Iranian Journal of Plant Physiology
Volume:8 Issue: 3, Spring 2018

This work evaluated the effect of drought stress on seedling growth, protein, soluble sugars, and phenolic compounds of two cultivars of canola (RGS003 and Sarigol). Drought stress was induced with polyethylene glycol (PEG) at 0, 5, 10, and 15%. Drought stress increased root fresh weight in both cultivars and the effect of drought was more pronounced in RGS003. Shoot fresh weight reduced in Sarigol at 10 and 15% of PEG. Drought stress significantly increased seedling fresh weight in RGS003. Sarigol accumulated higher amounts of protein as compared to RGS003. At all PEG concentrations, the soluble sugars contentwas higher in Sarigol as compared to control. Total phenol content was enhanced at higher drought level (15%) while flavonol content increased at lower level (5%) in both cultivars. Phenylalanine ammonia-lyase (PAL) activity and its relative expression were increasedin RGS003 at 10% of PEG. Overall, RGS003 cultivar had more capacity to tolerate drought stress than Sarigol cultivar.

A pot experiment was conducted based on a factorial study and complete random block design with three replicates to investigate the phytoremediation potential of Sorghum biocilor L. in soils polluted with nickel and manganese during 2017-2018. The first factor was nickel nitrate (0, 60, and 120 mg kg-1 soil) and the second factor comprised of manganese sulphate (0, 50, and 100 µM). The characteristics under investigation were shoot height, root length, shoot dry weight, root dry weight, nickel concentration of shoots and roots, manganese concentration of shoots and roots, and nickel and manganese translocation factors. Findings suggested that under nickel and manganese stress, shoot height, root length, shoot dry weight, and root dry weight reduced. Also, with an increase in the soil nickel and manganese, so did the concentration of these heavy metals in roots and shoots of the plants under study. Maximum effect of nickel and manganese were recorded in the treatments comprising 120 mg Kg-1 Nickel and 100 µM manganese sulphate, respectively while compared with nickel, manganese caused less damage to the plants under study. Application of nickel to the soil increased the translocation factor while there was no difference between the two levels of nickel applied. On the other hand, application of manganese did not affect the translocation factor compared to the control and the translocation factors for both elements were less than 1. Therefore, based on the findings of the study, sorghum showed a relatively good tolerance to nickel and manganese, the absorbed nickel and manganese were mostly concentrated in the plant root, and Sorghum biocilor L. is not recommended for phytoremediation.

This study was conducted to determine the effects of Artemisia sieberi extract (0.2%, 0.4%, and control) on germination, some morphological characteristics, photosynthesis pigments, and nutrients uptake of Peganum harmala. Results showed that the extract of A. sieberi had a significant effect on seed germination and morphological characteristics of P. harmala. The highest seed germination was calculated in 0.2% treatment. The lowest seed germination was observed in the control treatment.The highest and lowest radicle lengths were calculated in the control and 0.4% treatments, respectively. With increasing concentration of the extract, dry weight and pedicel length of P. harmaladecreased. A. sieberiextract had phytotoxic effect on chlorophyll contents of P. harmala. The highest photosynthesis pigments were related to the control treatment, and by increasing the concentration of extract, photosynthesis pigments decreased. The highest contents of nitrogen and zinc were found in 0.2% treatment. The lowest amounts of nitrogen and zinc were related to 0.4% treatment. The highest amount of phosphorus was related to the control treatment and with increasing concentration of extract, phosphorous content decreased.0.2% treatment exhibited the highest potassium content while the lowest amount of potassium was related to the 0.4% treatment. In general, results showed that A. sieberibesser, increased nutrients uptake of P. harmala, in 0.2% treatment, but increased concentrations of the extract prevented germination and growth of P. harmala. It is recommended not to cultivate the two plants together if we considerP. harmala as a medicinal plant.

Specific plants can remove heavy metals from the soil and contribute to pollution remediation in cropping systems. Determining the level of highest heavy metals that a super-accumulator crop can withstand without reducing its yield is important for management. The objective of this study was to investigate the heavy metal-removing capacity of purslane by studying different stress criteria and by tracking its nickel and cadmium removal from germination to harvest. Therefore, pot experiments in outdoor condition were performed by heavy metal levels including nickel (0, 30, 60, 120 mg/kg) and cadmium (0, 10, 20, 40 mg/kg) in two seasons. The results of this research showed that different levels of nickel and cadmium had significant effects on the morphological and physiological characteristics of purslane and increased heavy metals concentration decreased significantly these characteristics. Comparisons of mean shoot and root dry weight and extraction percentage showed that the highest level belonged to the control plants while the lowest level was observed in the plants under combined treatment of nickel (120 mg/kg) and cadmium (40 mg/kg) and the single treatment of cadmium (40 mg/kg). Perhaps heavy metals by their effect on dry and fresh matter made negative influence on extraction. Furthermore, the toxic properties of cadmium were more than nickel and decreased most of the measured characteristics.

This research involved in and coordinated multidisciplinary and complementary natural resources in the area of sustainable soil and plant nutrient management as well as economic benefits of edible herb production systems. The main concern was selection of the right growing media to achieve optimum yield and growth rate while avoiding application of synthetic fertilizers.Froriepia subpinnata is a medicinal and edible endemic vegetable which grows naturally in the north of Iran. In order to evaluate the effect of compost tea, vermicompost, and mycorrhizal symbiosis on morphophysiological traits of Froriepia subpinnata, a factorial experiment was conducted in Sari, Mazandaran based on randomized complete block design with four replications. The factors included Glomus moseae at two levels (inoculated and non-inoculated), vermicompost at two levels (without application and application at 2 tons/ ha), and compost tea at two levels (no application and application at 1.5 liter/ ha). Results showed that the impact of dual interactions of vermicompost and mycorrhizal symbiosis were significant on the length and diameter of flowering stems, flower diameter, leaf width, and plant fresh weight at p

In order to study the effects of salinity stress on growth indices of three clover species including, Trifolium resupinatum, T. alexandrinum, and T. incarnatum, an experiment was conducted as factorial based on a completely randomized design arrangement with three replications. Factors included seven levels of salinity stress (0, 41, 82, 123, 164, 205, and 246 mM) and three clover species. Different performance was observed for germination and seedling parameters among the species. In addition, results indicated significant differences among the treatments in all traits and showed that the effects of salinity on all traits were the same at low-stress levels (0 and 41 mM), but differed at higher stress levels. The experimental results revealed that with an increase in salinity level, the greater reduction was observed in vigor index, seedling length, and root and shoot fresh and dry weight while MGT and GU increased. The highest levels of vigor index and root and shoot fresh and dry weight was related to T. resupinatum and T. incarnatum, respectively, while MGT and GU in T. resupinatum were higher than those of the other two species. In addition, T. resupinatum seedling length was higher than the other two species.

TrnL-F region including intron trnL (UAA) and trnL (UAA) - trn (GAA) spacer in the large single-copy region of the chloroplast genome is widely used to infer phylogenetic relationships in plants. In this study, we obtained the trnL-F sequences from 8 samples of Arum L. in Iran. Phylogenetic analyses were conducted by the Bayesian inference, maximum parsimony, and maximum likelihood methods. The cladistics analysis of phylogenetic relationships indicated that all species constituted a monophyletic group within the Arae clade. Eminium spiculatum were considered as outgroups. Biarum and Arum species were placed in a monophyletic clade. A. conophalloides Schott. and A. virescense Stapf. were placed in one clade. A. kotschyi Boiss.and A. korolkowii L. formed a sister group. Arum giganteumGhahreman. has been introduced as a new species in Iran, but in Arum monograph it is mentioned as potential equivalent to Arum rupicola Boiss. Molecular studies in this research can separate these two species and confirm previous studies.

Valeriana officinalis (valerian), as a nutraceutical herb, is widely used for its sedative and hypnotic properties. It is known that C15 sesquiterpenoid valerenic acid (VA) is active ingredient responsible for pharmacological effects of V. officinalis. To evaluate the effect of methyl jasmonate (MeJA) concentrations (50 and 100 µM) in the modulation of expression patterns of the genes involved in valerenic acid (VA) biosynthesis, transcript abundance of the identified sesquiterpene synthase (Sesqui-TPS) genes in the root of V. officinalis was monitored by quantitative real time PCR (qRT-PCR) within a 144 h time period. In addition, valerenic acid contents were measured by high-performance liquid chromatography (HPLC). The highest amount of VA (12.45 mg/g dry weight (DW)) was found at 100 µM MeJA with a 12-fold increase over control culture (1.03 mg/g DW) at exposure time of 72 h. Moreover, MeJA in a concentration dependent manner, enhanced transcription rate of VoTPS1 and VoTPS7 genes. Accordingly, exposure to 100 µM MeJA for 24 h can be more effective on induction of these genes than observed for 50 µM. Such enhancement correlated with increased VA accumulation suggesting that these genes may be responsible for the biosynthesis of intermediates involved in the VA-biosynthetic pathway. However, MeJA treatment seemed to have a less significant effect on VoTPS3 expression than VoTPS1 and VoTPS7 genes. These results provide insights for more effective biosynthesis of VA by MeJA-mediated transcriptional changes of putative sesqui-TPS.