Nurul Jadid

Characterization of Plant Carotenoid Cyclases as Members of the Flavoprotein Family Functioning with No Net Redox Change

The later steps of carotenoid biosynthesis involve the formation of cyclic carotenoids. The reaction is catalyzed by lycopene β-cyclase (LCY-B), which converts lycopene into β-carotene, and by capsanthin-capsorubin synthase (CCS), which is mainly dedicated to the synthesis of κ-cyclic carotenoids (capsanthin and capsorubin) but also has LCY-B activity. Although the peptide sequences of plant LCY-Bs and CCS contain a putative dinucleotide-binding motif, it is believed that these two carotenoid cyclases proceed via protic activation and stabilization of resulting carbocation intermediates. Using pepper (Capsicum annuum) CCS as a prototypic carotenoid cyclase, we show that the monomeric protein contains one noncovalently bound flavin adenine dinucleotide (FAD) that is essential for enzyme activity only in the presence of NADPH, which functions as the FAD reductant. The reaction proceeds without transfer of hydrogen from the dinucleotide cofactors to β-carotene or capsanthin. Using site-directed mutagenesis, amino acids potentially involved in the protic activation were identified. Substitutions of alanine, lysine, and arginine for glutamate-295 in the conserved 293-FLEET-297 motif of pepper CCS or LCY-B abolish the formation of β-carotene and κ-cyclic carotenoids. We also found that mutations of the equivalent glutamate-196 located in the 194-LIEDT-198 domain of structurally divergent bacterial LCY-B abolish the formation of β-carotene. The data herein reveal plant carotenoid cyclases to be novel enzymes that combine characteristics of non-metal-assisted terpene cyclases with those attributes typically found in flavoenzymes that catalyze reactions, with no net redox, such as type 2 isopentenyl diphosphate isomerase. Thus, FAD in its reduced form could be implicated in the stabilization of the carbocation intermediate.

Antioxidant activities of different solvent extracts of Piper retrofractum Vahl. using DPPH assay

Piper retrofractum Vahl., which belongs to the family Piperaceae, is geographically dispersed in tropical region including Indonesia. They are well-known spice possessing high medicinal properties. This study aimed to determine the antioxidant activity of P. retrofractum fruit, extracted with different solvents (methanol, ethyl acetate, n-hexane) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This research was carried out using different concentrations of methanol, ethyl acetate, and n-hexane extracts, (0, 5, 15, 30, 45, 60 ppm). Ascorbic acid was also used as positive antioxidant control. The percentage of inhibition and IC50 were measured. The results showed that the DPPH free radicals were scavenged by all plant extracts in a concentration dependent manner. Moreover, the IC50 values for DPPH radicals with methanol, ethyl acetate and n-hexane extract of the P. retrofractum Vahl. were found to be 101.74; 66.12 and 57.66 ppm, respectively. Interestingly, the IC50 value of n-hexane extract (57.66 ppm) w...

Reverse Transcription-PCR analysis of geranylgeranyl diphosphate synthase (JcGGPPS) in Jatropha curcas L. and in silico analysis of Casbene Synthase (JcCS) among Euphorbiaceae

Recently, Euphorbiaceae have attracted much attention for their potential uses in biodiesel production. Their seeds have been well known as the principal resource for oil production. The seed-derived oil content ranged from 28 % to 39 % by dry weight for all Euphorbiaceae species. Meanwhile, their seed also possesses relatively high protein content, ranged from 22 % to 35 %, making them a new alternative for livestock animal feed resources. Nevertheless, the development of this new animal feed resource is limited to the toxicity of the seeds. Its toxicity is mainly caused by the presence of anti-nutrient agents and toxins, such as curcin, trypsin inhibitor and phorbol ester (PE). The later is known to be tetracyclic diterpenes, which represents the primary toxic substances in one of the Euphorbiaceae plants, Jatropha curcas L. To date, little is known about the biosynthesis of these toxic substances. This research aims to analyze the expression of JcGGPPS gene encoding the geranylgeranyl diphosphate synth...

Particular variety of tobacco Nicotiana tabacum) exhibits distinct morphological and physiological responses against periodic waterlogging stress

Waterlogging Stress influences crop productivity, especially high commercial crop like tobacco, which is very sensitive to an excess of water. This type of environmental stress might happen because of unpredictable season occurred in tropical region, including Indonesia. Global climate change as a consequence of rapid growing industries all over the world might responsible for this. This study aims to investigate the response of some Nicotiana tabacum varieties which are treated with periodic waterlogging stress. Some morphological aspects including plant height, stem diameter, leaves width and the emergence of adventitious roots were investigated. In addition, total chlorophyll content was also measured as physiological parameter. Three different varieties are used such as var. Jepon Pelakean, Jinten, Manilo and Morakot. Data were analyzed using One-Way Annova followed by Tukey post-hoc analysis. In all morphological aspects var. Jepon Pelakean demonstrated best responses compared to other varieties. Meanwhile, we observed a sharp decline of total chlorophyll content in var. Manilo under this periodic waterlogging stress. The overall results suggest that each variety of tobacco possess a specific mechanism against periodic waterlogging stress.

Data of root anatomical responses to periodic waterlogging stress of tobacco (Nicotiana tabacum) varieties

The data of root anatomical structure and the formation of aerenchyma tissues of five varieties of tobacco under waterlogging stress were obtained by modified paraffin method. Each tobacco varieties performed distinct anatomical adaptation response, including changes of cortical tissue, stele diameter, xylem diameter and the formation of aerenchyma under periodic waterlogging stress.

Transcription profile data of phorbol esters biosynthetic genes during developmental stages in Jatropha curcas

Jatropha curcas is currently known as an alternative source for biodiesel production. Beside its high free fatty acid content, J. curcas also contains typical diterpenoid-toxic compounds of Euphorbiaceae plant namely phorbol esters. This article present the transcription profile data of genes involved in the biosynthesis of phorbol esters at different developmental stages of leaves, fruit, and seed in Jatropha curcas. Transcriptional profiles were analyzed using reverse transcription-polymerase chain reaction (RT-PCR). We used two genes including GGPPS (Geranylgeranyl diphospate synthase), which is responsible for the formation of common diterpenoid precursor (GGPP) and CS (Casbene Synthase), which functions in the synthesis of casbene. Meanwhile, J. curcas Actin (ACT) was used as internal standard. We demonstrated dynamic of GGPPS and CS expression among different stage of development of leaves, fruit and seed in Jatropha.

Proximate composition, nutritional values and phytochemical screening of Piper retrofractum vahl. fruits

Objective: To investigate the proximate and mineral composition of the Piper retrofractum (P. retrofractum) vahl. Fruit and to evaluate its total alkaloids, phenol and flavonoid. Methods: The proximate composition of P. retrofractum fruit was ananlyzed using standard protocols according to Indonesian Standard and Association of Official Analytical Chemist. Meanwhile, mineral composition of the fruit was analyzed using inductively coupled plasma-mass spectrometry. Phytochemical screening and quantification were performed using standard protocols according to Harborn and spectrophotometric methods. Results: The results showed that P. retrofractum fruit contained carbohydrate (63.4%), crude protein (11.4%), total ash (4.29%), dietary fiber (28.8%) and total fat (2.97%). The fruit also contained calcium, copper, iron, magnesium, phosphor, potassium, sodium and zinc in different concentrations. Additionally, quinone, sterol, glycosides and alkaloid were detected in both n-hexane and ethyl acetate extracts. Moreover, tannin was presented also in ethylacetate and methanol extracts. Meanwhile, methanol extract contained sterol, glycosides, flavones, tannin and alkaloid. The results also revealed that methanol extract of the fruit contained highest phenol compared to other extract. Finally, small quantity of flavonoid (0.060 0%±0.000 2%) was observed. Conclusions: The overall results show that P. retrofractum contains potential nutritional and phytochemicals values, which support their function for pharmaceutical purposes.

Response morphology and anatomy of tobacco (Nicotiana tabacum L.) plant on waterlogging

This study has conducted research on morphological and anatomical responses of some varieties of tobacco plants to waterlogging stress. Parameters measured were morphology, anatomy, and plants sensitivity index. Results were analyzed using two-way ANOVA followed by the Tukey test. The results show that waterlogging stress can reduce the growth of tobacco plants, including a decrease in plant height with the lowest value of 15.6 cm, root length reduction to the lowest value of 4.6 cm and plant dry weight reduction to the lowest value of 0.26 gr. But waterlogging stress can increase the number of adventitious roots with the highest value of 18.33. In addition, waterlogging stress can lead to the formation of aerenchyma tissue. The sensitivity index showed that plant varieties that are resistant to waterlogging stress are the varieties Kemloko 3 (index value of 0.03), varieties of Paiton 2 (index value of 0.18), and the varieties Kemloko 2 (index value of 0.42).

Traditional pattern of cashew cultivation : A lesson from Sumenep-Madura, Indonesia

Belonging to the Anacardiaceae family, the cashew tree (Anacardium Occidentale, Linn.) is one of the important tropical plants that possess high economic value. This plant is commonly grown in Indonesian regions including Sumenep, Madura, where the red sandy loam type of soil is commonly present. This study aims to obtain rough data on the pattern of cashew cultivation and identify the cashew cultivation knowledge of local communities. Data were taken in Bringin village, Sumenep-Madura. Our field survey showed that the cashew’s cultivation pattern in this village applies the so-called traditional organic farming. Cashew trees are planted along the boundaries of the owner’s farm field, functioning as a fence of their farm. Nevertheless, our survey also indicated that this pattern of cultivation is still below standard of cultivation. The planting distance between the cashew trees with one another is relatively close (< 5 meters), causing the cashew branches to overlap with each other. Moreover, we observed...