Nazif Ullah

Kinetin modulates physio-hormonal attributes and isoflavone contents of Soybean grown under salinity stress

Crop productivity continues to decline due to a wide array of biotic and abiotic stresses. Salinity is one of the worst abiotic stresses, as it causes huge losses to crop yield each year. Kinetin (Kn) has been reported as plant growth regulator since long, but its role in improving plant growth and food quality under saline conditions through mediating phytohormonal cross-talk is poorly studied. Current study was designed to evaluate the impact of exogenously applied Kn on growth, isoflovones and endogenous phytohormones of soybean grown under NaCl induced salt stress. Soybean plants were grown in perlite (semi hydroponic), and under controlled green-house conditions. Elevated levels of exogenous Kn significantly mitigated the adverse effect of NaCl and rescued plant growth attributes, i.e., plant height, fresh and dry biomass of soybean plants grown in all treatments. Higher diadzen, glycitin, and genistin contents were observed in plants treated with elevated Kn in the presence or absence of NaCl induce salt stress. The gibberellins (GAs) biosynthesis pathway was up-regulated by Kn as the bioactive GA1 and GA4 contents were significantly higher in Kn treated plants, as compared to control, while GAs level reduced in NaCl treated plants. Contrary to GAs, the abscisic acid contents declined with Kn but promoted in NaCl stressed soybean plants. The endogenous jasmonic acid and salicylic acid contents of soybean enhanced with elevated Kn application, but they showed an antagonistic response under salt stress. Current study supports the active role of Kn to ameliorate the adverse effects of salt stress on the growth and food quality of soybean. The favorable role of Kn toward soybean growth under salt stress may be attributed to its potential to modulate cross-talk between the various phytohormones involved in soybean growth and its resistance to salinity stress.

Phytotoxicity evaluation and phytochemical analysis of three medicinally important plants from Pakistan

This work examines the crude methanolic extracts of three medicinally important plants native to Pakistan for potent phytotoxic activities and important phytochemicals. These plants include Euphorbia wallichii, Bergenia ciliata and Phytolacca latbenia. The phytotoxic effects were checked at 10,000, 1000, and 100 µg/ml against two economically important standard target species, Triticum aestivum (monocot representative) and Brassica napus (dicot representative). The phytotoxicity effects on seed germination, seedling growth and seedling weight were checked. A simple, cost-effective in vitro phytotoxicity assay (that uses petri plates) was used to evaluate the allelopathic properties of crude extracts. At highest concentration, extracts from all the three plants showed phytotoxic activities such that P. latbenia > E. wallichii > B. ciliata. In seedling growth, root length was affected more than shoot length, whereas among the target species B. napus was found to be more sensitive towards extracts when compared with T. aestivum. Phytochemical analysis showed that P. latbenia is rich in saponins and terpenoids, while E. wallichii and B. ciliata are rich in tannins, terpenoids and cardiac glycoside. P. latbenia also carries a moderate amount of cardiac glycosides.

Physiological and biochemical mechanisms of allelopathy mediated by the allelochemical extracts of Phytolacca latbenia (Moq.) H. Walter

In allelopathy, one plant suppresses the growth and development of other plant/plants by negatively affecting a variety of physiological and biochemical reactions. We checked the effects of methanolic extracts (allelochemical extracts) of Phytolacca latbenia (Moq.) H. Walter on antioxidant enzyme activities such as peroxidases (PODs), super oxide dismutases (SODs) and catalase (CAT) and on total protein contents (TPC), cellular injury (CI), and malondialdehyde (MDA) in the germinating seeds of Brassica napus L. (dicot) and Triticum aestivum L. (monocot). Both the crude methanolic extract root (CMER) and crude methanolic extract aerial (CMEA) of P. latbenia at 10000 ppm significantly reduced the POD activity in both the test seeds. The activity of SODs was significantly decreased by both CMER and CMEA in B. napus germinating seeds. A linear increase in the activity of CAT, CI, and MDA contents was found in both the test seeds with the increasing concentrations of CMEA and CMER, while TPC of the germinating seeds was found decreased. It is inferred that both the CMEA and CMER inhibited/delayed the seed germination, reduced the seedling growth by affecting a variety of biochemical and physiological attributes, and also caused cellular membrane injury in the germinating seeds of both the monocot and dicot seeds.

Impacts of hormonal elicitors and photoperiod regimes on elicitation of bioactive secondary volatiles in cell cultures of Ajuga bracteosa

Light is an important physical factor necessary for the growth, morphogenesis and production of bioactive compounds in plants. In this study, effects of different photoperiod regimes and hormonal elicitors were investigated on the accumulation of biomass, antioxidant potential and biosynthesis of secondary volatiles in the cell cultures of Ajuga bracteosa. Maximum accumulation of biomass (13.2 g/L) was recorded in cell cultures established at 1.0 mg/L benzylaminopurine (BA) in exposure to continuous dark. Biochemical assays showed that in the presence of 0.5 methyl jasmonate (Me-J), cell cultures grown under continuous dark had the higher activities of superoxide dismutase (SOD: 4.5 U/mg), peroxidase (POD: 3.1 U/mg), total phenolic content (TPC: 8.1 mg GAE/g of DW) and total flavonoid content (TFC: 5.2 mg QE/g of DW) respectively. Nonetheless, the free radical scavenging activity (FRSA) was found correlated with the phenyl ammonia lyase (PAL) activity in the dark grown cell cultures. Analysis through gas chromatography-mass spectrometry (GC-MS) showed, biosynthesis of 29 compounds in the in vitro raised cell cultures. The major identified compounds consisted of monoterpene hydrocarbons such as β-pinene (2.1-9.5%), β-ocimene (1.4-8.3%), 1-terpinene-4-ol (5.8-9.6%), caryophyllene (1.3-6.2%), β-farnesene (0.82-7.8), oxygenated monoterpenes including myrtenal (2.2-8.4%), citronellyl acetate (2.1-7.3%) and sesquiterpenes such as caryophyllene oxide (1.5-5.5) and β-elemene (2.2-8.8%). This protocol has the potential for commercial production of important secondary volatiles.

Five Indigenous Plants of Pakistan with Antinociceptive, Anti-Inflammatory, Antidepressant, and Anticoagulant Properties in Sprague Dawley Rats

Five medicinal plants of Pakistan were investigated for their antinociceptive, anti-inflammatory, antidepressant, and anticoagulant potential. Antinociceptive activity was estimated by hot plate and writhing assay. In hot plate assay, Quercus dilatata (52.2%) and Hedera nepalensis (59.1%) showed moderate while Withania coagulans (65.3%) displayed a significant reduction in pain. On the other hand, in writhing assay, Quercus dilatata (49.6%), Hedera nepalensis (52.7%), and Withania coagulans (62.0%) showed comparative less activity. In anti-inflammatory assays crude extracts showed significant edema inhibition in a dose dependent manner. In carrageenan assay, the highest activity was observed for Withania coagulans (70.0%) followed by Quercus dilatata (66.7%) and Hedera nepalensis (63.3%). Similar behavior was observed in histamine assay with percentage inhibitions of 74.3%, 60.4%, and 63.5%, respectively. Antidepressant activity was estimated by forced swim test and the most potent activity was revealed by Withania coagulans with immobility time 2.2s (95.9%) followed by Hedera nepalensis with immobility time 25.3s (53.4%). Moreover, the crude extracts of Fagonia cretica (74.6%), Hedera nepalensis (73.8%), and Phytolacca latbenia (67.3%) showed good anticoagulant activity with coagulation times 86.9s, 84.3s, and 67.5s, respectively. Collectively, the results demonstrate that these five plants have rich medicinal constituents which can be further explored.

Hedera nepalensis K. Koch: A Novel Source of Natural Cancer Chemopreventive and Anticancerous Compounds.

Traditional medicinal plants are often used for both the prevention and the treatment of local diseases. Taking into consideration the medicinal importance of Hedera nepalensis within local Pakistani traditions, the present study was undertaken to analyze the in vitro cancer chemopreventive and cytotoxic properties of the plant. The in vitro cancer chemopreventive testing was performed using nitrite assay, NFκB assay, aromatase assay, and quinone reductase 1 (QR1) assay. The cytotoxic potential was evaluated on three cancer‐cell lines: MCF‐7, MDA‐MB‐231, and HeLa using sulforhodamine B (SRB) assay. The results of cancer chemopreventive assays show that n‐hexane and ethyl acetate fractions of tested plant have promising cancer chemopreventive potential. Lupeol isolated from n‐hexane as well as ethyl acetate fraction showed lowest IC50 (0.20 ± 1.9 μM) in NFκB assay. Crude extract and its fractions inhibited the growth of three cancer cell lines by more than 60%, IC50 value of lupeol varied from 2.32 to 10.2 μM. HPLC‐DAD‐based quantification of lupeol in different plant tissues demonstrated that leaves of H. nepalensis are a rich source of lupeol (0.196 mg/100 mg dry weight). Our data have shown that H. nepalensis harbors cancer chemopreventive and cytotoxic agents. Copyright