The relation between apomictic seed production and morpho-physiological characteristics in a world collection of castor bean (Ricinus communis L.).

Ricinus communis is one of the most important oilseed plants with many medicinal and industrial applications. Variation in 30 genotypes of castor bean collected from different regions of the world was evaluated for two consecutive years and the difference in seed production with two different reproductive modes (including apomixis and open-pollination) was compared based on yield components, agronomic traits, and phytochemical properties. Results of data analysis demonstrated that castor bean has the ability for a wide range of apomixis for seed production and the highest percentages of apomixis ability in the first and second years were 86.3% and 92.31%, respectively. Apomixis ability had a high positive correlation with yield components, seed oil content, and the amount of leaf rutin. Two genotypes from Brazil and Syria revealed the highest phenolic content in the first and second years, respectively. In addition, the Afghanistan genotype in two modes of apomixis and open-pollination in the first year and the Syria and Yazd genotypes in apomixis and open-pollination modes, respectively, in the second year showed the highest content of seed fatty acids. It is possible to maintain superior genotypes of castor bean in terms of phytochemical traits, yield, and oil quality through apomixis reproduction.

Elevated atmospheric CO2 combined with Epichloë endophyte may improve growth and Cd phytoremediation potential of tall fescue (Festuca arundinacea L.).

Complex environmental conditions like heavy metal contamination and elevated CO2 concentration may cause numerous plant stresses and lead to considerable crop losses worldwide. Cadmium is a non-essential element and potentially highly toxic soil metal pollution, causing oxidative stress in plants and human toxicity. In order to assess a combination of complex factors on the responses of two genotypes of Festuca arundinacea (75B and 75C), a greenhouse experiment was conducted on plants grown in two Cd-contaminated soil conditions and two soil textures under combined effects of elevated ambient CO2 (700 ppm) and Epichloë endophyte infection. Plant biomass, Cd, Fe, Cu, Zn, and Mn concentrations in the plant shoots and roots, Fv/Fm, chlorophyll (a & b), and carotenoid contents were measured after 7 months of growth in pots. Our results showed that endophyte-infected plants (E+) grown in elevated CO2 atmosphere (CO2+), clay-loam soil texture (H) with no Cd amendment (Cd-) in the genotype 75B had significantly greater shoot and root biomass than non-infected plants (E-) grown in ambient CO2 concentration (CO2-), sandy-loam soil texture (L) with amended Cd (Cd+) in the genotype 75C. Increased CO2 concentration and endophyte infection, especially in the genotype 75B, enabled Festuca for greater phytoremediation of Cd because of higher tolerance to Cd stress and higher biomass accumulation in the plant genotype. However, CO2 enrichment negatively influenced the plant mineral absorption due to the inhibitory effects of high Cd concentration in shoots and roots. It is concluded that Cd phytoremediation can be positively affected by the increased atmospheric CO2 concentration, tolerant plant genotype, heavy soil texture, and Epichloë endophyte. Using Taguchi and AIC design methodologies, it was also predicted that the most critical factors affecting Cd phytoremediation potential were CO2 concentration and plant genotype.

Effects of inoculation with four mycorrhizal species on seed phenolic and fatty acids of sesame plants grown under different irrigation regimes.

This study evaluated the interaction effects of irrigation level (well-watered and water stress conditions) and inoculation by different mycorrhizal species (non-inoculated, Funneliformis mosseae, Rhizophagus irregularis, Claroideoglomus claroideum, and Glomus fasciculatum) on mycorrhizal colonization, antioxidant activity, seed yield and oil quality of two sesame cultivars (Yekta and Naz). Water deficit decreased mycorrhizal colonization, seed yield and oil concentration but increased antioxidant activity and seed total phenol and flavonoid concentrations. However, mycorrhizal inoculation increased antioxidant activity, seed yield, oil concentration and total phenolic and flavonoids. The lowest reduction by water stress and the highest increase by inoculation in seed yield were observed in Naz plants inoculated by Cl. claroideum. Principal component analysis showed the highest differentiation effect of water stress compared to mycorrhizal inoculation on both cultivars, indicating the relative sensitivity of the two cultivars to water deficit. However, the application of different species of mycorrhizal fungi versus the non-inoculation conditions was somewhat discriminative. In terms of fatty acids, in most cases, water stress increased oleic, palmitic and stearic acids and decreased linoleic and linolenic acids but inoculation increased oleic and linoleic acids and decreased linolenic, palmitic and stearic acids. Regarding phenolic and flavonoids components, the contents of chlorogenic and caffeic acids were increased by water stress but no consistent trend was noted in response to water stress for the other compounds. Mycorrhizal inoculation generally decreased chlorogenic acid but increased gallic, caffeic, p-coumaric, and ferulic acids. In conclusion, the results of the present study may help to increase the level of valuable compounds in sesame for further pharmaceutical purposes under water stress conditions and mycorrhizal symbiosis.

Phytochemical, Morphological, and Physiological Variation in Different Ajowan (Trachyspermum ammi L.) Populations as Affected by Salt Stress, Genotype × Year Interaction and Pollination System.

In the present research, 28 populations of ajowan (Trachyspermum ammi L.) were evaluated for agro-morphological traits and essential oil yield in two consecutive years. Then, selected ajowan populations from these two years were used for further morphophysiological and biochemical studies under different salinity levels (control, 60, 90, and 120 mM NaCl). The main components of the oil were thymol (32.7-54.29%), γ-terpinene (21.71-32.81%), and p-cymene (18.74-26.16%). Salt stress caused an increase in essential oil content in the Esfahfo and Qazvin populations. The highest total phenolic and flavonoid contents were found in the Arak population grown in 60 mM NaCl (183.83 mg TAE g-1 DW) and the Yazd population grown in 90 mM NaCl (5.94 mg QE g-1 DW). Moreover, the Yazd population exhibited the strongest antioxidant activity based on DPPH (IC50 = 1566 µg/mL) under 60 mM NaCl and the highest reducing power (0.69 nm) under 120 mM NaCl. The results revealed that low and moderate salt stress improves the phytochemicals of ajowan seeds, which are useful for pharmaceutical and food applications. In this research, some morphological traits, as well as essential oil yield, were evaluated in open pollinated versus self-pollinated plants. As a result, plant height, number of flowering branches, and crown diameter significantly decreased in some populations, while a significant increase was obtained for number of flowers per umbel and seed numbers per umbel. Finally, self-pollination of ajowan might provide new insights for further breeding programs to increase oil or thymol content in ajowan.

Essential Oil Composition and Antioxidant Activity of Oregano and Marjoram as Affected by Different Light-Emitting Diodes.

Oregano and marjoram are important aromatic spices in the food industry, as well as medicinal plants with remarkable antioxidant properties. Despite their popularity, little is known about treatments that would influence the antioxidant capacity of essential oils. In this study, different spectra of LED light, namely blue, red, white, blue-red, and natural ambient light as a control, were applied to assess the essential oil content, composition, flavonoid, phenolic, and antioxidant capacity of oregano and marjoram. GC-MS analysis revealed thymol, terpinen-4-ol, sabinene, linalool, p-cymene, and γ-terpinene as the main compounds. In oregano, the thymol content ranged from 11.91% to 48.26%, while in marjoram it varied from 17.47% to 35.06% in different samples. In oregano and marjoram, the highest phenolic contents were in blue (61.26 mg of tannic acid E/g of DW) and in white (65.18 mg of TAE/g of DW) light, respectively, while blue-red illumination caused the highest increase in total flavonoids. The antioxidant activity of oregano and marjoram extract was evaluated using two food model systems, including DPPH and ß-carotene bleaching. The highest antioxidant capacity was obtained in control light in oregano and blue-red light in marjoram. The results provide information on how to improve the desired essential oil profile and antioxidant capacity of extracts for industrial producers.

Water Stress and Seed Color Interacting to Impact Seed and Oil Yield, Protein, Mucilage, and Secoisolariciresinol Diglucoside Content in Cultivated Flax (Linum usitatissimum L.).

Flaxseed (Linum usitatissimum L.) is a plant with a wide range of medicinal, health, nutritional, and industrial uses. This study assessed the genetic potential of yellow and brown seeds in thirty F4 families under different water conditions concerning seed yield, oil, protein, fiber, mucilage, and lignans content. Water stress negatively affected seed and oil yield, while it positively affected mucilage, protein, lignans, and fiber content. The total mean comparison showed that under normal moisture conditions, seed yield (209.87 g/m2) and most quality traits, including oil (30.97%), secoisolariciresinol diglucoside (13.89 mg/g), amino acids such as arginine (1.17%) and histidine (1.95%), and mucilage (9.57 g/100 g) were higher in yellow-seeded genotypes than the brown ones ((188.78 g/m2), (30.10%), (11.66 mg/g), (0.62%), (1.87%), and (9.35 g/100 g), respectively). Under water stress conditions, brown-seeded genotypes had a higher amount of fiber (16.74%), seed yield (140.04 g/m2), protein (239.02 mg. g-1), methionine (5.04%), and secondary metabolites such as secoisolariciresinol diglucoside (17.09 mg/g), while their amounts in families with yellow seeds were 14.79%, 117.33 g/m2, 217.12 mg. g-1, 4.34%, and 13.98 mg/g, respectively. Based on the intended food goals, different seed color genotypes may be appropriate for cultivation under different moisture environments.

Essential oil composition and total phenolic content in Cupressus arizonica G. in response to microbial inoculation under water stress conditions.

Arizona Cypress is one of the drought-resistant, aromatic, and aesthetically pleasing trees having several pharmacological uses. Certain microorganisms contribute to the secondary metabolism and synthesis of bioactive compounds in aromatic and medicinal plants. This study aimed to determine the photosynthetic pigments, total phenolic content, antioxidant capacity, and essential oil composition of Arizona cypress under two irrigation regimes and microbial inoculations. We established a factorial experiment with three mycorrhizae inoculations (Rhizophagus irregularis, Funneliformis mosseae, and a mixture of R. irregularis and F. mosseae), a rhizobacterium inoculation (Pseudomonas fluorescens), and two irrigation regimes (well-watered and water stress). Under the water stress regime, seedlings inoculated with F. mosseae (0.46%) and non-inoculated control plants (0.29%) had the highest and lowest essential oil contents, respectively. GC-MS analysis revealed that limonen, a-pinene, terpinen-4-ol, and umbellulone were the most abundant compounds in the seedlings and treatments under study. The water stress regime had a significant and dominant effect on essential oil and antioxidant capacity, whereas seedling growth and photosynthetic pigments tended to decrease under stress conditions. However, co-inoculation of seedlings with mycorrhizae and the bacterium resulted in an increase in phenolic compounds and carotenoids. Under conditions of water stress and mycorrhizal symbiosis, the results of the current study may help increase the level of valuable compounds in Arizona cypress for further pharmaceutical applications.

Changes in polyphenolic composition, physiological characteristics, and yield-related traits of Moshgak (Ducrosia anethifolia Boiss.) populations in response to drought stress.

Ducrosia anethifolia (DC.) Boiss. is an aromatic medicinal plant that has been traditionally used as an analgesic to treat headaches, backaches, colic, and cold. This study evaluated the yield, physiological, and phytochemical traits of 24 populations for 2 consecutive years under the water stress condition. The seed yield and physiological traits demonstrated the highest values in the first and second year, respectively. Hydrogen peroxide (H2O2), proline, malondialdehyde (MDA), and antioxidant activity enzymes were elevated, while chlorophyll, carotenoids, relative water content (RWC), and yield decreased under drought stress. High-performance liquid chromatography (HPLC) was also applied to assess the changes in some polyphenolic compounds in response to water stress. The increase in some phenolic compounds, such as p-coumaric acid, was recorded due to drought stress, while there was a decrease in flavonoids, that is luteolin and quercetin. Among the populations, Abarkuh2 indicated the highest increase in p-coumaric acid (96%) in response to drought stress. In general, high diversity among the studied populations provides new insights into choosing the beneficial populations for medicinal and food purposes. HIGHLIGHTS: • Changes in polyphenolics of Moshgak populations were obtained in response to water stress. • Gallic acid, ferulic acid, p-coumaric acid and vanillic acid were the major components. • The phenolic compounds was increased due to drought stress while flavonoids were decreased High variation was obtained between Moshgak populations.

Foliar spray of commercial seaweed and amino acid-derived biostimulants promoted phytoremediation potential and salinity stress tolerance in halophytic grass, Puccinellia distans.

Plants pretreatment with various chemicals has often been used to diminish salinity stress impact on plants. An experiment was carried out to determine the effect of foliar spray of two commercially available biostimulants (Algabon® [0.5 g/l] and Bonamid® [2 g/l]) on the growth and tolerance of halophytic grass, Pucccinellia distans under non-salinity condition (NSC) and salinity condition (SC). The greenhouse experiment was set up in a completely randomized design with three treatments repeated three times. Our results showed that biomass, leaf relative water content, chlorophyll content, K+ content, K+/Na+ ratio, and protein and N contents were all negatively affected by 300 mM NaCl. The results obtained in the present study showed the beneficial effects of the pretreatments of two biostimulants on P. distans seedlings under non-salinity stress conditions with respect to increasing plant biomass, photosynthetic pigments, K+ content, the content of proteins, and nitrogen percentage. The results suggested that foliar spray of Bonamid® could partly diminish NaCl-caused stress on P. distans seedlings, probably due to higher accumulation of shoot biomass, photosynthetic pigments, K+/Na+ ratio, protein and N contents, phytoremediation potential, as well as upregulation of Na+/H+ antiporters located in plasma membranes and vacuoles. The highest phytoremediation potential (PP) of shoots and total biomass was detected in the plants sprayed with Bonamid® by 50.8 and 42.7% respectively, relative to that in salinity-stressed control plants. Interestingly, foliar spray with two biostimulants decreased osmoprotectants and antioxidant compounds content of shoots under salinity stress conditions. Collectively, it could be concluded that a noticeable feature of pretreatment of P. distans seedlings with Algabon® and Bonamid® is the increase in growth under NSC, whereas under SC only pretreated plants with amino acid-derived biostimulant (Bonamid®) can (partly) diminish the NaCl-induced deleterious effects in P. distans seedlings through the compartmentalization of salts in vacuoles (by upregulation of Na+/H+ antiporters).

We report for the first time that foliar spray of two commercially biostimulants (Algabon^® and Bonamid^®) could improve growth and phytoremediation potential of halophytic grass, Pucccinellia distans under the subsequent salinity stress. We also illustrated the impact of biostimulants on the mechanisms behind the improvement in tolerance of P. distans to the following salinity in regard to K⁺/Na⁺ ratio, protein and N contents, antioxidant capacity, osmoprotectant compounds, and the upregulation of Na⁺/H⁺ antiporters located in plasma membranes and vacuoles.

Metabolic and physiological effects of water stress on Moshgak (Ducrosia anethifolia Boiss) populations using GC-MS and multivariate analyses.

Ducrosia anethifolia Boiss is a medicinal and aromatic plant that is used as a food additive and drug in the areas of natural distribution. In this study, eight populations from different geographical regions of Iran were evaluated for their essential oil composition, total phenolics and flavonoids as well as for free radical scavenging activity during two consecutive years under water deficit. Analysis of variance was performed using a randomized block design at three levels of irrigation and 2 years, using the GLM procedure of SAS software and cluster analysis was used according to Ward's method using squared Euclidean dissimilarity. The highest essential oil and total phenolics/flavonoids content were obtained in the second year. GC-MS analysis was used to analyze the essential oil components. In normal conditions, cis-chrysanthenyl acetate (39.1-66.4%) and α-pinene (1.02-4.7%) were recognized as major compounds. The essential oil components were elevated under water stress. The highest increase in cis-chrysanthenyl acetate (21.32%) in response to water stress was observed in Abarkuh1. Elevation in total phenolic, flavonoid and antioxidant activity was also observed in plants subjected to water deficit. The highest content of phenolic acids was measured in Semirom (136.74 mg TAE/g DW), while the highest flavonoid content was in Kerman (6.05 mg QUE/g DW) in severe water stress condition. Finally, a high diversity in the studied populations can be used to select advantageous populations for other pharmaceutical and food purposes.

Light emitting diodes improved the metabolism of rosmarinic acid and amino acids at the transcriptional level in two genotypes of Melissa officinalis L.

In the present study, we used different LEDs to evaluate their effect on metabolic and transcriptional reprogramming of two genotypes (Ilam and Isfahan) of lemon balm grown under narrow-band LED lighting. Lemon balm plants were grown in four incubators equipped with artificial lighting and subjected to four LED lamps [White, Blue, Red, and mixed RB (Red+Blue) (70%:30%)] and in greenhouse conditions for 7weeks. The results showed significant increases in leaf number, pigment and soluble sugar contents, secondary metabolites, and calcium, magnesium, potassium and amino acid contents achieved in growth under mixed RB LEDs. As observed for the content of total phenolics, rosmarinic acid, and amino acids, the expression of genes involved in their production, including TAT , RAS , and DAHPS were also enhanced due to the mixed RB LED lighting. The best condition for both the plant growth and expression of genes was under the mixture of Red+Blue LED lamps. These observations indicate that the increase in secondary metabolites under mixed Red+Blue lights may be due to the increase in primary metabolites synthesis and the increased expression of genes that play an essential role in the production of secondary metabolites.

Morpho-Physiological and Molecular Characterization Reveal Low Genetic Variation for Conservation of Endangered Iranian Moshgak (Ducrosia anethifolia Boiss).

Ducrosia anethifolia Boiss is an aromatic vegetable and medicinal plant of Apiaceae family. In this study, morphological and essential oil studies as well as ISSR analyses were employed to investigate genetic diversity in 120 Moshgak accessions of 24 Iranian populations. High variations were observed in morpho-physiological traits (morphological and essential oil contents) of the populations in 2 consecutive agronomic years. In both studied years, the highest leaf (1% and 1.2%) and seed (2.46% and 2.9%) essential oil contents were recorded for the Abarkuh population. For ISSR analysis, 15 primer combinations were employed that produced 120 polymorphic bands. Dendrogram and STRUCTURE software grouped the accessions into four clusters although such grouping did not fit the geographic regions perfectly. Among the populations, Abarkuh and Kerman exhibited the highest genetic distance. Based on analysis of molecular variance (AMOVA), only 4.32% of the total genetic diversity was observed among the populations, while 95.68% was detected within the populations. Moreover, the studied populations exhibited a low genetic differentiation (Gst = 0.13) but a high gene flow (Nm = 3.26). It may be concluded that the results of the study provide new insights regarding the genetic diversity of Moshgak germplasm that will be useful for its conservation management and breeding programs for oil- and yield-related traits.

Pretreatment with LEDs regulates antioxidant capacity and polyphenolic profile in two genotypes of basil under salinity stress.

In the present study, we evaluated a pretreatment with four LED light sources (red, blue, red + blue, and white) in two genotypes (green and purple) of basil on the growth parameters, stress oxidative markers, non-enzymatic antioxidants, osmoprotectant compounds, ion content, and polyphenolic profile under both control and salinity stress conditions. The results indicated that 150 mM of NaCl decreased biomass, RWC, and K+/Na+ ratio but increased the content of proline and antioxidant capacity in the leaves of both genotypes of basil grown under GH (greenhouse) conditions. The results suggested that RB LED-exposed plants in the green genotype and R LED-exposed plants in the purple genotype improved accumulation of shoot biomass, K+/Na+ ratio, proline and soluble sugars, glutathione and ascorbate, polyphenolic profile, and thioredoxin reductase activity in the leaves of basil under both control and salinity stress conditions. NaCl stress (150 mM) increased oxidative markers, which are responsible for disturbance of routine functions of various plant cellular modules. LED light pretreatments diminished these markers under both control and salinity stress conditions. It could be concluded that intensification of non-enzymatic antioxidant systems during light-mediated priming can diminish the deleterious effects of ROS induced by NaCl stress (150 mM) through preventing the lipid peroxidation, scavenging cytotoxic H2O2, and enhancement of antioxidant potentials. Therefore, usage of LED lighting systems as a pretreatment or to supplement natural photoperiods under both control and salinity stress conditions may be advantageous for increasing biomass and phytochemical accumulation in basil.

Relationships between grain, flour, and dough quality characteristics and solvent retention capacity tests of twelve triticale cultivars and parental species.

Relationships amongst solvent retention capacity (SRC) profiles and quality characteristics of triticale cultivars were investigated. Superior triticale grains resulted into flours with preferable quality attributes for baking bread. Standard and supplementary SRC-values exhibited significant correlation with grain, flour, and dough quality. Positive correlations among sucrose-SRC with ash, pentosan, and ferulic acid (FA) contents were significant. The standard SRC-profiles along with metabisulfite-SRC (MBS-SRC) and ethanol-SRC exhibited significant correlation with damaged starch (DS) content. The ethanol-SRC demonstrated strong correlations with water absorption capacity, FA, and Dmax-value alveolab parameter. Triticale flours containing a higher amount of anti-parallel ß-sheets and tyrosine exhibited higher lactic acid-SRC (LA-SRC) and gluten-performance-index (GPI). Positive correlations between sodium dodecylsulphate-SRC (SDS-SRC) and anti-parallel ß-sheets percentages were noticed. The LA-SRC, GPI, MBS-SRC, SDS-SRC, and SDS+MBS-SRC were positively correlated with SDS-sedimentation, gluten index and negatively to sulfhydryl-groups content. Triticales having higher LA-SRC and MBS-SRC resulted in dough with higher strength and tenacity.

Water stress intensified the relation of seed color with lignan content and seed yield components in flax (Linum usitatissimum L.).

This study aimed to investigate the effect of yellow and brown seed coat color of flax on lignan content, seed yield, and yield components under two contrasting environments of non-stress and water stress conditions. The water stress environment intensified the discrimination between the two seed color groups as the yellow seeded families had lower values for seed yield components under the water stress. Heritability and the genetic advance for seed yield were significantly higher in brown-seeded families than those of yellow-seeded ones at water stress conditions. Secoisolariciresinol diglucoside (SDG) as the chief lignan in flaxseed was more abundant in yellow-seeded families under the non-stress environment but under water stress conditions, it increased in brown seeded families and exceeded from yellow ones. Considering that the brown and yellow seed color families were full sibs and shared a similar genetic background but differed in seed color, it is concluded that a considerable interaction exists between the flax seed color and moisture stress concerning its effect on seed yield and yield components and also the seed SDG content. Brown-seeded genotypes are probably preferred for cultivation under water stress conditions for better exploitation of flax agronomic and nutritional potentials.

LED light sources improved the essential oil components and antioxidant activity of two genotypes of lemon balm (Melissa officinalis L.).

BACKGROUND: Nowadays, light-emitting diodes (LEDs) as a new lighting technology, have been emerged as an alternative source of light for plants due to their wavelength specificity, the narrow width of their bands, small size, solid structure, long lifetime, and low heat generation. Here we investigated the effect of different LED light sources on the essential oil components and antioxidant activity of Melissa officinalis. Two genotypes of lemon balm (Ilam and Isfahan) were subjected to four artificial light treatments, including white, red, blue, red + blue LEDs, and greenhouse light as natural lighting. RESULTS: The LED lights significantly increased shoot fresh and dry weights and leaf number in the two genotypes as compared to greenhouse condition. The results showed that the content and composition of essential oil in the two genotypes were variable under different light treatments and the total amount of compounds in the Ilam genotype was higher than the other genotype. The results of analysis of the essential oil by GC/MS indicated that the highest amount of monoterpenes in the genotypes was related to citronellal under red + blue LED lamps (15.3 and 17.2% in Ilam and Isfahan genotypes, respectively) but blue, white, and greenhouse condition had the most effect on sesquiterpenes content in both genotypes. The results showed that the observed variation between the two genotypes in the essentials oil composition was related to the relative percentage of the constituents and not to the appearance or lack of a specific component. Red + blue lighting also provided the highest radical scavenging activity in both genotypes (80.77 and 82.09% for Ilam and Isfahan genotypes, respectively). Based on principal component analyses (PCA), three main groups were identified regarding genotypes and all light treatments. CONCLUSIONS: Overall, results indicated that the essentials oil composition of two genotypes of lemon balm was affected both qualitatively and quantitatively by different LED light sources; hence, LED lights might be used to improve monoterpenes, sesquiterpenes, and antioxidant activity in the selected genotypes.

Variation of Essential Oil Content and Composition, Phenolics, and Yield Related Traits Using Different Pollination Systems in Populations of Thymus Species.

The production of self-pollinated plants could be important for improving medicinal plants secondary metabolites. In this study, 11 Thymus populations from eight species were evaluated to determine the effect of self and open pollination on agro-morphological characteristics, total phenolic content (TPC), essential oil (EO) content, and EO components. Inbreeding led to some positive effects of above mentioned traits in most of the studied populations. Total phenolic content ranged from 7.07 to 52.69 mg tannic acid equivalents (TAE) g-1 dry weight (DW) in open pollinated derived populations, while it varied from 1.2 to 55.03 mg TAE g-1 DW in self-pollinated ones. Under open and self-pollination condition, the highest EO content was obtained in T. trautvetteri (3.37 %) and T. pubescens (1.96 %), respectively. Gas chromatography-mass spectrometry (GC/MS) identified 42 compounds including thymol, carvacrol, linalool, p-cymene, γ-terpinene, terpinen-4-ol, and α-terpineol as the main compounds. In most cases, selfed plants compared to open pollinated ones, revealed higher thymol content. T. daenensis-1 showed a significant increase in thymol content (from 25.22 % to 74.3 %) due to self-pollination. Moreover, self-pollination led to emergence of some new compounds. Carvacrol methyl ether was the constituents of Thymus EO that are being reported in self-pollinated populations. Finally, inbreeding in Thymus might be suggested as a useful tool to increase genetic homogeneity for the selection of superior plants for improving secondary metabolite.

Gamma radiation negatively impacted seed germination, seedling growth and antioxidant enzymes activities in tall fescue infected with Epichloë endophyte.

Plants and their accompanying microorganisms growing in contaminated sites with long-lived gamma-emitting radionuclides may be affected by radiation stress. The present study aimed to investigate the effects of gamma radiation on symbiotic relationship between Epichloë endophyte and Festuca arundinacea plant along with the radio-sensitivity of a pair of clones of tall fescue with (E+) and without (E-) symbiotic Epichloë endophyte exposed to different doses of gamma radiation including 25, 50, 75, 100, 150, 200, 300, and 400 Gray (Gy) from a Cobalt-60 source. Both irradiated and non-irradiated seeds of each status were grown under controlled conditions. Seed germination indices, seedling growth and certain physiological criteria associated with plant responses to oxidative stress were examined. The results revealed that low doses (up to 75 Gy) of gamma radiation stimulated seed germination indices and seedling growth. However, high doses (100-400 Gy) significantly reduced the final germination percentage, germination rate index, coefficient of velocity of germination, and the seed reserve depletion percentage, and enhanced the mean germination time. Further, high doses of radiation reduced root and shoot lengths, root and shoot fresh weights, and activities of antioxidant enzymes (especially catalase and superoxide dismutase), and increased the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) of the seedlings. The results showed that the endophyte was present in seeds after gamma ray irradiation. However, the presence of endophyte in seedlings started to be reduced significantly (18.45% reduction rather than the control) at 50 Gy of gamma radiation. High doses (100 Gy and above) dramatically declined the presence of endophyte down to zero in seedlings compared to the control. In this study, the E- clone had higher seed germination and seedling growth as well as lower H2O2 and MDA contents under radiation stress as compared with the E+ clone. Additionally, shoot tolerance index (STI) indicated more radiation tolerance in the E- clone. According to the results of the present study, it is concluded that biological impacts of gamma radiation stress and the harmful effects on endophyte viability may cause more radio-sensitivity and changes in the growth and physio-biochemical aspects of the host plant.

Performance of new biodegradable chelants in enhancing phytoextraction of heavy metals from a contaminated calcareous soil.

Chelant-assisted phytoextraction has widely been exploited as a feasible option for removing heavy metals from the contaminated soils. Some synthetic chelants have shown promising performances for this option, but they have also revealed several negative environmental consequences. This study has sought to investigate the feasibility of two biodegradable eco-friendly chelants, namely methylglycinediacetic acid (MGDA) and N,N-Bis(carboxymethyl)-L-glutamic acid (GLDA), as compared to the resistant ethylenediaminetetraacetic acid (EDTA), in enhancing phytoextraction of Zn and Pb from a contaminated calcareous soil. For this purpose, a greenhouse experiment was carried out comparing the growth and metal absorption of maize (Zea mays L.) grown on soils treated with EDTA, MGDA, and GLDA chelants at 2, 4 and 8 mmol kg- 1 levels. Results showed that the heavy metal uptakes by the plant shoots generally increased with increasing the chelant application level. Pb uptake by maize shoots increased from 10.6 mg plant- 1 in control to 416, 398, and 416 mg plant- 1 in the soils treated with 8 mmol kg- 1 MGDA, GLDA, and EDTA, respectively. The corresponding increases in Zn uptake were from 100.9 mg plant- 1 to 798.9, 718.9, and 530.4 mg plant- 1 in the MGDA-, GLDA-, and EDTA-amended soils, respectively. Moreover, the amounts of water-extractable, and thereby potentially leachable, Pb and Zn in the post-harvest soil were considerably greater in the soil treated with EDTA than those treated with MGDA and GLDA. Therefore, MGDA and GLDA would be potential alternatives to environmentally-persistent EDTA for enhanced metal phytoextraction from contaminated soils.

Comparative physiological and proteomic analysis indicates lower shock response to drought stress conditions in a self-pollinating perennial ryegrass.

We investigated the physiological and proteomic changes in the leaves of three Lolium perenne genotypes, one Iranian putative self-pollinating genotype named S10 and two commercial genotypes of Vigor and Speedy, subjected to drought stress conditions. The results of this study indeed showed higher RWC (relative water content), SDW (shoot dry weight), proline, ABA (abscisic acid), nitrogen and amino acid contents, and antioxidant enzymes activities of S10 under drought stress in comparison with the two other genotypes. A total of 915 proteins were identified using liquid chromatography-mass spectrometry (LC/MS) analysis, and the number of differentially abundant proteins between normal and stress conditions was 467, 456, and 99 in Vigor, Speedy, and S10, respectively. Proteins involved in carbon and energy metabolism, photosynthesis, TCA cycle, redox, and transport categories were up-regulated in the two commercial genotypes. We also found that some protein inductions, including those involved in amino acid and ABA metabolisms, aquaporin, HSPs, photorespiration, and increases in the abundance of antioxidant enzymes, are essential responses of the two commercial genotypes to drought stress. In contrast, we observed only slight changes in the protein profile of the S10 genotype under drought stress. Higher homozygosity due to self-pollination in the genetic background of the S10 genotype may have led to a lower variation in response to drought stress conditions.