مجله پژوهشهای گیاهی (زیست شناسی ایران)
سال سی و پنجم شماره 3 (پاییز 1401)

Water stress is one of the most important factors affecting the metabolic pathways in the plant and thus alters the synthesis and accumulation of natural compounds such as fatty acids and hydrocarbons in medicinal plants. This study aimed to investigate the effect of different levels of water stress (Full irrigation at field capacity, irrigation at 70% of field capacity and irrigation at 40% of field capacity) on fatty acid and hydrocarbon quantities of Milk thistle. Drought stress was applied at flowering stage. Then the oil extract was extracted from the seeds using Soxhlet method and analyzed by GC-MS. Information about the pathway of the reactions of the identified compounds was extracted from bioinformatics databases. The results showed that the yield of fatty acids and hydrocarbons increased with increasing drought stress intensity. The predominant fatty acids identified in Milk thistle oil extract was linoleic acid (15.2-27.4%) and its dominant hydrocarbon was dodecane (12.3-14.1%). The percentage of fatty acids detected under stress was reduced, probably due to their degradation into hydrocarbons to maintain osmotic pressure under dehydration.

In this study, antimicrobial effects of two accession of Thymus fedtschenkoi originated from Semnan and Zanjan against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Bacillus subtilis were investigated. The essential oil was extracted by Clevenger apparatus and compounds identified by GC and GC-MS instruments. Disc diffusion and microdilution methods were used to determine antimicrobial activity. The experiment was done on factorial design based on complete randomized design. The effect of microorganism type (as first factor) and essential oil concentration and antibiotics (as second factor) and their interaction was evaluated. According to the results, essential oil yield was %0.73 and %0.95 in Zanjan and %0.83 and %0.86 in Semnan accession in two successive years. The main chemical compounds of Zanjan accession was p-cymene, linalool, thymol and carvacrol and Semnan accession was p-cymene, thymol and carvacrol. Statistical analysis showed that the effect of microorganism type, essential oil concentration and their interaction on inhibition zone was significant at 1% level. In Semnan accession, the highest diameter of inhibition zone was observed in C. albicans and in dilution of one fifth of essential oil. C. albicans and B. subtilis had the most sensivity to Zanjan accession and C. albicans to Semnan accession. The observed difference in antimicrobial effects can be related to difference in chemical composition and their activity.

Respiratory Burst Oxidase Homologue (RBOH) is involved in the perception and response to environmental stresses in plants by producing reactive oxygen molecules. In the present study, the expression of RBOH gene and morphophysiological parameters of Citrullus colocynthis in different concentrations of nickel chloride were investigated. 15-day-old seedlings were treated with different concentrations of nickel chloride (0, 150, 300 and 450 µM). The results showed that with increasing nickel chloride concentration, shoot and root length, shoot and root dry weight and relative water content decreased and the activity of superoxide dismutase and catalase, and content of proline, malondialdehyde and hydrogen peroxide increased significantly compared to the control group. Also, in treated plants, the uptake of elements such as manganese and zinc decreased. The expression level of RBOH gene also increased with increasing the amount of nickel chloride compared to untreated plants. According to the results of this study, nickel metal stress induces the expression of RBOH gene in C. colocynthis.

Cotton scientifically known as Gossypium hirsutum L. is a dwarf plant from the Malvaceae family and from the Gossypeae clan, that is native to tropical and subtropical regions. Cotton is one of the most important sources of oils globally and is rich in fiber and protein. It can also be used as animal feed. The purpose of this study was to compare the primary and secondary metabolites of the seed of two species, G. hirsutum L. and G. arboreum L. Compounds such as flavonoids, alkaloids, tannins, saponins, and steroids were detected in the two types of cotton. The biochemical properties of gossypol, flavonoid, flavonol, phenol and the antioxidant capacity of the cotton-seeds were evaluated. The results of the study indicated that G. arboreum L. as compared to G. hirsutum L. is valuable for use as animal feed and oil extraction, due to its higher amounts of fat, fiber and protein. A comparative study of the two species showed that both species had high antioxidant capacity and gossypol levels. Type G. hirsutum L. has greater quantities of phenol and flavonol than G. arboreum L. which can lead to the use of this species for breeding purposes and the creation of resistant strains to biological stress. The presence of large amounts of gossypol in the studied species indicates that consideration should be given for their utilization in various applications in the food and feed industry.

Selenium is a beneficial element with antioxidant and antiviral properties that promotes plant growth. In order to investigate the effect of selenium on some morphological, physiological and quantitative and quality of lemon essential oil, an experiment was conducted with 5 treatments and 3 replications in hydroponic culture system. Selenium in form of sodium selenate was applied either in nutrient solution or by foliar spraying at levels (0, 2.0, 5.0, 10.0 and 15µM). The results showed that selenium treatment significantly increased leaf dry weight, leaf area and total chlorophyll content in both application methods compared to the control. Application of 5 µM Se in nutrient solution and of 10µM Se by foliar spraying successfully enhanced total phenolic compounds and DPPH free radical scavenging in leaves. The lowest amount of malondialdehyde by foliar application (13.4) and addition to nutrient solution (10.7) was observed in 10 and 5 ?M treatments, respectively. Also, this element increased the amount of essential oil in the treatment levels of 5 ?M nutrient solution and 10 ?M foliar application by 94.92 and 100%, respectively, compared to the control treatment. The survey of essential oil components showed that the highest amount of oxygenated monoterpenes, especially citral (48.3%) was measured from foliar samples with a concentration of 10 ?M selenium. In fact, the results of this study showed that the selenium in low concentrations (5-10 ?M) had improving effects on growth, physiological and quantity and quality of essential oils of Lemon verbena.

Drought stress is one of the most impactive factors of Severe modification in plant physiology, eventually leading to a reduction in crop productivity. Increasing growth, yield, crop quality, and reducing the side effects of drought stress are some of the important roles that potassium silicate plays in plants. In order to study the effects of late-season drought stress and foliar application of potassium silicate on yield and yield components of spring genotypes of canola, a factorial split-plot experiment was conducted in Karaj, Iran in a randomized complete block configuration with three replications for two years of cultivation (2016-2018). The irrigation was performed at two levels in this study, including routine irrigation (control) and interruption of irrigation from the pod formation stage. Potassium silicate foliar application at two levels comprised of 0 and 4 g liter-1 in factorial status in main plots and five Brassica napus L. genotypes including OG×AL, RGS×SLM, DALGAN, RGS003 and RGS×Okapi in subplots. The authors found that the interaction impact of irrigation, the application of potassium silicate foliar, the genotype of the number of pods per plant, the number of seeds per pod, the yield of seeds, the level of leaf proline, the glucosinolate and the temperature of the canopy were significant. It is proposed that OG×AL genotype be used in regular irrigation and application of potassium silicate and in late-season dry conditions and in the application potassium silicate of RGS×SLM and DALGAN genotypes.

In order to study the effect of salinity stress and different concentrations of lead under the influence of stress ameliorator, a factorial experiment was carried out in a completely randomized design with three replications. The experiment consisted of salinity stress at three levels (0, 25 and 75 mM of sodium chloride), lead in three concentrations (0, 10-5, 10-3 M of Lead nitrate) and stress ameliorators included 0 and 5 mg/L sodium selenate and 200 μm sodium hydrogen sulfide. The results showed that salinity and lead caused a significant reduction in root and shoot dry weight, absorption of potassium and zinc in root and shoot. Different concentrations of Lead had different effects on the studied traits. At 10-5 M of lead nitrate was observed, the reduction in absorption of lead and as a result improvement in root and shoot dry weight than without salinity. Whereas, application of selenium and hydrogen sulfide significantly improved the growth traits of garlic under salinity stress and Lead. Application of 5 mg/L sodium selenate and 200 μm sodium hydrogen sulfide cause reduce in the accumulation Pb in garlic seedlings and this is followed by an improvement in the content of the elements and as a result, growth increased under salinity stress and lead concentration especially at 10-5 Pb However, in the concentration of lead 10-3M, this effect was not observed. It is worth noting that in the present experiment, the positive effect of selenium on sodium hydrogen sulfide was more pronounced.

It is a well established fact that stigma part of the Crocus sativus L. flower is the actual site for synthesis of many important carotenoids and apocarotenoids, and that too done at specific stages of development, but nothing is known about the mechanism that regulates its synthesis. Extensive researches on enzymes involved in the biosynthesis of saffron apocartenoids, especially crocin, indicates the presence of one of these enzymes, CsLcy-β2a in the stigma and also it activates and boosts b-carotene accumulation. Transcription factors, as a group of regulators, regulate many developmental and physiological processes in plants via their ability to tissue-specific and time-specific binding to promoters of target genes in order to control of gene expression. In this study, constructs contains of sequences CsMYB, CsARF8, CsERF2, CsZinc-finger CCCH and sequence CsLcyβ2a promoter fused with firefly luciferase reporter gene made by GoldenBriad system, and they was transferred to tobacco leaves (Nicotiana benthamiana) by agro-infiltration .The interaction between transcription factors and promoter was evaluated using Dual-Luciferase System assays .luciferase/Renilla (Luc/Ren) luminescence ratio was changed for only one transcription factor )CsMYB). Taken together, our findings illustrate that CsMYB is a positive regulator of carotenoid/apocarotenoid biosynthetic pathway in saffron.

The medicinal plant of Pulicaria gnaphalodes which belongs to Asteraceae family, is a perennial, herbaceous and growing in some regions of Iran. The aim of this study was to investigate the habitat and behavior characteristics of Pulicaria gnaphalodes in the ecosystem of Noferest region for 2 years to evaluate the feasibility of domestication of this species. Systematic random sampling was used to determine the percentage of canopy cover, frequency and density. Characteristics of climatic, soil, phenology, morphological and yield traits, essential oil percent and reproduction method and preference value of the plant were investigated. The results showed that this species grows in Noferest habitat with an average annual rainfall of 176 mm, an average annual temperature of 16.5°C, canopy cover of 27%, frequency of 76% and density of 1650 plants per hectare. Soil experiments showed that Pulicaria gnaphalodes prefered sandy loam soil and soil acidity and electrical conductivity were 7.9 and 0.33 dS/m, respectively.T he highest percentage of shoot essential oil (0.5%) was obtained in full flowering stage. Phenological studies also showed that the vegetative growth of Pulicaria gnaphalodes started in mid-April and continued until late September. Flowering startede in early June and continued until late September. Seed maturation also started in early July. After maturation, the seeds fell off and the stagnation period started in early October.

Preparation of cell suspension is an important step in the study of plant cells which is often done by the culture of friable embryogenic callus. The primary objective of this research was to produce friable callus and to determine an optimum culture medium for the induction of friable callus in maize plant. Using two basic media, Murashige-Skoog and Chu, with different concentrations of 2, 4 Dichlorophenoxyacetic acid and Benzyl adenine hormones (overall 16 different culture media), callus induction was performed on maize mature embryo explants. Selection criteria including high friable callus induction index, high callus size index, high callus fresh weight index, and low regeneration index were measured, and the mean values were compared using analysis of variance. Considering each of these selection criteria alone, different optimum media for callus induction were introduced. In order to determine one optimum medium considering all the criteria, the analytical hierarchy method was utilized. The optimum medium in this study was MS supplemented with 1 mg/L 2, 4-D wherein the induction, weight, and size indices were high, and the regeneration index was low. In order to evaluate and verify the selected medium, the explants were cultivated in in silico- selected medium and the growth curves were plotted for callus fresh and dry weights. Several successive subculturing of the callus was performed on the selected medium wherein no regeneration was observed. The results suggested the analytical hierarchy approach can be used as a reliable decision-making method for optimum-medium selection for inducing maize friable callus.

This research aimed to determine the most important environment factors affecting morphological distribution of Salvia hydrangea DC. ex Benth in protected region of Tang-e-sayad of Chaharmahal and Bakhtiari Province. This species is one of the medicinal and aromatic plants found in the natural habitats of mountainous areas of the country and contains essential oil of leafs and flowers. To measure morphological characteristics were taken 10 sample of S.hydrangea in each populations (5 plant stands). Leaf, sepal and corolla length and surface, flower stem and panicle inflorescence height and flower number of each panicle inflorescence were studied at the end of the growing season. In each plant populations, 2 soil sampling were executed of two depths 0-15 and 15-30 cm. Some soil parameters including texture, electrical conductivity, acidity, nitrogen, potassium and phosphorus were measured. The average comparison results showed that there was a significant difference between the populations in terms of most traits. PLS analysis results also showed plant height had a positive correlation with apparent specific weight of first depth and had a negative correlation with the soil acidity of first depth. The flowers number in cycle and sepal surface had a positive correlation with slope, gravel, sand and calcium carbonate equivalent (CCE) of second depth. Panicle inflorescence height had a positive correlation with clay, EC and potassium. Leaf length and surface had a positive correlation with slope, sand, CCE and gravel of second depth. The analysis results can determine effective environmental factors on each morphological specification of the species.

In sour cherry, as in other species of the genus Prunus, there is a gametophytic self-incompatibility (GSI) phenomenon. In this research, relations between pollen and pistil of 10 superior sour cherry genotype were investigated by using biological and molecular methods. In biological methods, pollen grains are prepared in balloon stage (D phenological stage) and then after evaluating the growth and percentage of pollen germination in medium, in suitable time flowers were emasculated, open pollination, controlled self and cross pollination were carried out in the orchard. In the molecular method, PCR-based methods were used to identify S alleles. The results showed that the highest pollen germination was observed on the stigma in self-pollination, and regarding of the number of pollen tube at the upper and lower parts of the pistil and ovary, the highest was related to open pollinating. Nine known S-haplotypes (S4, S6, S9, S6m2, S24, S26, S35, S36b and S36a) were identified, that alleles S6/S6m2, S9, S24 have a high frequency. Our study showed the low diversity of S alleles between studied genotypes. According to the growth of pollen tubes in style and ovary in all cases of pollination all of studied genotypes are compatible.

NAC (NAM, ATAF1/2, and CUC2) proteins are the plant-specific transcription factors (TFs) that play roles in diverse developmental processes and stress responses. In the present study, a total of 68 NAC genes were identified in Aeluropus littoralis, a salt secreting halophytic grass, belongs to family Poaceae. By analysis of cis regulatory elements of AlNAC genes promoter, many cis-acting regulatory elements related to growth and development, phytohormone and stresses defense were found in the promoter of AlNAC genes. These hormone-responsive elements, include P-box, TCA element, CGTCA-motif and TGACG-motif, TGA-element, ERE and ABRE, which were associated with gibberellic acid, salicylic acid, jasmonic acid, Auxin, ethylene and abscisic acid response, respectively. For stress responsive elements, TC-rich repeats, ARE, MBS, LTR; and W box, can be noted which are related to defense and stress, anaerobic induction, drought inducibility, low-temperature inducibility, and wound stress, respectively. The different types of cis regulatory elements in the promoter of AlNAC genes and the variability in transcription factors associated with these regulatory elements indicates the important role of these genes in plant development and defense against stress. By analyzing AlNAC32 candidate gene expression using RT-qPCR it was revealed that AlNAC32 was up-regulated under salt, drought and ABA phytohormone stresses in leaf, stem and root tissues, implying its role in multiple abiotic stresses tolerance. These findings provided valuable information for further research on the functions and applications of AlNACs in A. littoralis growth and adaptation to stress.

The present research aims to study pollen grain and ovule development in Ageratum houstonianum. It can be suitable pattern for several species of capitule inflorescence, The flowers and buds in different developmental stages were removed, fixed in FAA70, stored in 70% ethanol, embedded in paraffin and sectioned with a thickness of 5-7 μm by microtome. Staining was carried out with Eosine and Hematoxylin. Then slides were studied using light microscope and were photographed. Results indicated that in bisexual florets, consist of five stamens with free filaments and apart from each other. Anthers are tetrasporangiated and development of anther wall is of dicotyledonus type and composed of one-layered epidermis, an endothecium, one middle layer and tapetum. the tapetum was plasmodial. Microspore tetrads are tetrahedral. Pollen grains are three colpated with echinated sculpturing, at the shedding time. Ovule was anatropous, unitegumic and tenuinucellate. Cell division of megaspore mother cells is of both longitudinal and transverse type and resulted to form linear or massive tetrads.The embryo sac development is of the polygonum type. Results of this research showed the presence of formed crystals in anther, the layer endothecium wall anther, epidermal cells of ovary, ovule, style, stigma and petal that was species specific characteristic. secretory (papillate) epidermis on the adaxial surface of petals, On the outer surface of petal long, filamentous and one-celled trichoms were visible.

Arbuscular mycorrhizas are able to reduce the adverse effects of biotic and abiotic stresses on crops. To investigate the effect of inoculation with Glomus mosseae on physiological characteristics of two rice cultivars under water deficit conditions, an experiment was conducted in a randomized complete block design in the greenhouse. Irrigation conditions included flooding, stop irrigation up to 70% and 50% of field capacity. In general, in both groups of plants, inoculated and control plants (non-inoculated), increased levels of phenol, tannin, glycine and betaine, as well as polyphenol oxidase and guaiacol peroxidase enzymes were observed under water deficit conditions. However, the change amount of each trait in inoculated plants was significantly higher than the non-inoculated plants. In case of stopped irrigation up to 70% of field capacity, the amount of proline, antioxidant enzymes in Nemat cultivar was higher than Tarom Hashemi, while Glycine betaine, tannin and phenol content was higher in Tarom Hashemi than Nemat cultivar. In case of stopped irrigation up to 50% of field capacity, the amount of phenol, tannin, glycine and betaine as well as antioxidant enzymes in Nemat cultivar was higher than Tarom Hashemi, which can be a reason for different effects of arbuscular mycorrhizal colonization on the response of rice cultivars to water deficit conditions. Based on the results, it seems that inoculation of rice plant with mycorrhizal fungus can play a role in reducing the adverse effects of water deficit in case of water shortage conditions during the critical stages of plant growth.