The efficacy of chemical inducers and fungicides in controlling tomato root rot disease caused by Rhizoctoniasolani.

Chitosan is an environmentally friendly natural substance that is used in crop disease management as an alternative to chemical pesticides. A significant issue restricting output in Egypt is root rot, which is a disease, caused by Rhizoctonia solani. Therefore, a greenhouse experiment was conducted to assess the effects of R. solani on 60-day-old tomato plants under fungal infection and to determine the antifungal activity of chitosan and Rizolax T fungicide against the pathogenic fungus. The findings demonstrated that 4 g/L of chitosan seed application completely obstructed the radial mycelial growth of R. solani and decreased the disease severity. Pathogenic infection significantly decreased morphological characteristics and total chlorophyll but significantly increased carotenoid, total thiol, non-protein thiol, protein thiol, antioxidant enzymes, oxidative stress, total phenolic, total flavonoid, and isoflavone compared to healthy plants. Tomato plants treated with chitosan exhibited lower rates of oxidative stress, but higher levels of all previously mentioned parameters compared to untreated infected plants. The number and molecular mass of protein banding patterns varied in all treated tomato plants as compared to the healthy control. There are 42 bands in the treatments, and their polymorphism rate is 69.55%. Moreover, the number and density of α- and ß-esterase, and peroxidase isozymes in treated tomato plants exhibited varied responses. Moreover, in treated and control plants, chitosan treatment raised the expression levels of phenylalanine ammonia-lyase, pathogenesis-related protein-1, ß-1,3-glucanases and chitinase. In conclusions, chitosan reduces R. solani infection by controlling the biochemical and molecular mechanisms in tomato plants during infection.

Exogenous Calcium Reinforces Photosynthetic Pigment Content and Osmolyte, Enzymatic, and Non-Enzymatic Antioxidants Abundance and Alleviates Salt Stress in Bread Wheat.

One of the main environmental stresses that hinder crop development as well as yield is salt stress, while the use of signal molecules such as calcium (Ca) has a substantial impact on reducing the detrimental effects of salt on different crop types. Therefore, a factorial pot experiment in a completely randomized design was conducted to examine the beneficial role of Ca (0, 2.5, and 5 mM) in promoting the physiological, biochemical, and growth traits of the wheat plant under three salt conditions viz. 0, 30, and 60 mM NaCl. Foliar application of Ca increased the growth of salt-stressed wheat plants through increasing photosynthetic pigments, IAA, proline, and total soluble sugars contents and improving antioxidant enzymes in addition to non-enzymatic antioxidants glutathione, phenol and flavonoids, ß-carotene, and lycopene contents, thus causing decreases in the over-accumulation of free radicals (ROS). The application of Ca increased the activity of antioxidant enzymes in wheat plants such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), which scavenge reactive oxygen species (ROS) and relieved salt stress. An additional salt tolerance mechanism by Ca increases the non-antioxidant activity of plants by accumulating osmolytes such as free amino acids, proline, and total soluble sugar, which maintain the osmotic adjustment of plants under salinity stress. Exogenous Ca application is a successful method for increasing wheat plants' ability to withstand salt stress, and it has a considerable impact on the growth of wheat under salt stress.

Biosorption effect of Aspergillus niger and Penicillium chrysosporium for Cd- and Pb-contaminated soil and their physiological effects on Vicia faba L.

Phytoremediation is an important solution to soil pollution management. The goal of this study is to determine the biosorption ability of the two selected fungi (Aspergillus niger and Penicillium chrysosporium) under heavy metal stress on faba bean plants. The fungal strains produced phytohormones, siderophore, ACC deaminase, and secondary metabolites. The biosorption capacity of A. niger and P. chrysosporium was 0.09 and 0.06 mg g-1 and 0.5 and 0.4 mg g-1 in media containing Cd and Pb, respectively. Fourier transform infrared spectroscopy of the fungal cell wall show primary functional groups like hydroxyl, amide, carboxyl, phosphoryl, sulfhydryl, and nitro. Therefore, A. niger and P. chrysosporium were inoculated to soils, and then the faba bean seeds were sown. After 21 days of sowing, the plants were irrigated with water to severe as control, with 100 mg L-1 of Cd and 200 mg L-1 of Pb. The results show that Cd and Pb caused a significant reduction in morphological characteristics, auxin, gibberellins, photosynthetic pigments, minerals content, and antioxidant enzymes as compared to control plants but caused a substantial boost in abscisic acid, ethylene, electrolyte leakage, lipid peroxidation, glutathione, proline, superoxide dismutase, secondary metabolites, and antioxidant capacity. In inoculated plants, metal-induced oxidative stress was modulated by inhibiting the transport of metal and decreased electrolyte leakage and lipid peroxidation. Finally, the inoculation of endophytic fungi contributed actively to the absorption of heavy metals and decreased their content in soil and plants. This could be utilized as an excellent technique in the fields of heavy metal-contaminated sustainable agriculture.

Physiological and molecular genetic studies on two elicitors for improving the tolerance of six Egyptian soybean cultivars to cotton leaf worm.

Cotton leaf worm (Spodoptera littoralis) is considered one of the most destructive agricultural pests in Egypt. Six soybean cultivars (Giza-21, Giza-22, Giza-35, Giza-82, Giza-83 and Giza-111) were grown under natural infection with cotton leaf worm. The effect of two elicitors, methyl jasmonate and sodium nitroprusside on enhancing the ability of susceptible cultivars to tolerate (Spodoptera littoralis) was studied. Giza-35 and Giza-111 showed tolerance performance under natural infection compared to Giza-22 and Giza-82 as sensitive ones, while Giza-83 and Giza-21 showed moderate tolerance. Both treatments positively affected seed yield and its components and fatty acid composition. Extracted fatty acids showed variable changes in treated plants compared with the untreated controls. Plants treated with the two elicitors showed an increase in Linoleic acid and Linolenic acid fatty acids and decrease in Palmitic acid and Palmitolic acid content. Treatment with methyl jasmonate was found to be more effective than sodium nitroprusside and enhanced resistance of the susceptible cultivars. Eight IRAP and iPBS retrotransposon-based markers were used to detect genetic differences among studied soybean cultivars and to develop molecular genetic markers for cotton leaf worm infestation. The technique successfully identified soybean genotypes in addition to nineteen molecular markers related to soybean tolerance.