فصلنامه فرآیند و کارکرد گیاهی
سال یازدهم شماره 3 (پیاپی 49، Aug and Sep 2022)

Oleuropein, Hydroxytyrosol and Tyrosol are three major phenolic compounds present in olive with remarkable pharmacological effects. In this study, leaves and fruit of four olive cultivars including ‘Fishomi’, ‘Mary’, ‘Roghani’ and ‘Zard’ grown in the north of Iran were collected for comparative evaluation of the concentration of Oleuropein, Hydroxytyrosol and Tyrosol as well as antioxidant properties. According to the results, the highest and lowest levels of Tyrosol were detected in ‘Mary’ and ‘Zard’ leaves, respectively. There were significant differences between levels of Hydroxytyrosol in ‘Mary’ leaves compared with other examined cultivars. ‘Mary’ fruit had the highest level of Oleuropein, Hydroxytyrosol and Tyrosol, while ‘Fishomi’ fruit had the lowest level of these compounds. The total phenol content of leaf extracts was significantly higher than those detected in fruit extracts. In the leaves and fruits of the examined cultivars, the highest and the lowest Phenylalanine ammonia-lyase (PAL) activity was found in ‘Mary’ and ‘Fishomi’ cultivars, respectively. PAL activity in the leaves of all examined cultivars was significantly higher than their fruits. Meanwhile, the results showed that the antioxidant activities of the leaves in all cultivars were higher than the fruits. These results suggest that olive leaves, as well as fruits, might also be used as rich sources of natural antioxidants.

Secondary metabolites with low molecular weight and high economic, pharmaceutical and industrial values play an important role in protecting plants against biotic and abiotic stresses. Astragalus is a medicinal herb, rich in secondary metabolites. Selenium (Se) is an essential element for humans, animals, many bacteria, and a beneficial element for plants. The plants response to selenium is depending on their species and the Se supply concentration. In the present study, calli were established from the seeds of Astragalus verus and suspension cultures were established from the calli. The cells were treated with different concentrations of sodium selenate (0, 0.5, 2.5, 12.5, and 62.5 μM) for 1 week at their logarithmic growth phase (based on growth curve). Cell growth and viability significantly decreased by selenium at concentrations higher 2.5 μM. In comparison with control group, significant increases in Abscisic acid and Salicylic acid were observed at higher Se concentrations, whereas methyl jasmonate significantly increased at lower Se supply. At 62.5 μM Se supply the contents of alkaloids, phlobaphene, steroidal and triterpenoid saponins, and tannin respectively increased by 5.1, 1.51, 1.62, 1.75, and 2.04 times of control. The results provides a practical method for remarkable stimulation of natural compounds of Astargalus by Se.

Mexican lime is one of the commercial citrus cultivars in the world, which is commonly used as a citrus rootstock in the southern regions of Iran. This cultivar is one of the most sensitive citrus cultivars to cold stress and is used as a cold-sensitive plant in many citrus studies. This study aimed to investigate the effect of melatonin (0 and 500 μM), mannitol (0 and 50 μM), acetic acid (0 and 15 μM) and their combination on photosynthetic apparatus of Mexican lime seedlings under cold stress (0 and -6 °C). According to the results, the combined application of melatonin, mannitol, and acetic acid, by improving the photosynthetic parameters, reduced the destructive effects of cold stress (0 and -6 ºC) on photosynthetic machinery in Mexican lime seedlings. This treatment led to the highest performance index (PItotal) at both stress levels. The most suitable chlorophyll fluorescence parameters for identifying the best reducing treatment against cold stress were indicator of the activity of the oxygen evolving complex on the donor side of PSII (Fv/F0), variable fluorescence (Fv), maximum quantum yield of PSII photochemistry (Fv/Fm), thermal dissipation quantum yield (F0/Fm), and maximal fluorescence (Fm), respectively. The results of this experiment showed that the exogenous use of natural compounds (melatonin, mannitol) and a cost-effective agent (acetic acid) can protect Mexican lime photosynthetic apparatus under cold stress. Generally, the interactions of melatonin, mannitol, and acetic acid at both 0 and -6 °C provided the best results.

Excessive consumption of nitrogen (N) to enhance production, which may lead to environmental pollution. While sustainable production is threatened due to low soil fertility and organic matter. This study was carried out as a factorial experiment in the randomized complete block design and three replications at the research field of the University of Jiroft in 2018-2019. The present study investigates the effects of sources of N fertilizers and cow manure on safflower products in the arid climates of Iran. Two levels of cow manure (0 and 30 t ha-1), and six levels of sources of N fertilizer (control, 130 Kg ha-1 N from the sources of urea with a sulfur coating, ammonium nitrate, nano-N, urea, and 1L nitroxin per Kg grain) were used according to the results of soil analysis. Interaction of cow manure and different sources of N fertilizer increased 32-47 % SPAD index at the late vegetative and 37-50 % at the early reproductive stage, 58-81% oil percent and oil yield, 28-81% protein yield, 42-57 % plant height, 52-72 % lateral branches number and 49-78 % grain yield compared to the control. Among the sources of nitrogen fertilizers, nitroxin, nano N, urea with a sulfur coating, ammonium nitrate, and urea had a more positive effect on evaluated characteristics, respectively. There was a significant positive correlation (P≤0.01) between yield components. The best result in this study, earned by simultaneous use of cow manure to the soil and inoculating the grains to nitroxin before being planted. Therefore, the simultaneous use of organic and biological fertilizers, in addition to reducing environmental pollution due to the non-use of chemical fertilizers and reducing production costs, can produce healthy products and byproducts of safflower in arid climates.

Guava (Psidium guajava L.), is adapted to an extensive range of soils, however, its development is strongly affected by salinity. Environmental stresses are of the major and influential factors in the amount of secondary metabolites, especially phenolic compounds present in plants. The purpose of this investigation was to study the leaf antioxidant and flavonoid contents (catechin, quercetin and rutin) of guava seedlings grown under normal growth conditions or exposed to 100 mM salinity through irrigation water. Leaf samples collected 12 weeks after salinity stress treatment and total phenol, antioxidant capacity, malondialdehyde, catalase, peroxidase and protease activities and high performance liquid chromatography were examined.  According to the results, salinity enhanced the amount of total phenol from 15.31 mgg-1 GA (control) to 32.12 mgg-1 GA. The MDA value improved in guava leaves from 0.42 mg g-1FW under non-stress conditions to 0.76 mgg1 FW under salinity. The most catalase (182.11 μmol min-1g-1FW), protease (9.70 μmol min-1g-1 FW) and peroxidase (19.99 μmol min-1g-1 FW) activities were observed in salt exposed plants. The antioxidant capacity of leaf extract was 62.90% in control plants, which enhanced to 77.46% after salt treatment. The most abundant flavonoid composition of leaf extract was rutin (770 μg mg-1DW) in the control treatment and catechin (1110 μg mg-1DW) in salt exposed plants. We concluded salinity stress, in addition to a noticeable increase in the activities of catalase, peroxidase and protease enzymes; enhanced phenol, catechin and quercetin contents.

Zataria multiflora is one of the valuable medicinal plants belonging to the Lamiaceae family. The aromatic aerial parts of this species are traditionally used by endemic folks to flavor some native foods, also for numerous therapeutic functions. In the present study, different plant organs (leaf, flower, stalk and whole aerial organ) were collected from Fanuj region of Sistan & Balouchestan province, in the southeast of Iran, and the variability in the essential oil contents and compositions of them were studied. The essential oils of air-dried samples were extracted by hydro-distillation. The experiment was arranged in a completely randomized design with three replications for the essential oil contents. The essential oil yields were calculated based on dry weight and the oils were analyzed by a combination of GC-FID and GC-MS techniques, to check for chemical variability. The essential oil yields of leaf, flower, stalk and aerial part were 4.8, 5.3, 0.6 and 2.7 % (w/w), respectively. The total number of compounds identified and quantified were 17 in leaf, 17 in flower, 19 in stalk, and 19 in whole aerial organ, representing 99.0, 99.2, 97.3, and 96.2% of the total essential oil, respectively. Results of essential oil compound analysis demonstrated that thymol (31.0 – 67.1 %), carvacrol (8.4 – 36.7 %) and p- cymene (6.5 – 23.2 %) were the main compounds in the evaluated plant organs of Z. multiflora. Chemical diversity of the essential oil of Z. multiflora plant parts can be considered by medicinal plants breeders and pharmaceutical, food and cosmetic industries for breeding and processing uses.

In order to investigate the role of potassium and zinc fertilizers in increasing yield and reducing water consumption of wheat (Triticum aestivum L.), a field experiment was conducted in the form of a randomized complete block design with five treatments and three replications in November 2017 in Kahnooj city in Kerman province. Experimental treatments in this study include; the first treatment: control (consumption of all fertilizers except potassium based on the results of soil analysis with 7 irrigations); The second treatment: the conventionl fertilizing by the local farmers (NP) with 7 irrigations; Third treatment: first treatment + application of potassium sulfate (SOP) before planting, with 7 irrigations; Fourth treatment: first treatment + application of 33% sulfate-potassium (SOP) before planting and 67% of the remaining source of soluble potassium sulfate (SSOP) as foliar application with 7 irrigations; Fifth treatment: The first treatment + application of 33% of sulfate-potassium (SOP) before planting and 67% of the remaining source of sulfate-potassium solution containing chelate (SSOP + Zn-EDTA) as foliar application and irrigation in 5 times. The results showed that A) application of potassium and zinc fertilizers had a significant effect on yield, protein content, phosphorus, potassium and zinc concentrations and also, molar ratio of phytic acid to zinc (unfavorable nutritional index) Zn) in grain as well as water and potassium use efficiency. B) While the yield and percentage of protein in the grain in the control treatment was 4648 kg/ha and 11.68%, respectively, in the second, third, fourth and fifth treatments were 4077 and 8.57, 5402 and 69, 12.12, 6137 and 13.62, increased 6022 kg/ha and 13.85%, respectively. C) Unfavorable nutritional index (molar ratio of phytic acid to zinc) - (PA/Zn) in wheat grain in the control treatment was 46, while this ratio in the second, third, fourth and fifth treatments were 74, 33, 23, respectively. D) While the water use efficiency in the control was equal to 0.62 kg/m3, the values in the second, third, fourth and fifth treatments were 0.54, 0.72, 0.82 and 1.11 kg/m3, respectively. The efficiency of potassium fertilizer in the third treatment was 2.51 kg/kg, in the fourth treatment this value improved to 4.96 and in the fifth treatment to 4.58 kg/kg. E) Despite the reduction of water consumption from 7560 cubic meters in all four treatments to 5400 cubic meters in the fifth treatment, the yield in the fifth treatment compared to the control treatment had a 31% increase in yield, which was significant at the a percent probability level. Considering the above results, it is concluded that in soils where the concentration of potassium and zinc is less than the critical limit, it is better to use potassium and zinc fertilizers in several stages.