Total Photosynthetic Pigments Research Articles

Growth and biomass yield responses of Sphenostylis stenocarpa (Hochst. Ex A. Rich.) Harms accessions to waterlogging stress

Effects of waterlogging on the growth of six accessions of Sphenostylis stenocarpa were investigated. There accessions were TSs-5, TSs-7, TSs-8, TSs-9 TSs-10 and TSs-11. After growing S. stenocarpa for 4 weeks, results indicated that waterlogging significantly (p=0.05) reduced its growth parameters of S. stenocarpa. For shoot length; TSs-9 recorded the highest value (48.27±2.92 cm) above its control while TSs-11 (17.96±1.13 cm) had the lowest value. For petiole length, TSs-9 (3.62±0.33 cm) recorded the highest value while TSs-8 (0.93±0.93 cm) recorded the lowest value. Internode length had TSs-7 (6.10±0.78 cm) had the highest value while TSs-8 (2.87±2.87 cm) had the lowest value. The total photosynthetic pigment measurement showed that TSs-5 (45.0±0.65 mg/kg) with the highest value and TSs-8 (33.37±14.00 mg/kg) had the lowest value. For leaf area, TSs-7 (25.73±4.21 cm2) had the highest value while TSs-11 (16.13±2.82 cm2) recorded the lowest value. Total Fresh Weight (TFW), TSs-7 recorded the highest value (4.96 g) while TSs-8 recorded the lowest value (1.75 g). Root Fresh Weight (RFW), Tss-5 was observed to have the highest value (1.44 g) while Tss-11 recorded the lowest value (0.56 g). However, at 2 weeks after planting the effect of waterlogging stress on the growth parameter was not significant. The reduction in the growth of S. stenocarpa as a result of waterlogging stress might be due to the detrimental effect of flooding on O2 availability for plant cells and other plant metabolic activities of the plant. In areas with waterlogged soil conditions, S. stenocarpa should not be cultivated as it has poor and relatively low tolerance towards withstanding the impact of waterlogging; however, accession TSs-9 showed promising waterlogging tolerance ability.

Screening of Vigna subterranean L. Verdc. accessions for waterlogging stress tolerance

<p>This study evaluated the influence of waterlogging stress on the growth of six (6) accessions (TvSu-1, TvSu-2, TvSu-3, TvSu-4, TvSu-5, and TvSu-10) of <em>Vigna subterranean</em> in a pot experiment. The experiment was setup in a complete block design (CBD) with 3 replicates per treatment. Results of growth parameters of <em>V. subterranean</em> accessions under waterlogging stress, such as plant height, leaf area, petiole length, and number of nodes, were significantly (<em>p </em>= 0.05) decreased when compared to their controls after 8 weeks of planting. For shoot length, TvSu-2 (1.60 ± 0.20 cm) and TvSu-4 (1.60 ± 0.20 cm) recorded the highest values, while TvSu-5 (1.23 ± 0.03) and TvSu-10 (1.23 ± 0.03) had the lowest values, respectively. TvSu-5 (19.03 ± 0.59 cm<sup>2</sup>) and TvSu-10 (19.03 ± 0.59 cm<sup>2</sup>) recorded the highest values in leaf area (LA), while TvSu-3 (14.40 ± 0.51 cm<sup>2</sup>) had the lowest LA. For total photosynthetic pigment (TPP), TvSu-2, TvSu-4, and TvSu-10 had the highest values, with 57.35 ± 1.82 mg/kg, 55.80 ± 2.70 mg/kg, and 55.77 ± 1.90 mg/kg, respectively. TvSu-3 (41.50 ± 8.29 mg/kg) maintained the lowest value. In petiole length, TvSu-5 (15.23 ± 0.33 cm) and TvSu-4 (14.20 ± 0.66cm) had the highest values, while TvSu-3 (8.97 ± 0.33 cm) had the lowest. For the number of nodes, TvSu-2 (15.00 ± 1.76) and TvSu-4 (12.00 ± 1.73) recorded the highest values, while TvSu-10 (10.00 ± 1.00) had the lowest value. Biomass yield analysis of the stressed <em>V. subterranean</em> showed that total fresh weight (TFW), root length (RL), root fresh weight (RFW), shoot fresh weight (SFW), leaf fresh weight (LFW), leaf turgid weight (LTW), total dry weight (TDW), root dry weight (RDW), shoot dry weight (SDW), and leaf dry weight (LDW) of the six accessions were significantly (<em>p </em>= 0.05) decreased when compared to their control. Tvsu-5 had a better biomass yield when compared to other accessions, recording the highest values in SDW (1.62 g), RDW (0.55 g), LFW (0.75 g), SFW (10.31 g), and RL (18.53 ± 0.66). Conclusively, waterlogging stress negatively impacted <em>V. subterranean</em> accessions, but Tvsu-5 had a better waterlogging stress tolerance than other accessions, especially TvSu-3, which was generally poor.</p>

Growth and total photosynthetic pigment responses of five accessions of Zea mays L. grown under waterlogging stress

Growth and total photosynthetic pigment responses of five accessions of Zea mays L. grown under waterlogging stress

Biocontrol potential of the endophytic Epicoccum nigrum HE20 against stripe rust of wheat

Biological control using endophytic microorganisms represents an eco-friendly and effective alternative to the health-hazardous chemical fungicides used to control devastating plant diseases such as stripe rust in wheat. In this study, the inhibitory potential of the endophytic Epicoccum nigrum HE20, isolated from a healthy wheat plant, was screened against uredospores germination in vitro. A high suppression (96%) in the germination of the uredospores was recorded. GC‐MS analysis of the culture filtrate of E. nigrum HE20 showed a production of various secondary metabolites with an antifungal background such as butyric acid, α-linolenic acid, hexanoic acid, lactic acid, 10,12-Tricosadiynoic acid, and pentadecanoic acid. Results from the greenhouse experiment revealed that the application of E. nigrum HE20 suspension led to a reduction in the disease severity by 87.5%, compared with the untreated-infected plants. Real-time PCR results exhibited an overexpression in three defensive genes (JERF3, GLU, and PR1) in the infected wheat plants, in response to the application of E. nigrum HE20, recorded 8-, 15.8-, and 3.5-fold, respectively. In addition, an increment in the phenolic content, activity of POD, PPO, and CAT, and a reduction in the lipid peroxidation were recorded due to the endophyte application. Transmission electron microscopic observations indicated mitigation of the pathogen in wheat cells after the treatment with E. nigrum HE20 metabolite. Furthermore, a growth-promoting effect was also observed due to E. nigrum HE20 application, as well as an increment in the total photosynthetic pigments in wheat leaves. Based on these results, it can be concluded that E. nigrum HE20 is a probable efficient bioagent against stripe rust in wheat. However, its field evaluation is highly necessary in the future studies.

Curcumin-polyvinyl alcohol nano-composite enhances tolerance of Helianthus annuus L. against salinity stress

BackgroundNanotechnology is a promising technology in many fields including agriculture. So, this investigation aimed to study effect of curcumin (CUR) with polyvinyl alcohol (PVA) nano-compositeat 0, 20, 40 and 60 mg L−1 on physiochemical attributes of sunflower plants grown under salinity stress (3000 ppm).ResultsResults showed that salinity stress significantly reduced all growth indiceslike plant height, number of leaves/plant, fresh and dry weight of shoot and leaf area accompanied by significant increases in proline content, secondary metabolites (total phenolic compound contents and flavonoids), malondialdehyde (MDA) and hydrogen peroxide (H2O2). In addition, catalase, peroxidase, superoxide dismutase, and glutathione reductase increased significantly. The decreases in chlorophyll a, chlorophyll b and carotenoids due to salinity stress were non-significant. On the other hand, curcumin with polyvinyl alcohol (CUR-PVA) nano-composite at all concentrations significantly promoted all vegetative growth parameters, total photosynthetic pigments, secondary metabolites, antioxidant enzyme activities accompanied by significant decreases in proline content, MDA and H2O2 either in plant irrigated with tap water or saline solution relative to corresponding control. CUR-PVA nano-composite at 20 mg L−1 was the most optimum treatment either in plant irrigated with tape water or saline solution since it caused the highest significant increases in vegetative growth parameters, total photosynthetic pigments, secondary metabolites and antioxidant enzyme activities accompanied by highest significant decreases in proline content, MDA and H2O2 relative to control.ConclusionsIn brief that CUR-PVA nano-composite employs no ticeable effect in decreasing the deleterious effect of salinity on quality of sunflower.

Фотосинтетические пигменты в листьях березы повислой при техногенном воздействии

The content of photosynthetic pigments in silver birch leaves (Betula pendula Roth.) is studied in areas with technogenic load and in baseline conditions. The research is performed in a forb type of birch forest in the suburbs of Krasnoyarsk. The wood stands exposed to a high level of technogenic pressure are located to the east of the city in the prevailing direction of air mass movement. The reference stands are under the least technogenic pollution and grow in western and northern areas of the city. The photosynthetic pigments are determined in ethanol extracts, calculated per 1 g of absolute dry mass (a.d.m.) of the leaves. A level of dust deposition on leaf surfaces is evaluated according to the method of J. Detrie (1973). The amounts of zinc, lead, aluminum, and fluorine ions are estimated in the washed leaves. It is found that the content of chlorophyll a inside the birch leaves from a relatively clean environment is slightly lower compared to the concentration in the leaves with the technogenic load. The chlorophyll b concentration is 2.5–3 times less than chlorophyll a and is close to the amount of carotenoids. The total chlorophyll content in birch leaves from different locations ranges from 5.4 to 7.3 mg/g a.d.m., the ratio of chlorophyll forms varies from 2.5 to 3, the proportion of net chlorophyll to carotenoids is between 3.4 and 3.8. As the level of dust increases, the content of the total photosynthetic pigments also rises. The accumulation of zinc ions in the birch leaf cells has a negative effect on pigment content, especially chlorophyll a, but doesn’t correlate with the ratio of the pigments. There has not been any correlation found between the lead and the photosynthetic pigments. It is noted that the rise in the concentration of aluminum significantly affects the contents of the chlorophylls and the carotenoids, while no relationship has been discovered between the concentration of aluminum and the proportion of the pigments. The relationship between fluorine and different forms of chlorophyll is absent as well. The results indicate the adaptive response of the photosynthetic system to the presence of pollutants in concentrations below the threshold values that are indicated in the literature. For citation: Stasova V.V., Skripal’shchikova L.N., Astrakhantseva N.V., Barchenkov A.P. Photosynthetic Pigments in Silver Birch Leaves (Betula pendula Roth.) with Technogenic Load. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 35–47. (In Russ.). https:// doi.org/10.37482/0536-1036-2023-3-35-47

Effect of Light Conditions on Polyphenol Production in Transformed Shoot Culture of Salvia bulleyana Diels.

Various strategies have been used to increase the efficiency of secondary metabolite production in Salvia plants. This report is the first to examine the spontaneous development of Salvia bulleyana shoots transformed by Agrobacterium rhizogenes on hairy roots and the influence of light conditions on the phytochemical profile of this shoot culture. The transformed shoots were cultivated on solid MS medium with 0.1 mg/L of IAA (indole-3-acetic acid) and 1 mg/L of m-Top (meta-topolin), and their transgenic characteristic was confirmed by PCR-based detection of the rolB and rolC genes in the target plant genome. This study assessed the phytochemical, morphological, and physiological responses of the shoot culture under stimulation by light-emitting diodes (LEDs) with different wavelengths (white, WL; blue, B; red, RL; and red/blue, ML) and under fluorescent lamps (FL, control). Eleven polyphenols identified as phenolic acids and their derivatives were detected via ultrahigh-performance liquid chromatography with diode-array detection coupled to electrospray ionization tandem mass spectrometry (UPLC-DAD/ESI-MS) in the plant material, and their content was determined using high-performance liquid chromatography (HPLC). Rosmarinic acid was the predominant compound in the analyzed extracts. The mixed red and blue LEDs gave the highest levels of polyphenol and rosmarinic acid accumulation (respectively, 24.3 mg/g of DW and 20.0 mg/g of DW), reaching two times greater concentrations of polyphenols and three times greater rosmarinic acid levels compared to the aerial parts of two-year-old intact plants. Similar to WL, ML also stimulated regeneration ability and biomass accumulation effectively. However, the highest total photosynthetic pigment production (1.13 mg/g of DW for total chlorophyll and 0.231 mg/g of DW for carotenoids) was found in the shoots cultivated under RL followed by BL, while the culture exposed to BL was characterized as having the highest antioxidant enzyme activities.

Bursa ilinde (Türkiye) liken çeşitlilik değeri ve fotosentetik pigment içeriği arasındaki ilişkinin belirlenmesi

In this study, 48 epiphytic lichen species on the trunk of oak trees from seven localities were reported in Bursa province. The correlation between Lichen Diversity Value (LDV) and photosynthetic pigment content at a location were evaluated for each locality. A negative correlation was found between LDV and photosynthetic pigment contents. The LDV was higher in rural areas, and decreased in areas affected by anthropogenic and agricultural activities. LDV values were increased from 21% to 47% from degraded areas exposed to environmental pollution and stress to undisturbed areas, whereas total photosynthetic pigment contents decreased from 39% to 19%, and Phaeophytinization ratio (PR) values from 36% to 30%.

Inductive role of the brown alga Sargassum polycystum on growth and biosynthesis of imperative metabolites and antioxidants of two crop plants.

The potential of macroalgae as biostimulants in agriculture was proved worthy. Vicia faba and Helianthus annuus are socioeconomic crops owing to their increasing demand worldwide. In this work, we investigated the energetic role of seed presoaking and irrigation by the brown seaweed, Sargassum polycystum aqueous extract (SAE) on certain germination and growth traits, photosynthetic pigments, carbohydrates, phenolics, flavonoids, and the total antioxidant activity. Compared to the control plants, our consequences revealed that seeds that received the SAE improved all the germination and growth criteria for both crop plants. Furthermore, the SAE significantly increased the carotenoids, total photosynthetic pigments, and total carbohydrates by (14%, 7%, and 41%) for V. faba and (17%, 17%, and 38%) for H. annuus, respectively. Phenolics and flavonoids were significantly induced in Vicia but slightly promoted in Helianthu plants, whereas the total antioxidant activity in both crops non significantly elevated. Even though The NPK contents were significantly stimulated by the SAE in Vicia plants, the effect was different in Helianthus, where only nitrogen content was significantly enhanced, whereas phosphorus and potassium showed little enhancement. Thus, the SAE treatment is one of the superlative sustainable strategies for food, feed, and as excellent plant conditioner.

Genome-mining for stress-responsive genes, profiling of antioxidants and radical scavenging metabolism in hyperaccumulator medicinal and aromatic plants

Medicinal and aromatic plants (MAPs) possess phytoremediation potential owing to antioxidants, secondary metabolites, and morphological features. Moringa oleifera, Pelargonium graveolens, Tagetes patula, and Calotropis gigantea are known for their phytoremediation properties in heavy metals polluted soil. These plants with phytoremediation properties due to antioxidants, specific secondary metabolites synthesis, and distinctive morphological characteristics ultimately become the ideal choice for effective remediation. The main aim of the current study is to provide a genetic evaluation using bioinformatics techniques, antioxidant compounds, metabolites, and their activity. Genomic and transcriptomic studies endorsed genes related to hyperaccumulation in these plant species having essential domains as catalase (CAT) and superoxide dismutase (SOD_Cu, SOD_Fe_C, and SOD_Fe_N). The phylogenetic study showed its close evolutionary relationship to other plant species. The accumulation of total photosynthetic pigments, carotenoids, non-enzymatic antioxidants, and enzymatic antioxidants determined spectrophotometrically, involved in stress tolerance and ROS homeostasis maintenance mechanisms. Tagetes leaves showed the highest proline, flavonoids, and phenolics content, while Moringa showed higher CAT, guaiacol peroxidase (G-POD), and glutathione peroxidase (GPX) activities. Results also revealed that plants accumulated more primary and secondary metabolites in young tissue to tackle pathogens, herbivores, attract pollinators, and in mature tissues to develop strong physiology. Total antioxidant activity, reducing power, and radical scavenging activities were observed. These MAPs have intriguing antioxidant characteristics and a phytochemical composition that might give scientific support for their stress tolerance and ROS management activities. The study establishes the groundwork for using MAPs as phytoremediators; further confirmatory research is required for their use in sustainable phytoremediation.

Enhanced Tolerance to Cowpea Mosaic Virus in Vigna unguiculata L. Plants Pretreated with Salicylic Acid

Cowpea mosaic virus (CPMV) is one of the most economically critical pathogen infecting cowpea plants. Recently, eco-friendly strategies have been developed for enhancing the tolerance level of crops against virus infection. The present investigation evaluates the effect of salicylic acid (SA) on the response of three cultivars of Vigna unguiculata plants [Libyan Black eye (LB), Libyan red eye (LR) and Egyptian Black eye hybrid (Kafr El Sheikh1cv.; EBH)] to CPMV. The leaves of 15-d old cowpea plants were foliar sprayed with 50 or 100 µM SA, 24 h before inoculation with CPMV. Most measured growth indices as well as total photosynthetic pigment and photosynthetic efficiency were all diminished in CPMV inoculated plants of all three cultivars. Nonetheless, SA utilization could enhance cowpea growth and lower virus severity, notably in the Libyan cultivars. Furthermore, the CPMV-induced oxidative damages as well as phenolics accumulation were lesser upon SA application to all infected cowpea cvs. CPMV infection triggered an increase in catalase (CAT), guaiacol peroxidae (GPX) and polyphenol oxidase (PPO) activity in all cowpea cultivars, except for the EBH cultivar where the PPO was insignificantly changed. Interestingly, SA pretreatment significantly inhibited CAT activity only in the LR and LBH cv. compared to infected plants while it induced GPX and PPO in the three tested cultivars, most obviously in the Lybian ones. In general, SA was effective in induction of systematic resistance to CPMV in the two Libyan cowpea cultivars rather than the Egyptian one

English

The present study investigated the role of inoculation with Nitrobien biofertilizer (N-Bio, Azospirillum and azotobacter spp.) on the response of maize plants to cadmium-toxicity (applied as 2 and 10 mM CdSO4). Cd-stress caused a significant reduction in the fresh and dry biomass of leaves and roots as well as a marked disturbance in the anatomical features of roots and stomatal structure and behavior. Cd-stress significantly depressed the total photosynthetic pigments, photochemical efficiency of PS II, total carbohydrates, and proteins content. Furthermore, increasing Cd level prompted oxidative stress measured in terms of malondialdehyde and H2O2 contents in maize plants. Application of N-Bio improved these attributes in Cd-stressed maize plants. Moreover, NO3- uptake and its assimilating enzymes (nitrate reductase, NR; glutamine synthase, GS; and, glutamate dehydrogenase GDH) were significantly increased in N-Bio-pretreated Cd-stressed plants than Cd- stressed ones and that was associated with a decrease of NH4+ content. N-Bio pretreatment also stimulated the accumulation of amino acids and markedly increased endogenous phytohormone content (IAA, GA3) of Cd-stressed maize plants. These results revealed the potentiating effect of N-Bio pretreatment in regulating Cd-induced damages in maize plants. © 2021 Friends Science Publishers

Effect of glutathione and/or selenium levels on growth, yield, and some biochemical constituents of some wheat cultivars grown under sandy soil conditions

BackgroundTwo field experiments were carried out at the Agricultural Production and Research Station, National Research Centre (NRC), El-Nubaria Province, Behaira Governorate, Egypt, during two successive winter seasons to study the effect of glutathione (100, 200, and 300 mg/l) and/or selenium (5 and 10 mg/l) on growth, yield, and yield components of three wheat cultivars (Egypt-2; Shandaweel-1; Gemmeiza-11).ResultsThe results indicate that the Gemmeiza-11 cultivar was the most adapted cultivar to grow in the Nubaria region. Individually, glutathione at 300 mg/l or selenium at 10 mg/l caused the highest significant increases in shoot dry weight/plant of three wheat cultivars relative to other levels. Likewise, glutathione treatment at 300 mg/l was the optimum treatment in increasing photosynthetic pigments in three wheat cultivars. Selenium treatment at 10 mg/l was better than selenium treatment at 5 mg/l. Interaction between glutathione at 300 mg/l and selenium at 10 mg/l caused the highest significance increases in total photosynthetic pigments. It is obvious that glutathione at 300 mg/l or selenium at 10 mg/l as individual treatment showed the highest significant increase in grain yield (ton/fed).ConclusionGlutathione treatments at 200 or 300 mg/l interacted with selenium treatment at 10 mg/l showed the highest significant increases in grain yield and its components as compared with other treatments in three wheat cultivars. Moreover, It is noted that the highest increases in IAA and phenolic content in the leaves as well as the content of carbohydrate, flavonoid, and phenolic in the yielded grains appeared by the interaction between glutathione at 300 mg/l and selenium at 10 mg/l in the three wheat cultivars under investigation.

Comparative investigation of therapeutic plant Withania somnifera for yield, productivity, withanolide content, and expression of pathway genes during contrasting seasons

Several environmental factors such as weather, season, temperature, biotic, and abiotic factors affect the plant productivity and content of secondary metabolites. Present work is carried out to investigate the physiological and biochemical effects owing to seasonal variation on prestigious Indian medicinal plant, Withania somnifera. Furthermore, the regulatory role of transcription factors (TFs) in the management of plant growth and withanolide biosynthesis was also analysed. Direct sowing of our developed elite variety of W. somnifera i.e. NMITLI-118 was done in two contrasting seasons; winter (NMITLI-118-W) and summer (NMITLI-118-S) seasons. Plant growth parameters such as plant biomass production, plant height, shoot/root production, and total photosynthetic pigments were recorded in both and compared for analysis in terms of productivity. Key pathway genes having role in terpenoid-isoprenoid pathway viz WsDXS, WsDXR, WsHMGR, and WsCAS were higher in expression. Higher pathway genes expression also reflected higher expression of secondary metabolite-with-anolide content in different tissues of W. somnifera (NMITLI-118-W than NMITLI-118-S). Tissue‐wide gene expression analysis of important transcription factors such as WsWRKY, WsbHLH, WsMYB, and WsWuschel reflected their involvement in tissue-specific regulation of withanolide biosynthesis and WsAP-2ERF &WsLWD1 in the regulation of plant growth and development. Our results established the relation between biomass production and total photosynthetic pigments & withanolide biosynthesis. This is the first study which revealed the effect of the seasonal variation on W. somnifera under natural field conditions in overall productivity, pathway gene expression and in withanolide biosynthesis. The study also reflected the regulation of various transcription factors in secondary metabolite biosynthesis and in plant growth & development in W. somnifera.

Effects of salt stress on growth parameters of some (Beta vulgaris L.) varieties

Aim. The effect of various concentrations of sodium chloride on growth parameters, the activity of antioxidant enzymes, the amount of photosynthetic pigments and total sugar beet proteins was studied. Methods. The objects of study were varieties of sugar beets Tarifa, Taltos and Cooper. Plants were grown in a controlled greenhouse for 60 days at different salinity levels (0.2 and 0.5% NaCl and Na 2 SO 4 ). The parameters of leaves and roots, the activity of catalase (CAT) and benzidyl-peroxidase (BPO), the content of photosynthetic pigments and total proteins during the growing season were determined. Results. Although leaf and root parameters were stimulated or not affected at low salinity, a higher salt concentration significantly reduced all signs of growth. At a high salinity level, the Tarifa variety had a significantly higher leaf area and root with compared to other varieties. In the variety Tarifa, the activity of CAT was higher than in other varieties, but the activity of BPO, the content of total protein and photosynthetic pigments was higher in the varieties Taltos and Cooper. The salinity of the medium reduced physiological and biochemical parameters in different varieties of sugar beets to varying degrees, and these features of the varieties should be taken into account in breeding work.

Morpho-Physiological Responses of Abelmoschus esculentus (L.) Moench to Arbuscular Mycorrhizal Fungi Inoculation under Drought Stress

Aims: To assess the potential impacts of arbuscular mycorrhizal fungi (AMF) (G. geosporum) inoculation on the survival of A. esculentus under drought stress.
 Study Design: This experiment was set up in a completely randomized design (CRD) with all treatments replicated thrice. This gave a total of 7 treatments, 21 replicates.
 Place and Duration of Study: The experimental soil used for this study was collected from the Botanical Garden of the Department of Biological Sciences, Ritman University (Latitude 5º11’44ºN and Longitude 7º42’12ºE), Akwa Ibom State, Nigeria. All analysis was carried out in Soil Science Laboratory and Botany Laboratory, Akwa Ibom State University, between January and march 2019.
 Methodology: Soil samples were analyzed following the standard procedures outlined for wet acid digestions. Growth parameters were determined using standard methods. At Leaf chlorophyll meter was employed in the assessment of the photosynthetic pigments of the experimental plant. Biomass yield were calculated using standard formulas.
 Results: The physicochemical analysis of the experimental soil used in this study revealed the physical and chemical properties of the soil; pH (6.12), EC (0.06dS/m), organic matter (2.90%), Av. P (44.62 mg/kg) and textural class of the soil was described as loamy sandy soil. Shoot length, petiole length, internode length, number of leaves and leaf area as well as the total photosynthetic pigments (TPP) contents of A. esculentus were significantly (P =.05) reduced (from 38.77±3.01 mg/kg to 29.83±1.89 mg/kg) by drought stress. There was also significantly (P = .05) reduction in N, P, K, Ca and Mg composition of A. esculentus as well as its biomass yield. However, the inoculation of A. esculentus roots with AMF (G. geosporum) in this study through several morphological and physiological processes exhibited remarkable improvement in growth morphology, total photosynthetic pigments, macronutrients composition as well as biomass yield.
 Conclusion: The results of this work have shown that AMF can enhance the ability of A. esculentus to resist drought stress possibly through some morphological and physiological changes which improves water and nutrients uptake.

Enhancement of Salt Tolerance via <i>Glomus geosporum</i> Inoculation in <i>Telfairia occidentalis</i> Hook. F. Seedlings

The leafy vegetable Telfairia occidentalis is a tropical vine grown in West Africa; it is indigenous to Southern Nigeria and is usually subjected to extreme salt stress in Southern Nigeria as well as in the world that results in significant loss of T. occidentalis production. Therefore, the present investigation was aimed at evaluating the response of T. occidentalis seedlings inoculated with arbuscular mycorrhizal fungi (Glomus geosporum) in saline soil and further to determine the threshold of T. occidentalis salinity tolerance in association with G. geosporum. The total photosynthetic pigments contents in saline soil treatment were significantly (p=0.05) reduced as well as percentage arbuscular mycorrhizal fungi colonization (53.97 to 22.41%). Mycorrhizal dependency was significantly (p=0.05) higher in saline soil treatments compared to control (100.00% to 15.13%). Mineral analysis of T. occidentalis leaves revealed increased uptake and accumulation of Na+ (500.00 mg/kg in control to 2920.13 mg/kg in saline soil treatment). Saline soil treatments significantly (p=0.05) reduced the K, Mg, N, P and Ca. AM Fungi significantly (p=0.05) increased the photosynthetic pigments and minerals both in saline and non-saline soil treatments. Using different mechanisms T. occidentalis by association with G. geosporum showed better salt tolerance thank the uninoculated plants. G. geosporum was able to impose some physiological and root morphological changes such as an extensive network of the mycorrhizal-plant roots to improve water and mineral nutrient uptake. Physiologically G. geosporum inoculation enriched T. occidentalis vigour, attuned the rate of K+/Na+ which restored nutrient and water balance in the plant and directly resulting in the enhancement of salt tolerance in T. occidentalis seedlings, thus improving growth and yield.

Enhancement of Salt Tolerance via <i>Glomus geosporum</i> Inoculation in <i>Telfairia occidentalis</i> Hook. F. Seedlings

The leafy vegetable Telfairia occidentalis is a tropical vine grown in West Africa; it is indigenous to Southern Nigeria and is usually subjected to extreme salt stress in Southern Nigeria as well as in the world that results in significant loss of T. occidentalis production. Therefore, the present investigation was aimed at evaluating the response of T. occidentalis seedlings inoculated with arbuscular mycorrhizal fungi (Glomus geosporum) in saline soil and further to determine the threshold of T. occidentalis salinity tolerance in association with G. geosporum. The total photosynthetic pigments contents in saline soil treatment were significantly (p=0.05) reduced as well as percentage arbuscular mycorrhizal fungi colonization (53.97 to 22.41%). Mycorrhizal dependency was significantly (p=0.05) higher in saline soil treatments compared to control (100.00% to 15.13%). Mineral analysis of T. occidentalis leaves revealed increased uptake and accumulation of Na+ (500.00 mg/kg in control to 2920.13 mg/kg in saline soil treatment). Saline soil treatments significantly (p=0.05) reduced the K, Mg, N, P and Ca. AM Fungi significantly (p=0.05) increased the photosynthetic pigments and minerals both in saline and non-saline soil treatments. Using different mechanisms T. occidentalis by association with G. geosporum showed better salt tolerance thank the uninoculated plants. G. geosporum was able to impose some physiological and root morphological changes such as an extensive network of the mycorrhizal-plant roots to improve water and mineral nutrient uptake. Physiologically G. geosporum inoculation enriched T. occidentalis vigour, attuned the rate of K+/Na+ which restored nutrient and water balance in the plant and directly resulting in the enhancement of salt tolerance in T. occidentalis seedlings, thus improving growth and yield.

Role of Salicylic Acid in Alleviating Cobalt Toxicity in Wheat (Triticum aestivum L.) Seedlings

Heavy metals pollution of soils become the most serious environmental problem resulted in decreased soil fertility and crop yield losses. Cobalt (Co), as a beneficial element, can be a contaminant in soils due to agricultural additives or metal refineries, it causes irreversible damage to several physiological and metabolic constituents at higher concentrations. In this investigation we study the effects of different Co concentrations (0, 50,150, 250, 350 µM as CoCl2) on growth and physiological processes in wheat (Triticum aestivum) plants and discuss the role of spraying with salicylic acid (0.5 mM) for ameliorating effect of cobalt toxicity in wheat leaves. Cobalt causing a significant reduction in fresh and dry biomass, shoot height, water content and total photosynthetic pigments. This was accompanied with accumulation of H2O2 and MDA contents and induction of some antioxidant enzymes activities. There was an increase in SOD activity with increasing Co concentration then decline, a significant increase in APX and PPO activities while CAT was significantly declined. Spraying wheat seedlings with salicylic acid can be recognized to significantly increase in all tested growth parameters and that was attributed to decrease, to some extent, the accumulation of H2O2 and MDA and improve the activity of antioxidant enzymes.

Enhancement quality and quantity of faba bean plants grown under sandy soil conditions by nicotinamide and/or humic acid application

BackgroundTwo field experiments were conducted at the Research and Production Station, National Research Centre, El-Nubaria Province, El-Behira Governorate, Egypt, during the two successive winter seasons of 2014/2015 and 2015/2016. This work aimed to study the enhancement effect of foliar application of nicotinamide at 5, 10, and 20 mg/L and/or humic acid at 5% on quality and quantity of faba bean plants (cultivar Sakha 4) grown under sandy soil conditions.ResultsData show that nicotinamide at 5, 10, and 20 mg/L and/or humic acid at 5% had a positive effect on growth parameters, photosynthetic pigments, seed yield, and yield components as well as some biochemical constituents of the yielded faba bean seeds (total carbohydrate, total phenolic content, proline, and free amino acids). Individually, nicotinamide treatments had a more positive effect than humic acid treatment and their effect was increased by increasing nicotinamide concentrations. The most promising treatment appeared due to the interaction between nicotinamide at 10 mg/L and humic acid. Hence, this treatment increased plant dry weight/plant by 32.67%, total photosynthetic pigments by 113.2%, seed yield/feddan by 110.16%, total carbohydrate by 9.4%, total phenolic content by 0.33%, proline by 24.83%, and free amino acids by 21.33%.ConclusionsWe can conclude that nicotinamide and/or humic acid had a positive effect on growth parameters, photosynthetic pigments, seed yield, and yield components as well as some biochemical constituents of the yielded faba bean seeds. The most promising treatment appeared due to the interaction between nicotinamide at 10 mg/L and humic acid.