Enhanced tolerance to salinity stress in grapevine plants through application of carbon quantum dots functionalized by proline.

Salinity has destructive impacts in plant production; therefore, application of new approaches such as nanotechnology and plant priming is attracting increasing attention as an innovative means to ameliorate salt stress effects. Considering the unique properties and recorded beneficial influence of carbon quantum dots (CQDs) and proline in plant growth and physiological parameters when applied individually, their conjugation in the form of carbon quantum dot nanoparticles functionalized by proline (Pro-CQDs NPs) could lead to synergistic effects. Accordingly, an experiment was conducted to evaluate the impact of this advanced nanomaterial (Pro-CQDs NPs) as a chemical priming agent, in grapevine plants cv. 'Rasha'. For this purpose, proline, CQDs, and Pro-CQDs NPs at three concentrations (0, 50, and 100 mg L-1) were applied exogenously 48 h prior to salinity stress (0 and 100 mM NaCl) that was imposed for a month. Three days after imposing salt stress, an array of biochemical measurements was recorded, while agronomic and some physiological parameters were noted at the end of the stress period. Results revealed that proline treatment at both concentrations, as well as CQDs and Pro-CQDs NPs at low concentration, positively affected grapevine plants under both non-stress and stress conditions. Specifically, the application of proline at 100 mg L-1 and Pro-CQDs NPs at 50 mg L-1 resulted in optimal performance identifying 50 mg L-1 Pro-CQDs NPs as the optimal treatment. Proline treatment at 100 mg L-1 increased leaf fresh weight (FW) and dry weight (DW); chl a, b, and proline content; SOD activity under both non-stress and stress conditions; Y (II) under salinity and carotenoid content; and CAT activity under control conditions. Pro-CQDs NP treatment at 50 mg L-1 enhanced total phenol, anthocyanin, and Fv/Fo, as well as APX and GP activities under both conditions, while increasing carotenoid, Y (II), Fv/Fo, and CAT activity under salinity. Furthermore, it decreased MDA and H2O2 contents at both conditions and EL and Y (NO) under salt stress. Overall, conjugation of CQDs with proline at 50 mg L-1 resulted in further improving the protective effect of proline application at 100 mg L-1. Therefore, functionalization of NPs with chemical priming agents appears to be an effective means of optimizing plant-priming approaches towards efficient amelioration of abiotic stress-related damage in plants.

Composite core set construction and diversity analysis of Iranian walnut germplasm using molecular markers and phenotypic traits.

Iran is a center of origin and diversity for walnuts (Juglans regia L.) with very good potential for breeding purposes. The rich germplasm available, creates an opportunity for study and selection of the diverse walnut genotypes. In this study, the population structure of 104 Persian walnut accessions was assessed using AFLP markers in combination with phenotypic variability of 17 and 18 qualitative and quantitative traits respetively. The primers E-TG/M-CAG, with high values of number of polymorphic bands, polymorphic information content, marker index and Shannon's diversity index, were the most effective in detecting genetic variation within the walnut germplasm. Multivariate analysis of variance indicated 93.98% of the genetic variability was between individuals, while 6.32% of variation was among populations. A relatively new technique, an advanced maximization strategy with a heuristic approach, was deployed to develop the core collection. Initially, three independent core collections (CC1-CC3) were created using phenotypic data and molecular markers. The three core collections (CC1-CC3) were then merged to generate a composite core collection (CC4). The mean difference percentage, variance difference percentage, variable rate of coefficient of variance percentage, coincidence rate of range percentage, Shannon's diversity index, and Nei's gene diversity were employed for comparative analysis. The CC4 with 46 accessions represented the complete range of phenotypic and genetic variability. This study is the first report describing development of a core collection in walnut using molecular marker data in combination with phenotypic values. The construction of core collection could facilitate the work for identification of genetic determinants of trait variability and aid effective utilization of diversity caused by outcrossing, in walnut breeding programs.

Synthesis of Self-Targeted Carbon Dot with Ultrahigh Quantum Yield for Detection and Therapy of Cancer.

This study aims to engineer a new type of ultrahigh quantum yield carbon dots (CDs) from methotrexate (MTX-CDs) with self-targeting, imaging, and therapeutic effects on MDA-MB 231 breast cancer cells. CDs were synthesized via a straightforward thermal method using a methotrexate (MTX) drug source. The physicochemical characteristics of the prepared MTX-CDs were studied using Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). TEM and DLS revealed which MTX-CDs have homogeneous spherical morphology with a smaller average size of 5.4 ± 2.2 nm, polydispersity index (PDI) of 0.533, and positive surface charge of around +3.93 mV. Results of FT-IR spectroscopy and high-resolution XPS indicated the presence of residues of MTX on CDs. Therefore, the synthesized MTX-CDs could be targeted and be taken up by FR-positive cell lines without the aid of additional targeting molecules. In vitro epifluorescence images demonstrated high-contrast cytoplasm biodistribution of MTX-CDs after 2 h of treatment. A much stronger fluorescent signal was detected in MDA-MB 231 compared to MCF 7, indicating their ability to precisely target FR. The highest cytotoxic and apoptotic effects were observed in MTX-CDs compared to free MTX obtained by the MTT assay, cell cycle arrest, and annexin V-FITC apoptosis techniques. Results revealed that the novel engineered MTX-CDs were capable of inducing apoptosis (70.2% apoptosis) at a lower concentration (3.2 µM) compared to free MTX, which was proved by annexin V and cell cycle. This work highlights the potential application of CDs for constructing an intelligent nanomedicine with integration of diagnostic, targeting, and therapeutic functions.

Targeted co-delivery of curcumin and doxorubicin by citric acid functionalized Poly (ε-caprolactone) based micelle in MDA-MB-231 cell.

This study aimed to design an effective targeted combination of doxorubicin (Dox)-Curcumin (Cur) delivery system to eradicate the MDA-MB231 cell line. A novel biodegradable poly ε-Caprolactone-co-maleic anhydride-graft-citric acid copolymer micelle (PCL-co-P(MA-g-CA)) was synthesized through thiolen radical copolymerization and ring-opening polymerization. The unique micelle structure allowed simultaneous loading of hydrophilic Dox and hydrophobic Cur with a loading efficiency of above 98 % for each drug. The physicochemical characterization of copolymeric micelle was analyzed by 1HNMR, 13CNMR, FTIR, DSC, CMC, DLS and SEM. The in vitro cytotoxicity was assessed by MTT assay, cell cycle analysis, annexin V-FITC apoptosis, qRT-PCR and western blot. The final obtained micelles with critical micelle concentration (CMC) of 0.5 µg/mL, and particle size and surface charge was 60 nm and -14.1 mV, respectively. Beside the fast uptake of designed micelle, Dox@Cur loaded micelle showed a synergistic effect with the combination index (CI) value of below 1. Our results revealed that this novel engineered combinatorial micelle induced apoptosis (96 %) which was proved by annexin V and cell cycle. qRT-PCR and western blot assays demonstrated involvement of intrinsic apoptosis pathways in the genetic and protein levels. Finally, the penetration of Dox@Cur loaded micelle was evaluated by 3D in vitro tumor formation. Our findings showed the penetration behavior of micelles is in a concentration-dependent manner. In conclusion, combinational therapy by using Dox and Cur nano-formulation has boosted the cytotoxicity in MDA-MB231 cells by promoting the apoptotic response.

Modified multiwall carbon nanotubes display either phytotoxic or growth promoting and stress protecting activity in Ocimum basilicum L. in a concentration-dependent manner.

Carbon-based materials including multiwall carbon nanotubes (MWCNTs) have been recently implicated in a number of reports dealing with their potential use in agriculture, leading to contradictory findings. In this study, MWCNTs were successfully functionalized with carboxylic acid groups (MWCNTs-COOH) in order to increase water dispersion. Hydroponically cultured sweet basil (Ocimum basilicum L.) seedlings were subjected to four concentrations (0, 25, 50 and 100 mg L-1) of MWCNTs-COOH under three salt stress levels (0, 50 and 100 mM NaCl). An array of agronomic, physiological, analytical and biochemical parameters were evaluated in an attempt to examine the potential use of MWCNTs in plants under optimal and abiotic stress conditions. Application of MWCNTs-COOH at optimum concentration (50 mg L-1) could ameliorate the negative effects of salinity stress by increasing chlorophyll and carotenoids content and inducing non-enzymatic (i.e. phenolic content) and enzymatic antioxidant components (i.e. ascorbate peroxidase (APX), catalase (CAT) and guaiacol peroxidase (GP) activity). Furthermore, MWCNTs-COOH treatments under optimal conditions induced plant growth, while a significant increase (P ≤ 0.01) was recorded in essential oil content and compound profile. On the other hand, biochemical and epifluorescence microscopy evidence suggested that high dosage (100 mg L-1) of MWCNTs-COOH leads to toxicity effects in plant tissue. Overall, the positive response of plants to low concentrations of MWCNTs-COOH under control and abiotic stress conditions renders them as potential novel plant growth promoting and stress protecting agents, opening up new perspectives for their use in agriculture.

Novel nano-vehicle for delivery and efficiency of anticancer auraptene against colon cancer cells.

The aim of this study is to devise, prepare and characterize nano encapsulated auraptene (AUR) and evaluate cytotoxic and apoptotic effects on HT-29 colon cancer cells. Herein, AUR nano formulations were prepared by triblock (PCL-PEG-PCL) and pentablock (PLA-PCL-PEG-PCL-PLA) biodegradable copolymers in order to increase AUR bioavailability as an anticancer agent. The preparation of nano particles (NPs) was done with rotor stator homogenization (RSH) and Ultrasonic homogenization (USH) methods. The physicochemical characteristics of prepared nanoparticles (NPs) were studied using HNMR, FTIR, GPC, DLS and SEM techniques. The smaller hydrodynamic size (110 nm) and polydispersity index (PDI: 0.288) as well as higher cellular uptake (89%) were observed in PB NPs rather than TB NPs. The highest cytotoxic and apoptotic effects were observed in AUR loaded PB NPs compared to AUR loaded TB NPs and free AUR obtained by MTT assay, cell cycle arrest, Annexin V-FITC, DAPI staining and RT-PCR techniques. Real time PCR results indicated that Bax /Bcl2 expression ratio as an apoptosis predicting criterion, in free AUR, AUR loaded TB and AUR loaded PB have increased 6, 9 and 13 times, respectively (p value < 0.05). In conclusion, using biodegradable nano-vehicles for sustained delivery of natural anti-cancer compounds may open new perspectives for treatment of cancer patients.

Titanium dioxide nanoparticles (TiO2 NPs) promote growth and ameliorate salinity stress effects on essential oil profile and biochemical attributes of Dracocephalum moldavica.

Considering titanium dioxide nanoparticles (TiO2 NPs) role in plant growth and especially in plant tolerance against abiotic stress, a greenhouse experiment was carried out to evaluate TiO2 NPs effects (0, 50, 100 and 200 mg L-1) on agronomic traits of Moldavian balm (Dracocephalum moldavica L.) plants grown under different salinity levels (0, 50 and 100 mM NaCl). Results demonstrated that all agronomic traits were negatively affected under all salinity levels but application of 100 mg L-1 TiO2 NPs mitigated these negative effects. TiO2 NPs application on Moldavian balm grown under salt stress conditions improved all agronomic traits and increased antioxidant enzyme activity compared with plants grown under salinity without TiO2 NP treatment. The application of TiO2 NPs significantly lowered H2O2 concentration. In addition, highest essential oil content (1.19%) was obtained in 100 mg L-1 TiO2 NP-treated plants under control conditions. Comprehensive GC/MS analysis of essential oils showed that geranial, z-citral, geranyl acetate and geraniol were the dominant essential oil components. The highest amounts for geranial, geraniol and z-citral were obtained in 100 mg L-1 TiO2 NP-treated plants under control conditions. In conclusion, application of 100 mg L-1 TiO2 NPs could significantly ameliorate the salinity effects in Moldavian balm.

Comparative study of inflorescence development in Oleaceae.

PREMISE OF THE STUDY: Investigations of inflorescence architecture offer insight into the evolution of an astounding array of reproductive shoot systems in the angiosperms, as well as the potential to genetically manipulate these branching patterns to improve crop yield and enhance the aesthetics of horticultural species. The diversity of inflorescences in the economically important family Oleaceae was studied from a comparative developmental point of view for the first time, based on species of seven genera (Chionanthus, Fontanesia, Fraxinus, Jasminum, Ligustrum, Olea, Syringa). METHODS: Series of developmental stages of chemically fixed inflorescences were studied with epi-illumination light microscopy. KEY RESULTS: All taxa studied have inflorescences with terminal flowers. The inflorescences are mostly panicles, but in some cases thyrsoids or compound botryoids. Phyllotaxis of the flower-subtending bracts is mostly decussate, rarely tricussate (Fraxinus) or spiral (Jasminum). Accessory flowers or accessory inflorescences, almost unknown in Oleaceae as yet, were found in two genera. In Syringa, common bract-flower primordia are formed by a delay in early bract development compared to flower development. Such a delay is also expressed by the loss of bracts in the distal part of inflorescence branches in Syringa and Chionanthus. CONCLUSIONS: Significant variation in branching pattern and phyllotaxy was observed among the studied species of Oleaceae. The suppression of bracts and formation of accessory flowers were found as special features of inflorescence ontogeny. The occurrence of accessory flowers and accessory partial inflorescences is interesting from the point of view of dense and flower-rich inflorescences in ornamental species.

Floral ontogeny in Astragalus compactus (Leguminosae: Papilionoideae: Galegeae): variable occurrence of bracteoles and variable patterns of sepal initiation.

Comparative studies of floral ontogeny represent a growing field that promise to provide new insights on floral evolution. Floral ontogenetic information has been used successfully in Leguminosae for re-examining phylogenetic relationships at different levels. Using epi-illumination light microscopy, we present original ontogenetic data in Astragalus compactus, which was chosen because of its unusual arrangement of inflorescence and variable occurrence of bracteoles on flowers. Based on our results, uncommon ontogeny of the inflorescence led to the arrangement of flowers in four different positions. Variation was observed not only in the presence of bracteoles, but also in the order of sepal initiation in flowers of the same inflorescence. Surprisingly, besides the widely stated unidirectional pattern, bidirectional, sequential and an atypical unreported order were observed. High degree of overlapping between whorls and formation of two types of common primordia also were found. The variable occurrence of bracteoles suggests that the species is in an intermediate state towards fully lacking of bracteoles. We propose that the variability of the sequence of sepal initiation is possibly a consequence of the function of mechanical forces generated by surrounding leaves. Relationships between mechanical force and auxin signalling are discussed.

Ontogenetic variation of volatiles and antioxidant activity in leaves of Astragalus compactus Lam. (Fabaceae).

The genus Astragalus is a rich source of a variety of biologically active compounds including phenols, saponins, polysaccharides and essential oils. The present study was conducted to determine ontogenetic variation of the volatile organic compounds as well as total phenolic contents and antioxidant activity in leaves of A. compactus. The leaves of plant were harvested at vegetative, flowering and fructification stages and were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). Total phenolic content (TPC) was determined using the Folin-Ciocalteau reagent and the antioxidant capacity was evaluated with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) test. Different classes of volatile compounds were identified including alcohols, esters, hydrocarbons, sterols and terpenoides. Significant variation of these compounds was found during phenological stages of development. Sterols and hydrocarbons were the main components of essential oils at the vegetative stage. The presence of terpenoides (phytol) and alcohols (docosanol) was significant at the flowering stage. Fructification phase was characterized by the high content of sterols and hydrocarbons and absence of phytol. The antioxidant activity and phenolic content were related to the physiological stage and the highest amount detected at fructification phase. The ontogenetic variations of phenolic contents and antioxidant properties are largely contributed by climatic factors such as temperature and solar radiation.

Ontogenetic Variation of Total Phenolics and Antioxidant Activity in Roots, Leaves and Flowers of Astragalus compactus Lam. (Fabaceae).

INTRODUCTION: The potential health risks and toxicity of synthetic antioxidants resulted in an upsurge of interest in phytochemicals as new sources of natural antioxidants. Phenolics of Astragalus L. (Fabaceae) possess antioxidant properties and have been shown to have a protective effect against several degenerative diseases. The objective of this study was to determine total phenolics and antioxidant activity of methanolic extracts from different parts of A. compactus Lam. at different phenological phases and to investigate the correlations between antioxidation and the contents of the total phenolics. METHODS: Total phenolic content (TPC) was determined using the Folin-Ciocalteau reagent and the antioxidant capacity was evaluated with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) test. RESULTS: Generally, the TPC in leaves was higher than that of the roots and flowers. TPC in leaves, roots and flowers of the species varied from 5.01-8.25, 4.29-7.89 and 4.19 µg GAE/mg DW, respectively. In addition, roots and leaves at fructification stage possessed higher TPC than vegetative and flowering stages. Therefore, the leaf extracts at fructification phase showed the highest TPC that accompanied with best antioxidant activity. In the root extracts, fructification stage was also characterized by the highest antioxidant activity. CONCLUSION: A positive relationship between antioxidant activity and TPC showed that phenolics were the dominant antioxidant components in the species. The results obtained suggest that A. compactus methanolic extracts may serve as potential sources of natural phenolic antioxidants and that the fructification phase could be considered as the best stage for the harvesting of this plant.