مجله پژوهشهای گیاهی (زیست شناسی ایران)
سال سی و ششم شماره 2 (تابستان 1402)

MicroRNAs (miRNAs) are small, non-coding, and regulatory molecules that play an important role in post gene expression regulation in response to biotic and abiotic stresses. Although Canola (Brassica napus) is a globally important oilseed, little is known about its regulation mechanisms target genes of drought-responsive miRNAs. Then, in this study drought-responsive miRNAs target genes of bna-miR156b, bna-miR156c, bna-miR156g, bna-miR171a, bna-miR171d, bna-miR171e, bna-miR172d, bna-miR399a, bna-miR399b, bna-miR396a, bna-miR395d, bna-miR395e and bna-miR395f in Canola were identified by bioinformatics tools. Molecular function, biological process, cellular component, proteins interaction, and relation of their pathways were investigated. In the present study were identified 225 target genes for miRNAs. Bioinformatics study showed that ribosome, proteasome, and chaperon-related genes of RPP1C, RPL36AA, RPL9D, RPS11, RPT1A, RPT2a, RPT4A, RPN11, HSF1, HSFA1E, HSF4, and HSFB2B are targets of drought-responsive miRNAs of bna-miR172d ،bna-miR156b/c/g، bna-miR860، bna-miR396a and bna-miR395d. Ribosomes, proteasomes, and chaperons are regulated by drought-responsive miRNAs for protein regulation and stress tolerance under drought conditions. Laboratory study of identified genes in this study can be a fundamental step in the production of drought-resistant Canola cultivars in inbreeding and genetic engineering programs.

Strawberry (Fragaria × ananassa L. Duch.) from the family Rosaceae is a hybrid species belongs to Fragaria that is cultivating in broad surface all over the world for the use of its fruit. The use of organic fertilizers and soilless ture beds instead of inorganic fertilizers and soil culture has been recommended for increasing the yield of the plants especially agronomic and horticultural species. In the present investigation, four types of cultivation beds; peat + perlite + sand (b1), cocopeat + perlite + sand (b2), cocopeat + perlite + sand + composted azolla (b3), perlite + sand + composted azolla (b4) and spraying by concentrations of 0, 0.5 and 1.5 mg l–1 humic acid were evaluated on function of Fragaria. Results showed that the interaction of humic acid and cultivation bed was significant on most traits. Concentration of 1.5 mg l–1 humic acid and b4 cultivation bed had the maximum impact on changing the most measured traits especially increase of fruit function.

Genetic engineering and elicitors are useful strategies to optimize high level production of secondary metabolites. In this study, hairy roots were produced with inoculated cotyledon explants of Hyoscyamus reticulatus L. with strain A4 of Agrobacterium rhizogenes and strain C58C1 (pRiA4-pBMI) carrying the pmt gene of Agrobacterium tumefaciens. Then, the effect of pmt gene overexpression and optimal concentration of yeast extract (250 mg l-1 after 48 h) were evaluated on morphological, biochemical characteristics and production of tropane alkaloids in hairy roots obtained from two strains. The results of the effect of different Agrobacterium strains with the optimal concentration of yeast extract showed that in hairy roots obtained from C58C1 strain, fresh weight (2.85 times) and dry weight (2.27 times), total phenol (1.74 times), flavonoid (1.76 times) and alkaloid (1.77 times) were higher than the hairy roots obtained from A4 strain. The maximum antioxidant capacity using two methods IC50 (1.62 µg ml-1) and FRAP (14.77 mmol Fe2+ g-1 FW) were observed in hairy roots obtained C58C1 strain. Also, the highest production of hyoscyamine (1.37 times) and scopolamine (1.34 times) was obtained in hairy roots from C58C1 strain. The results showed that the combination of pmt gene overexpression and the optimal concentration of yeast extract could be used as a suitable method to increase the production of phytochemicals, antioxidant capacity, activity of antioxidant enzymes and tropane alkaloids in Hyoscyamus reticulatus L. hairy roots.

In the present experiment, the effect of sodium chloride (0, 75 and 150 mM NaCl) and Urea (0, 60 and 120 mg/kg soil) on nitrate reductase activity (NRA) and accumulation of nitrate, total amino acids and some ions in the seedlings of pistachio (P. vera L. cv. ´´Badami Zarand´´) were studied. The results showed that application of 60 mg Urea per kg of soil in 0 and 75 mM sodium chloride treatments significantly increased the NRA in leaves (7.52 and 7.14 µ NO2-, respectively). In the seedlings treated with 75 mM sodium chloride, the total leaf amino acid content (AA) after application of Urea (120 mg/kg soil) increased significantly (22.91 µg. g FW), however, the AA in root of both salinity treatments (75 and 150 mM sodium chloride) was increased after application of 60 mg Urea per kg of soil. Application of 60 mg Urea per kg of soil resulted in a significant increase in the root/leaf ratio of the AA in 75 mM sodium chloride, but in 150 mM sodium chloride treatment, application of 120 mg Urea per kg of soil increased this proportion. Also, application of urea had a significant effect on nitrate accumulation in leaves and roots and root/leaf nitrate in pistachio seedlings that treated with 150 mM NaCl. The effect of sodium chloride or urea on Na+, K+ and Na+ concentration was significant. The results showed that application of urea under salt stress conditions improved some biochemical indices related to nitrogen metabolism in pistachio seedlings.

Zofai (Thymbra spicata L.) is a shrub plant belonging to the Lamiaceae family, with the local name Jaatenah, which has not been reported to grow in Lorestan province. This species is distributed in the range mountains of Darab Rika and Zaruni of Kouhdasht city. Zofai has long been used as a spice in traditional medicine to treat respiratory and gastrointestinal problems. This plant species has strong antimicrobial and antifungal properties due to its strong active ingredients. The samples were collected from the natural habitat and after identification and approval, they were dried at room temperature to provide essential oil. The water distillation method was used to extract the essential oil and ,and the chemical compounds of essential oil were characterized using Gas chromatography–mass spectrometry (GC-MS). According to the results of Zofai essential oil analysis, 25 compounds were identified that made up 97.04% of the total volume of essential oil. The major compounds identified in the essential oil of Zofai include Carvacrol (65.88%), γ-terpinene (9.71%), P-cymene (7.82%), Caryophyllene (2.51%), Myrcene (2.09%) , α-terpinene (2.04%). Phenolic compounds act as antimicrobials, antifungals, antioxidants and reduce inflammation. The presence of high Carvacrol in the essential oil of T. spicata, as a phenolic compound, confirms the traditional uses of the T. spicata medicinal species and this medicinal plant can be considered as a source of carvacrol production.

Aspergillus niger is one of the most common species of the genus Aspergillus with a wide distribution and multiple hosts. Given the importance of this species in the economy, health and hygiene, the identification of this species is important, although morphological identification methods are suitable for detecting Aspergillus species, they are generally ineffective in identifying the races and populations of species of this genus. therefore some molecular techniques are using to dissolve this problem, In this study, isolated population of Aspergillus niger form five crops including: Wheat, Barley, Corn, Soybean and Rapeseed, identified by morphological methods. To determine of genetic diversity of that population, twenty standardized primers based on ISSR method used. SPSS, GeneAlex and PAST software use to statistical analysis, The results of statistical analysis based on ISSR findings showed, using this method, Aspergillus niger varieties isolated from different hosts and different regions can be distinguished from each other.

To determine some bioactive compounds of Amaranthus blitoides in different phenological stages, an experiment was conducted in a randomized complete block design with three treatments and three replications. Three phenological stages, including eight-leaf, flowering and seed production stages, were considered three treatment of experiment, some phytochemical traits and phenolic acids, including quercetin, rutin, chlorogenic acid and caffeic acid, were measured. The highest total chlorophyll content (2.05 mg g-1) was observed at the seed production stage, while the lowest total chlorophyll content (0.94 mg g-1) was observed at the eight-leaf stage. The highest content of chlorophyll a and b was observed in the seed production stage, whereas the lowest amount of chlorophyll a and b was observed in the eight-leaf stage. The highest content of carotenoids was observed at the seed production stage. At different phenological stages, the evaluated traits had significant differences. The highest amount of total phenolic compounds, total flavonoids, total tannins, and antioxidant capacity were observed in the flowering stage. HPLC analysis of extracts showed that quercetin and rutin production increased during growth until the flowering stage and then decreased. Also, the biosynthesis of two phenolic acids, including chlorogenic acid and caffeic acid, was high at the eight-leaf stage and reduced after this phenological stage. In general, the highest amount of bioactive compounds and phenolic acids quercetin and rutin of this plant was observed in the flowering stage and the highest amount of plant pigments was observed in the seed production stage.