At two distinctive habitats, the chlorophyll contents (Chl.), its thermostability (CSI) and some metabolic substances in four shrubs were studied. The obtained results revealed that, the Chl. content, Chl. a/b ratio and CSI were variables among the investigated species in response to seasonality, habitat, species and their interactions. Generally, the low Chl. contents were accompanied by an increased in CSI. Statistically, the single factors and their interactions had significant effects on the investigated constituents of plants with some exceptions. It was found that, the seasonality was greatly affected the Chlb, Chl. a/b ratio and total chlorophyll. The species factor had a major role on the Chla and CSI. The same was true in case of the rest constituents in plant tissues, whereas the habitat factor had a dominant role on Mg+2. The results showed that the C. procera was the highest in chlorophyll stability to heat and the lowest in the amount of chlorophyll, and vice versa was in the O. europaea plant. The correlations between CSI and free amino acids were significantly positive. Also, the Chl. contents were positively correlated with soluble sugars. Within species, the specific correlations between different chlorophyll parameters and other components in plant tissues were discussed.

The huge applications of cellulosic and lignocellulosic materials in the various fields of life lead to accumulation of its wastes that became one of the major sources of environmental pollution. In this study, a Gram-positive cellulose-decomposing endophytic bacterium (Chi-04) was isolated from medicinal plant Chiliadenus montanus which inhabitant Saint Catherine (Sinai) region in Egypt. The bacterial strain was identified based on the sequence analysis of 16S rRNA genes as Lysinibacillus xylanilyticus. This isolate was capable of degrading 58% of cellulosic filter paper (100 g/l) within 15 days of incubation. The soluble and reduced sugars were spectrophotometrically determined as cellulose decomposition metabolites. The bacterial isolate exhibited an obvious activity toward cellulase enzyme production. The maximum cellulase activity (0.18 U/min) was detected after 12 days of incubation while the …

To discriminate the specific response of ion toxicity versus osmotic stress on altering leaf solute contents, contributing of organic and/or inorganic components in osmotic adjustment and its reflection on plant performances under ionic and osmotic stresses, two cotton (Gossypium barbadense L.) cultivars, Giza 90 and Giza 83, were subjected to iso-osmotic concentration (–0.57 and–1.05 MPa) created by; NaCl, KCl and polyethylene glycol-6000. The three used osmotica altered seedling length, chlorophyll, leaf dry weight, relative water content, organic and inorganic solutes and proline. Contribution of organic solutes to osmotic adjustment tittered among the two cultivars, it was higher in PEG˃ KCl˃ NaCl in Giza 83, suggesting that the character of osmotic adjustment via salt attuned to high yield with moderate ion toxicity is effectively achieved by KCl than NaCl. At high-stress intensities, regardless to cultivar, the salt stress-induced nutritional imbalance, leaf chlorosis than osmotic stress that could be attributed to specific ion toxicity, not to osmotic stress of salt. In salt sensible cultivar only NaCl, among different osmotica, reduced leaf K+ content implying that avoidance of Na-induced K+ deficiency in leaf might stimulate salt tolerance in cotton. In our study, the capacity of plants to regulate their metabolic and physiological functions had superiority in water stress tolerance rather than osmotic adjustment.

The outstanding role of spermine in eliciting defense adaptation of soybean to different levels of water deficit (0, -0.1, -0.5 and -1.1 MPa) was investigated by determining the changes in growth, photosynthetic pigments, osmolytes, water relations, and antioxidants. All the studied traits clearly revealed cultivar-dependent variation in response to water deficit where cv. Giza 111 was tolerant and cv. Giza 21 was sensitive. Both cultivars came in agreement that photosynthetic limitation (chlorophylls reduction) was the troubling shot induced by water deficit. Such limitation was reflected on three directions (a) disturbances of water relations (stomatal conductance, transpiration rate, relative water content and water use efficiency), (b) down regulation of metabolites which affect osmotic adjustment and (c) elevated reactive oxygen species (increased hydrogen peroxide) and destruction of membrane stability (increment of …

The population acceleration and better lifestyle submit new challenges for wheat researchers to breed wheat (Triticum sativum) cultivars with upgraded yield, quality, and resistance against abiotic stresses such as drought, so exploiting all available natural relatives of cultivated wheat and introducing even sensitive ones may be a useful approach to save time and efforts. Normally, the seedling stage is highly drought vulnerable, but for sensitive cultivars, the situation is more frustrating. We examine the potentiality of two regulating hormones in the upregulation of two wheat cultivars varying in their drought susceptibility at the seedling stage comparatively evaluated by morpho-physiological traits as indicators of drought tolerance. All the studied traits revealed cultivar-dependent variation in response to water deficit where cv. Sids 1 was tolerant and cv. Beni-suef 5 was sensitive. Shoot/root ratio, total water content, total dry weight, chlorophyll stability, total osmotic potential, osmoregulatory components, viz., soluble carbohydrates, soluble proteins and proline, membrane damage trait in terms of LOX, antioxidant defense system enzymatically in terms of APX, CAT, POD, SOD, and total antioxidant as drought tolerance indicators were the troubling shot due to water shortage in both cultivars. The damaging impacts of water deficit on these traits were conceived for sensitive cultivar compared with the tolerant one. Exogenous application of jasmonic acid (JA) or kinetin (K) efficiently conferred drought tolerance to sensitive cultivar to withstand harsh conditions in earlier stages and to perform comparably with tolerant ones. Applied hormones prompted unequivocal inversion from a state of downregulation to upregulation regarding all drought tolerance traits via reallocation of photoassimilates to vegetative sinks, thus promoting growth, increasing the accumulation of some osmoregulation compounds and thus increased tissue vigor and regulated the activity of antioxidant enzymes as well as morphological modulation attained by the restoration of shoot/root ratio. The results would promisingly be supportive of research programs seeking to develop anti-drought stress practices for sensitive wheat cultivars.

Potassium use efficiency (KUE) in faba bean production is often low, and the luxury of fertilization has negative environmental impacts. The current study aims to reduce the recommended dose of potassium (K) for faba bean by potassium solubilizing bacteria (PSB) and humic acid (HA). The studied treatments were 50 and 100% of K recommended dose with or without PSB and 40 kg of HA ha⁻¹. The studied treatments were applied to faba bean ((Vicia faba L., cv. Giza 843) plants grown in sandy loam soils for two successive seasons. In this study, the maximum KUE (40%) was obtained in the soil treated with HA and PSB while the lowest one (14%) was found in the case of the full recommended dose of mineral form. Humic acid and PSB that were applied to the plants fertilized with 50% of the recommended dose gave the maximum growth and yield. Humic acid and PSB increased the soil cation exchange capacity (CEC) by 6% and the soil organic matter (SOM) by 12%. Chlorophyll and carbohydrates in the leaves were increased by 36 and 50%, respectively, above the control, as results of HA and PSB application. Adding half of K requirements for faba bean in a mineral form with 40 kg of HA and PSB led to 14% and 19% increases in the seed and straw yield compared to the full mineral fertilization without bacterial inoculation. Humic acid and potassium solubilizing bacteria can be used to improve soil quality and increase the availability and uptake of nutrients, and thus increase the yield of faba bean plants. The experimental results from our 2-year research on faba bean grown on sandy loam soils establish a deductive scientific basis for using bio-fertilizers and organic materials to produce cleaner food and better environment conditions.

In recent times, significant attention has been directed toward the synthesis and application of nanoparticles (NPs) in agriculture sector. In current study, nanoceria (CeO₂ NPs) synthesized by green method were employed to address cadmium (Cd) accumulation in wheat (Triticum aestivum L.) cultivated in field with excess Cd. The application of CeO₂ NPs was carried out through foliar spraying, performed twice during the growth of T. aestivum. Four levels of CeO₂ NPs were used: T0, T1, T2, and T3 as 0, 50, 75, and 100 mgL⁻¹, respectively. Results highlighted the positive effects of CeO₂ NPs on various growth parameters, including plant height, spike length, photosynthetic related attributes, as well as straw and grain of grains in comparison to T1 (control group). Furthermore, CeO₂ NPs led to a reduction in oxidative stress in the leaves and enhanced in enzyme activities in comparison to T1. Notably, Cd concentrations in straw, roots, and grains exhibited a decline following the treatment with CeO₂ NPs, in contrast to the control group. In terms of health implications, the calculated health risk index associated with dietary consumption of grains by adults remained below the defined threshold with supply of nanoparticles. Foliar application of CeO₂ NPs proved to be an effective approach in reducing cadmium content in wheat grains. This reduction holds significant potential for minimizing the risk of cadmium exposure to human health through the food chain. Employing the green synthesis method amplifies the potential for extensive production and a wide array of environmental applications for CeO₂ NPs. This dual capacity makes them proficient in tackling environmental stresses while concurrently mitigating adverse ecological effects.

This study aimed to use organic fertilizers, e.g., compost and manures, and a halophytic plant [wavy-leaved saltbush (Atriplex undulata)] to remediate an agricultural soil polluted with toxic elements. Compost or manure (1% w/w) was added to a polluted soil in a pot trial. The application of the organic fertilizer, whether compost or manure, led to a significant improvement in the growth of the tested plant. From the physiological point of view, the application of organic fertilizers to polluted soil significantly increased the content of chlorophyll, carotenoid, and proline and, furthermore, led to a clear decrease in malondialdehyde (MDA) in the plant leaves. The highest significant values of organic carbon in the polluted soil (SOC) and cation exchange capacity (CEC) were found for the soil amended by compost and planted with wavy-leaved saltbush. Manure significantly reduced the soil pH to 7.52. Compost significantly decreased Zn, Cu, Cd, and Pb availability by 19, 8, 12, and 13%, respectively, compared to the control. On the other hand, manure increased Zn, Cu, Cd, and Pb availability by 8, 15, 18, and 14%, respectively. Compost and manure reduced the bioconcentration factor (BCF) and translocation factor (TF) of Cd and Pb. Compost was more effective in increasing the phytostabilization of toxic metals by wavy-leaved saltbush plants compared to manure. The results of the current study confirm that the application of non-decomposed organic fertilizers to polluted soils increases the risk of pollution of the ecosystem with toxic elements. The cultivation of contaminated soils with halophytic plants with the addition of aged organic materials, e. g., compost, is an effective strategy to reduce the spreading of toxic metals in the ecosystem, thus mitigating their introduction into the food chain.

Soil salinization and its associated problems are becoming a potential threat to the sustainability of agriculture. Deficiency of micronutrients like zinc (Zn) is a common growth limiting factor in salt-affected soils. The current study aimed to evaluate the effects of Zn enriched amino acids (ZnAAC) on the growth, nutrient uptake, and Zn fortification in rice plants under salt stress. Different ZnAAC including Zn glycine (ZnGly), Zn methionine (ZnMet), Zn tryptophan (ZnTrp) and conventional ZnSO₄ were applied at the rates of 8, 10, and 12 mg/kg with three replicates. The results of the current experiment revealed that ZnTrp applied at 12 mg/kg showed the maximum increase in root, shoot, and paddy weight (g/pot), which remained 12.9, 49.0, and 33.9, respectively. Maximum chlorophyll contents, photosynthetic rate, transpiration rate, stomatal conductance, and sub-stomatal carbon dioxide were with the application of ZnTrp to rice grown on salt affected soil. Maximum increase in Zn concentration in soil (391.3 %), roots (251.8 %), shoots (232.9 %), and paddy (287.8 %) were increased with the application of ZnTrp at 12 mg/kg compared to that with control. Maximum decrease in phytic acid in rice paddy was observed with the application of ZnTrp at higher application rate. It is concluded that the application of ZnTrp is an effective remedy to enhance the growth response and Zn fortification in rice grown on salt affected soil.