Isolation and Identification of NIF Gene Homologue of Locally Isolated Azorhizobium Strains from Stem Nodules of Sesbania Rostrata

Characterisation of UPMR 43, UPMR 44 and X was conducted. Morphological studies of colonies showed that all strains gave a relatively large gummy, watery, translucent or whitely opaque colour on a modified glutamate agar. Intrinsic antibiotic resistance (IAR) patterns of all strains indicated that they were resistant to ampicillin of up to 50 mg/l but susceptible to streptomycin, tetracycline and kanamycin at concentrations of 25, 15 and 10 mg/l, respectively. The growth characteristics of UPMR.43 and UP"MR.44 (in a modified glutamate medium (GM) and peptone medium (PA)) was studied using shake flask method. UPMR43 grew better in GM compared to PA but the reverse was true for UPMR44. PA significantly reduced the cell concentration and affected growth characteristic. The generation times for both strains in both media were less than 6 h indicating that they were fast growers. The banding pattern of total DNA of three strains digested with EcoRI showed that they were very similar. A large plasmid, subject to confirmation was detected in UPMR44 using Hirsch method and one small plasmid in UPMR43 using Casse method. A 13.5 kb BamHI and a 7.0 kb EcoRI DNA fragment from total DNA extracts of all local strains were detected in Southern blot experiments using probes carrying the nifHDK genes of Klebsiella pneumoniae and Azotobacter vinelandii. The results showed that the nif genes of the Azorhizobium strains were detectable using the heterologous nif probes from K. pneumoniae and A. vinelandii. The similar results obtained from colony morphology, generation time, IAR patterns, total DNA restriction patterns and DNA-DNA hybridisation of the three strains studied suggests that they may be the same strain. The obtained results also showed that local strains have a similar characteristics with A. caulinodans ORS571. Strain X may be considered a unique strain since S. rostrata was easily infected although it is not native to Malaysia. It is postulated that this strain may have an alternative host plant

Isolation of high quality RNA from plant rich in flavonoids, Melastoma decemfidum Roxb ex. Jack.

Chalcone synthase (CHS) is a plant-specific enzyme that synthesises naringenin chalcone, an essential precursor of the flavonoid biosynthetic pathway. Naringenin and kaempferol are two flavonoids that have been demonstrated to inhibit the proliferation of HeLa cells. To study chalcone synthase gene regulation in Melastoma decemfidum, we developed a high-yield total RNA isolation method to assemble a partial putative CHS cDNA sequence. Our results indicated that a modified CTAB method produced the highest total RNA yield (8.26±3.99 μg/gFW) compared to other methods. Thus, we used this method to isolate total RNA from different types of tissues from this plant. Our improved protocol produced high-quality total RNA from different tissues, including the mature leaf (7.02±2.60 μg/gFW), stem (4.27±1.72 μg/gFW), flower bud (37.54±10.61 μg/gFW), flower (21.31±5.20 μg/gFW), and root (3.38±1.89 μg/gFW). The total RNA was then converted into cDNA, and a putative CHS gene product (~1049 bp fragment) was amplified using degenerate primers. A partial CHS gene sequence shared 80% homology with an Anthurium andraeanum CHS gene sequence (AY232492) and 92% homology with the amino acid sequence of the Acer maximowiczianum CHS gene (AEK80412.1), as determined using BlastN and BlastX, respectively. This study shows that our modified CTAB method allows for the isolation of high-quality and high-yield total RNA from various tissues of M. decemfidum. A partial putative CHS gene was amplified,thus confirming that the modified CTAB method is suitable for RT-PCR and gene isolation

Optimisation of Indole-3-Butyric Acid (IBA) concentrations for production of biomass and phenolics from adventitious roots of Justicia Gendarussa

We investigated different concentrations of lBA to determine its effect on biomass increase and the accumulation of total phenols and flavonoids in adventitious roots of Justiciu gendarussa. Leaf extracts were cultured in MS-based medium supplemented with different concentrations of lBA (2. 3 or 5 mgl." ). These roots were cultured under darkness in shake flasks for 5 weeks. Total phenolic and t1avonoids contents were determined using colorimetric method. Gallic acid and catechin were used as standards. Among the different concentrations of lBA. 2 mgl.' lEA was proven as the best concentration 1';1' adventitious roots biomass production (5.90 g of fresh weight (FW) and 0.53 g of dry weight (OW)). On contrary. 3 mgl," lBA induced higher phenolic and l1avonoid contents than other treatments ( 16.68 rug GAE/g OW and 10.72 mg CTE/g OW). The result indicates that. different lBA concentrations affects biomass and the accumulation of phenolics from adventitious root cultures of.J. gendarussu. Our finding revealed that. lEA was determined the most suitable aux in for adventitious root proliferation of.J. gendurussa . Therefore. the optimisation of auxin concentrations is beneficial to large scale production of biomass and secondary metabolites in 1. gendarussa

Detection of naringenin and kaempferol in justicia gendarussa leaf extracts by GC-FID

Justicia gendarussa methanolic leaves extract from four different locations in Southern region of Malaysia and distribution of two flavonoids, naringenin and kaempferol in plant organs (young and mature leaves) were determined using gas chromatography-flame ionization detector (GC-FID) analysis. Naringenin and kaempferol contents were detected and quantified in leaves extract. The results indicated that mature leaves contained more naringenin and kaempferol compared to young leaves. The highest concentration of naringenin and kaempferol were recorded in mature leaves from Skudai and Muar regions which were 507.692 and 1226.964 mgkg-1, respectively. Data analysis showed that naringenin content was directly proportional to the amount of kaempferol in the leaf extracts. In conclusion, this study suggested geographical variation among plant samples and physiological stage of organ parts could contribute to variation in flavonoids concentration in a plant species

Cytotoxicity activities in local justicia gendarussa crude extracts against human cancer cell lines

The present study was designed to evaluate the cytotoxic activity of Justicia gendarussa methanolic leaf extracts from five different locations in Johor and also two standards flavonoids (naringenin and kaempferol) as these two compounds were detected in the chromatogram. In this study, leaf extracts and compounds were tested against various human cancer cell lines (HT-29, HeLa and BxPC-3) by using MTT assay. The results showed that methanolic leaf extracts from Mersing and kaempferol were very toxic against BxPC-3 and HeLa cells with IC50 values of 16 µg/ml and 5 µg/ml, respectively. It is suggested that J. gendarussa leaf extracts from Mersing have potential cytotoxic activity on human cancer cell lines particularly BxPC-3 cell

Physical and antioxidative responses of Orthosiphon stamineus towards various copper and lead concentrations

Plants normally change their physiological and biochemical properties when exposed to heavy metal stress. We investigated the response of Orthosiphon stamineus towards different concentrations of Pb (0, 2, 5, 8 mg/L) and Cu (1, 2, 4, 5 mg/L). Heavy metals left in soil, plant physical characteristics, and the level of antioxidants in O. stamineus were determined. Our results showed that the tested Pb concentrations did not significantly affect stem elongation, but at 2 mg/L, Pb increased the leaf growth. Pb at 5 and 8 mg/L increased the total plant biomass. In contrast, 5 mg/L Cu treatment affected stem elongation and the root length of O. stamineus. The concentrations of Pb and Cu in soil were significantly reduced after the plants were harvested. Biochemically, 5 mg/L Pb had significantly increased the activity of catalase, while Cu at 5 mg/L significantly reduced the activity of superoxide dismutase and ascorbate peroxidase. Total flavonoid content increased in Pb-treated plants, but the total phenolics content decreased. Cu treatment at 2 mg/L, on the other hand increased the total phenolics content. Our results demonstrated that O. stamineus adapt to metal stress via physical changes, and scavenge oxygen radicals through enzymatic and non-enzymatic antioxidant productions

Stigma, Sociodemographic Factors, and Clinical Factors Associated with Psychological Distress among COVID-19 Survivors during the Convalescence Period : A Multi-Centre Study in Malaysia

High rates of psychological distress among COVID-19 survivors and stigmatisation have been reported in both early and late convalescence. This study aimed to compare the severity of psychological distress and to determine the associations among sociodemographic and clinical characteristics, stigma, and psychological distress among COVID-19 survivors across two different cohorts at two different time points. Data were collected cross-sectionally in two groups at one month and six months post-hospitalisation among COVID-19 patient from three hospitals in Malaysia. This study assessed psychological distress and the level of stigma using the Kessler Screening Scale for Psychological Distress (K6) and the Explanatory Model Interview Catalogue (EMIC) stigma scale, respectively. At one month after discharge, significantly lower psychological distress was found among retirees (B = −2.207, 95% confidence interval [95% CI] = −4.139 to −0.068, p = 0.034), those who received up to primary education (B = −2.474, 95% CI = −4.500 to −0.521, p = 0.014), and those who had an income of more than RM 10,000 per month (B = −1.576, 95% CI = −2.714 to −0.505, p = 0.006). Moreover, those with a history of psychiatric illness [one month: (B = 6.363, 95% CI = 2.599 to 9.676, p = 0.002), six months: (B = 2.887, CI = 0.469–6.437, p = 0.038)] and sought counselling services [one month: (B = 1.737, 95% CI = 0.385 to 3.117, p = 0.016), six months: (B = 1.480, CI = 0.173–2.618, p = 0.032)] had a significantly higher severity of psychological distress at one month and six months after discharge from the hospital. The perceived stigma of being infected with COVID-19 contributed to greater severity of psychological distress. (B = 0.197, CI = 0.089–0.300, p = 0.002). Different factors may affect psychological distress at different periods of convalescence after a COVID-19 infection. A persistent stigma contributed to psychological distress later in the convalescence period

Mapping geographical inequalities in access to drinking water and sanitation facilities in low-income and middle-income countries, 2000-17

Background: Universal access to safe drinking water and sanitation facilities is an essential human right, recognised in the Sustainable Development Goals as crucial for preventing disease and improving human wellbeing. Comprehensive, high-resolution estimates are important to inform progress towards achieving this goal. We aimed to produce high-resolution geospatial estimates of access to drinking water and sanitation facilities. Methods: We used a Bayesian geostatistical model and data from 600 sources across more than 88 low-income and middle-income countries (LMICs) to estimate access to drinking water and sanitation facilities on continuous continent-wide surfaces from 2000 to 2017, and aggregated results to policy-relevant administrative units. We estimated mutually exclusive and collectively exhaustive subcategories of facilities for drinking water (piped water on or off premises, other improved facilities, unimproved, and surface water) and sanitation facilities (septic or sewer sanitation, other improved, unimproved, and open defecation) with use of ordinal regression. We also estimated the number of diarrhoeal deaths in children younger than 5 years attributed to unsafe facilities and estimated deaths that were averted by increased access to safe facilities in 2017, and analysed geographical inequality in access within LMICs. Findings: Across LMICs, access to both piped water and improved water overall increased between 2000 and 2017, with progress varying spatially. For piped water, the safest water facility type, access increased from 40·0% (95% uncertainty interval [UI] 39·4–40·7) to 50·3% (50·0–50·5), but was lowest in sub-Saharan Africa, where access to piped water was mostly concentrated in urban centres. Access to both sewer or septic sanitation and improved sanitation overall also increased across all LMICs during the study period. For sewer or septic sanitation, access was 46·3% (95% UI 46·1–46·5) in 2017, compared with 28·7% (28·5–29·0) in 2000. Although some units improved access to the safest drinking water or sanitation facilities since 2000, a large absolute number of people continued to not have access in several units with high access to such facilities (>80%) in 2017. More than 253 000 people did not have access to sewer or septic sanitation facilities in the city of Harare, Zimbabwe, despite 88·6% (95% UI 87·2–89·7) access overall. Many units were able to transition from the least safe facilities in 2000 to safe facilities by 2017; for units in which populations primarily practised open defecation in 2000, 686 (95% UI 664–711) of the 1830 (1797–1863) units transitioned to the use of improved sanitation. Geographical disparities in access to improved water across units decreased in 76·1% (95% UI 71·6–80·7) of countries from 2000 to 2017, and in 53·9% (50·6–59·6) of countries for access to improved sanitation, but remained evident subnationally in most countries in 2017. Interpretation: Our estimates, combined with geospatial trends in diarrhoeal burden, identify where efforts to increase access to safe drinking water and sanitation facilities are most needed. By highlighting areas with successful approaches or in need of targeted interventions, our estimates can enable precision public health to effectively progress towards universal access to safe water and sanitation

Potential of tissue cultured medicinal plants in Malaysia

Medicinal plants possess many secondary products that exhibit biological activities such as antioxidant, anticancer, anti-inflammatory, antibacterial and anti microbial. Scientific findings have demonstrated that tissue culture techniques could be an alternative tool to propagate plant in vitro and manipulate secondary metabolites in medicinal plants. This review aims to give an update on the various plant regeneration of some locally used medicinal plants in Malaysia such as Eurycome longifolia Jack, Zingiber officinale Roscoe, Centella asiatica L., Justicia gendarussa Burm. f, Kaempferia galanga L. and Orthosiphon stamineus Benth. Different type of cultures including organ, callus and cell cultures is also discussed