IRANIAN JOURNAL OF PLANT PHYSIOLOGY
Year:2018 | Volume:8 | Issue:3 |Papers Count:8

A pot experiment was conducted based on a factorial study and complete random block design with threereplicates to investigate the phytoremediation potential of Sorghum biocilor L. in soils polluted with nickeland manganese during 2017-2018. The first factor was nickel nitrate (0, 60, and 120 mg kg-1 soil) and thesecond factor comprised of manganese sulphate (0, 50, and 100 μ M). The characteristics under investigationwere 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. Findingssuggested that under nickel and manganese stress, shoot height, root length, shoot dry weight, and root dryweight reduced. Also, with an increase in the soil nickel and manganese, so did the concentration of theseheavy metals in roots and shoots of the plants under study. Maximum effect of nickel and manganese wererecorded in the treatments comprising 120 mg Kg-1 Nickel and 100 μ M manganese sulphate, respectivelywhile compared with nickel, manganese caused less damage to the plants under study. Application of nickelto the soil increased the translocation factor while there was no difference between the two levels of nickelapplied. On the other hand, application of manganese did not affect the translocation factor compared tothe control and the translocation factors for both elements were less than 1. Therefore, based on the findingsof the study, sorghum showed a relatively good tolerance to nickel and manganese, the absorbed nickel andmanganese were mostly concentrated in the plant root, and Sorghum biocilor L. is not recommended forphytoremediation.

This work evaluated the effect of drought stress on seedling growth, protein, soluble sugars, and phenoliccompounds of two cultivars of canola (RGS003 and Sarigol). Drought stress was induced with polyethyleneglycol (PEG) at 0, 5, 10, and 15%. Drought stress increased root fresh weight in both cultivars and the effectof 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 amountsof protein as compared to RGS003. At all PEG concentrations, the soluble sugars content was higher in Sarigolas compared to control. Total phenol content was enhanced at higher drought level (15%) while flavonolcontent increased at lower level (5%) in both cultivars. Phenylalanine ammonia-lyase (PAL) activity and itsrelative expression were increased in RGS003 at 10% of PEG. Overall, RGS003 cultivar had more capacity totolerate drought stress than Sarigol cultivar.

This study was conducted to determine the effects of Artemisia sieberi extract (0. 2%, 0. 4%, and control) ongermination, some morphological characteristics, photosynthesis pigments, and nutrients uptake ofPeganum harmala. Results showed that the extract of A. sieberi had a significant effect on seed germinationand 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 lowestradicle lengths were calculated in the control and 0. 4% treatments, respectively. With increasingconcentration of the extract, dry weight and pedicel length of P. harmala decreased. A. sieberi extract hadphytotoxic effect on chlorophyll contents of P. harmala. The highest photosynthesis pigments were relatedto 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 nitrogenand zinc were related to 0. 4% treatment. The highest amount of phosphorus was related to the controltreatment and with increasing concentration of extract, phosphorous content decreased. 0. 2% treatmentexhibited the highest potassium content while the lowest amount of potassium was related to the 0. 4%treatment. In general, results showed that A. sieberi besser, increased nutrients uptake of P. harmala, in 0. 2%treatment, but increased concentrations of the extract prevented germination and growth of P. harmala. Itis recommended not to cultivate the two plants together if we consider P. harmala as a medicinal plant.

Specific plants can remove heavy metals from the soil and contribute to pollution remediation in croppingsystems. Determining the level of highest heavy metals that a super-accumulator crop can withstand withoutreducing its yield is important for management. The objective of this study was to investigate the heavymetal-removing capacity of purslane by studying different stress criteria and by tracking its nickel andcadmium removal from germination to harvest. Therefore, pot experiments in outdoor condition wereperformed 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 significanteffects on the morphological and physiological characteristics of purslane and increased heavy metalsconcentration decreased significantly these characteristics. Comparisons of mean shoot and root dry weightand extraction percentage showed that the highest level belonged to the control plants while the lowest levelwas observed in the plants under combined treatment of nickel (120 mg/kg) and cadmium (40 mg/kg) andthe single treatment of cadmium (40 mg/kg). Perhaps heavy metals by their effect on dry and fresh mattermade negative influence on extraction. Furthermore, the toxic properties of cadmium were more than nickeland decreased most of the measured characteristics.

This research involved in and coordinated multidisciplinary and complementary natural resources in thearea of sustainable soil and plant nutrient management as well as economic benefits of edible herbproduction systems. The main concern was selection of the right growing media to achieve optimum yieldand growth rate while avoiding application of synthetic fertilizers. Froriepia subpinnata is a medicinal andedible endemic vegetable which grows naturally in the north of Iran. In order to evaluate the effect ofcompost tea, vermicompost, and mycorrhizal symbiosis on morphophysiological traits of Froriepiasubpinnata, a factorial experiment was conducted in Sari, Mazandaran based on randomized completeblock design with four replications. The factors included Glomus moseae at two levels (inoculated and noninoculated), vermicompost at two levels (without application and application at 2 tons/ ha), and composttea at two levels (no application and application at 1. 5 liter/ ha). Results showed that the impact of dualinteractions of vermicompost and mycorrhizal symbiosis were significant on the length and diameter offlowering stems, flower diameter, leaf width, and plant fresh weight at p< 0. 01. The triple interactions ofthe factors on leaf area, plant dry weight, and essential oil yield were significant at p< 0/01. The highestplant dry weight (0. 81 g/plant) and the highest essential oil content % 0. 82 were observed with applicationof vermicompost and mycorrhizal symbiosis.

In order to study the effects of salinity stress on growth indices of three clover species including, Trifoliumresupinatum, T. alexandrinum, and T. incarnatum, an experiment was conducted as factorial based on acompletely randomized design arrangement with three replications. Factors included seven levels of salinitystress (0, 41, 82, 123, 164, 205, and 246 mM) and three clover species. Different performance was observedfor germination and seedling parameters among the species. In addition, results indicated significantdifferences among the treatments in all traits and showed that the effects of salinity on all traits were thesame at low-stress levels (0 and 41 mM), but differed at higher stress levels. The experimental resultsrevealed that with an increase in salinity level, the greater reduction was observed in vigor index, seedlinglength, and root and shoot fresh and dry weight while MGT and GU increased. The highest levels of vigorindex 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 ofthe chloroplast genome is widely used to infer phylogenetic relationships in plants. In this study, we obtainedthe trnL-F sequences from 8 samples of Arum L. in Iran. Phylogenetic analyses were conducted by theBayesian inference, maximum parsimony, and maximum likelihood methods. The cladistics analysis ofphylogenetic 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 monophyleticclade. A. conophalloides Schott. and A. virescense Stapf. were placed in one clade. A. kotschyi Boiss. and A. korolkowii L. formed a sister group. Arum giganteum Ghahreman. has been introduced as a new species inIran, but in Arum monograph it is mentioned as potential equivalent to Arum rupicola Boiss. Molecularstudies 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 pharmacologicaleffects of V. officinalis. To evaluate the effect of methyl jasmonate (MeJA) concentrations (50 and 100 μ M)in the modulation of expression patterns of the genes involved in valerenic acid (VA) biosynthesis, transcriptabundance of the identified sesquiterpene synthase (Sesqui-TPS) genes in the root of V. officinalis wasmonitored by quantitative real time PCR (qRT-PCR) within a 144 h time period. In addition, valerenic acidcontents were measured by high-performance liquid chromatography (HPLC). The highest amount of VA(12. 45 mg/g dry weight (DW)) was found at 100 μ M MeJA with a 12 fold increase over control culture (1. 03mg/g DW) at exposure time of 72 h. Moreover, MeJA in a concentration dependent manner, enhancedtranscription rate of VoTPS1 and VoTPS7 genes. Accordingly, exposure to 100 μ M MeJA for 24 h can be moreeffective on induction of these genes than observed for 50 μ M. Such enhancement correlated with increasedVA accumulation suggesting that these genes may be responsible for the biosynthesis of intermediatesinvolved in the VA-biosynthetic pathway. However, MeJA treatment seemed to have a less significant effecton VoTPS3 expression than VoTPS1 and VoTPS7 genes. These results provide insights for more effectivebiosynthesis of VA by MeJA-mediated transcriptional changes of putative sesqui-TPS.