Journal of Plant Biological Sciences
Year:2018 | Volume:10 | Issue:36 |Papers Count:6

Salt stress is one of the most destructive abiotic stress which affects compatible osmolytes and protein pattern. In the current study, the effect of rosmarinic acid as a polyphenolic quencher on compatible solutes such as glycine betaine, total carbohydrates and protein, Na+and K+ and fresh weight were determined to evaluate osmotic adjustment as a stress tolerance mechanism inSolanum tuberosum L. c.v. White Desire in vitro condition. In the other experiments, SDS-PAGE was performed to verify feasible hypothesis of ameliorative effects of RA on biosynthesis of proteins. In vitro-grown cells of potato were incubated on Murashige and Skoog (MS) medium containing 0, 20, 40, and 60 mg/L RA and 0, 90, and 120 mM NaCl. Data showed increase in fresh weight in 120 mM-stress calli pretreated with rosmarinic acid compare to 120 mM stressed calli. Carbohyadrate content increased notably by using RA in exposure to NaCl. The results showed a significant increase in glycine betaine in 90 mM NaCl+20 mg/L RA treated calli compared with 90 mM NaCl-stressed calli. There was a notable increase in contents of Na+and decline in K+content in in vitro calli cells grown under 90 and 120 mM salt levels. Interestingly, K+contents in RA-treated calli cells were remarkably higher than Na+contents. However, no pronounced changes in K+/ Na+ratio were observed. Data showed that in vitro RA-treated calli responded rapidly to external RA supplement showing higher proteins contents compared to controls. SDS-PAGE data indicated a positive impact of RA on protein pattern. In vitro calli cells treated with 20 and 60 mg/l RA showed the induction of 2 new protein bands with approximately 50 KD while, 3 protein bands with approximately 16, 17 and 25 KD were down-regulated by RA.Consequently, data presented in the current study indicated a positive link between salt tolerance and improved metabolites biosynthesis in potato White Desire following RA treatment.

Lead as an enormous pollutant in the environment affects the metabolic and physiological activities of living organisms, therefore, has attracted more attention in recent years. In this research, the effect of seed priming with sodium hydrosulfide (hydrogen sulfide donor) on growth parameters, total chlorophyll content, soluble sugars and total protein and anatomical index in maize plant under lead stress was investigated. For this purpose, maize seeds were soaked in sodium hydrosulfide (0.5 mM) for 12 hours. Seedlings were treated with Pb 2.5 mM after planting. The results showed that lead stress reduced growth parameters, total chlorophyll, soluble sugars and total protein contents, and in case of structural studies, increased thickness of root and vascular cylinders and size of root parenchymal and epidermal cells, and decreased the thickness of leaf and middle vein. Seed pretreatment with sodium hydrosulfide resulted in an improvement in growth parameters and increased total chlorophyll, soluble sugars, and total protein contents. Regarding the anatomical parameters, sodium hydrosulfide pretreatment, depending on the parameter type, could compensate anatomical factors that were affected by the Pb stress. According to the results, it seems that Pb stress has harmful effects on maize plant, and hydrogen sulfide as a signaling molecule in different ways could increase plant adaptation to stress conditions.

Zinc (Zn2+) is one of the essential micronutrient elements for plant growth. In the present study, effect of different concentrations of zinc on some physiological and biochemical properties of basil (Ocimum basilicum) was investigated. Basil seedlings were exposed to six zinc (ZnSO4) levels (0, 50, 100, 200, 400, and 800 mg/L) in 3 days’intervals for a period of 30 days. The root and shoot growth, leaf number and area, photosynthetic pigments content, total soluble sugars and proteins, phenolic compounds, antioxidant power and mineral elements contents including zinc and potassium were significantly increased in effect of zinc levels up to 200 mg/L.Inversely, ferrous and calcium contents was drastically decreased concomitant with increasing zinc concentration but magnesium content remained unchanged. Our results indicated a dual role of zinc with optimum concentration of 200 mg/L, and a decrease in the root and shoot growth, pigment and phenolic contents under and over optimum concentration, whereas sugars and protein accumulation were occurred concomitantly with increasing zinc in the medium. However, the decrease of these parameters at the highest zinc concentration did not reach the level of control plants, which means that this species has a high resistance against zinc metal stress and because of the relative accumulation of zinc in polluted areas may has an important role for human nutrition. In general, the results point to important role of zinc in maintaining and protecting of basil seedlings against radical oxygen species.

Since the photochemical mechanisms of iodine-mediated adaptation to salt stress is not yet clear, the present study was performed to address this issue. Strawberry (Fragaria × ananassaDuch.) plants were grown under controlled conditions, and soils of iodine treatment were fertilized with potassium iodate (KIO3) (5 and 50 mg/kg soil) before filling the pots. Salt stress (50 mM) negatively affected protein synthesis and photochemical reactions of strawberry, as evaluated by a decrease in performance index (PIabs) as well as higher levels of hydrogen peroxide (H2O2) and malondialdehyde, whereas application of KIO3 (at both 5 and 50 mg/kg) alleviated the detrimental effect of sodium chloride (NaCl) stress. Plants treated with 50 mg/kg showed an increase in the soluble sugars content with respect to no KIO3 supply under salinity stress. In saltstressed plants, the OJIP chlorophyll fluorescence curve showed a quicker fluorescence decrease in the I-P phase. Notably, I-P phase in plants treated with KIO3 was increased.These results indicated that KIO3 application could protect the photosystem II from damage under salinity stress. Additionally, application of KIO3 raised free radical scavenging activities of strawberry leaf because of an enhancement of catalase activity.These data provided the first evidence that the root-applied KIO3 pretreatment alleviated salt stress in strawberry by decreasing reactive oxygen species production, resulting in better photochemical functioning under salt stress.

In order to evaluate the tolerance of watermelon (Citrullus lanatus L.) accessions to water deficit stress, an experiment was carried out in a split plot based on randomized complete block design with three replicates in research filed of university of Zanjan during 2016. Treatments consisted of three irrigation levels 100%, 70% and 50% Crop Evapotranspiration (ETc) and watermelon accessions (Ananasi, Sharif Abadi, Mahbubi and Charleston Gray commercial cultivar). The results showed that water deficit stress significantly decreased leaf area, plant length, fruit yield, stomata conductance and relative water content (RWC), and increased total soluble solids, peroxidase activity and electrolyte leakage. Amount accessions, the highest leaf area, plant length and yield (84.6 ton/ha) was obtained in Mahbubi accession. The lowest electrolyte leakage and the highest RWC was showed in Ananasi accession, and the highest peroxidase activity in Charleston Gray. Water deficit stress decreased fruit number per plant and fruit weight, although water deficit had no effects on fruit number in Mahbubi accession. The increase in waterdeficit stress, decreased water use efficiency in “Ananasi”, “Sharif Abadi” and “Charleston Gray”, but the highest WUE (54.85 kg.m-3) was obtained in“Mahbubi” underwater deficit 50% ETc. water deficit had no significant effects on fruit pH. According to the results, “Mahbubi” with 46.9% reduction in fruit yield under water deficit 50% ETc had the lowest reduction in fruit yield compared to other accessions that was higher tolerance accession to water deficit stress.

The purpose of this study was to check the possibility of callus and somatic embryogenesis in date palm cv. Khazravi using different explants including leaves, green fruit, immature seed, endosperm and green fruit pericarp. In the culture of leaves in the medium contains different plant growth regulators including 2, 4-D, BAP and TDZ, highest callus induction was achieved in medium supplemented with, 5 mg.L-1 2, 4-D, 2 mg.L-1 BAP and 4 mg.L-1 TDZ, and in treatment with 5 mg.L-1 2, 4-D, 1 mg.L-1 BAP and 4 mg.L-1 TDZ. By using explant of immature fruit, found that when two growths regulative, TDZ and 2, 4-D in amount of 5 mg.L-1 are in the culture medium callugenesis and embryogenesis was achieved. The endosperm cultivation with pericarp and embryo in the same medium showed that the presence of two growth regulators 2, 4-D and TDZ have been useful for callus production. Also in endosperm with zygotic embryo culture, embryo development and the root and shoot were formed after three months. Endosperm culture, in the culture medium containing various auxins and pericarp culture showed no any reactions. In general, these results showed that in date palm cv. Khazravi, treating the explants of leave and immature fruits with appropriate concentrations of plant growth regulators auxin and cytokinin, can induce callus and embryo.