Sewage sludge improves agricultural soil and plant growth, but there are risks associated with its use, including high heavy metal content. In this study, experiments were carried out to investigate the role of endophytic Talaromyces pinophilus MW695526 on the growth of Triticum aestivum cultivated in soil amended with sewage sludge and its phytoremediation ability. T. pinophilus could produce gibberellic acid (GA) and stimulate T. aestivum to accumulate GA. The results showed that inoculation with T. pinophilus boosted plant growth criteria, photosynthetic pigments, osmolytes (soluble proteins, soluble sugars and total amino acids), enzymatic antioxidants (catalase, superoxide dismutase and peroxidase), K, Ca and Mg. On the other hand, it reduced Na, Na/K ratio, Cd, Ni, Cu and Zn in the growth media as well as in the shoot and root of T. aestivum. The results suggest that endophytic T. pinophilus can work as a barrier to reduce the absorption of heavy metals in T. aestivum cultivated in soil amended with sewage sludge.

THIS WORK was undertaken to evaluate the effects of salicylic acid (SA) (0.0 and 0.5 mM) and ascorbic acid (AsA) (0.0 and 100 ppm) on enzymes activity, soluble sugars, and some physiological traits of maize seedlings (Zay mays L.) under drought stress using PEG-6000. In general, under drought conditions, significant reduction in plant biomass and photosynthetic pigments was detected. On the other hand, soluble sugars (glucose, fructose and sucrose), soluble proteins, antioxidant enzymes activity [catalase (CAT), ascrobate peroxidase (APOX) and superoxide dismutase (SOD)], glutathione (GSH), proline and malondialdehyde (MDA) contents were increased significantly under drought as compared to control. Shoots of tested plants were more affected by drought stress than roots. Seed presoaking in AsA or SA solutions resulted in massive increase in growth parameters, chlorophyll contents, osmoprotectants (soluble sugars, free amino acids and soluble proteins), antioxidant enzymes activity [ascrobate peroxidase (APOX) and superoxide dismutase (SOD)] and non-enzymatic antioxidants [carotenoids, and glutathione (GSH)] content as compared to control. Conversely, proline, catalase (CAT) and malondialdehyde (MDA) content were decreased significantly. The present study established that, both salicylic acid and ascorbic acid alleviate drought stress in maize plants which could attribute to the increased in osmotic solutes and antioxidative capacity of maize plants.

THE PRESENT work investigated the possible protective role of aqueous Ocimum basilicum leaves extract (OLE) on Vicia faba plants irrigated with different leves of salinity (0.0, 50, 100 or 150 mM NaCl). The toxic effects of salinity on Vida faba plants were assessed by determining oxidative stress such as lipid peroxidation. Furthermore, growth parameters, antioxidant enzymes activity [catalase (CAT), peroxidase (POD) and ascrobate peroxidase (APX)], organic solutes (soluble sugars, soluble proteins and proline) and ions content (Na+, K+, Ca-2 and Mg2+) on Vicia faba plants grown under salinity stress in the presence or absence of aqueous extract of O. basilicum leaves were also measured. The obtained results revealed that salinity stress resulted in a significant increase in the activity of antioxidant enzymes, organic solutes, lipid peroxidation and ions content, which were associated with a significant reduction in growth parameters compared with control plants. OLE significantly alleviated the harmful effect of salinity on Vicia faba plants and increased the activity of antioxidant enzymes activity, osmolytes (soluble sugar and soluble protein), and ions content (K+, Ca2+ and Mg2+), which could be an induced defensive mechanism against salinity stress.

It has been shown that application of inorganic nano-materials on cereal plants during their growth cycle improves the rate of plant productivity by supplying a micro-nutrient source. This study aimed to evaluate the impact of seed priming with zinc oxide nanoparticles (ZnONPs) (0.0 and 100 ppm) on maize Triple-hybrid 321 seedling grown in soil containing different levels of salinity (0.0, 50, 100 and 150 mM NaCl) for three weeks. Parameters were determined for growth (fresh and dry mass (FM, DM), osmotic concentration (OC) of organic/inorganic solute, photosynthesis pigment content (PPC), and selective antioxidant system (AOS) enzymes that might be involved in the stress remediation. The toxic effects of salinity on Zea mays L plants were assessed by determining growth parameters, antioxidant enzymes activity [catalase (CAT), peroxidase (POX) and ascrobate peroxidase (APOX)], osmotic concentration (OC) of organic/inorganic solute organic solutes (soluble sugars, soluble proteins, free amino acids and proline) and ions content (Na+, K+, Ca2 and Mg2+) in the presence or absence of ZnONPs. The obtained results revealed that, salinity stress resulted in a significant increase in antioxidant enzymes activity, organic solutes and ions content which are associated with significant reduction in growth parameters compared with control plants. Seed priming with ZnONPs significantly alleviated the harmful effect of salinity on Zea mays L seedlings and increased the activity of antioxidant enzymes, organic solutes and ions content (Na+, K+, Ca2+ and Mg2+), which could be an induced defensive mechanism against salinity stress.

This work was undertaken to evaluate the effect of ascorbic acid (AsA) and potassium (K) on some morpho-physiological parameters of two Vicia faba L cultivars (Giza 843 and Giza 716) grown in nutrient solutions containing different concentrations of NaCl (50, 100 and 150 mM NaCl) and K (0.5, 1.0 and 1.5 M) for two weeks. In general, under saline conditions, significant reduction in plant biomass and chlorophylls was detected. Seed presoaking in AsA solution resulted in massive increase in growth parameters and chlorophyll contents in both genotypes of stressed and non-stressed plants, but it depended on K concentration, 1.5 M K was the best. The positive effect of AsA on growth of salt stressed plants was not manifested when K concentration was low (0.5 M). In both genotypes, carbohydrate and protein contents increased as NaCl increased. Further significant-increase in their contents was detected when seeds were soaked in AsA and plants were cultured under salt stress; it depended on K concentration in the nutrient solution, 1.5 M K was the best. This type of synergizing between AsA and K on carbohydrate and protein contents was absent under low concentration of K. Sodium increased but K, Mg and Ca contents decreased in both cultivars under salt stress especially when K concentration was low (0.5 M). Under stressed or unstressed conditions, significant decrease in Na but significant increase in K, Ca and Mg contents due to AsA was detected and it was proportional to K concentration, 1.5 M K was the best.

Long-term culture of a fast-growing plant species such as moringa in partially closed vessels led to the appearance of hyperhydricity which retard mass multiplication. Therefore, the overall goal of this study was to know the physiological changes associated with avoiding the phenomenon by antiethylenes (AgNO3, CoCl2 , and salicylic acid (SA)) and the effect of these compounds on the genetic changes resulting from long-term culture. Moringa multiplication was successfully obtained when hyperhydricity was successfully avoided using MS medium containing 0.56 mg/l BAP and 1.70mg/L AgNO3 or 6.91mg/L SA and it was associated with a significant increase in photosynthetic pigments, carbohydrates, proteins and Mg++ contents. In addition, no significant changes were detected in free amino acids, Na+, K+ , and Ca++ contents with decreasing the activities of CAT, POX, APX and SOD. Therefore, improvement due to antiethylenes application, in particular 1.70mg/L AgNO3, which led to the disappearance of hyperhydricity could be attributed to modulations in some physiological processes and avoidance of genetic changes under the influence of long-term culture (11 subculture), as the genetic changes decreased from 45.2% and 40.3% to 29.6% and 30.8% using RAPD and ISSR, respectively. Application of antiethylenes was recommended for improvement and mass propagation of plants suffering from hyperhydricity under tissue culture conditions.