فصلنامه فرآیند و کارکرد گیاهی
سال ششم شماره 2 (پیاپی 20، تابستان 1396)

Lemon balm (Melissa officinalis L.), a member of Lamiaceae family, is an important medicinal plant that has many useful properties. Micronutrients are necessary in low dose for the growth and the development of plants. Present research was conducted to study the effects of micronutrients including manganese (Mn) and copper (Cu) on morpho-physiological traits and essential oil of lemon balm. Field trials were established in 2015 at Shahrekord (50°56/ E 32°18/ N) South Western Iran. Experiment was arranged in a randomized complete block design with a factorial layout and three replications. Micronutrients concentrations (Cu and Mn in 0, 150 and 300 ppm) were employed since of planting to beginning of flowering of plants. Of the two micro nutrients, copper was more effective in stimulating the accumulation of Caryophyllene β, Citronellal, Geranial, Geraniol, Geranyl Acetate, Linalool and Neral. At 150 ppm, micro nutrients enhanced the production of citronellal, Chavicol. Although combination of Cu2橷 Mn2 at 300 ppm in some of essential oils like neral, e-caryophyllene, caryophyllene oxide and 14-hydroxy-Z-caryophyllene were more produced than 150 ppm combinations but most of essential oils significantly increased in 150 ppm concentration of micronutrients. Trans-piperitone epoxide was upper extracted in 300 ppm concentration of Mn2 but in many combination this essential oil was no extracted in little concentration. Geranial, Geraniol, (E-) Caryophyllene, Caryophyllene oxide and Neral were the main components in all treatments.

==The effects of selenium (Se) on the growth and antioxidant activity in Spirulina platensis were investigated. S. platensis was grown in zarrouk medium containing three different concentrations of selenate (Na2SeO4) (0 as a control, 5 and 10 mg l-1) for 7 days. Selenate at the concentration of 5 mg l-1was found to improve S. platensis growth. However, selenate was toxic to S. platensis at the concentration of 10 mg l-1. Selenium increased the activity of enzymatic (peroxidase and catalase) and non-enzymatic (carotenoids) antioxidants when Se was applied to the microalgae at low concentration (5 mgl-1). Phenolic compounds were significantly increased in Se-treated samples. The contents of chlorophyll a and carotenoids in Se-treated S. platensis did not significantly change as compared to control. The FTIR analysis clearly indicated that the spectra of cells grown on different Se concentrations did not significantly change as compared to control. In addition, the variety of different compounds such as aromatic, phosphine, alcohols and carboxylic acids were synthesized in all examined treatments. The present results suggest that Se at low concentration has suitable effects on the physiology of S. platensis.

Induction of hairy roots in Perovskia abrotanoides Karel, a medicinally important member of the Lamiaceae family, was evaluated using different strains of Agrobacterium rhizogenes and various carbon sources. An efficient Agrobacteriummediated transformation system was established for the first time for this plant species using the bacterial strains of ATCC15834, TR105, and R1000. Meanwhile, the effects of acetosyringone and carbon sources on both rooting and root biomass production were investigated and the potential of hairy root cultures for producing tanshinones was explored. Hairy root induction in the nodes of intact seedlings was found to be successful with all the bacterial strains tested but R1000 was found to be more effective than TR105. The highest transformation frequency belonged to the nodes infected with ATCC15834 (47.33%). Moreover, transformation frequency increased by up to 60.99% when 100 µM of acetosyringone was added. The strain ATCC15834 recorded the highest root dry and fresh weights per 50 mL of the nutrient medium (0.149 and 1.996 g, respectively) and root length (34.45 cm) in a medium containing 3% sucrose. However, R1000 induced maximum lateral root density in hairy roots (7.1 branches cm-1) in a medium containing 3% glucose. PCR analysis using rolC specific primer with an amplicon of 612 bp confirmed the transgenic nature of the hairy roots. Finally, HPLC analysis revealed that the cryptotanshinone and tanshinone IIA levels in the hairy roots induced by TR105 (clone T7) were 53.17±0.26 and 14.48±0.30 µg g-1 DW, respectively.

Micronutriens deficiency is prevalent in case of drought stress conditions, so complementary boron and zinc nutrition are important for crops to overcome drought stress. This study evaluated the effect of zinc and boron foliar application on physiological traits of sesame under different irrigation levels. The experiment was conducted as a split plot in a randomized complete block design with three replications at Fars Research Center for Agriculture and Natural Resources in 2013. The main factor included three irrigation levels (irrigation after 75, 110 and 145 mm evaporation from class A evaporation pan) and sub-factor included foliar spraying water, zinc sulphate, boric acid and application of the mixture of zinc sulphate with boric acid. Results showed that proline content of leaf significantly increased by foliar application of boric acid in 75 mm evaporation treatment and by boric acid and mixture of zinc sulphate and boric acid in 110 and 145 mm evaporation treatments. Maximum Glycinebetaine was acquired by foliar zinc sulphate application in all three irrigation levels. Foliar application of zinc sulphate and boric acid helped to obtain the highest leaf relative water content compared to control. Maximum seed zinc content in 75 mm evaporation treatment was obtained from zinc sulphate and the mixture of zinc sulphate with boric acid application. Generally, results showed that foliar application of zinc sulphate and boric acid improved physiological traits of sesame, especially under drought stress so the plant can tolerate the impact of drought stress better.

This investigation was carried out with the aim of determining the effect of polyethylene glycol 6000 (PEG; 0, 3%, 6% and 9% w/v) treatment on six cultivars of Medicago sativa. PEG treatment significantly decreased the germination index in cultivars of Isfahani, Hamedani, Bami, Baghdadi, Yazdi and Ghare-Medicago, with the highest reduction in Ghare-Medicago and Hamedani cultivars by about 50% and 44%, respectively. PEG treatment significantly decreased germination percentage and germination rate in two cultivars of Ghare-Medicago (22% and 20%, respectively) and Hamedani (28% and 27%, respectively) while increased mean germination time in them. The seedlings height, fresh weight and water content significantly decreased in all PEG-treated cultivars. The highest reduction in mentioned factors was observed in Ghare-Medicago (43%, 24% and 55%, respectively) and Hamedani (57%, 23% and 53%, respectively), while the lowest reduction was observed in Yazdi, by about 28%, 9% and 17%, respectively. Data showed that PEG treatment reduced seedling dry mass only in Ghare-Medicago and Hamedani cultivars by about 16% in both cultivars. PEG treatment significantly decreased the chlorophyll a, b and total, anthocyanins, phenols and α-tocopherol contents of six Medicago cultivars. The results of greenhouse experiments showed that PEG treatments resulted in a significant reduction in fresh weigh, dry weight and water content of all studied cultivars. In conclusion, the findings of both petri dish and greenhouse experiments suggested that Ghare-Medicago and Hamedani cultivars can be considered as drought sensitive cultivars while Yazdi is a drought tolerant cultivar. It should be noticed that Bami and Baghdadi cultivars were also relatively drought tolerant. Also, our study on paclobutrazol (PBZ) treatment showed that PBZ effectively decreased the negative effect of drought stress on growth of all cultivars of Medicago.

The objective of the study was to investigate the effect of exogenous nitric oxide on cellular response and production of secondary metabolites in Catharanthus roseus callus. The Cell suspension and callus of C. roseus were treated with sodium nitroprusside, then cell viability, morphology, the amount of H2O2, proline, lipid peroxidation, the activity of superoxide dismutase, catalase and peroxidase were evaluated. Also production of total antioxidant, alkaloid, flavonoid and phenolic compounds were estimated. A Significant (p

Effects of accelerated aging and seed priming treatments were studied on milk thistle seeds during germination process. Experiment was performed in a factorial based on Complete Randomized Design (CRD). Treatments were Salicylic acid concentrations (0, 500, 1000, 1500 and 2000 ppm) and accelerated aging for (0, 48, 96 and 144 hours under 45 °C and 95% humidity) with three replications. Our results showed thatsalicylic acid dramatically enhanced seed germination, seed vigor and primary seedling growth. Catalase, polyphenol oxidase and peroxidase activity was increased by seed priming. Reduction in germination parameters were observed by increase in accelerated aging durations The highest antioxidant activity, germination percentage and daily germination rate and seed vigour were observed at primed seeds with 1000 ppm Salycilic acid on non-aged seeds. Treatment salicylic acid at a concentration of 1000 ppm has the greatest impact and cause harmful effects healing was aging.

Selenium (Se) at high concentrations can cause toxic effects in plants, whereas at low concentrations it enhances resistance to certain abiotic stresses. The possible mechanisms of the Se-enhanced tolerance of plants to salinity stress remain elusive. In this work, effect of Se supplementation at 0, 0.1, 1 and 10 mg l-1 sodium selenate was studied in Lallemantia iberica plants subjected to salt stress. In pre-experiment design, The toxicity threshold for selenate was determined at the concentration of 10 mg l-1, as the biomass of L. iberica plants decreased if selenate concentrations in the growth medium reached 10 mg l-1. Thereafter, we used 0.1 mg l-1 Se to mitigate salt stress in L. iberica plants. Se at low concentration (0.1 mg l-1) mitigated salt-induced oxidative stress because of the NaCl-induced lipid peroxidation was smallest in the plants treated with Se, and was highest in the plants grown without Se addition. This occurred as a result of glutathione (GSH) accumulation in Se-supplied plants. Additionally, Se-supplied plants exhibited higher glutathione peroxidase (GSH-Px) activity than –Se ones after 2 days salt stress. These data provided the first evidence that the low-level Se pretreatment alleviated salt stress in L. iberica by increasing GSH levels and by decreasing ROS production; and therefore less reduction of biomass production during salt stress.