A new isolate cold-adapted Ankistrodesmus sp. OR119838: influence of light, temperature, and nitrogen concentration on growth characteristics and biochemical composition using the two-stage cultivation strategy.

Natural-based chemicals from microalgae such as lipids and pigments are the interests in industries and the bioeconomy. Cold-adapted Ankistrodesmus sp. OR119838, an isolated strain from Cheshmeh-Sabz Lake in northeastern Iran, was cultivated using a two-stage culture strategy under different environmental conditions. With doubling the nitrate concentration at the vegetative stage (170 mg/L) and increasing the light intensity (180 µmol photons/m2/s) the highest specific growth rate (0.61 ± 0.02 per day) and biomass productivity (121.1 ± 7.2 mg/L/day) were observed at 25 °C. In the optimal growth condition Chl a and Chl b contents of Ankistrodesmus sp. OR119838 reached the highest amount (11.07 ± 0.14 and 11.23 ± 0.29 µg/mL, respectively) at 25 °C. While carotenoid content correlated negatively with optimum biomass productivity (- 0.708) and had the best value (12.23 ± 0.29 µg/mL) in nitrogen deficiency (42 mg/L) and intense light conditions (180 µmol photons/m2/s) at 15 °C. Lipid content was increased with declined nitrate concentration (42 mg/L), high light intensity, and 180 µmol photons/m2/s at 25 °C. The highest percentage of polyunsaturated fatty acids (71.94%) and α-linolenic acid (57.73 ± 6.63%) was observed in conditions with 170 mg/L nitrate concentration and low light intensity (40 µmol photons/m2/ s) at the low temperature (15 °C). While saturated fatty acids content (43.27%) and palmitic acid reached the highest amount under 40 µmol photons/m2/s, 42 mg/L nitrate at 25 °C (35.02 ± 5.33%). Biomass productivity of Ankistrodesmus sp. OR119838, as a cold-adapted strain, decreased by only 8.2% with a 10-degree decline in temperature. Therefore, this strain has good potential to grow in open ponds by tolerating the daily temperature fluctuations.

Beneficial effects of endophytic fungi inoculation on tanshinones and phenolic compounds of Salvia abrotanoides.

Objectives: Salvia abrotanoides is considered as a new source of tanshinone-producing plants in Iran. Symbiosis of endophytic fungi with their host plants is an effective tool to promote the growth and secondary metabolism of medicinal herbs. Therefore, using endophytic fungi as a biotic elicitor is a proper solution to increase the yield of plant products. Materials and Methods: In this study, some endophytic fungi were first isolated from the root of S. abrotanoides, then two of them (Penicillium canescens and Talaromyces sp.) were co-cultivated with the sterile seedling of S. abrotanoides in pot culture. After proving the colonization of these fungi in the root tissues by microscopic studies, their effects on the production of critical medicinal compounds such as tanshinones and phenolic acids were investigated in the vegetation stage (120 days). Results: Our results showed that the content of cryptotanshinone (Cry) and tanshinone IIA (T-IIA) in plants inoculated with P. canescens increased by 77.00% and 19.64%, respectively, compared with non-inoculated plants (control). The contents of mentioned compounds in plants inoculated with Talaromyces sp. increased by 50.00% and 23.00%, respectively. In this case, in plants inoculated with P. canescens, it was found that the level of caffeic acid, rosmarinic acid, and its PAL enzyme activity increased by 64.00%, 69.00%, and 50.00%, respectively, compared with the control. Conclusion: Endophytic fungi have specific modes of action and the ability to provide multiple benefits. Each of the two strains is a highly considerable microbial resource for the growth and accumulation of active compounds of S. abrotanoides.

The variability of phenolic constituents and antioxidant properties among wild populations of Ziziphora clinopodioides Lam.

In this study, phenolic derivatives and antioxidant activities of fourteen Ziziphora clinopodioides populations, as well as LC-MS/MS analysis of three specific flavonoids were evaluated. Generally, high contents of phenolic derivatives were found in shoot extracts compared to roots. LC-MS/MS, a powerful analytical technique, was employed for the identification and quantify the individual flavonoids in Z. clinopodioides populations' extracts, in a quantity order of quercetin > rutin > apigenin. Scavenging activity by DPPH and FRAP was performed, and accordingly, in the shoot, the highest values for the DDPH were 4.61 ± 0.4 and 7.59 ± 0.26 µg ml- 1 in populations 1 and 13, respectively, and for the FRAP were 328.61 ± 5.54 and 292.84 ± 2.85 mg g DW- 1, in populations 6 and 1 respectively. Multivariate analysis results of the principal component analysis indicated the amount of polyphenols to be useful indicators in differentiating the geographical localities which explain 92.7% of the total variance. According to the results of hierarchical cluster analysis, the studied populations could be separated into two groups in that the contents of phenolic derivatives and antioxidant activities of different plant parts. Both shoot and root samples were well discriminated with the orthogonal partial least squares discriminant analysis (R2X: 0.861; Q2: 0.47) model. The validity of the model was confirmed by using receiver operating characteristic curve analysis and permutation tests. Such data make an important addition to our current knowledge of Ziziphora chemistry and are decisive in the identification of germplasms with a homogeneous phytochemical profile, high chemical content and bioactivity. The present results could also be helpful for the potential application of Z. clinopodioides in different kinds of industries as natural antioxidants. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01283-y.

Plant elicitation and TiO2 nanoparticles application as an effective strategy for improving the growth, biochemical properties, and essential oil of peppermint.

Mentha piperita L., which is an abundant source of essential oils (EO) and phenolic acids, is well known for its medicinal significance. The present research aimed to evaluate the impact of various concentrations of methyl jasmonate (MeJA; 0, 0.1, and 0.5 mM), titanium dioxide nanoparticles (TiO2 NPs; 0 and 150 mg L-1), and salicylic acid (SA; 0, 0.1, and 1 mM) on growth, EOs, and phenolic compounds of M. piperita L. The results demonstrated that the simultaneous application of SA (0.1 mM) and TiO2 NPs (150 mg L-1) enhanced shoot dry weight, the shoot length, and membrane stability index of peppermint by 56.17, 19.52, and 36%, respectively, compared to control. Moreover, phenolic content (76%), caffeic acid content (78%), rosmarinic acid content (87%), 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability (78%), and catalase (155%), ascorbate peroxidase activities (95%) were further improved by simultaneously applying MeJA (0.1 mM) and TiO2 NPs (150 mg L-1) compared to control. The highest menthol production (44.51%) was obtained with exogenous application of MeJA (0.1 mM) with 150 mg L-1 TiO2 NPs. The findings of the current study presented an ideal combination of TiO2 NPs with plant growth regulators for promoting antioxidant activities and increasing major components of EO in peppermint plants.

ICP-OES assessment of trace and toxic elements in Ziziphora clinopodioides Lam. from Iran by chemometric approaches.

The aim of the study was to evaluate the concentrations of some essential and toxic elements (including Ca, K, Mg, Na, Fe, Cu, Mn, Zn, Co, Mo, Pb, Ni, Cr, and Cd) in Ziziphora clinopodioides Lam. (endemic Iranian herb) from 14 different regions by ICP-OES (inductively coupled plasma-optical emission spectrometry) method followed by multivariate statistical analyses. The analytical performances were assessed as the limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. Multivariate analysis (CA, PCA and HCA) showed the elemental distribution in the roots were higher than the shoots and significant element was Ca between regions. Three principal components (PCs) explained 77.94% of the total variance. They were as follows: PC1 with Cu, Zn, K, Cr, Ni, and Mn; PC2 with Na, Ca, Pb, and Fe; and PC3 with Mg. Hierarchical cluster analysis indicated four groups of Z. clinopodioides samples from the 14 regions based on their trace and toxic element levels. These chemometric approaches with multivariate analysis enable researchers to understand and quantify the relationship between the variables in a data set, and the analysis considers more than one factor. The concentrations of Cu, Na, Mn, Zn, and Pb in most Z. clinopodioides samples were below the WHO (world health organization) limit for herbal medicines (10, 51,340, 200, 50, and 10 µg g-1 respectively), while Fe and Ca levels were higher than allowed (15 and 614 µg g-1 respectively). However, the WHO limit for Mg, K, Co, and Mo in medicinal plants has not yet been determined. The results of this study confirmed that different parts of Z. clinopodioides can be used as an important source for human nutrition due to its essential mineral elements.

Beneficial worm allies warn plants of parasite attack below-ground and reduce above-ground herbivore preference and performance.

Antagonistic interactions among different functional guilds of nematodes have been recognized for quite some time, but the underlying explanatory mechanisms are unclear. We investigated responses of tomato (Solanum lycopersicum) to two functional guilds of nematodes-plant parasite (Meloidogyne javanica) and entomopathogens (Heterorhabditis bacteriophora, Steinernema feltiae below-ground, and S. carpocapsae)-as well as a leaf mining insect (Tuta absoluta) above-ground. Our results indicate that entomopathogenic nematodes (EPNs): (1) reduced root knot nematode (RKN) infestation below-ground, (2) reduced herbivore (T. absoluta) host preference and performance above-ground, and (3) induced overlapping plant defence responses by rapidly activating polyphenol oxidase and guaiacol peroxidase activity in roots, but simultaneously suppressing this activity in above-ground tissues. Concurrently, we investigated potential plant signalling mechanisms underlying these interactions using transcriptome analyses. We found that both entomopathogens and plant parasites triggered immune responses in plant roots with shared gene expression. Secondary metabolite transcripts induced in response to the two nematode functional guilds were generally overlapping and showed an analogous profile of regulation. Likewise, we show that EPNs modulate plant defence against RKN invasion, in part, by suppressing active expression of antioxidant enzymes. Inoculations of roots with EPN triggered an immune response in tomato via upregulated phenylpropanoid metabolism and synthesis of protease inhibitors in plant tissues, which may explain decreased egg laying and developmental performance exhibited by herbivores on EPN-inoculated plants. Furthermore, changes induced in the volatile organic compound-related transcriptome indicated that M. javanica and/or S. carpocapsae inoculation of plants triggered both direct and indirect defences. Our results support the hypothesis that plants "mistake" subterranean EPNs for parasites, and these otherwise beneficial worms activate a battery of plant defences associated with systemic acquired resistance and/or induced systemic resistance with concomitant antagonistic effects on temporally co-occurring subterranean plant pathogenic nematodes and terrestrial herbivores.

Variation in phenolic compounds, α-linolenic acid and linoleic acid contents and antioxidant activity of purslane (Portulaca oleracea L.) during phenological growth stages.

Purslane (Portulaca oleracea L.) contains a variety of natural products with different biological properties. The objective of this research was to estimate changes in total phenolics, flavonoids, and fatty acids (α-linolenic acid and linoleic acid) contents as well as antioxidant activity of P. oleracea at different growth stages. Seeds were germinated in soil-filled plastic pots at greenhouse. Leaves and stems were collected at the vegetative and flowering stages. Total phenol and flavonoid contents of the samples were determined by Folin-Ciocalteau and aluminum chloride methods, respectively. The contents of α-linolenic and linoleic acids were determined using gas chromatography analysis after transesterification of fatty acids. Furthermore, Ferric reducing antioxidant power and 1,1-diphenyl-2-picrylhydrazyl assays were used to determine the antioxidant activities. The highest contents of total phenols (698.6 mg GAE 100 g-1 DW), flavonoids (46.9 mg QE 100 g-1 DW), α-linolenic acid (2.7 mg g-1 DW) and linoleic acid (0.8 mg g-1 DW) were determined in the leaves at flowering stage. Free radical scavenging capacity was significantly affected (P ≤ 0.05) by age; and the leaves of purslane had more antioxidant potential compared to stems. A positive correlation was observed between the antioxidant activities and total phenols content. Overall, purslane leaves at flowering stage can be regarded as a valuable source of fatty acids (especially α-linolenic acid) and antioxidants in human diet.

Optimization of Callus Induction with Enhancing Production of Phenolic Compounds Production and Antioxidants Activity in Callus Cultures of Nepeta binaloudensis Jamzad (Lamiaceae).

BACKGROUND: World Health Organization (WHO) reported that more than 80% of people in the world use herbal traditional medicines nowadays. Many endemic medicinal plants, especially Nepeta species, are facing to extinction as a result of high harvesting, limited distribution, and habitat destruction.Tissue culture is a successful method for plant secondary metabolites production. Nepeta binaloudensis is a medicinal plant belonging to family Lamiaceae. OBJECTIVE: Our study was focused on devising an optimum procedure for callus induction and phenolic compounds production in N. binaloudensis. First, we are focused on finding suitable explants and media for callus induction. Then, subsequent experiments were conducted to find an optimal concentration of plant growth regulators (PGRs) and reduced- glutathione for maximum biomass production, and phenolic compounds production in calli. MATERIAL AND METHOD: In this study, the usage of whole plant grown in Hoagland nutrient solution, were used as a source of explants. Also, different media including, ½ MS, MS, and B5 and different combination of PGRs (NAA and BAP) were used for optimization of calli induction. RESULTS: Based on the results of the first experiment, leaf-originated explants, and macro half strength MS (½ MS) medium were used for the next experiments. The highest FW (Fresh Weight) and DW (Dry Weight) of calli were observed in ½ MS medium, supplemented with 2 µM/L reduced-glutathione, 2 mg.L-1 BAP, and 2 mg.L-1 NAA. The maximum amount of total phenolic, flavonoid, tannin contents and free-radical scavenger were observed in calli which were grown in ½ MS medium supplemented with 2 µM/L reduced-glutathione, 2 mg.L-1 BAP, and 2 mg.L-1 NAA. CONCLUSION: Our study finds the optimum condition for calli induction and phenolic compounds production in N. binaloudensis.

Developmental role of phenylalanine-ammonia-lyase (PAL) and cinnamate 4-hydroxylase (C4H) genes during adventitious rooting of Juglans regia L. microshoots.

Phenylalanine-ammonia-lyase and cinnamate-4-hydroxylase play important role in the phenylpropanoid pathway, which produces many biologically important secondary metabolites participating in normal plant development. Flavonol quercetin is the main representant of these compounds that has been identified in numerous Juglans spp. In this survey, the developmental expression patterns of PAL and C4H genes during in vitro rooting of two walnut cultivars 'Sunland' and 'Howard' was examined by RT-PCR. To understand the potential role in rooting, the changing pattern of endogenous content of quercetin was also analyzed by HPLC. The 'Sunland' with better capacity to root had more quercetin content during the "inductive phase" of rooting than 'Howard'. In each cultivar, the level of PAL transcripts showed the same behavior with the changing patterns of quercetin during root formation of microshoots. The positive correlation between the changes of quercetin and PAL-mRNA indicated that PAL gene may have an immediate effect on flavonoid pathway metabolites including quercetin. Although the behavioral change of C4H expression was similar in both cultivars during root formation (with significantly more level for 'Howard'), it was not coincide with the changes of quercerin concentrations. Our results showed that C4H function is important for the normal development, but its transcriptional regulation does not correlate with quercetin as an efficient phenolic compound for walnut rhizogenesis.