جستجوی مقالات مرتبط با کلیدواژه « اتیلن » در نشریات گروه « زیست شناسی »

Potato (Solanum tuberosum L.) is a key crop within the Solanaceae family and ranks as the most significant non-cereal crop globally following major staples such as wheat, rice, and corn. Potatoes can reproduce sexually and asexually via tubers, and plant tissue culture is emerging as an effective method for vegetative propagation, addressing the increasing global demand for agricultural products. Ethylene, a critical plant growth regulator, influences various physiological processes including growth and development. During in vitro culture and due to the wounding of explants, ethylene accumulation can lead to abnormal biological responses, with potato seedlings being susceptible. Thus, investigating the effects of ethylene biosynthesis inhibitors such as pyrazinamide (PZA) and AgNO₃ on potato growth in vitro is essential.

In this study, potato seedlings were cultivated in Murashige and Skoog (MS) medium, with concentrations of PZA ranging from 0 to 6 mg L⁻¹ and AgNO₃ at 2 mg L⁻¹. After four weeks, the seedlings were harvested and stored at -70°C for later analysis. The growth parameters measured included fresh weight (FW), dry weight (DW), stem and root lengths, leaf area, and leaf and root number. In addition, biochemical parameters, such as photosynthetic pigment levels, total phenol content (TPC), total reactive oxygen species (ROS), and proline concentration were analyzed. Statistical evaluations were conducted using SPSS and PAST software

The results showed that the 2 mg L⁻¹ PZA treatment led to the highest FW and DW and increased leaf numbers; however, it was also correlated with a lower number of rooted plants. Conversely, treatments with 6 mg L⁻¹ PZA promoted longer stem growth, whereas control plants exhibited the largest leaf area, and AgNO3-treated plants produced the longest roots. The accumulation of H₂O₂ in plants treated with ethylene inhibitors was like controls, but total ROS levels soared by 36% in those treated with 6 mg L⁻¹ PZA compared to controls. This suggests a link between reduced ethylene production, oxidative stress mitigation, and enhanced potato growth. Additionally, total ROS was positively correlated with stem length, but negatively correlated with root length.Plants use several strategies to combat the damaging effects of ROS, such as the production of antioxidant compounds such as phenolics. Although PZA did not significantly alter TPC compared to controls, treatment with AgNO₃ caused a 61% reduction in TPC. Therefore, PZA did not appear to significantly affect phenolics production in the potato seedlings.Proline, another critical antioxidant in plants, was found to accumulate significantly in the leaves of plants treated with 6 mg L⁻¹ PZA, which was more than 2.3 times higher than that in controls. This accumulation correlated positively with ROS levels at higher PZA concentrations but showed an inverse relationship with photosynthetic pigment levels.The PCA revealed the relationships between the measured parameters and the applied elicitors. The samples were categorized into four distinct groups:Control group: This group primarily exhibited higher FW, DW, and longer roots compared to the treated plants.Low PZA dose group: These plants displayed elevated levels of photosynthetic pigments, TPC, and leaf area.Medium PZA dose group: Correlations were observed with an increased number of roots.6 mg L⁻¹ PZA and AgNO₃ group: These samples contained elevated levels of total ROS and proline.

The study concludes that low concentrations of PZA can stimulate growth while inhibiting ethylene production, resulting in fewer growth abnormalities compared to control plants. However, at elevated PZA concentrations, increased ROS levels may lead to oxidative stress, emphasizing the delicate balance in ethylene's role in plant growth and the necessity for further research to optimize conditions for potato cultivation in vitro. The findings contribute to a deeper understanding of how ethylene inhibitors can enhance potato propagation and possibly other crops in controlled agricultural environments.

Ultraviolet radiation divides to three bands UV-A (320-390 nm), UV-B (280-320 nm) and UV-C (254-280 nm). Different bands of ultraviolet radiation have different effects on growth, physiological and biochemical plants. In this research the effect of different bands of UV radiation on the shoot and root length, quantity of flavonoids, anthocyanine, protein, ethylene, peroxidase and polyphenol oxidase activities and the concentration of Ca2, K, Mg2 in seedlings of the pepper (Capsicum annuum L.) were studied. After 10 days, seedlings were for 3 days under treatment UV-A, UV-B and UV-C. To assess the effect of ultraviolet treatments on electrophoretic polypeptide patterns, shoot proteins were separated on SDS-PAGE gels. The results showed that under the experimental conditions, UV-B and UV-C radiation reduces the length of shoot and root. Studied showed that irradiation of the plant with UV-B and UV-C caused significant increase in quantity of protein, anthocyanine, flavonoids, ethylene, the concentration of Ca2, K, Mg2, activity of enzymes peroxidase and polyphenol oxidase, while in those plants which were treated with UV-A, the activity of enzymes were not significantly different in comparison to the control. These pigment have high absorption in UV spectrum of light and therefore could be used as UV absorption compounds by plants to prevent penetration of UV to the more sensitive tissues. The role of flavonoids in quenching of hydrogene peroxide and defensive reaction of plants against UV radiation which will discaused in this paper.

In calcareous and alkaline soils, which include most of Iran soils, iron deficiency is prevalent. The main cause of iron deficiency chlorosis is high pH of soil. Among fruit trees, peach shows high sensitivity to iron deficiency. Chelated iron fertilizers with a great ability to make iron soluble and readily absorbed by the plant are used for iron deficiency. For this purpose, an experiment based on a randomized complete block design with three replications was designed and the effect of foliar spray of chelated iron at concentrations of 0, 5 and 10 mg/l on fruit quality of peach (CV. Alberta) was studied. In this experiment the parameters such as amount of soluble solids, titratable acid, flavor index, firmness, antioxidant activity, vitamin C, cell membrane electrolyte leakage, ethylene production and leaf pigments were studied. The results showed that by increasing iron concentration leaf chlorophyll content and antioxidant activity of fruit were increased. Significant effect on carotenoid content of leaves, vitamin C and fruit firmness under different concentrations of iron wasn’t observed. Ethylene production and cell membrane electrolyte leakage also decreased with increasing iron concentration. According to the results, peach fruit quality improved by foliar application of chelated iron during growth.

Ethylene (C2H4), although is a simple molecule, play several important roles in plant growth and development. Triple response approach is a great possibility for evaluation of ethylene biosynthesis and signaling in Arabidopsis thaliana. In this research, by using the various mutant plants, we investigate function of several key genes including EIN2, EDR1, JAR1, PAD4 and NahG on plant responses to ethylene. The Arabidopsis seedlings that had some defection in ethylene biosynthesis, perception or signaling may explicate some changes in triple response. Therefore, several mutants including ein2، jar1، NahG، pad4، edr1 and their wild type plant, Col-0, have been employed. The seeds have been grown on MS medium consisting of several concentrations (0, 1, 5, 10 and 20 mM) of ACC (1-aminocyclopropane-1-carboxylic acid). The triple response assay performed on seedlings after incubation for 5 days in darkness. According to the obtained results, non of the mutants fall into eto (Ethylene over expression) and his (Less hook) groups. Most of mutant plantlets displayed a significant difference with the wild type, Col-0, and only pad4 showed the same response as the parental genotype, meaning that ethylene biosynthesis and signaling in pad4 seedlings is probably the same as the wild type. Therefore, mutation in key genes involving in various hormone biosynthesis can induce a different response to ethylene in plants. The triple response approach could be very useful manner to predict the responses of plants in mature stage.

The plant hormone ethylene regulates a variety of processes، such as growth، seed germination، flower initiation، organ abscission، adventitious root formation، leaf expansion، fruit ripening، and petal senescence after fertilization. Flower senescence is one of the developmental processes in which ethylene plays a key role. The climacteric rise of endogenous ethylene in these flowers has been shown to play a regulatory role in the events leading to death of some of the floral organs. In recent studies، loss-of-function ETHYLENE INSENSITIVE2 (EIN2) mutation showed ethylene insensitivity which indicated an essential role of EIN2 in ethylene signaling. As the EIN2 gene، a positive regulator، plays a central role in ethylene signal transduction، we characterized its expression pattern in Petunia. The results showed that EIN2 transcript was present in all of tissues، with highest levels in style/stigma and ovary opened petunia flowers. Also، expression analysis was carried out to evaluate the effects of pollination، glucose، ABA، ACC on ethylene biosynthesis and signaling in petunia flower. The results indicate that glucose may play an important role in ethylene-associated regulation of flower senescence. These results demonstrate that NtEIN2 mediates ethylene signals in wide range of physiological processes and also cross-talk with other hormones like ABA in environmental stresses.

Ethylene، a phytohormone، is produced during in vitro plant tissue culture and its accumulation is associated with reduction of growth and morphological changes. The aim of this study was to evaluate application of CoCl2، as ethylene synthesis inhibitor، on growth and some physiological parameters as well as expression of ACC oxidase gene of potato. In this study، nodal segments of potato (Solanum tuberosum L.) cv. White Desiree were cultured on MS medium containing concentration of 0، 5، 10، 15، 20، 30، 40، 60 mg/L CoCl2. After 5 weeks، chlorophyll a،b، total، cartenoied، content، leaf area and expression level of ACC oxidase gene were investigated. CoCl2 inhibited root production in aerial parts and increased leaf areas and amount of chlorophyll a،b and carotenoid. Application of 20 mg/L CoCl2 was the best for potato growth. ACC oxidase gene expression was decreased at this concentration. Application of CoCl2 decreased ACC oxidase gene expression and prevented ethylene accumulation in the in vitro culture and consequently improved growth of potato plant.

To evaluate the effects of methyl salicylate vapor on Catalase (CAT) and Ascorbate Peroxidase (APX) activity، Vitamin C content، ethylene production and decay index of kiwifruit (Actinidia deliciosa cv Hayward) an experiment was conducted by five methyl salicylate concentrations (0، 0/06، 0/12، 0/18 and 0/24 mM) through five months shelf life period in 0. 5 Cº. The results of this experiment show that 0/24 mM methyl salicylate treated fruits had lowest decay percent in compare with control at the end of the shelf life period. The methyl salicylate vapor treatments in all of the exampling times caused alleviation in the activity of CAT and APX antioxidant enzymes and ethylene production، this inhibition effect was increased by induction in methyl salicylate concentration and the highest impact of methyl salicylate was assayed in 0/24 mM. Use of 0/24 mM MeSA led to slower reduction trend in Vitamin C content. In conclusion، 0/24 mM methyl salicylate treated fruits have had greatest effects on decay control، CAT and APX activities، ethylene production and Vitamin C content.

Studies have shown that salicylic acid (SA) is the caused of resistance the plants to environmental stress (cold, heat, salinity and drought stress). The effects of salicylic acid are probably caused by inhibition of ethylene biosynthesis. In this research the effects of ethylene and salicylic acid treatments on the quantity of carotenoid, anthocyanin, flavonoids, lipid peroxidation, ascorbic acid, dehydroascorbic acid and total ascorbate in leaves of canola were studied. The plants were grown in pots until they grow to 4 leaf stages. Therefore the leaves were sprayed with salicylic acid at 4 levels (0, 0.5, 1 and 1.5 mM) lasted for 2 days. Plants were treated with 4 level of ethylene (0, 50, 100 and 150 ppm) for 3 days. Triton X-100 was used as surfactant. At the end of ethylene treatment parameters were measured. Study showed that in those plants which were treated with ethylene and salicylic acid (lower than 1mM), anthocyanin were decreased. Combination treatment of salicylic acid and ethylene caused significant increase in flavonoids, ascorbic acid, dehydroascorbic acid and total ascorbate. Lipid peroxidation in plants that were treated with either salicylic acid or ethylene was increased significantly but combination treatment with salicylic acid and ethylene caused decreased in lipid peroxidation. Our results showed that salicylic acid at 1mM concentration or lower can be used as a antistress agent to reduce oxidative stress caused by ethylene but salicylic acid at 1.5 mM salicylic acid will enhance stress. Therefore we concluded that application of salicylic acid at lower than 1mM can protect plants against oxidative stress.

Jasmonates (Jasmonic acid and its methyl ester, methyl jasmonate) are a new group of plant growth regulator that involve in many morphology andphysiological processes and have role of defense in plants. In this research the effects of methyl jasmonate and ethylene on seed germination and the effect of methyl jasmonate on lipid peroxidation and content of chlorophyll, carotenoids and protein were investigated in canola seedling. Seeds of Brasssica napus L. were sown in plastic pots containing sand, clay and peat in proportion of 1:1:2. After 13 days, seedlings were sprayed with methyl jasmonate (100 µM) for 3 days then treated with ethylene (50, 70 ppm) for 40 hours. Control plants were sprayed with distilled water only. Data were analyzed using SPSS and Mstatc and averages were compared by LSD test. The results indicated that methyl jasmonate inhibited seed germination but ethylene induced seed germination. Our results also showed that ethylene neutralized effects of methyl jasmonate on inhibition of seed germination and methyl jasmonate mitigated ethylene-induced lipid peroxidation, revealing that less oxidative damage occurred in this group. Chlorophyll and protein content were significantly decreased under ethylene treatment but methyl jasmonate reverse these effects.Results suggested that methyl jasmonate inhibited seed germination but it improved seedling growth under ethylene treatment.

Salicylic acid (SA) or orthohydroxybenzoic acid and other compounds which are belong to this group are plant phenolics that play a major role in regulation of many physiological processes e.g. growth, development, ion absorption and germination. In this study, the effects of salicylic acid (0.1, 1, 1.5, 2, 2.5 and 5mM) on seed germination of Brassica napus were investigated. 20 seeds were transferred on whattman paper inside of each Petri dish. All Petri dishes were incubated to germinator. The condition of germinator was: 16h day light and 8h dark period with 230C and 160C respectively and the humidity condition inside germinator was 58%. Germination percentage and the rate of germination were measured up to 5 days. Triton X-100 was used as surfactant for either control or treated plants. For drought treatment, solutions of polyethylene glycol 6000 were prepared with water potential 0, -0.4, -0.6, -0.9and -1.1 Mpa. 6 levels of ethylene treatment were applied (0, 10, 30, 50, 70, 90 ppm). For interaction effects of salicylic acid on drought stress, 4 levels of salicylic acid (0, 1, 1.5, 2 mM) and 3 levels water potential of (0, -0.4, -0.6 Mpa) were investigated. The seeds were treated for 2 days in salicylic acid and therefore 3 days in polyethylene glycol 6000. For observation of interaction effects of ethylene on salicylic acid and ethylene on drought stress, 4 levels of salicylic acid treatment (0, 0.5, 1, 1.5 mM), 3 levels of ethylene in (0, 10, 50 ppm) and 3 levels of water potential (0, -0.4, 1.1 Mpa) were applied. Results showed that the percentage of seed germination was reduced significantly in treated seeds with salicylate when compared with control. However, osmotic stress did not effect on germination percentage but seed germination rate reduced significantly. Interaction effect of salicylic acid and ethylene on seed germination was significant as well as drought stress. Mean of the required for day germination isnt sometimes applied for calculation of germination rate. Therefore, we suggest that the sum of instantaneous velocity used germination rate calculation. Priming with salicylic acid is advisable to be done in low temperature. Treatment with ethylene reduced negative effects of salicylic acid and drought stress on seeds germination, thus we suggest ethylene can be used for better germination.