Iranian Journal of Plant Physiology
Volume:12 Issue: 3, Spring 2022

Piriformospora indica is an endophytic fungus with plant-promoting properties in a wide range of host plants. This study aimed to assess and compare the effects of different P. indica inoculants through morphological and physiological analysis at different times (4, 8, and 12 weeks) after inoculation. The study was conducted in a completely randomized design with three levels of fungus inoculation (non-inoculated, inoculated with P. indica spore and mycelium). The results showed that both P. indica inoculants have a positive effect on measured traits at different times after inoculation. Root and shoot dry weight were increased significantly at 4, 8, and 12 weeks after inoculation. P. indica improved the reproductive phase of tomato resulting in increased dry weight of fruits by up to 51%. Most importantly, the endophyte enhanced tomato fruit yield by up to 73%. Based on experiment data, P. indica increased total chlorophyll (25%), protein (143%), and carbohydrate (44%) content in inoculated plants compared to non-inoculated plants. Besides, P. indica promoted the antioxidant capacity of inoculated plants by increasing CAT and APX activity. In our study, plant inoculation with P. indica also remarkably led to an increase in K (172%) and P (41%) content. Our data showed that both P. indica spore and mycelium have a long-term effect on tomato growth. The application of fungus inoculants promotes plant growth and yield. Hence, P. indica represents a suitable plant-stimulating biofertilizer for tomato in sustainable agriculture.

Light is an energy source for photosynthetic organs and the type of optical wavelength plays an important role in growth. The effect of blue light investigated on delta-1-pyrroline-5-carboxylate (proline precursor) in 2-wheat cultivar, BAM (resistant to salinity) and Tajan (sensitive to salinity) in a culture medium. There were 5 salinity treatments including 0 (control), 50, 100, 150, and 200 mM NaCl. In addition, there were two light treatments, namely exposure to blue and white light. After five days of growth of wheat seedlings, the growth indices (fresh weight, dry weight, and longitudinal growth), proline, chlorophyll a and b, sodium, and potassium contents, peroxidase enzyme activity, malondialdehyde, and pyrolin-5- Carboxylate (proline precursor) contents were measured. Data were analyzed using Duncan statistical test. Blue light increased the amount of proline and PSC in the salinity-resistant cultivar. In the sensitive cultivar, the amount of potassium under the white light was higher than that under the blue light in different levels of salinity. The amount of sodium accumulated under the influence of blue light in different concentrations of salt in the resistant cultivar was higher than that in the sensitive cultivar. Peroxidation activity of the resistant wheat cultivar was higher and blue light did not increase this attribute, but the amount of malondialdehyde in the sensitive cultivar increased under the blue light regime and with increasing level of salinity. Fresh and dry weight of plants in the resistant cultivar was the highest under the white light. In addition, plant length in the resistant cultivar under increasing concentration of salt was more than that in the sensitive cultivar under both light regimes.

Salinity is one of the rising problems causing tremendous crop productivity losses in different parts of the globe. Silicon can be regarded as multi-talented quasi-essential element due to its versatile role in providing several benefits for plant growth particularly under stress conditions. The present investigation deals with the impact of potassium silicate on the germination and biochemical parameters of tomato under salt stress. Maximum seed germination of tomato seeds 98% was observed with potassium silicate. The seed germination and other growth characteristics followed the order: PS > C > NaCl (1mM)+PS > NaCl (1.5 mM)+PS > NaCl (2mM)+PS > NaCl. Application of potassium silicate significantly increased biochemical components such as pigment content, sugar, proline, protein and total antioxidant contents in tomato seedlings. Maximum total antioxidant content 55% was observed in NaCl (2mM)+PS treatment. The results revealed that potassium silicate acts as a plant growth promoter and it can be used as fertilizer for tomato under salt stress.

The morpho-phytochemical responses of purple coneflower (Echinacea purpurea (L.) Moench) to foliar application of salicylic acid (SA) and citric acid (CA) at 0, 1, 5 and 10 mM (in four-leaves stage and two weeks later) were determined in a field experiment. The results indicated that elevated levels of SA and CA induce plant growth and biomass, including plant height, number of branches, leaves and flowers, fresh and dry weight of aerial parts and SPAD value. The highest flower number, flower yield/plant, shoot fresh and dry weight were obtained by 10 mM SA combined with 5 or 10 mM CA. DPPH radical scavenging activity increased about 1.9 fold with 5 or 10 mM SA combined with 10 mM CA. HPLC analysis revealed that SA and CA enhanced phenolic acids (cynaric acid, chichoric acid, echinacoside, chlorogenic acid and caftaric acid) production in plants. There was a significant positive correlation between number and yield of flowers with all morpho-phytochemical attributes except root weight. The data suggested that combination of SA and CA especially at 5 and 10 mM may have higher capacity to improve morpho-physiological traits and phenolic contents of E. purpurea.

In this experiment, the effect of four extraction methods including; percolation, maceration, ultrasound-assisted extraction and microwave on the amount of polyphenolic compounds and antioxidant activity of Froriepia subpinnata and Eryngium planum were investigated. In percolation and maceration methods, 70% methanolic extract was used to measure antioxidant compounds. In ultrasonic method, 1 g of powdered dry material with 10 ml of methanol 70% was exposed to a sonicator at rate of 20 KHz at 40 °C for 10 minutes. In microwave assisted extraction, 1 g of powdered dry material and 10 ml of methanol 70% was extracted with a household automatic microwave oven at 300 w irradiation for 30 second. The highest amount of total phenol in F. subpinnata and E. planum was observed in the microwave method and the highest amount of flavonoids was observed in the maceration and percolation methods, respectively. The highest antioxidant activity of F. subpinnata was 98.48% in the microwave method. Antioxidant activity data of E. planum showed that percolation method with 96.54% and microwave method with 90.82% in comparison with other methods played a special role in increasing of this trait. Therefore, it can be concluded that the use of microwave method can lead to better extraction of F. Subpinnata and E. planum.

A mapping population of 96 inbred line derived by cross Neda (NAD) and Ahlamitaroum (ATM), was used to detect quantitative trait loci (QTLs) for fresh biomass (FB), root length (RL), shoot length (SL), root number (RN), leaf width (LW), root fresh weight (RFW), root dry weight (RDW) and K content (KC) under K deficiency condition in rice. Two parents and 96 inbred lines were phenotyped for the traits by growing them in K deficiency nutrient solution. In K deficiency, 16 QTL was able to explain a great deal of phenotypic variation in features. qSL-7a, qRL-6, qRL-10b, qRL-12b, qRN-6b, qRN-12b, qLL-6, qLL-7, qLW-6b, qLW-10b, qLW-12a, qLW-12b, qLW-12c, qKC-6b, qKC-10b and qKC-12c were on chromosomes 6, 7, 10 and 12. Their LOD are 4.732, 5.826, 5.01, 5.067, 11.346, 5.867, 5.973, 5.85, 7.077, 8.055, 5.577, 6.439, 8.012, 14.057, 6.432 and 858/6, respectively. In normal conditions, 5 QTL with a large effect were identified. qKCN-6c, qKCN-7a, qKCN-10, qKCN-12b and qKUN-6 were located on chromosomes 6, 7, 10, 12 and 6, respectively. Owing to the high percentage of explanation, the major QTLs can be a suitable candidate for marker assistance programs in recombinant Iranian rice lines after validation.

In order to assess genetic diversity, the number of 38 Iranian rice cultivars were evaluated using 15 agronomic traits and 14 SSR markers. Rice genotypes were cultivated in a Randomized Complete Block Design in a Research Farm located in Azadshahr in 2013. According to analysis of variance (ANOVA) genotypes showed a significant difference for all traits (P <0.01). Regression analysis showed that the weight of filled grains was correlated with panicle number and chlorophyll content and explained 93.5% of the filled grains weight variations. The highest and lowest content of polymorphic information was recorded in RM262 (0.81) and RM241 (0.33) respectively, the mean PIC was 0.51. The average Shannon index was 0.33. The genotypes were categorized according to morphological traits in three groups but based on molecular and chlorophyll data assigned to three and two groups, respectively. Among the microsatellite markers used in this study, the RM142 RM255, RM341, RM262 markers had a high degree of polymorphism. RM297, RM104, RM274 showed the most correlation with rice chlorophyll content, which can be promising in marker selection programs.

Canola oil is a vegetable oil derived from a variety of rapeseed with lower erucic acid contents. To investigate the mechanism of response to salinity induced by sodium chloride in canola, Fornax cultivar was evaluated in greenhouse conditions. Results showed that salinity stress affected morphological and physiological traits so that leaf relative water content and photosynthesis-related traits decreased while proline and glycine betaine concentrations were higher than in control plants. In addition, under stress conditions, imbalances in ionic concentrations were caused by an increase in sodium ion concentration and a decrease in intracellular potassium ion, as well as a decrease in the potassium / sodium ratio in leaf cells. Proteomic analysis results also detected 7 protein spots with expression difference and significant induction factor (IF) between control plants and severe salinity stress. Each protein, identified by mass spectrometry, was related to antioxidant defense, involved in photosynthetic light reaction, Calvin cycle, and nitrogen assimilation, respectively.