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

Assessment of genetic diversity by phenological traits, field performance, and Start Codon Targeted (SCoT) polymorphism marker of seventeen soybean genotypes (Glycine max L.)

The Egyptian-farmed soybeans have a wide range of genetic diversity which is most important in plant improvement programs in order to develop new higher yielding soybean genotypes. The present study is designed to determine the genetic variability among seventeen genotypes of cultivated soybean (Glycine max L.) by examining the phenotypic level at the seedling stage, field performance over two years 2022/2023 and genetically using Start Codon Targeted (SCoT) markers. Results indicated that the SCoT markers, 100 seed weight, and tip angle (TA) traits were positively correlated with H2L12, DR 101, H15L5, and H117 genotypes. In addition, the number of branches per plant and plant height were associated with H113, H32, Crowford, H129, and D7512035. Furthermore, the length of the first internode (LFI), root width (RW), root length (RL), and shoot length (SL) were more associated with Giza 111, NC105, and Hutcheson. The hierarchical cluster analysis (HCA) and its associated heatmap explored the differences among the genotypes. It showed that all examined parameters were clustered into four distinct clusters. The obtained results showed that genotypes NC105, H30, D75_12035, and H2L12 have promising phenological and morphological traits besides tracking the inheritance of nearby genes surrounding the ATG translation start codon since they are in a monoclades. The obtained results will help the breeder plan appropriate selection strategies for improving seed yield in soybeans through hybridization from divergent clusters.

Investigation of genetic diversity using molecular and biochemical markers associated with powdery mildew resistance in different flax (Linum usitatissimum L.) genotypes

Under greenhouse conditions, the resistance of 18 different genotypes of flax to powdery mildew was evaluated. To investigate genetic diversity and identify the molecular and biochemical markers linked to powdery mildew resistance in the tested genotypes, two molecular marker systems-start codon targeted (SCoT) and inter-simple sequence repeat (ISSR)-as well as a biochemical marker (protein profiles, antioxidant enzyme activity, and secondary metabolites) were used. Based on the results, the genotypes were classified into four categories: highly susceptible, susceptible, moderately susceptible, and moderately resistant. The genotypes differed significantly in powdery mildew severity: Polk had a severity of 92.03% and Leona had a severity of 18.10%. Compared to the other genotypes, the moderately resistant genotypes had higher levels of flavonoids, antioxidant enzymes, phenolics, and straw yield; nevertheless, their hydrogen peroxide and malondialdehyde levels were lower. Protein profiles revealed 93.75% polymorphism, although the ISSR marker displayed more polymorphism (78.4%) than the SCoT marker (59.7%). Specific molecular and biochemical markers associated with powdery mildew resistance were identified. The 18 genotypes of flax were divided into two major clusters by the dendrogram based on the combined data of molecular markers. The first main cluster included Leona (genotype number 7), considered moderate resistance to powdery mildew and a separate phenetic line. The second main cluster included the other 17 genotypes, which are grouped together in a sub-cluster. This means that, besides SCoT, ISSR markers can be a useful supplementary technique for molecular flax characterization and for identifying genetic associations between flax genotypes under powdery mildew infection.

Genetic variability and diversity analysis in Oryza sativa L. genotypes using quantitative traits and SSR markers

The present study was aimed at evaluating the genetic variation and population structure in a collection of 22 rice genotypes. Twenty-two rice genotypes were assessed using quantitative traits and SSR molecular markers for genetic variability and genetic diversity. As for genetic diversity, the genotypes were clarified based on twelve quantitative traits. Clustering produced two large groups: the IR70423-169-2-2 variety was in a branch alone due to its long duration, while, the second group included all rest of genotypes and was split up into two sub-groups. The first sub-group included IR67418-131-2-3-3-3, IR67420-206-3-1-3-3, Giza181, Giza182, Sakha104, and P1044-86-5-3-3-2M. However, pedigree played in divided clustering with Giza181 and Giza182, which were belonging to the Indica type and produced from the same parents. SSR markers produced 87 alleles, with a mean of 4.3 alleles per locus, which were detected in 22 rice genotypes. A higher number of alleles were found with primers RM262, RM244, RM3843, RM212, and RM3330. With an overall mean of 0.837, the polymorphic information content values were high for all SSR markers, ranging from a low of 0.397 for M254 to a high of 0.837 for RM244. The dendogram was divided into six groups according to the types of genotypes, with the pedigree playing a major role for the genetic distance. In order to help breeders choose parents and create suitable hybrids to achieve genetic improvement in crops, particularly rice, SSR is a useful technique for analysing genotype diversity and aiding in the genetic fingerprinting of each variety.

A review on endophytic fungi: a potent reservoir of bioactive metabolites with special emphasis on blight disease management

Phytopathogenic microorganisms have caused blight diseases that present significant challenges to global agriculture. These diseases result in substantial crop losses and have a significant economic impact. Due to the limitations of conventional chemical treatments in effectively and sustainably managing these diseases, there is an increasing interest in exploring alternative and environmentally friendly approaches for disease control. Using endophytic fungi as biocontrol agents has become a promising strategy in recent years. Endophytic fungi live inside plant tissues, forming mutually beneficial relationships, and have been discovered to produce a wide range of bioactive metabolites. These metabolites demonstrate significant potential for fighting blight diseases and provide a plentiful source of new biopesticides. In this review, we delve into the potential of endophytic fungi as a means of biocontrol against blight diseases. We specifically highlight their significance as a source of biologically active compounds. The review explores different mechanisms used by endophytic fungi to suppress phytopathogens. These mechanisms include competing for nutrients, producing antifungal compounds, and triggering plant defense responses. Furthermore, this review discusses the challenges of using endophytic fungi as biocontrol agents in commercial applications. It emphasizes the importance of conducting thorough research to enhance their effectiveness and stability in real-world environments. Therefore, bioactive metabolites from endophytic fungi have considerable potential for sustainable and eco-friendly blight disease control. Additional research on endophytes and their metabolites will promote biotechnology solutions.

Biogenic Selenium Nanoparticles: Anticancer, Antimicrobial, Insecticidal Properties and Their Impact on Soybean (Glycine max L.) Seed Germination and Seedling Growth

Selenium nanoparticles (SeNPs) have demonstrated significant potential in a variety of disciplines, making them an extremely desirable subject of research. This study investigated the anticancer and antibacterial properties of my-co-fabricated selenium SeNPs, as well as their effects on soybean (Glycine max L.) seeds, seedling growth, cotton leafworm (Spodoptera littoralis) combat, and plant pathogenic fungi inhibition. SeNPs showed anticancer activity with an IC50 value of 1.95 µg/mL against MCF-7 breast adenocarcinoma cells. The myco-synthesized SeNPs exhibited an antibacterial effect against Proteus mirabilis and Klebsiella pneumoniae at 20 mg/mL. The use of 1 µM SeNPs improved soybean seed germination (93%), germination energy (76.5%), germination rate (19.0), and mean germination time (4.3 days). At 0.5 and 1.0 µM SeNPs, the growth parameters of seedlings improved. SeNPs increased the 4th instar larval mortality of cotton leafworm compared to control, with a median lethal concentration of 23.08 mg/mL. They inhibited the growth of Fusarium oxysporum, Rhizoctonia solani, and Fusarium solani. These findings demonstrate that biogenic SeNPs represent a promising approach to achieving sustainable progress in the fields of agriculture, cancer therapy, and infection control.

Ultraviolet-B radiation in relation to agriculture in the context of climate change: a review

Over the past few decades, the amount of ultraviolet-B radiation (UV-B) reaching the earth's surface has been altered due to climate change and stratospheric ozone dynamics. This narrow but highly biologically active spectrum of light (280-320 nm) can affect plant growth and development. Depletion of ozone and climate change are interlinked in a very complicated manner, i.e., significantly contributing to each other. The interaction of climate change, ozone depletion, and changes in UV-B radiation negatively affects the growth, development, and yield of plants. Furthermore, this interaction will become more complex in the coming years. The ozone layer reduction is paving a path for UV-B radiation to impact the surface of the earth and interfere with the plant's normal life by negatively affecting the plant's morphology and physiology. The nature and degree of the future response of the agricultural ecosystem to the decreasing or increasing UV-B radiation in the background of climate change and ozone dynamics are still unclear. In this regard, this review aims to elucidate the effects of enhanced UV-B radiation reaching the earth's surface due to the depletion of the ozone layer on plants' physiology and the performance of major cereals.

Mulching as a Sustainable Water and Soil Saving Practice in Agriculture: A Review

This research was carried out in order to demonstrate that mulching the ground helps to conserve water, because agricultural sustainability in dryland contexts is threatened by drought, heat stress, and the injudicious use of scarce water during the cropping season by minimizing surface evaporation. Improving soil moisture conservation is an ongoing priority in crop outputs where water resources are restricted and controlled. One of the reasons for the desire to use less water in agriculture is the rising demand brought on by the world’s growing population. In this study, the use of organic or biodegradable mulches was dominated by organic materials, while inorganic mulches are mostly comprised of plastic-based components. Plastic film, crop straw, gravel, volcanic ash, rock pieces, sand, concrete, paper pellets, and livestock manures are among the materials put on the soil surface. Mulching has several essential applications, including reducing soil water loss and soil erosion, enriching soil fauna, and improving soil properties and nutrient cycling in the soil. It also reduces the pH of the soil, which improves nutrient availability. Mulching reduces soil deterioration by limiting runoff and soil loss, and it increases soil water availability by reducing evaporation, managing soil temperature, or reducing crop irrigation requirements. This review paper extensively discusses the benefits of organic or synthetic mulches for crop production, as well as the uses of mulching in soil and water conservation. As a result, it is very important for farmers to choose mulching rather than synthetic applications.

Appraisal of kinetin spraying strategy to alleviate the harmful effects of UVC stress on tomato plants

Increasing ultraviolet (UV) radiation is causing oxidative stress that accounts for growth and yield losses in the present era of climate change. Plant hormones are useful tools for minimizing UV-induced oxidative stress in plants, but their putative roles in protecting tomato development under UVC remain unknown. Therefore, we investigated the underlying mechanism of pre-and post-kinetin (Kn) treatments on tomato plants under UVC stress. The best dose of Kn was screened in the preliminary experiments, and this dose was tested in further experiments. UVC significantly decreases growth traits, photosynthetic pigments, protein content, and primary metabolites (proteins, carbohydrates, amino acids) but increases oxidative stress biomarkers (lipid peroxidation, lipoxygenase activity, superoxide anion, hydroxyl radical, and hydrogen peroxide) and proline content. Treatment of pre-and post-kinetin spraying to tomato plants decreases UVC-induced oxidative stress by restoring the primary and secondary metabolites' (phenolic compounds, flavonoids, and anthocyanins) status and upregulating the antioxidant defense systems (non-enzymatic antioxidants as ascorbate, reduced glutathione, α-tocopherol as well as enzymatic antioxidants as superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, glutathione-S-transferase, and phenylalanine ammonia-lyase). Thus, the application of Kn in optimum doses and through different modes can be used to alleviate UVC-induced negative impacts in tomato plants.

Pathogenicity of Bacillus Strains to Cotton Seedlings and Their Effects on Some Biochemical Components of the Infected Seedlings

Pathogenicity of eight Bacillus strains to seedlings of four cotton cultivars was evaluated under greenhouse conditions. Each of the tested cultivars was individually treated with powdered inoculum of each bacterial strain. Untreated seeds were planted as control treatments in autoclaved soil. Effects of the tested strains on levels and activities of some biochemical components of the infected seedlings were also assayed. The biochemical components included total soluble sugars, total soluble proteins, total free amino acids, peroxidase, polyphenol oxidase, phenols, and lipid peroxidation. ANOVA showed that Bacillus strain (B) was a very highly significant source of variation in damping-off and dry weight. Cotton cultivar (V) was a nonsignificant source of variation in damping-off while it was a significant source of variation in dry weight. B × V interaction was a significant source of variation in damping-off and a nonsignificant source of variation in dry weight. Bacillus strain was the most important source of variation as it accounted for 59.36 and 64.99% of the explained (model) variation in damping-off and dry weight, respectively. The lack of significant correlation between levels and activities of the assayed biochemical components and incidence of damping-off clearly demonstrated that these biochemical components were not involved in the pathogenicity of the tested strains. Therefore, it was hypothesized that the pathogenicity of the tested strains could be due to the effect of cell wall degrading enzymes of pathogenic toxins. Based on the results of the present study, Bacillus strains should be considered in studying the etiology of cotton seedling damping-off.

Agro-morphological and genetic diversity studies in Rice (Oryza sativa L.) germplasm using microsatellite markers

BACKGROUND

Knowledge of the genetic diversity and population structure of germplasm collections is an important foundation for crop improvement. Rice production across a broad range of rice-growing environments results in a diverse array of local rice varieties. Many rice varieties have been lost as a result of biodiversity loss and are now grown in Pakistan.

METHODS AND RESULTS

To protect the biodiversity of rice varieties, an experiment was carried out to check the genetic and morphological variations between 8 exotic and 7 local rice genotypes, using 5 different SSR markers, i.e., RM3, RM259, RM341, RM520, and RM11943. The analysis of morphological and quality traits of rice observed significant variation across genotypes. The results revealed that genotype Irri-Pak attained the highest plant height and primary branch plant-1, while genotype Mushkan produced a higher number of productive tillers and obtained a higher fertility factor (%). Similarly, the highest value for panicle length was observed for genotype Faker-e-Malakand, 1000-grains weight in genotype Calmochi, and maximum days to maturity was noticed in genotype Swati-2014. Moreover, the genotype Brio attained the highest value of stem diameter, while maximum seed length was noted in the genotype Sug Dasi. The highest number of primary branches plant^-1 in genotype Ibge-I and secondary branches plant^-1 in genotype Calmochi were noticed. A higher concentration of sodium and potassium was observed for the genotype Marte, while the genotype Muskan attained the maximum content of copper. Moreover, the highest concentration of iron in genotype Originario, zinc in genotype JP-5, and cadmium content were noticed in genotype Ibge. Similarly, the dendrogram analysis for quantitative parameters showed three clusters at 74.13% similarities. Whereas all the genotypes of European origin formed a separate cluster. A set of 5 simple sequence repeat primers, covering four chromosomes, amplified a total of 14 alleles and showed 100% polymorphism with an average PIC value ranging from 0.39 to 0.91. The UPGMA cluster analysis separated the 15 rice genotypes into 3 main groups based on 32.5% similarities and the highest genetic distance (45.1%) was observed between two genotypes (Fakher-e-malakand and Musa), having different geographical origins. There was no genetic distance between the genotypes Marte and Brio, irrespective of having the same origin.

CONCLUSIONS

The maximum genetic distances were noted for genotype, Fakhre-e-Malakand and Musa having a different origin, while the minimum genetic distance was shown by genotypes, Marte and Onice, from the same origin.

Comparative studies of eco-friendly compounds like humic acid, salicylic, and glycyrrhizic acids and their nanocomposites on French basil (Ocimum basilicum L. cv. Grand verde)

As the green tactics for enhancing plant growth and production using naturally occurring materials are highly needed, it is important to use the nanoformulation of these materials as an attractive novel technique. Therefore, this research has been performed to evaluate the plants' morphological traits, the qualitative parameters, and molecular genetic characteristics using random amplified polymorphic DNA (RAPD) of French basil independence on growth biostimulators and their nanocomposite. The treatments included normal formulations and nanocomposite formulation of humic acid (5 mM HA), salicylic acid (1.4 mM SA), and glycyrrhizic acid ammonium salt (0.4 mM GA) and control treatment (water application). The results show that foliar spray with HA, SA, GA, and their nanocomposites significantly increased (p ≤ 0.05) on all vegetative growth characters, photosynthetic pigments, oil yield/plant, mineral content, and antibacterial activity as compared with control plants. Also, 1,1-diphenyl-2-picrylhydrazyl (DPPH) values of different samples used varied from 70.63 to 74.93%, with a significant increase compared to untreated plants. The most marked increases have been observed in treated plants with biostimulants in the nanocomposites form than in the natural form. On the other hand, GA and its nanocomposite showed variable effects on basil plants and gave the lowest increase values in all parameters than the other biostimulant but have high antimicrobial activity. For the molecular study, ten selected primers displayed a total of 288 amplified fragments scored per primer ranging from 7 to 46 fragments; 157 bands were polymorphic with 69% polymorphism. It could be concluded that humic acid and its nanocomposite are the most effective biostimulants that increased plant productivity and oil content.

Protective role of fat hen (Chenopodium album L.) extract and gamma irradiation treatments against fusarium root rot disease in sunflower plants

One of the most drastic diseases causing economic losses in sunflower crops is fusarium root rot caused by Fusarium solani. Plant extracts and ionizing radiation provide alternative environmentally safe control agents that have a significant role in controlling and overcoming this fungal plant pathogen. In the present study, the effect of different concentrations of aqueous Chenopodium album extract (2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6.0%) and gamma radiation at a dose of 6 Gy were examined for their efficacy in inducing resistance of sunflower plants against fusarium root rot caused by F. solani MG-3 by evaluation of some physiological and biochemical parameters of infected and healthy plants under greenhouse conditions. The pre-treatment of sunflower seeds with 6% C. album extract and 6 Gy gamma radiation reduced fusarium incidence from 47.49% to 28.25%. Also, nucleic acid content, ascorbic acid, α-tocopherol, anthocyanin, total flavonoids, proline, glycine betaine and lipid components significantly increased in irradiated infected plants treated with C. album extract, while H₂ O₂ content and lipid peroxidation markedly decreased as compared with healthy control plants. Moreover, treatment with gamma radiation reduced the amount of unsaturated fatty acids through accumulation of saturated fatty acids compared with non-irradiated plants; treatment with C. album extract also enhanced the content of unsaturated fatty acids, with a noticeable decrease in saturated fatty acid content. Hence, C. album extract and gamma radiation can be used to enhance biological control of fusarium root rot of sunflower plants.

Biological control: a novel strategy for the control of the plant parasitic nematodes

Plant parasitic nematodes (Root-knot nematodes, Meloidogyne spp.) are rounded worms, microscopic, and cause many agricultural economic losses. Their attacks have a direct impact on the productivity of cultivated crops by reducing their fruit quantity. Chemical control is widespread all over the world, but biological control is the most effective way to reduce the number of pests that infect crops, particularly by the use of microorganisms like fungi and bacteria. Biological control is rapidly evolving, and more products are being sold worldwide over time. They can be produced by fungi, bacteria, or actinomycetes that can destruct plant parasite nematodes and feed on them. Nematophagous microorganisms as the natural enemies of nematodes have a promising way of controlling nematodes. Some of them create net-like substances and traps to take the worms from outside and finally kill them. Other parasites serve as internal parasites in order to produce toxins and to produce virulence to kill nematodes. Comprehension of the molecular basis for microbial nematode interactions gives important insights into how successful biological nematode control agents can be created. We discuss recent advances in our understanding of nematodes and nematophagous microorganisms, with an emphasis on molecular mechanisms that infect nematodes with nematophagous microorganisms and on nematode safety from pathogenic attacks. Finally, we addressed numerous key areas for future research and development, including possible approaches to the application of our recent expertise in the development of successful biocontrol strategies.

Ursolic Acid Limits Salt-Induced Oxidative Damage by Interfering With Nitric Oxide Production and Oxidative Defense Machinery in Rice

Crops frequently encounter abiotic stresses, and salinity is a prime factor that suppresses plant growth and crop productivity, globally. Ursolic acid (UA) is a potential signaling molecule that alters physiology and biochemical processes and activates the defense mechanism in numerous animal models; however, effects of UA in plants under stress conditions and the underlying mechanism of stress alleviation have not been explored yet. This study examined the effects of foliar application of UA (100 μM) to mitigate salt stress in three rice cultivars (HZ, 712, and HAY). A pot experiment was conducted in a climate-controlled greenhouse with different salt stress treatments. The results indicated that exposure to NaCl-induced salinity reduces growth of rice cultivars by damaging chlorophyll pigment and chloroplast, particularly at a higher stress level. Application of UA alleviated adverse effects of salinity by suppressing oxidative stress (H2O2, O2-) and stimulating activities of enzymatic and non-enzymatic antioxidants (APX, CAT, POD, GR, GSH, AsA, proline, glycinebutane), as well as protecting cell membrane integrity (MDA, LOX, EL). Furthermore, UA application brought about a significant increase in the concentration of leaf nitric oxide (NO) by modulating the expression of NR and NOS enzymes. It seems that UA application also influenced Na+ efflux and maintained a lower cytosolic Na+/K+ ratio via concomitant upregulation of OsSOS1 and OsHKT1;5 in rice cultivars. The results of pharmacological tests have shown that supply of the NO scavenger (PTI) completely reversed the UA-induced salt tolerance in rice cultivars by quenching endogenous NO and triggering oxidative stress, Na+ uptake, and lipid peroxidation. The PTI application with UA and sodium nitroprusside (SNP) also caused growth retardation and a significant increase in Na+ uptake and oxidative stress in rice cultivars. This suggests that UA promoted salt tolerance of rice cultivars by triggering NO production and limiting toxic ion and reactive oxygen species (ROS) accumulation. These results revealed that both UA and NO are together required to develop a salt tolerance response in rice.

Minimizing Adverse Effects of Pb on Maize Plants by Combined Treatment with Jasmonic, Salicylic Acids and Proline

Lead (Pb) is a toxic heavy metal (HM) that harms plant growth and productivity. Phytohormones, such as jasmonic acid (JA) and salicylic acid (SA), and osmoprotectants, such as proline (Pro), play an important role in the physiological and biochemical processes of plants. We investigated the effect of exogenous applications of JA, SA, Pro, and their combination on Pb-stress tolerance in maize as well as their effect on physiological, biochemical, and yield traits. Pb exposure severely affected maize plants, reducing growth, yield, photosynthetic pigments, and mineral (nitrogen, phosphorus, and potassium) nutrients, as well as enhancing electrolyte leakage (EL), malondialdehyde (MDA) accumulation, osmolytes, and non-enzymatic and enzymatic antioxidants. The application of JA, SA, Pro, and their combination enhanced plant growth and induced pigment biosynthesis, and decreased EL, MDA accumulation, and Pb concentration. All treatments enhanced Pro and total soluble sugar production, glutathione activity, ascorbic acid, phenol, superoxide dismutase, catalase, peroxidase, and mineral nutrients. JA, SA, and Pro application improved physiological processes directly or indirectly, thereby enhancing the ability of maize plants to overcome oxidative damage caused by Pb toxicity. The combination of JA, SA, and Pro was the most efficient treatment for maize plant growth and development, eliminating the negative consequences of Pb stress.

Lead Toxicity in Cereals: Mechanistic Insight Into Toxicity, Mode of Action, and Management

Cereals are the major contributors to global food supply, accounting for more than half of the total human calorie requirements. Sustainable availability of quality cereal grains is an important step to address the high-priority issue of food security. High concentrations of heavy metals specifically lead (Pb) in the soil negatively affect biochemical and physiological processes regulating grain quality in cereals. The dietary intake of Pb more than desirable quantity via food chain is a major concern for humans, as it can predispose individuals to chronic health issues. In plant systems, high Pb concentrations can disrupt several key metabolic processes such as electron transport chain, cellular organelles integrity, membrane stability index, PSII connectivity, mineral metabolism, oxygen-evolving complex, and enzymatic activity. Plant growth-promoting rhizobacteria (PGPR) has been recommended as an inexpensive strategy for remediating Pb-contaminated soils. A diverse group of Ascomycetes fungi, i.e., dark septate endophytes is successfully used for this purpose. A symbiotic relationship between endophytes and host cereal induces Pb tolerance by immobilizing Pb ions. Molecular and cellular modifications in plants under Pb-stressed environments are explained by transcription factor families such as bZIP, ERF, and GARP as a regulator. The role of metal tolerance protein (MTP), natural resistance-associated macrophage protein (NRAMP), and heavy metal ATPase in decreasing Pb toxicity is well known. In the present review, we provided the contemporary synthesis of existing data regarding the effects of Pb toxicity on morpho-physiological and biochemical responses of major cereal crops. We also highlighted the mechanism/s of Pb uptake and translocation in plants, critically discussed the possible management strategies and way forward to overcome the menace of Pb toxicity in cereals.