Iranian Journal of Plant Physiology
Volume:11 Issue: 2, Winter 2021

The increasing of paddy production give an environmentally impact, because paddy cultivation contributes 46.2% of the total greenhouse gas emissions from agriculture. The paddy cultivation emission amounted to 76% of methane. Meanwhile, the grain produced by paddy consists of 16.3% to 28% husk with 18 to 22.3% silica. Silica contained in the soil can increase the root oxidation power of paddy, thus it will reduce methane emissions. The objective of this research was to evaluate the reduction of methan emissiom from paddy field by using silica from rice husk. This research used experiment with randomized block design and has eight treatments with three repetitions. The dose of biosilica is equivalent with 200 kg ha-1 of ameliorant in the form of ash, biochar, and compost. The methane analysis was carried out at 1, 5, 8, 12, and 15 weeks after planting. The methane was analized by GC with FID. The result of the research show that the ash produced from rice husk is the best single source of biosilica in paddy soil that can reduce methane emissions by 80.75%. The composition of ash, biochar, and compost (1:1:1) can increase the paddy growth and paddy production as well as reduce methane emissions effectively. The reduction of methane emission by giving silica into the soil is happened through the dissolved silica mechanism. The dissolved silica causes the increasing of pH and the root oxidation power of paddy.

The negative impact of contaminated soil with heavy metals on plant and human health is an important global concern. To evaluate the effect of lead (Pb(NOз)2) stress (0, 25, 75, 100, and 150 µM) on the germination, growth, physiological, and biochemical of sweet basil (Ocimum basilicum L.), a pot experiment based on completely randomized design (CRD) with three replicates was conducted at the Department of Horticultural Science, Shahed University of Tehran, in 2018. The contaminated soil with Pb had a negative impact on germination indices (percentage and rate), growth and morphological parameters (shoot and root length and dry weight), and physiological parameters (LAI, photosynthetic pigments, and number of leaf secretory glands). Pb stress (150 µM) led to a reduction in the average of germination percentage (43.33%), germination rate (62.92%), shoot and root dry weight (60.22 and 77.43%, respectively), LAI (64.68%), total chlorophyll content (73.10%), and number of leaf secretory glands (33.3%) in compared to the control treatment (without Pb), while increased peroxidase activity (62.3%), proline content (70.14%), and the root and shoot Pbcontent (92.10 and 97.6%,respectively). On the Other hand, Pb stress led to a change in the content of essential oil compounds. In general, low levels of Pb (25 µM) appear to increase the predominance of oil compounds. In conclusion, common basil cultivation in the Pb contaminated soil could cause undesirable effects on the germination indices, growth and morphological traits, and physiological attributes but might behave a positive influence under low level (25 µM) on the essential oil composition.

In our investigation, effect of auxin on rooting and sprouting behavior of stem cutting of Excoecaria agallocha has been studied. Initially stem cuttings was pretreated to remove the phenol content in the cutting and then the stem cuttings that was devoid from phenols cuttings were subjected to hormonal treatment with auxins derivatives as IBA 2000ppm, IPA 2000ppm, NAA 2000ppm and IBA+NAA combination 2000ppm. The root length and their number, rooting and sprouting percentage, number of leaves per cutting, leaf area and photosynthetic pigments were analyzed on 40, 50 and 60 day after planting(DAP) and isoenzyme pattern of peroxidase of root and leaf were also analyzed. Among the auxin treatments IBA 2000ppm vastly enhances rooting and sprouting behavior followed by IPA, IBA+NAA and NAA of Excoecaria agallocha. The isoenzyme analysis for peroxidase were clearly shown that peroxidase (POX) were highly supports both root initiation and elongation processes in Excoecaria agallocha L.

Plants adjust physiochemical attributes to maintain sustainable growth under different agricultural practices such as the management of sowing date and planting pattern.The present experiment aims to investigate the important role of sowing date (SD) and planting pattern (row arrangement) on physiochemical attributes of tepary bean (Phaseolusacutifolius L.) as a split-split plot designs with three replications during 2017 and 2018 .The main plots were two planting patterns (PP1: one-row and PP2: two-row plantation) and sub plots were three sowing dates (early, medium and late planting respectively June 15:SD1, June 30:SD2, and July15:SD3). The results showed increased chlorophyll (Chl) and carotenoid content was observed under two-row plantation and medium sowing date . Although Chl content improved at PP2, carotenoid had no response to planting pattern .The greater relative water content (RWC) was observed in plants under SD2, but the increased proline accumulation was reported at SD3. The least catalase and superoxide dismutase aggregation with 19 and 9.3(Umg-1protein) was obtained in plants under two-row plantation and medium sowing date respectively. Photosynthesis pigments represented the significant and positive correlation with RWC, but they negatively correlated with proline, CAT and SOD. Sowing date and planting pattern influence the microclimate of tepary bean, which affect the physiochemical properties. Therefore, physiochemical attributes are recommended to observe the optimal situation of tepary bean under the management of sowing date and planting pattern in arid and semiarid areas.

In order to investigate the compensation of vermicompost application was tested on antioxidant enzymes and chlorophyll contents in borage (Borago officinalis) grown under salinity, a factorial experiment was conducted based on completely randomized design with three replications. Treatments included of vermicompost (zero, 6, 12 and 18 % of w/w soil) and four levels of salinity (Zerro (control), 4, 8 and 12 dS m-1 NaCl). As salinity increased, the activity antioxidant enzymes (catalase, superoxide dismutase, ascorbate peroxidase, glutathione peroxidase, malondialdehyde) were increased significantly against photosynthetic pigments decreases. The use of vermicompost caused to significantly increase chlorophyllb, carotenoids and malondialdehyde. The maximum activity antioxidant enzymes were obtained by treatment with vermicompost (18%) at salinity level of 12 dS m-1 and the highest amount of chlorophylla and total chlorophyll were obtained in the treatment composition of 18% vermicompost and non-salinity stress (control). Therefore, the use of vermicompost as an organic fertilizer, in addition to increasing the activity antioxidant enzymes and the amount of photosynthetic pigments, could be a good strategy to reduce the negative effects of high concentrations of sodium and chlorine ions in soils on borage (Borago officinalis) growth.

Different concentrations (1.5, 3.16, 15, and 30 mM) and forms (K2SO4 and KNO3) of potassium applied through Hoagland’s nutrient solution. Ascorbic acid in concentrations of 750 and 1500 mg L-1 sprayed twice on seedlings (age 68 and 78 days). Wet and dry weight, plant height, photosynthetic pigments, sodium, and potassium contents measured at the end of the growing season. Also, total free amino acids measured by HPLC. The excess of potassium increased the total wet (62%) and dry weight (54%), leaf area (31%), shoot and root height (49% and 15%, respectively), total chlorophyll (44%), and K+/Na+ ratio (100%), while the total free amino acids (2 times) and sodium content (28%) decreased. Ascorbic acid showed an almost similar trend to potassium in the mentioned factors, but it did not affect the root height and total sodium and potassium contents. There was a positive interaction between the potassium and ascorbic acid on the plant weight and height, leaf area, photosynthetic pigments, and K+/Na+ ratio. Regarding the positive effect of potassium and ascorbic acid on the growth parameters along with the similar changes on the photosynthetic pigments and the K+/Na+ ratio with the reduction of total free amino acids, it may suggest both treatments improved plant growth through plant stability and increasing photosynthetic rate, production of more protein and other metabolites in Catharanthus roseus. Due to the importance of chemical compounds in Catharanthus roseus, any increase in the growth parameters to an increase in the yield of the plant can be very valuable.

Spearmint (Mentha spicata) is widely utilized in traditional medicine and folk remedies. The fresh and dried plants and their essential oils are widely used in food, cosmetics, confectionery, chewing gum, toothpaste, and pharmaceutical industries. In this research, the essential oil of air-dried samples was obtained by hydro-distillation and was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Changes in essential oil compositions were detected during storage for 3 months in refrigerator (4 ◦C), freezer (−20 ◦C), and at room temperature (25 ◦C). The results indicated that at room temperature, the proportions of the compounds with lower boiling temperatures such as 1,8-Cineole (3.78-3.34%), Limonene (7.33-6.61%), and Germacrene D (6.26-1.90%) were decreased significantly. Furthermore, the essential oil composition showed the least alterations and Mentha spicata L. kept its primary quality when stored at low temperatures, particularly in the freezer, and carvone had an increased significantly in all of the treatments

Licorice (Glycyrrhiza glabra L.) is a valuable plant for the treatment of several diseases. Negative effects of aluminum stress on plants have been reported and silicon may alleviate these negative effects through promoting antioxidant system. This study was conducted to investigate the effects of silicon on glycine-betaine, phytochelatin, and antioxidant parameters in licorice plant under aluminum stress. The plants were treated with silicon (0, 0.5, and 1.50 mM) and submitted to aluminum stress (100, 250, and 400 µM). Glycine-betaine contents of roots and shoots were investigated. Also, guaiacol peroxidase (GPx), peroxidase (POX), superoxide dismutase (SOD), phenylalanine ammonia lyase (PAL), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, and hydrogen peroxide (H2O2) and root phytochelatin were assessed after treatment with aluminum. Results showed that aluminum stress increased the contents of glycine-betaine and root phytochelatin, activities of GPx, POX, SOD, PAL, DPPH radical scavenging, and H2O2 content (p <0.05). Application of silicon application also increased the contents of glycine-betaine, activities of GPx, POX, PAL, DPPH radical scavenging, and root phytochelatin (p <0.05) while it decreased H2O2 and SOD contents (p <0.05). Based on the findings, application of silicon is recommended for protection of licorice under aluminum stress.