tahereh a. aghajanzadeh

Cacti are among the most important and diverse plant families cultivated worldwide for various purposes, including food, medicine, cosmetic, and ornamental. To investigate the growth and physiological changes of Opuntia cylindrica under the treatment of auxin (IBA), cytokinin (Kin), and gibberellin (GA) hormones in concentrations of 250, 500, and 1000 mg/L, this study was conducted in a completely randomized design in the greenhouse of Islamic Azad University, Gorgan branch in 2020. The IBA treatment not only did not cause a significant change in the fresh weight (FW) and height, but also had no significant effect on the content of pigments, sugar, soluble protein, and phenolic compounds except flavonoids, the activity of phenylalanine ammonia-lyase (PAL) and superoxide dismutase (SOD) enzymes. But the treatment of cactus with Kin was caused a significant increase in FW, content of soluble protein, phenolic compounds, and increase the activity of PAL, SOD, and peroxidase (POD) enzymes. GA treatment caused a decrease in FW by 14 and 23%, a significant decrease in the content of pigments Chl. a by 31 and 70% and Chl. b by 37 and 68% and POD enzyme activity by 60 and 50% at 500 and 1000 mg/L, respectively. While the content of phenolic compounds and the activity of PAL and SOD enzymes were significantly enhanced. It seems that Kin at the concentrations of 500 and 1000 mg/L was the best treatment for reinforcement of the growth of O. cylindrica with high phenolic and antioxidant capacity. On the other hand, the decrease in FW and the content of chlorophylls in plant treated with GA, indicated the presence of stress in the plant, and the increase in the content of phenolic compounds and the activity of antioxidant enzymes specially at concentrations of 500 and 1000 mg/L probably moderated the stress.

The Hyrcanian Forest is a green belt in the north of Iran, and one of its distinctive features is the presence of an extraordinary variety of moss species. The Brachytheciaceae is distributed worldwide and comprises 62 genera and almost 570 species. Sciuro-hypnum curtum is one of the most variable species of the Brachytheciaceae and is here reported for the first time for the moss flora of Iran. The specimen was collected from northern Iran in the autumn of 2018 at an altitude of 581m in the southeast of Rezvanshahr city in Guilan Province. Here we provide description, illustrations, geographic distribution, and the locality and habitat of the new record.

In this study, the effects of auxin and gibberellin on Euphorbia trigona plants, grown in a complete randomized blocks design under greenhouse conditions were investigated. One-minute pretreatments including auxin regulators NAA, IBA and IAA, (0, or 500 mg / l), followed by treatments containing IAA, IBA and NAA, 250 mg / l, and GA treatments,250 mg/l, without any pretreatments were utilized on 2 month cuttings. After 4 months, fresh and dry weight of shoots and roots, and shoot total terpenoid content were measured. In some samples, shoot extract was analyzed using GC-MS. Fresh and dry weight of shoot did not show any sensitivity to the treatments and pretreatments. NAA treatment had the most positive effect on root fresh and dry weight. The highest significant increase in terpenoid content was observed in NAA treatment and NAA and IBA pretreatments. GC-MS analysis showed that the type of chemical compounds in the extract were mainly including sesquiterpenes, diterpenes, fatty acids, esters and steroids with various medicinal and antimicrobial properties as well as industrial applications. Four compounds including bis-2-ethylhexyl phthalate, hexadecanoic acid, 6,10,14-trimethyl-2-pentadecanone (Hexahydrofarnesyl acetone) and neophytadiene were observed in all treatments and controls with different percentages: Bis-2-ethylhexyl phthalate in NAA treatment 49.31%, in control 9.59%; Hexadecanoic acid in NAA treatment 2.73%, in control 2.12%; 6,10,14-trimethyl-2-pentadecanone, in NAA treatment 3.16%, in control, 1.42%, Neophytadiene in control 0.94% and in gibberellin treatment 1.64%. This comparison prominently showed that hormone utilization could have a positive effect on terpenoids and fatty acids anabolic pathways in Euphorbia trigona.

Environmental factors including climate factors and soil parameters affect growth, physiological processes and production of primary and secondary metabolites in plants. In addition, the responses of plants are widely varied to environmental factors. In the current study the impacts of rainfall, temperature and several soil factors such as soil texture, pH, electrical conductivity, organic matter, organic carbon, calcium carbonate and soil elements on nutrient elements, antioxidative compounds, activity, and isoenzymes patterns of peroxidase and superoxide dismutase in Stachys byzantina were investigated. S. byzantina as a valuable medicinal species was collected from three regions in the north of Iran with different altitudes and ecological conditions. The results showed that the content of nutrient elements (phosphorus, sodium, potassium, calcium), anti-oxidative compounds (phenols, flavonol, flavonoids, and anthocyanin) as well as the activity of peroxidase and superoxide dismutase enzymes along with intensity of their isoenzymes bands were positively correlated with temperature and rainfall, however, almost not correlated with soil parameters. Furthermore, the higher density of S. byzantina in the region with lower temperature and rainfall indicated greater adaptability of the plant in higher altitude areas, which is consistent with a decrease in the antioxidant compounds and activity of oxidative enzymes.

The Hyrcanian forests have a remarkable variety of moss species which research on their taxonomy is of great importance. Since Forsstroemia remotifolia, Homalia besseri and Pseudoleskeella catenulata are exclusive and native mosses species of Hyrcanian forests, so in the current study, fourteen populations from three provinces in the north of Iran including Golestan, Mazandaran and Guilan were collected at the same altitudes in autumn 2017. In order to reveal the relationships among these species and populations, a cluster analysis based on numerical taxonomy and zymogram patterns of peroxidases and superoxide dismutase with Euclidean distances was performed. Numerical taxonomy analysis showed plant length, marginal laminal cell length and middle laminal cell length are appropriate traits to distinguish the species of F. remotifolia, H. besseri and P. catenulata from each other as well as their populations. The zymogram analysis showed genetic variability among species and also within populations of F. remotifolia, H. besseri and P. catenulata. Accordingly, the isozyme banding pattern of peroxidases showed a total of 6, 7 and 5 bands for F. remotifolia, H. besseri and P. catenulata, respectively. However, 4 isozyme bands were detected for superoxide dismutase for all three species. Furthermore, the morphological analyses in some populations was not matched with the isoenzyme banding pattern of enzymes in the current study. In conclusion, the biosystematics studies (morphometry and zymogram patterns of peroxidase and superoxide dismutase) indicate the close relationship between F. remotifolia and P. catenulata.

Mosses are small, non-vascular and non-flowering plants. Forsstroemia remotifolia was previously belonging to Leskeaceae family and its old name is Pseudoleskeella laxiramea (Schiffn.) Broth. According to recent morphological researches, changed from Leskeaceae family to the Neckeraceae family. Therefore, in present study, to eliminate the ambiguities in classification of this species, phytochemical and palynological investigation in F. remotifolia, Homalia besseri, and P. catenulata seems necessary. The results of gas chromatography (GC/MS) are showed that, F. remotifolia has 21 different types of fatty acids, H. besseri contains 23 types and P. catenulata possesses 18 types. Analysis of fatty acids has been shown 61.53% similarity in fatty acid compounds between F. remotifolia, and P. catenulata. Results of palynology showed that spore shape in populations of F. remotifolia is spheroidal and spore shape in populations of H. besseri is oblate, but the spore shape in population of H. b. A belonging to H. besseri is prolate and also the spore shape in population of P. c. Do. belonging to P. catenulata is spheroidal. Overall results of chemotaxonomy and palynology indicate close relationship between F. remotifolia, and P. catenulata.

Nitrogen is taken up by plants in two forms - ammonium and nitrate and plays an important role in growth, metabolism and vital processes of plants. To investigate the relationship between these two nitrogen sources with sulfur metabolism, the rapeseed (Brassica napus) and broccoli (Brassica oleracea) plants were cultured in a hydroponic medium under nitrate and ammonium treatments for 14 days. The results showed fresh and dry weight of the shoot in both seedlings and also shoot to root ratio in canola seedlings exposed to ammonium nitrate were significantly increased compared to those of the plants grown in nitrate medium. The content of total sulfur in the shoot of the broccoli seedlings exposed to ammonium nitrate was higher than that of plant grown in nitrate medium. While the amount of sulfate in canola seedlings fed with ammonium nitrate was significantly decreased compared to nitrate-fed seedlings which it was accompanied by an increase in the gene expression of sulfate transporter 4:2. In addition, the expression of adenosine 5-phosphosulfate reductase and subsequently the synthesis of thiols and cysteine was increased in both seedlings exposed to ammonium nitrate compared to seedlings grown with nitrate. Therefore, nitrogen fertilizers in an equal proportion of ammonium and nitrate are of great importance in growth and synthesis of organic sulfur compounds in both seedlings. Although the positive effect of ammonium nitrate on growth and sulfur metabolism of canola with higher need for sulfur uptake and synthesis of organic sulfur compounds, was greater than those of broccoli plant.

Bryophytes are small, non-vascular, and non-flowering plants. Neckera complanata (Hedw.) Huebener and Neckera crispa Hedew.are one of the most prominent species in the Hyrcanian wetland found in glossy pale or yellowish-green patches. There is no evidence for morphometry and isoenzymes biochemical markers (Peroxidase/Superoxide dismutase) works on this genus in Iran. The purpose of this study is to investigate the differences and similarities among Neckera complanata and Neckera crispa moss populations in the north of Iran using morphometry and isoenzymes biochemical markers (Peroxidase / Superoxide dismutase). For this purpose, 18 populations from three provinces including Golestan, Mazandaran, and Guilan were collected at the same altitudes in autumn 2017. The results of morphometry were shown leaf length and leaf apex width/length were the most effective traits for the separation of populations. The results of the morphometry method and the results of isozyme banding patterns were the same, although very minor differences were observed. The largest diversity of Shannon (H́) belongs to the population of Neckera crispa from Hezarjarib while other populations have low genetic diversity. Because of the destruction of many habitats in the northern provinces of Iran and the increase in pollution in these areas, it can be said as a general result that perhaps the reason for low genetic diversity in Neckera complanata and Neckera crispa populations is the gradual extinction of these two species.

 Cadmium is a highly toxic and widespread soil pollutant threatening human and animal. Plants effectively help to eliminate environmental pollution by up taking of heavy metals and tolerate cadmium stress through a variety of mechanisms, but biochemical pathways and genes involved in the response of plants to cadmium stress have not been fully and comprehensively identified.  

Following proteomic studies on the Arabidopsis thaliana mutant in which AT2G37050 (receptor like kinase gene) was knocked-out, it was identified that 150 proteins that were present in the wild (control) plant have been disappeared in the mutant plant. In current study, biological function of AT2G37050 gene/GO terms has been investigated by GeneMANIA and agriGO algorithms. GO term is a controlled vocabulary system describing biological entities in three aspects (biological process, molecular function, and cellular component) in different organisms.  

Bioinformatics studies resulted from the GeneMANIA algorithm showed that the AT2G37050 gene is involved in the biological process of response to cadmium ion. The agriGO algorithm was then used to study GO terms at three levels of biological process, molecular function and cellular component, and role of the AT2G37050 gene and biological process of response to cadmium ion was reconfirmed. In addition, significant GO terms (FDR <0.05) such as "extracellular region", "plasmodesmata", "vacuole membrane" and "chloroplast" are associated with the mechanisms involved in plant tolerance to cadmium stress. This is another supporting evidence, which shows association of AT2G37050 gene and "response to cadmium ion". 

In addition to suggesting a new effective gene in response to cadmium stress, the result of current study can be considered in order to construction of transgenic plants, which are able to purify soil from cadmium contamination.