGR). It also contains two highly homologous regions, a 78–207 amino acids stretch at the N-terminal and a 221–304 amino acids stretch at the C-terminal domain. The putative plastid transit peptide is not found in VMPDXR and it is clustered into the plant DXRs in the phylogenetic tree. VMPDXR was differentially expressed in roots, leaves, sepals, petals and column. The VMPDXR transcript levels were preferentially high in blooming and fully bloomed flowers compared to the bud. The expression of VMPDXR at different times did not appear in a rhythmic manner and no drastic fluctuation was observed at night except at 2 pm during the day.

The nucleocapsid protein of Nipah virus produced in Escherichia coli assembled into herringbone-like particles. The amino- and carboxy-termini of the N protein were shortened progressively to define the minimum contiguous sequence involved in capsid assembly. The first 29 aa residues of the N protein are dispensable for capsid formation. The 128 carboxy-terminal residues do not play a role in the assembly of the herringbone-like particles. A region with amino acid residues 30–32 plays a crucial role in the formation of the capsid particle. Deletion of any of the four conserved hydrophobic regions in the N protein impaired capsid formation. Replacement of the central conserved regions with the respective sequences from the Newcastle disease virus restored capsid formation.

Genetic engineering of a wide variety of plant species has led to the improvement of plant traits. In this study, the genetic transformation of two potentially important flowering ornamentals, Melastoma malabathricum and Tibouchina semidecandra, with sense and antisense dihydroflavonol-4-reductase (DFR) genes using the Agrobacterium-mediated method was carried out. Plasmids pBETD10 and pBETD11, each harbouring the DFR gene at different orientations (sense and antisense) and selectable marker nptII for kanamycin resistance, were used to transform M. malabathricum and T. semidecandra under the optimized transformation protocol. Putative transformants were selected in the presence of kanamycin with their respective optimized concentration. The results indicated that approximately 4.0% of shoots and 6.7% of nodes for M. malabathricum regenerated after transforming with pBETD10, whereas only 3.7% (shoots) and 5.3% (nodes) regenerated with pBETD11 transformation. For the selection of T. semidecandra, 5.3% of shoots and 9.3% of nodes regenerated with pBETD10 transformation, while only 4.7% (shoots) and 8.3% (nodes) regenerated after being transformed with pBETD11. The presence and integration of the sense and antisense DFR genes into the genome of M. malabathricum and T. semidecandra were verified by polymerase chain reaction (PCR) and nucleotide sequence alignment and confirmed by southern analysis. The regenerated putative transformants were acclimatized to glasshouse conditions. Approximately 31.0% pBETD10-transformed and 23.1% pBETD11-transformed M. malabathricum survived in the glasshouse, whereas 69.4% pBETD10-transformed and 57.4% pBETD11-transformed T. semidecandra survived. The colour changes caused by transformation were observed at the budding stage of putative T. semidecandra transformants where greenish buds were produced by both T. semidecandra harbouring the sense and antisense DFR transgenes. Besides that, the production of four-petal flowers also indicated another morphological difference of putative T. semidecandra transformants from the wild type plants which produce five-petal flowers.

Agrobacterium-mediated transformation for both Melastoma malabathricum and Tibouchina semidecandra were optimized using green fluorescent protein (GFP) as a reporter. The binary vector pCAMBIA1304 harboring the modified green fluorescent protein (mgfp) gene driven by the CaMV 35S promoter was used. Parameters optimized were bacterial strain, bacterial concentration, pre-culture period, co-cultivation period, immersion time, acetosyringone concentration and wounding type. Results obtained were based on the percentage of GFP expression which was observed 3 days post-transformation. Agrobacterium tumefaciens strain LBA4404 and EHA105 at concentration 1 × 107 cfu ml-1 (OD600nm 0.8) showed the highest virulence on M. malabathricum and T. semidecandra, respectively. Four days of pre-culture and 2 days of co-cultivation were optimum for M. malabathricum transformation, while 3 days of pre-culture and co-cultivation for T. semidecandra. Result also showed that 60 min of immersion and addition of 200 μM acetosyringone gave the highest percentage of positive transformants for both M. malabathricum and T. semidecandra. Mild wounding also significantly increased the efficiency of M. malabathricum transformation. © 2006 Elsevier B.V. All rights reserved

Genetic engineering is a powerful tool for the improvement of plant traits. Despite reported successes in the plant kingdom, this technology has barely scratched the surface of the Melastomataceae family. Limited studies have led to some optimisation of parameters known to affect the transformation efficiency of these plants. The major finding of this study was to optimise the presence of selected enhancers [e.g., monosaccharides (D-glucose, D-galactose and D-fructose), tyrosine, aluminium chloride (AICI3) and ascorbic acid] to improve the transformation efficiency of Tibouchina semidecandra. Agrobacterium tumefaciens strain LBA4404 harbouring the disarmed plasmid pCAMBIA1304 was used to transform shoots and nodes of T. semidecandra. Different concentrations of the transformation enhancers were tested by using green fluorescent protein (GFP) as a reporter. The results obtained were based on the percentage of GFP expression, which was observed 14 days post-transformation. A combination of 120 μM galactose and 100 μM tyrosine supplemented with 600 μM AICI3 in the presence of 15 mg/l ascorbic acid gave the highest percentage of positive transformants for T. semidecandra shoots. Whereas 60 μM galactose and 50 μM tyrosine with 200 μM AICI3 in the presence of 15 mg/l ascorbic acid was optimum for T. semidecandra nodes. The presence of the hygromycin phosphotransferase II (hptII) transgene in the genomic DNA of putative T. semidecandra transformants was verified by PCR amplification with specific primers.Kejuruteraan genetik adalah satu peralatan canggih untuk memperbaiki ciri tumbuhan. Walaupun dilaporkan berjaya dalam alam tumbuhan, teknologi ini hanya mencalar sedikit permukaan famili Melastomataceae. Kajian terhad telah dilakukan untuk memperolehi keputusan yang terbaik bagi parameter yang diketahui mempengaruhi kecekapan transformasi tumbuhan ini. Hasil utama kajian ini adalah penemuan keadaan yang terbaik dengan kehadiran perangsang yang tertentu [contohnya, monosakarida (D-glukosa, D-galaktosa dan D-fruktosa), tirosina, aluminium klorida (AICI

Melastoma malabathricumLinn. is a perennial traditional medicine plants that grows abundantly throughout Asian countries. In this study,M. malabathricumLinn. leaf hot water crude extract with anticoagulant activity was purified through solid phase extraction cartridge and examined for the bioactive chemical constituents on blood coagulation reaction. The SPE purified fractions were, respectively, designated as F1, F2, F3, and F4, and each was subjected to the activated partial thromboplastin time (APTT) anticoagulant assay. Active anticoagulant fractions (F1, F2, and F3) were subjected to chemical characterisation evaluation. Besides, neutral sugar for carbohydrate part was also examined. F1, F2, and F3 were found to significantly prolong the anticoagulant activities in the following order,F1>F2>F3, in a dose dependent manner. In addition, carbohydrate, hexuronic acid, and polyphenolic moiety were measured for the active anticoagulant fractions (F1, F2, and F3). The characterisation of chemical constituents revealed that all these three fractions contained acidic polysaccharides (rhamnogalacturonan, homogalacturonan, and rhamnose hexose-pectic type polysaccharide) and polyphenolics. Hence, it was concluded that the presence of high hexuronic acids and polysaccharides, as well as polyphenolics in traditional medicinal plant,M. malabathricum, played a role in prolonging blood clotting in the intrinsic pathway.

Melastoma malabathricumLinn. is a shrub that comes with beautiful pink or purple flowers and has berries-like fruits rich in anthocyanins. This study was carried out with the aim to evaluate the inhibitory activities of different concentrations of theM. malabathricumLinn. flower and fruit crude extracts againstListeria monocytogenesIMR L55,Staphylococcus aureusIMR S244,Escherichia coliIMR E30, andSalmonella typhimuriumIMR S100 using the disc diffusion method. The lowest concentrations of the extracts producing inhibition zones against the test microorganisms were used to determine their minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). In addition, the growth ofListeria monocytogenesIMR L55 andStaphylococcus aureusIMR S244 grown in medium supplemented with the respective extracts at different temperatures (4°C, 25°C, and 37°C) and pHs (4, 6, 7, and 8) was determined.

Plant 3-hydroxy-3-methylglutaryl-CoA-reductase (HMGR) is involved in the conversion of HMG-CoA into mevalonate (MVA), which yields a biologically active isoprenoid precursor, isopentenyl pyrophosphate (IPP) unit. To date, heterologous expression of HMGR isolated from orchidaceae family has not been reported. The aims of this study were to isolate, clone, over-express and functionally characterize the cDNA encoding a 3-hydroxy-3-methylglutaryl-CoA-reductase of Vanda Mimi Palmer (VMPHMGR) in Escherichia coli strain BL21 (DE3) pLysS. The deduced VMPHMGR contains an open reading frame (ORF) of 1689 bp and generates a protein of 562 amino acids with a calculated molecular mass of 59780 Da and a predicted pI value of 6.63, which is 76% identical to other plant HMGRs. Expression analysis of VMPHMGR transcript by real-time RT-PCR showed that it was differentially regulated. Primers with appropriate restriction sites were used to amplify and facilitate in-frame cloning of the VMPHMGR into pET32(a). The expression of VMPHMGR, in E. coli, fused to N-terminal thioredoxin (Trx·Tag), S·Tag and His·Tag fusion proteins in pET32(a) yielded a partially soluble recombinant protein. This expressed VMPHMGR was subjected to functional enzymatic assay and GCMS analysis of the end products detected dehydromevalonic lactone and pantolactone, which were derivatives of mevalonate lactone.

Corybas is an elusive terrestrial orchid genus mostly inhabiting the high peaks in Peninsular Malaysia, which is the most vulnerable habitat to climate change. Nine species, of which seven are endemic, were studied based on natural populations, whereas information on another two was obtained from herbarium collections. Corybas caudatus was excluded from the study due to insufficient materials, and the type was not located. The species investigated were growing in small populations in the remaining moss-covered forests in the highlands. Human activities and temperature rise are two major threats to the wild populations. Our field observations revealed that Corybas species are good indicators of climate change as they are highly sensitive to temperature rise and drop in relative humidity. Judging from the current small number of specimens recollected, the small population sizes and degraded habitats where they grow, Corybas species in Peninsular Malaysia are all threatened by extinction in the wild.

Vanda Mimi Palmer is the product of a cross between Vanda Tan Chay Yan and Vanda tessellata. The flower of this hybrid produces a sweet-smelling fragrance during day time at the open-flower stage. This study aimed to investigate the floral scent constituents in Vanda Mimi Palmer. Scent emission analysis of this orchid was carried out at different time points in a 24-h cycle and also at different floral developmental stages. A comparison was also made on the volatiles emitted by Vanda Mimi Palmer and both of its parents. Gas chromatography-mass spectrometry (GC-MS) analysis showed that the scent of Vanda Mimi Palmer was dominated by terpenoid, benzenoid, and phenylpropanoid compounds. The identified terpenoids were ocimene, linalool oxide, linalool, and nerolidol; while the benzenoid and phenylpropanoid compounds were methylbenzoate, benzyl acetate, phenylethanol, and phenylethyl acetate. The emission of terpenoid, benzenoid, and phenylpropanoid compounds was developmentally and temporally regulated. Comparison of the volatiles emitted by both of its parents showed that the scent of Vanda Mimi Palmer is dissimilar to that of its fragrant parent, V. tessellata.

Anthocyanin is among the permitted pigments that can be used for food colourant and having been considered a potential replacement for synthetic dyes. The objective of this study is to analyse the colour pigment, anthocyanin, that can be detected in flower and their stability in extracted form. All the analysed results will be used in the next study for the production of new food colouring material. From the observation, it shows that S3 flower developmental stage contains the highest anthocyanin concentration. Simple linear regression method was used to find the significant level correlating the anthocyanin concentration and storage time. Throughout the whole experiments, the extracted anthocyanin contents are quite stable. The graphs show a small degradation rate in the anthocyanin total concentration, except for the extracts that were exposed to the light where the degradation level reached more than 50%. At different pH values, the anthocyanin concentration decreased and the colour faded at higher pH. Extracts that were stored at high temperatures (31°C) showed higher degradation levels compared to the one kept at lower temperatures (25°C). From the study we find that the suitable storage condition for coloured anthocyanin pigments is in acidic solution (pH 0.5 and 1.0) kept in the dark and at low temperature (4°C).Keywords: Anthocyanin, colourant, pigment, Melastoma malabathricum