Journal of Plant Process and Function

---

Abstract: Olive (Olea europaea L.) is an evergreen tree traditionally cultivated in the Mediterranean area, resistant to some degree to salinity and drought conditions. However, olive trees are not so resistant to low temperatures. In recent years, because of high demands for olive oil and fruit, the cultivation of olive trees has been increased in Iran. Different cultivars of olives have diverse reactions to cold stress and so, the selection of cold resistant cultivars is the most effective method to avoid frost damages. In order to compare the impact of cold stress on the content of total protein, lipid peroxidation and photosynthetic pigments, 1-years old olive cultivars of Sevillana and Frantoio, were exposed to low temperatures of 10, 5, 0, -5, -10, -15, -20 and control 20 °C for 12 h. The results indicated that the both examined cultivars were resistant to 0 °C temperature with no significant damages. The photosynthetic pigments of Frantoio did not change even in -15 °C and malondialdehyde levels slightly increased compared with the control (20 °C). Total protein content in Frantoio showed significant decrease from -10 °C, while in Sevillana cultivar there was significant decline of total protein content from -5 °C. Therefore, it can be concluded that Frantoio is more resistant to cold stress than Sevillana.

---

Ladan Bayat 1, Mehri Askari*2 Department of Biology, Faculty of Science, Arak University (Received: 29 November 2012 Accepted: 4 May 2013) Abstract: Plant growth promoting rhizobacteria are beneficial bacteria that increase growth of plants and induce resistance to various stresses. SO2 air pollution is one of these stresses that is known as a strong damaging air pollutants. Persian clover is one of legume family plants that consider as a forage crop and can form symbiosis with Rhizobium bacteria. In this study, the effects of Rhizobium (native and standard strains) on amounts of photosynthetic pigments and phosphorus and potassium elements of Persian clover under different concentrations of SO2 (0, 0.5, 1, 1.5 and 2ppm) were evaluated. The results showed that inoculation has beneficial effects on the amounts of photosynthetic pigments and phosphorus and potassium content in compared with non-inoculated plants. High concentrations of SO2 (1, 1.5 or 2ppm) caused a significant decline in the amounts of photosynthetic pigments and phosphorus and potassium elements of clover plant in compared to the control plants, however low concentration of SO2 (0.5ppm) had positive effects on measured parameters. Inoculation of Persian clover with two strains of Rhizobium decreased negative effects of high concentrations of SO2 on the amounts of photosynthetic pigments and phosphorus and potassium elements. The highest values of these parameters were measured in combination of the local strain plus 0.5ppm of SO2. It was suggested that Rhizobium could increase plant resistance and tolerance against abiotic stresses such as air pollution.

---

Effects of decreased ozone and increased UV radiation have been studied by many researchers. The aim of this study was to investigate the effects of UV-B and UV-C radiations on Melissa Officinalis L and to study the Impact of salicylic acid in reducing the harmful effects of radiation on plants. The Melissa Officinalis L plants were treated with 28_+2 ºC temperature for about 60 days. The light intensity was 150 µ E mˉ² Sˉ¹ and the lightness-darkness condition was8-16 hours. UV treatment was applied after the six-leaf stage and UV-B radiation was applied for a period of 15 days in every other day the time for each application was 20 minutes. But UV-C radiation was applied for 15 days in every other day and time of each application was 8 minutes. Salicylic acid was sprayed on the plants after the six-leaf stage with a concentration of 1 Mm. The results indicated that the UV-B and UV-C radiations led to reduction in dry and wet weight, root elongation and shoots. The radiations also reduced the photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoid) and sugar rate and total soluble proteins amount. The Malondialdehyde and phenylalanine ammonialyase compounds rate and UV- absorbing compounds were increased under the effect of UV-B and UV-C radiations. Surveying results showed that treatment with salicylic acid caused a reduced damage to the plant which had been created due to UV-B and UV-C radiations and was able compensate for changed factors that had been changed because of ultra violet radiations.

---

Cadmium as an environmental pollutant heavy metals have effect on morphological and physiological activities in plants. Selenium, an essential element had beneficial effects on enhanced tolerance in plants against environmental stresses. In the investigation, from Cadmium chloride concentrations 0, 350, 700 µM supplied with added to soil and Sodium selenat 0, 1.5, 3 mg L-1 as a foliar application in two wheat cultivar (Kavir, Roshan) has been used. The test was done in December of 2014 in green house of biology department of Shahid bahonar university of Kerman. The tests were carried on in the form of completely randomed design with three replications in each treatment in two developmental stages, vegetative growth stage or stem elongation and flowering stage. Results showed that cadmium stress decreased content of photosynthetic pigment and increased indicator of EC and too decreased fresh and dry weight of shoots, stem and shoots length, spike length, spike weight, number and weight of seed. Treatments of selenium in 3 mg L-1 concentration decreased indicator of EC and increased content of chlorophyll a amount 35 percent in Kavir cultivar and content of chlorophyll a in Roshan cultivar amount 17 per in comparison with control and too this concentration of Se, promoted all parameters in spike in stress and non stress conditions. Results of weighting elements of Se and Cd, showed that under concentration of 700 µM Cd and concentration of 3 mg L-1 Se, Kavir cultivar in comparison with Roshan cultivar have been could accumulated of Se amount 42 percent inter of seed. Our results it could be concluded that the application of Selenium caused significant alleviation of Cadmium damaged to wheat plants.

---

Selenium is an essential element in some organisms, but high concentrations can leading to toxicity in plant. Methyl jasmonate hormone plays an important role in defence processes. In this research, the effect of Methyl jasmonate (Me JA) and sodium selenate (Na2SeO4 ) on growth, content of pigments, phenol, anthocyanin and proline in tomato plants were studied. The seeds to germinate in petri dishes were sterilized. After germination, the seedlings were transferred to pots containing moist sand. The plants with second leaves were treated with of 0, 30 and 60 µM Na2SeO4 and 0, 50 and 100 µM Me JA. After 20 days, plants were harvested and certain assays carried out. The plants were treated with Me JA and Na2SeO4 grew significantly compared with other treatments. In all of treatments chlorophyll a and b contents decreased, however, carotenoid contents in 60 µM Na2SeO4 increased. With addition of MeJA to culture solutions containing sodium selenate, the plants showed increase in amount of phenol and anthocyanin in comparison with plants treated with sodium selenate. MeJA had no significant effect on proline content, but sodium selenate with and without MeJA increased proline content. The results showed that interaction of Me JA and Na2SeO4 reduced the harmful effects of sodium selenate.

---

In this research the effect of four concentrations of nickel and copper (25, 50, 100, and 200 µM) on root and shoot length, fresh and dry weight, leaf surface, and photosynthetic pigments (Chlorophyll a, b and carotenoids), sugar, malondialdehyde, hydrogen peroxide content and antioxidant enzyme activity (CAT and APX) in Okra plants were evaluated. The results showed that in those plants which were treated with all concentrations of copper and nickel, the content of photosynthetic pigments and leaf surface were reduced significantly in comparison with control. In this investigation it was found that shoot and root length, dry weight and fresh weight of shoot and root which were treated with concentrations 50, 100, and 200 µM of cupper and 100 and 200 µM of nickel were reduced significantly when compared with the control. Content of soluble sugars in shoot and root plants which were treated with all concentrations of nickel and concentrations 50, 100, and 200 µM of cupper increased significantly in comparison with the control. Also, content of malondialdehyde, hydrogen peroxide content and antioxidant enzyme activity (CAT and APX) increased significantly in shoot and root plants which were treated with concentrations 50, 100, and 200 µM of copper and nickel when compared with control.

---

Abstract As nitrogen source is a necessary element in structure and cell metabolism, studying of nitrogen source and its effect on growth and different behave of photosynthetic organisms has received much attention. In this study, the comparative effects of three nitrogen sources (KNO3, NH4Cl and KNO3+NH4Cl) have been studied on physiological properties of two Dunaliella species, as Dunaliella sp. isolated from Gave-Khooni salt marsh and D.bardawil-UTEX2538, in different salt concentrations (0.1, 0.5 and 3 M NaCl) and cell division, changes in Chl a, Chl b, total Chl, total carotenoid total protein and fresh weight of the cells has been assayed during 24 days. D. bardawil had higher rates in cell growth, and in both strains the highest growth rates were observed at 0.5 M, treated with KNO3.Most of decreases in the amount of measured substances were happened on 8th day of assays and increases in Chl a, Chl b and total Chl contents were occurred in higher salt concentrations (0.5 M and 3 M) treated with KNO3. The cells in 0.5 M had the least fresh weight with the highest cell division rate. In D. bardawil, NH4Cl caused decrease in growth only in 0.1 and 3 M on 8th day. But noticeable decreases in Chl a, Chl b, total Chl, beta carotene and total carotenoid along with an increase in protein amount in both strains were observed only in 3M. After decreases on 8th day, the amount of assayed substances, increased at 3M. KNO3+NH4Cl as nitrogen source improved cell condition compared to cells treated with NH4Cl. D. bardawil responded to nitrogen source more different from other species and some increases in pigment contents occurred on 16th day. Overall, these results suggest that, NH4Cl make both species more sensitive to higher salt concentrations and after a short period of responses with decreased amount of pigments and arises in protein content, some increases could be a sign for coping with the new condition.

---

Madagascar periwinkle is one of the important medicinal plants belonging to Apocynaceae family. In this study the effects of nano zinc oxide on growth index wet and dry weight, leaf surface, photosynthetic pigments, total carbohydrates and amount of elements were investigated. Experiments were designed completely randomized in greenhouse culture conditions with three replications. Zinc oxide nanoparticle in different concentrations (2, 4, 5, 10 and 15 µM) and hogland nutrient as control was given to Catharanthus roseus plant for 70 days. In addition to study the symptoms of zinc deficit used zero concentration. The results indicate that nanooxide in concentrations higher than 2 µM reduced wet and dry weight, photosynthetic pigments, total carbohydrates, iron and phosphorus. Also the results indicate that uptake of zinc in nano scale is higher. Uptake of potassium and zinc increased with increasing the concentration of nano zincoxide. This means intraction between these elements is positive while the intraction of phosphorus and iron with zinc element is antagonisticand with increasing concentration of nano-ZnO the uptake of these elements will be reduced.

---

Drought stress stimulates the production of reactive oxygen species (ROS) in chloroplasts. ROS laed to lipid peroxidation and damage to the cell membrane. In the current study, the effect of different concentrations of silicon were examined on oxidative stress caused by drought in fennel plant. The experimental design was a split plot based on RCBD with three replications in which irrigation regimes includingirrigation at 100%, 70% and 40% of field capacity were assigned as main plots and five levels of silicon foliar sprays (0, 2.5, 5, 7.5 and 10 mM) were allocated to sub plots. The experiment was conducted in 2009 at the Zabol University research farm, Zabol, Iran. The results showed that drought stress significantly decreased chlorophyll a, chlorophyll b, carotenoids, leaf relative water content and catalase activity. In drought conditions, malondialdehyde levels and electrolyte leakage showed a 2 -fold increase over the control. Silicon treatment (7.5 mM) accompanied by drought, increased the activity of peroxidase and ascorbate peroxidase, proline and soluble sugars by 18, 25, 14 and 28%, respectively and decreased malondialdehyde and electrolyte leakage by 30 and 28%, respectively over the control, suggesting that silicon spraying (5 and 7.5 mM) could increase the ability of plants in response to drought stress by strengthening the antioxidant system of the plant and increasing osmolytes, and have protective effect against lipid peroxidation, induced by stress.

---

Cadmium (Cd) is easily absorbed by the root system in many plant species and due to its solubility in water and toxicity is considered as a major pollutant. The aim of this study was investigation of cadmium toxicity on some physiological characteristics of lentil seedlings. So, two-week-old plantlets were treated with different concentrations (0 as control, 0.125, 0.25, 0.5, 1, 2.5 and 5 μM) of cadmium chloride for 10 days and then the amounts of photosynthetic pigments, proline and soluble proteins were investigated. Survey results indicated that with increasing in cadmium concentration, a significant decrease was observed in photosynthetic pigments. In addition, the cadmium significantly was increased amount of proline in treated seedlings compared with control. Also, cadmium has imposed drastic decrease in total soluble proteins and the amount of proteins declined progressively with increasing concentrations of cadmium. Due to a decrease in protein content and photosynthetic pigments, the present results allow us to conclude that the lentil plants showed a negative response to cadmium toxicity. In addition, to overcome cadmium stress, seedling have increased the amount of non-enzymatic antioxidant compounds such as proline.

---

To study the effect of salinity on photosynthesis pigments, fluorescence and antioxidants of three varieties of peanut leaf as an indicator of resistance to salinity, research was carried out as factorial arrangement based on completely randomized design with three replications in the greenhouse of University of Guilan in 2013. The experiment consisted of a combination of 4 different salinity levels (0, 50, 100 and 150 mM) and three cultivars of peanut (Local Guilan, ICGV96177 and ICGV03060). The results showed that the interaction between cultivars and salinity measurement on characteristics of chlorophyll a, chlorophyll a + b the maximum fluorescence (Fm) initial fluorescence (F0), Peroxidase and phenol were significant except for carotenoids. This study indicated that increasing the concentrations of NaCl, Phenol and peroxidase increased the amount of chlorophyll a and b, and chlorophyll fluorescence yield decreased, and in general the local cultivar of Guilan was the most resistant one under different levels of salinity.

---

To investigate the effect of salicylic acid (0, 50 and 100 mM) on some physiological characteristics of henna, medicinal-industrial plant, under drought stress (0, -2 and -4 bar induced by PEG 6000) a factorial experiment based on completely randomized design was carried out in the research greenhouse of agriculture faculty of Shahid Bahonar University of Kerman. The content of photosynthetic pigment, protein, antioxidant activity of catalase and poly phenol oxidase and dry matter production were measured as some physiological response of henna. All measured traits affected significantly by drought stress (p<0.01). The highest amount of these traits except the activity of catalase and poly phenol oxidase were recorded for non-stress condition. The only trait that was not affected by salicylic acid significantly was the activity of poly phenol oxidase. The application of 50 mM salicylic acid led to the highest amount of these traits. The interaction of salicylic acid * drought stress was significant only for chlorophyll a, total chlorophyll, protein content, catalase activity and dry matter. Based on the obtained results, it can be concluded that application of salicylic acid on henna could largely improve the deleterious effects of drought stress through modification of physiological responses.

---

Abstract In this study, the effect of leaf spray of two salicylic acid concentrations, 100 and 500 µM, was studied on the some physiological and biochemical properties of grape cv. Ghizil Uzum in saline (EC=10) and non-saline (EC=2) conditions. The experiment was conducted in a Completely Randomized Design with 4 replications under greenhouse condition. The results showed the significant decreases in fresh and dry weights, water content, photosynthetic pigments, photochemical efficiency of PSII and total protein, starch and K+ concentrations of leaves in saline condition. But, the concentration of free amino acids, soluble sugars and Na+ were increased. The salt affected the plant antioxidant system by induction of superoxide dismutase, peroxidase and catalase activities and increasing malondialdehyde and H2O2 contents of leaves. Salicylic acid application in both concentrations in non-saline condition and in 500 µM in saline condition has not notable effects on studied parameters. Application of 100 µM salicylic acid in saline condition could ameliorates the negative effects of salt stress in grape cv. Ghizil Uzum by increasing the osmolytes and carotenoids concentrations, photochemical efficiency of photosystem II, capacity of antioxidant system and specially decreasing the Na+ ions transfer to growing plant organs.

---

The current experiment was designed to evaluate the effect of plant growth promoting rhizobactria (PGPR) on chlorophyll fluorescence and some physiological parameters in basil (Ocimum basilicum L.) leaf under salinity stress. The experiment was conducted in factorial arrangement based on completely randomized design. Treatments were four levels of salt stress (0, 40, 80 and 120 mM of NaCl) and three levels of PGPR inoculation (control, coinoculation with either Azotobacter+Azospirillum or Azospirillum+Pseudomonas+Bacillus). The results showed that increasing salinity stress significantly increased both minimum and maximum fluorescences (Fo and Fm) and quantum yield of non-regulated non-photochemical quantum efficiency [Y(NO)], while decreased variable fluorescence (Fv), maximum photochemical quantum yield of photosystem II (Fv/Fm) and photochemical quantum yield of photosystem II [Y(II)]. The trend of chlorophyll content and chlorophyll a and b (in control treatment) increased at low and medium level of salinity while decreased at higher salinity levels. However, with increasing the salinity level the relative water content (RWC) as well as the amount of carotenoids decreased and electrolyte leakage increased. Inoculation of basil plants with PGPR significantly reduced Fo and Y(NO) while increased Fv, Fv/Fm and NPQ as compared to the uninoculted control. Among the biological treatments, Azospirillum+Pseudomonas+Bacillus by 12% increase in Y(II) and 16% decrease in Y(NO), showed the most positive effects on plant photosynthetic system. Biological treatment also improved chlorophyll content, chlorophyll a and RWC and reduced electrolyte leakage. In conclusion, the current results indicated that the ameliorate effect of PGPR particularly coinoculation of Azospirillum+Pseudomonas+Bacillus on chlorophyll fluorescence and physiological parameters improvement of basil seedling leaves under salinity stress.

---

Sapodilla is one of the important fruit crops in tropical area which has problem with seed germination. So Manilkara hexandra (kherol) is generally used as a rootstock for sapodilla. This experiment was performed to assess the morphological changes and antioxidant enzymatic activity of Manilkara hexandra seedling under salinity condition. A pot experiment was carried out in a greenhouse using different concentrations of seawater (3, 6, 9, 12 ds/m) on the one-old age seedling and fresh water used as control. The experimental design was a Completely Randomized Design (CRD) experiment. Result showed that seawater irrigation had no significant effect on length and volume of root. However, fresh weight of leaf, stem and root decreased significantly by increasing seawater concentration. POD and CAT antioxidant enzymes showed the similar trend under stress and their activities increased strongly. However, APX activities increased gradually by increasing salinity level.This dramatic increase might show that POD and CAT are a major enzyme among antioxidant enzymes examined in Manilkara hexandra (kherol) under salt stress. Thus, antioxidant defense system induced by salinity plays important role in this plant under salinity stress.

---

One of the important goals of plant physiology in water ecosystems, is biomass and growth increment of green microalgae which led to access to their valuable production. In this regard, many factors are able to influence the increment and decrement of algal biomass. In this research different levels of vanillin (C₈H₈O₃), as 0 (control), 10, 25, 40, 50, 70, 90 and 100 mg. L^-1, were investigated during 24 days on cell number, fresh weight, dry weight and some of physiological indices (such as total sugar, reducing sugars, protein and photosynthetic pigments) in two algae, D. badawil-UTEX2538 and D. salina-UTEX200. All experiments were performed as completely randomized design (CRD) in three replications. The highest number of cells was observed at 25, 40 and 50 mg. L^-1 vanillin treatments. In D. bardawil, maximum specific growth rate (SGR) and minimum doubling time (DT) of cells were observed at 50 mg. L^-1 and in D. salina those were observed at 25 and 40 mg. L^-1. Fresh weight, dry weight and total sugar were increased by the most of treatments, but protein and reducing sugars were decreased compared to control. Chl a, total Chl and total carotenoid were increased only in D. bardawil, but Chl b and beta carotene showed decrements. D. salina had a higher growth rate but lower content of protein, total sugar and reducing sugars than D. bardawil. Overall, in contrast to some of the previous researches, vanillin which has phenolic nature induced faster growth rate and cell division in algal suspensions and also in the most of the cases, it led to improvement of physiological indices.

---

In order to evaluate the symbiotic effects of mycorrhiza-like fungi, Piriformospora indica (Pi), and mycorrhiza fungi, Glomus mosseae (Gm), on improving the chlorophyll pigments and chlorophyll fluorescence indices of maize (Zea mays L. cv. 'SC 704') under different levels of irrigation and triple super phosphate (TSP), a field experiment was conducted in a split factorial arrengment based on a randomized complete block design with three resplications. Two regions, Gharakhil (Ghaemshahr) and Bayekola (Neka) were investigated during the growing season of maize in 2015. Three different regimes of irrigation (100, 75 and 50% of crop water requirement) were used as the main plot, four levels of inoculations (control, Pi, Gm and Pi+Gm inoculations) and three levels of TSP (control, 50 and 100% of crop requirement) served as the subplots. The results indiacted that the amount of chlorophyll a, b, a+b and photochemical quantum yield of photosystem II (Fv/Fm) were significantly declined by limited irrigation regimes in both stations. The results also indicate a positive effect of fungi inoculation on Fv/Fm ratio resulted in significant increase of maximum fluorescence (Fm), particularly when maize seeds were inoculated with Pi and Gm together. Although, quantum yield of regulated non-photochemical (Y(NPQ)) increased by limited irrigation regimes, it appears that this parameter was significantly decreased by fungi inoculation treatments. This reduction was varied from 22% for Gharakhil to 33% for Bayekola, when applied Pi and Gm inoculation together. In general, the results indicated that these fungi could decrease the negative effects of water deficit stress on leaf chlorophyll pigments content and photochemical quantum yield of photosystem II by reducing damage to reaction centers of photosystem II. .

---

Light is one of the main limiting factors, specialy in warm regions, for growth and development in plants and shade levels play an important role in the cultivation of medicinal plants. The aim of this research was to investigate the effects of shade levels (0%, 50%, 75%, and 100%) to find the best environmental option with maximum flowering in Rosa damascena. The plants were evaluated after eight mounths of treatments for morphological characteristics, macroelements contents, chlorophyll and carotenoids contents, peroxidase activity and flower numbers. The results showed that 0% shade induced stress on plant growth and reduced morphology parameters including plant height, fresh and dry weight; chlorophyll content; nitrogen content; soluble carbohydrates and flower numbers were decreased compared to those grown in shade levels. Root length, ion lekage, cartenoides content, potassium and phosphorus contents and peroxidase activity were highest in Rosa damascena under 0% shade after 8 months of growth cycle. Numbers of flower was greatest in Rosa damascena grown under 50% shade. In conclusion, Rosa damascena is a semi shade loving plant suitable to grow under 50% shading forhigh yield, in warm regions.

---

     Salinity is a major environmental factor limiting plant growth in natural ecosystems. Glycyrrhiza glabra is an important Fabaceae (perennial plant) that its root and rhizome extracts are used in food, health, medical and pharmaceutical industries. To assess the effect of methyl  jasmonate (MeJA) and salinity on licorice, an experiment was conducted as factorial based on completely randomized design with three replications.  Accordingly, plants were exposed to the concentrations of 0, 100, 200 and 300 mM NaCl for five weeks, 24 h after foliar application of 0, 50 and 100 µM MeJA. In our experimental condition, a significant decrease in shoot dry weight, shoot and root fresh weights, plant height, leaf relative water content (RWC), Ca concentration of shoot and root and root Mg concentration were observed at 300 mM NaCl, while total chlorophyll, chl a and chl b concentrations and carotenoids were not affected significantly by salinity. Also, NaCl at 300 mM caused a significant increase in proline and total soluble sugar contents, Na⁺/K⁺ ratio and dry weight of roots. Results showed that exogenous application of MeJA at 50 µM level improved plant tolerance to salinity up to 200 mM NaCl and increased growth parameters, photosynthetic pigments, soluble sugar and proline content of shoot and root in comparison with control. Moreover, the application of MeJA caused a significant increase in Mg concentration of the shoot and root of control plants.

---

Salinity is one of the major challenges to increasing crop productivity. Besides these, in order to investigate of  proline and salicylic acid in the modulation of salt stress on soybean (Glycine max L.) , an experiment was conducted as split plot arrangement in a randomized completely design with four replication in 2016 in College of Agriculture, Shahrekord University. Main plot included three level irrigation by saline water with electrical conductivity 2 (control), 5 and 10 dS m^-1 NaCl) and sub plot in four level of foliar applied (10 mM proline, in combination with 10 mM proline + 3 mM salicylic acid, 3 mM salicylic acid and sprayed with water (control)). The results showed that the 5 and 10 dS m^-1 NaCl lead to increased and decreased of photosynthetic pigments compared with the control, respective. Proline and soluble sugars were increased under salt stress, while membrane stability index and relative water content decreased. Interaction between salt stress and foliar treatments showed that the highest increase in chl. b, carotenoid and proline were recorded in 5 dS m^-1 NaCl and proline plus salicylic acid with increase of 93, 53 and 143% as compared to the control, respectively. Membrane stability index and relative water content were decreased 63 and 38% as compared to the control, respectively. So, foliar application of 10 mM proline with 3 mM salicylic acid on physiological parameters of soybean was the best treatment to mitigate the detrimental effects of salt stress. So, proline function as compatible solute in osmotic adjustment and salicylic acid with the protective role through physiological reactions under salt stress.