Coccinellid predation efficiency on Aphis gossypii (Hemiptera: Aphididae) under laboratory conditions.

In this study, we investigated the biological aspects and predation efficiency of 3 aphidophagous ladybird beetles, Coccinella novemnotata, Hippodamia variegata, and Coccinella septempunctata, on the cotton aphid, Aphis gossypii, reared on cucumber plants (Cucumis sativus L. cultivar barracuda) under laboratory conditions. The developmental periods of C. novemnotata, H. variegata, and C. septempunctata were observed to be 16.00 ±â€…0.25, 16.00 ±â€…0.25, and 20.58 ±â€…0.40 days, respectively. The larvae of these ladybird beetles consumed an average of 218.93 ±â€…8.86, 254.77 ±â€…8.86, and 537.36 ±â€…10.49 aphids, respectively. Fourth-instar larvae were particularly efficient, consuming 53.68%, 52.68%, and 52.64% of total aphids for C. novemnotata, H. variegata, and C. septempunctata, respectively. Adult emergence rates were promising, with 91.67%, 100.00%, and 92.86%, accompanied by sex ratios of 63.64%, 53.84%, and 61.54%, respectively. Notably, a single female of C. novemnotata, H. variegata, and C. septempunctata consumed an average of 2,215.30, 2,232.00, and 3,364.50 aphids, respectively, over its lifespan. Coccinella septempunctata demonstrated the highest predation efficiency among the 3 species, suggesting its potential for biological control of A. gossypii in both open fields and greenhouses, promoting sustainable agricultural practices.

Exogenous application of nano-silicon, potassium sulfate, or proline enhances physiological parameters, antioxidant enzyme activities, and agronomic traits of diverse rice genotypes under water deficit conditions.

Water deficit is a critical obstacle that devastatingly impacts rice production, particularly in arid regions under current climatic fluctuations. Accordingly, it is decisive to reinforce the drought tolerance of rice by employing sustainable approaches to enhance global food security. The present study aimed at exploring the effect of exogenous application using different biostimulants on physiological, morphological, and yield attributes of diverse rice genotypes under water deficit and well-watered conditions in 2-year field trial. Three diverse rice genotypes (IRAT-112, Giza-178, and IR-64) were evaluated under well-watered (14400 m3/ha in total for the entire season) and water deficit (9170 m3/ha) conditions and were exogenously sprayed by nano-silicon, potassium sulfate, or proline. The results showed that drought stress substantially decreased all studied photosynthetic pigments, growth traits, and yield attributes compared to well-watered conditions. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased compared with those under well-watered conditions. However, the foliar application of nano-silicon, potassium sulfate, and proline substantially mitigated the deleterious effects of drought stress and markedly enhanced photosynthetic pigments, antioxidant enzyme activities, growth parameters, and yield contributing traits compared to untreated stressed control. Among the assessed treatments, foliar spray with nano-silicon or proline was more effective in promoting drought tolerance. The exogenous application of proline improved chlorophyll a, chlorophyll b, and carotenoids by 21.4, 19.6 and 21.0% followed by nano-silicon treatment, which enhanced chlorophyll a, chlorophyll b, and carotenoids by 21.1, 17.6 and 9.5% compared to untreated control. Besides, the application of proline demonstrated a superior improvement in the content of proline by 52.5% compared with the untreated control. Moreover, nano-silicon exhibited the maximum enhancement of catalase and peroxidase activity compared to the other treatments. The positive impacts of applied exogenously nano-silicon or proline significantly increased panicle length, number of panicles/plant, number of grains/panicle, fertility percentage, 1000-grain weight, panicle weight, and grain yield, compared to untreated plants under water deficit conditions. In addition, the physiological and agronomic performance of evaluated rice genotypes significantly contrasted under drought conditions. The genotype Giza-178 displayed the best performance under water deficit conditions compared with the other genotypes. Consequently, the integration of applied exogenously nano-silicon or proline with tolerant rice genotype as Giza-178 is an efficient approach to ameliorating drought tolerance and achieving agricultural sustainability under water-scarce conditions in arid environments.

Response of nine triticale genotypes to different salt concentrations at the germination and early seedling stages.

Salinity stress poses a major challenge to agricultural productivity worldwide, and understanding their responses at the early growth stage is vital for devising strategies to cope with this stress. Therefore, to improve triticale productivity, this study investigated the salinity stress tolerance of different salt-tolerant triticale genotypes aiming to cultivate them on saline soils. To this end, salinity stress impacts on nine triticale genotypes, i.e., Zhongsi 1084, Gannong No. 2, Gannong No. 4, Shida No. 1, C6, C16, C23, C25 and C36 at germination and early seedling stages was evaluated. Each genotype was subjected to six treatments inducing control, 40, 80, 120, 160, and 200 mM NaCl treatments to study their effect on seedling and termination traits of the nine genotypes. Compared to the overall mean seedling vigor index, the seedling vigor index was higher in the genotypes Zhongsi 1084 and C6 (39% and 18.1%, respectively) and lower in Gannong No.2 (41%). Increasing NaCl concentrations negatively affected germination and seedling traits. Compared to other genotypes, Zhongsi 1084 had the highest mean germination rate, germination vigor index, germination percentage, mean daily germination and germination energy. It also showed the lowest relative salt injury. The relative salt injury was higher in the genotype Shida No. 1 than those in Gannong No. 2, Gannong No. 4, Shida No. 1, C16, and C36 genotypes. All genotypes exhibited desirable mean germination time except for line C6. High significant positive correlations were observed among germination rate, germination vigor index, germination percentage, mean daily germination, seedling vigor index, and root length. Principal component analysis (PCA) grouped the most desirable genotypes into two clusters. Our study determined salt stress tolerance of nine triticale genotypes at germination and early seedling stages. to select salt-tolerant genotypes that can be cultivated on saline soil or after salt irrigation.

Gamma-rays induced mutations increase soybean oil and protein contents.

Mutation breeding is one of the effective techniques used for improving desired traits such as yield quality and quantity in economic crops. The present study aims to develop oil and protein contents in addition to high yield attributes in soybean using gamma rays as a mutagen. Seeds of the soybean genotypes Giza 21, Giza 22, Giza 82, Giza 83 and 117 were treated with gamma rays doses 50, 100, 200 and 300 Gy. Plants were then scored based on morphological parameters correlated with yield quantity including plant height, seed weight and valuable protein and oil contents. Mutant lines exhibiting the highest yield attributes were selected and used as parents for M2 generation. The M2 progeny was further assessed based on their ability to maintain their yield attributes. Twenty mutant lines were selected and used as M3 lines. The yield parameters inferred a positive effect of gamma irradiation on the collected M3 mutant lines compared to their parental genotypes. 100 Gy of gamma rays gave the highest effect on the number of pods, branches and seeds per plant in addition to protein content, while 200 Gy was more effective in increasing plant height, number of pods per plant, and oil content. Six mutant lines scored the highest yield parameters. Further assessment inferred an inverse relationship between oil and protein content in most of the tested cultivars with high agronomic features. However, four mutant lines recorded high content of oil and protein besides their high seed yield as well, which elect them as potential candidates for large-scale evaluation. The correlation among examined parameters was further confirmed via principal component analysis (PCA), which inferred a positive correlation between the number of pods, branches, seeds, and seed weight. Conversely, oil and protein content were inversely correlated in most of yielded mutant lines. Together, those findings introduce novel soybean lines with favorable agronomic traits for the market. In addition, our research sheds light on the value of using gamma rays treatment in enhancing genetic variability in soybean and improving oil, protein contents and seed yield.

Assessment of intra- and inter-genetic diversity in tetraploid and hexaploid wheat genotypes based on omega, gamma and alpha-gliadin profiles.

Durum and bread wheat are well adapted to the Mediterranean Basin. Twenty-three genotypes of each species were grown to evaluate the intra- and inter-genetic diversity based on omega (ω), gamma (γ) and alpha (α)-gliadin profiles. To achieve this purpose, the endosperm storage proteins (both gliadins and glutenins) were extracted from wheat grains and electrophoresed on sodium dodecyl sulfate (SDS)-polyacrylamide gels. The results of SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) revealed nine polymorphic loci out of 16 loci with durum wheat genotypes and nine polymorphic loci out of 18 loci with bead wheat genotypes. The polymorphisms revealed by the SDS-PAGE were 56% and 50% in durum and bread wheat genotypes, respectively. Using the cluster analysis, the durum wheat genotypes were clustered into five groups, while the bread wheat genotypes were grouped into six clusters using un-weighed pair group mean analyses based on ω, γ, and α-gliadins profiles. The 46 durum and bread wheat genotypes were grouped into seven clusters based on the combined ω, γ, and α-gliadins profiles revealed by the SDS-PAGE. The in silico analysis determined the intra-genetic diversity between bread and durum wheat based on the sequences of ω, γ, and α-gliadins. The alignment of ω-gliadin revealed the highest polymorphism (52.1%) between bread and durum wheat, meanwhile, the alignment of γ and α-gliadins revealed very low polymorphism 6.6% and 15.4%, respectively. According to computational studies, all gliadins contain a lot of glutamine and proline residues. The analysis revealed that the bread wheat possessed ω and γ -gliadins with a lower content of proline and a higher content of glutamine than durum wheat. In contrast, durum wheat possessed α-gliadin with a lower content of proline and a higher content of glutamine than bread wheat. In conclusion, the SDS-PAGE, in silico and computational analyses are effective tools to determine the intra- and inter-genetic diversity in tetraploid and hexaploid wheat genotypes based on ω, γ, and α-gliadins profiles.

Salinity stress-induced phosphorylation of INDETERMINATE-DOMAIN 4 (IDD4) by MPK6 regulates plant growth adaptation in Arabidopsis.

The INDETERMINATE DOMAIN (IDD) family belongs to a group of plant-specific transcription factors that coordinates plant growth/development and immunity. However, the function and mode of action of IDDs during abiotic stress, such as salt, are poorly understood. We used idd4 transgenic lines and screened them under salt stress to find the involvement of IDD4 in salinity stress tolerance The genetic disruption of IDD4 increases salt-tolerance, characterized by sustained plant growth, improved Na+/K+ ratio, and decreased stomatal density/aperture. Yet, IDD4 overexpressing plants were hypersensitive to salt-stress with an increase in stomatal density and pore size. Transcriptomic and ChIP-seq analyses revealed that IDD4 directly controls an important set of genes involved in abiotic stress/salinity responses. Interestingly, using anti-IDD4-pS73 antibody we discovered that IDD4 is specifically phosphorylated at serine-73 by MPK6 in vivo under salinity stress. Analysis of plants expressing the phospho-dead and phospho-mimicking IDD4 versions proved that phosphorylation of IDD4 plays a crucial role in plant transcriptional reprogramming of salt-stress genes. Altogether, we show that salt stress adaption involves MPK6 phosphorylation of IDD4 thereby regulating IDD4 DNA-binding and expression of target genes.

Exploring Salinity Tolerance Mechanisms in Diverse Wheat Genotypes Using Physiological, Anatomical, Agronomic and Gene Expression Analyses.

Salinity is a widespread abiotic stress that devastatingly impacts wheat growth and restricts its productivity worldwide. The present study is aimed at elucidating biochemical, physiological, anatomical, gene expression analysis, and agronomic responses of three diverse wheat genotypes to different salinity levels. A salinity treatment of 5000 and 7000 ppm gradually reduced photosynthetic pigments, anatomical root and leaf measurements and agronomic traits of all evaluated wheat genotypes (Ismailia line, Misr 1, and Misr 3). In addition, increasing salinity levels substantially decreased all anatomical root and leaf measurements except sclerenchyma tissue upper and lower vascular bundle thickness compared with unstressed plants. However, proline content in stressed plants was stimulated by increasing salinity levels in all evaluated wheat genotypes. Moreover, Na+ ions content and antioxidant enzyme activities in stressed leaves increased the high level of salinity in all genotypes. The evaluated wheat genotypes demonstrated substantial variations in all studied characters. The Ismailia line exhibited the uppermost performance in photosynthetic pigments under both salinity levels. Additionally, the Ismailia line was superior in the activity of superoxide dismutase (SOD), catalase activity (CAT), peroxidase (POX), and polyphenol oxidase (PPO) enzymes followed by Misr 1. Moreover, the Ismailia line recorded the maximum anatomical root and leaf measurements under salinity stress, which enhanced its tolerance to salinity stress. The Ismailia line and Misr 3 presented high up-regulation of H+ATPase, NHX2 HAK, and HKT genes in the root and leaf under both salinity levels. The positive physiological, anatomical, and molecular responses of the Ismailia line under salinity stress were reflected on agronomic performance and exhibited superior values of all evaluated agronomic traits.

Microbe-induced drought tolerance by ABA-mediated root architecture and epigenetic reprogramming.

The use of beneficial microbes to mitigate drought stress tolerance of plants is of great potential albeit little understood. We show here that a root endophytic desert bacterium, Pseudomonas argentinensis strain SA190, enhances drought stress tolerance in Arabidopsis. Transcriptome and genetic analysis demonstrate that SA190-induced root morphogenesis and gene expression is mediated via the plant abscisic acid (ABA) pathway. Moreover, we demonstrate that SA190 primes the promoters of target genes in an epigenetic ABA-dependent manner. Application of SA190 priming on crops is demonstrated for alfalfa, showing enhanced performance under drought conditions. In summary, a single beneficial root bacterial strain can help plants to resist drought conditions.