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

Exogenous application of glycine betaine alleviates salt induced damages more efficiently than ascorbic acid in in vitro rice shoots

Considerable amount of research have indicated that exogenous application various compounds such as compatible solutes, plant hormones and antioxidants could enhanced salt stress tolerance in plants. However, the salt stress alleviating effect of these compounds on Malaysian rice varieties has not been investigated. Therefore, this study was undertaken with the objective to examine the salt stress mitigating effect of glycine betaine and ascorbic acid on rice shoot apices of two Malaysian rice varieties under NaCl stress. Results clearly indicated that supplementation of glycine betaine at 5 and 10 mM effectively ameliorates salt stress induced damages resulted in improved plant height, root length, biomass and total chlorophyll in both varieties tested, MR220 and MR253 as compared to salt stress condition. However, further increased of glycine betaine to 15 and 20 mM did not showed further enhancement on the overall plant growth. Supplementation of 5 mM glycine betaine increased the plant height of MR220 and MR253 to 17.0 cm and 13.3 cm as compared to 9.8 cm and 10.3 cm in salt stress media. It was noted that supplementation of of glycine betaine successfully increase the total chlorophyll content from 7.0 mg/mL FW to 13.4 and 9.1 mg/mL FW for MR220 and 8.7 and 13.8 mg/mL FW for MR253 at 5 and 10 mM respectively. Conversely, supplementation of ascorbic acidat all concentrations tested did not showed salt stress mitigating effect on the growth of rice shoot. Furthermore, ascorbic acid supplemented at 10, 15 and 20 mM was found exerted negative impact on plant growth with reduction in all growth parameters measured. In short, results from the study clearly indicated the potential of glycine betaine in mitigating salt-stress induced damages. However, more studies need to be carry out in the near future based on glasshouse and field scale trials to study the changes in the rice agronomic traits, especially the yield component should be evaluated because tolerance in stress could not represent the final yield

Preliminary study to compare the prediction error of post operative refraction in pediatric cataract surgery between 2 different intraocular lens power calculation formula

Introduction: The treatment of paediatric cataracts has progressed tremendously in the past 15 to 20 years. There is a growing trend towards intraocular lens implantation in infants and younger children whose eyes are still undergoing rapid growth and refractive changes. Objective: This study is intended to assess the predictability of desired refractive outcomes at 3 month postoperative period in paediatric patients undergoing cataract surgery with primary placement of an intraocular lens. Methodology: This randomized interventional study of 31 eyes (24 patients) that successfully underwent cataract surgery and intraocular lens implantations. All patients were 12 years old and below. Intraocular lens power calculations were made using either SRK II or Modified Formula For Paediatric IOL Calculation. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 3 month postoperative follow-up. The prediction error was taken as the absolute difference between the predicted and the actual refraction. The data were analysed to compare the mean prediction error between SRK II and Modified Formula and evaluate the predictability. Results: The mean prediction error in the SRK II group was 1.03 D (SD, 0.69 D) while in Modified Formula 1.14 D (SD, 1.19 D). The SRK II group showed lower prediction error of 0.11 D compared to Modified Formula group, but this was not statistically significant (p > 0.05). There were 3 eyes (18.75%) in SRK II group achieved accurate predictability where the refraction postoperatively was within ± 0.5 D from predicted refraction compared to 7 eyes (46.67%) in the Modified Formula group. However the difference of the predictability between the two formulas was also not statistically significant (p = 0.097). Conclusion: The prediction error and the accuracy of predictability of postoperative refraction in paediatric cataract surgery are comparable between SRK II and Modified Formula. The existence of the Modified Formula provides an alternative to the ophthalmologist for intraocular lens calculation in paediatric patients

Addition of L-tyrosine to improve betalain production in red pitaya callus

The aim of this study is to enhance betalain production in red pitaya (Hylocereus polyrhizus) callus through supplementation of the precursor L-tyrosine. Red-pigmented calli were produced on Murashige and Skoog (MS) basal salt medium supplemented with 2 mg/L naphthaleneacetic acid (NAA), 4 mg/L thidiazuron (TDZ) and different concentrations of L-tyrosine (20, 40, 60, 80, 100 mg/L). The addition of 20 mg/L L-tyrosine was able to increase betacyanin production by 1.5-fold compared to calli grown on Murashige and Skoog (MS) basal salt medium (MSO). The results also revealed that betalain production (calli cultured with 20 mg/L L-tyrosine) was higher than MS medium with 2 mg/L NAA and 4 mg/L TDZ (without L-tyrosine) up to 1.7-fold. Four compounds, namely betacyanin, betaxanthin and two additional compounds, phenolic and flavonoid compounds, were detected in the red-pigmented calli treated with 20 mg/L L-tyrosine that were not found in the fresh fruit sample. This indicates that the callus system has potential to produce betalain pigment and that red-pigmented calli could be an important antioxidant source

Potential of plant's Bowman-Birk protease inhibitor in combating abiotic stresses: a mini review

Bowman-Birk Inhibitor (BBI) is one of the subfamilies of serine protease inhibitors. Numerous studies have shown that in plants, BBI functions as part of their defense mechanism against pathogens and microorganisms. The BBI is also known to have anti-carcinogenic properties. Furthermore, the BBI has been reported to function in controlling abiotic stresses such as salinity and drought stresses. Abiotic stresses are the major problems in agricultural industry. Therefore, numerous researches have been carried out to characterize the BBI and to determine its roles during biotic and abiotic stresses. This paper presents a review regarding the relationship between Bowman-Birk inhibitor and the plant defensive mechanism against abiotic stresses

Optimisation for Enhancement of Phenol Degradation by Arthrobacter sp. Strain AQ5-15 from Antarctic Soil Using Conventional and Statistical Approach

The Tenth Symposium on Polar Science/Ordinary sessions : [OB] Polar Biology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc

Effects of benzyladenine purine and its interaction with polyamines on growth of Spathoglottis plicata PLBs

Spathoglottis plicata is highly sought after by florists and orchid growers due to its unique structure and colors. However, this orchid is a slow-growing type and thus the planting materials are acutely limited. Therefore, there is a need to improve its multiplication efficiency and speed up its growth in order to meet the market demand. Benzyladenine purine (BAP) has been widely used to improve plantlet multiplication in plant cultures. Polyamines have also been reported to improve the growth and development of in vitro cultures. The objective of this study was to investigate the effects of BAP and different polyamines on the physical and biochemical changes of protocorm-like bodies (PLBs) of S. plicata. Different concentrations of BAP and polyamines (putrescine, spermine, and spermidine) were used. BAP and polyamines were supplemented singly in half-strength MS medium and PLBs were cultured for 2 weeks. It was observed that 5 µM BAP and 25 µM spermidine resulted in the highest fresh weights of 0.38 g and 0.31 g, respectively. The total soluble protein and carbohydrate content for PLBs treated with 25 µM spermidine was 4.85 mg/g FW and 6.36 mg/g FW. A separate experiment was carried out to investigate the interactive effects of 25 µM spermidine with 5 µM BAP. The presence of spermidine in the media reduced the peroxidase and catalase activities by increasing the nitrate reductase activity

Exogenous proline significantly affects the plant growth and nitrogen assimilation enzymes activities in rice (Oryza sativa) under salt stress

Salinity has been shown to be a major factor contributing to low nitrogen availability in plants. To verify the changes in nitrogen metabolism activity as affected by the exogenous application of proline under salt stress and its relation to salt tolerance, in vitro rice shoot apices were used as a model to study the growth performance and changes in nitrogen assimilation activities in two Malaysian rice cultivars MR 220 and MR 253. Results revealed that salt stress greatly reduced the plant height, shoot nitrate (NO3 −) content, shoot glutamine synthetase (GS), and root nitrate reductase (NR) activities in both cultivars. Supplementation of proline significantly increased the plant height, number of roots, root NO3 − content, root NR, and root GS activities under salt stress in both cultivars with greater enhancement in MR 253 than MR 220. The results also indicated that MR 253 possessed higher nitrite reductase (NiR) and glutamate synthase (NADH–GOGAT) activities as compared with MR 220 in all tested treatments. It was suggested that the NO3 − content, NR, and GS activities played important roles in regulating nitrogen metabolism under salt stress. Taken together, it was concluded that the ability of proline in mitigating salt stress-induced damages was correlated with the changes in nitrogen assimilation activities

Exogenous proline significantly affects the plant growth and nitrogen assimilation enzymes activities in rice (Oryza sativa) under salt stress

Salinity has been shown to be a major factor contributing to low nitrogen availability in plants. To verify the changes in nitrogen metabolism activity as affected by the exogenous application of proline under salt stress and its relation to salt tolerance, in vitro rice shoot apices were used as a model to study the growth performance and changes in nitrogen assimilation activities in two Malaysian rice cultivars MR 220 and MR 253. Results revealed that salt stress greatly reduced the plant height, shoot nitrate (NO3 −) content, shoot glutamine synthetase (GS), and root nitrate reductase (NR) activities in both cultivars. Supplementation of proline significantly increased the plant height, number of roots, root NO3 − content, root NR, and root GS activities under salt stress in both cultivars with greater enhancement in MR 253 than MR 220. The results also indicated that MR 253 possessed higher nitrite reductase (NiR) and glutamate synthase (NADH–GOGAT) activities as compared with MR 220 in all tested treatments. It was suggested that the NO3 − content, NR, and GS activities played important roles in regulating nitrogen metabolism under salt stress. Taken together, it was concluded that the ability of proline in mitigating salt stress-induced damages was correlated with the changes in nitrogen assimilation activities

Direct shoot organogenesis and clonal fidelity confirmation of Tongkat Ali (Eurycoma longifolia) using molecular markers

Eurycoma longifolia is a medicinally potent plant found in the tropical forest of South-East Asia. Every part of the plant, especially the root is traditionally used as an aphrodisiac, anticancer and anti-inflammatory. E. longifolia is conventionally propagated by seeds but with low germination rate and efficiency. This has made an in vitro propagation of E. longifolia a desirable alternative. Hence, this study reports an effective method of direct organogenesis of shoot. In vitro seedling’s leaves were cultured on Murashige and Skoog (MS) medium containing 1.0 mg L-1 6-benzylaminopurine (BAP), producing 1.8 ± 0.5 shoots per leaf with a regeneration frequency of 68.2%. The shoot buds were directly formed from leaves without intermediate callus formation. To obtain complete plantlets, the shoots were in vitro rooted with an average number of 4.2 ± 0.4 roots per shoot in half-strength MS (½MS) medium supplemented with 0.5 mg L-1 indole-3-butyric acid (IBA). Regenerated plantlets were successfully acclimatized to field conditions with an 85% survival rate. Genetic fidelity of the micropropagated plantlets was evaluated using Simple Sequence Repeat (SSR) and Inter Simple Sequence Repeat (ISSR) analysis. The results showed that the monomorphic banding patterns of in vitro raised plantlets and their mother plant were similar, confirming its homogeneity and the reliability of the multiplication system