Chlorophyll Content Research Articles

Toxicity mechanism of organosilicon adjuvant in combination with S-metolachlor on Vigna angularis

The widespread use of S-metolachlor (ME) in agriculture to suppress weeds and boost crop yields, particularly in cultivating Vigna angularis, is well established. However, the application of organosilicon adjuvants with herbicides has potential threats to non-target crops. This study investigates the toxicity symptoms and mechanisms when V. angularis is exposed to ME in conjunction with a common organosilicon adjuvant. Results indicate that ME inhibits the growth of V. angularis seedlings, and adding adjuvants could aggravate the negative effects of ME. According to the growth index of seedlings, the adjuvant increased the toxicity of ME by 84–96 %. Additionally, the chlorophyll content, root permeability, and antioxidant indicators in the seedlings were also adversely affected. Integrated metabolomics and transcriptomics analyses reveal that differentially abundant metabolites (DAMs) and differentially expressed genes (DEGs) are mainly enriched in four ways: "lysine degradation," "ABC transporters," "phenylalanine metabolism," and "monoterpenoid biosynthesis." The metabolic pathways and gene regulatory network involving 11 DAMs and 22 DEGs are associated with the physiological processes affected by ME and the adjuvant. This study provides guidance for the application of herbicides and their adjuvants in agricultural production to minimize adverse effects on non-target crops.

Heat shock factor ZmHsf17 positively regulates phosphatidic acid phosphohydrolase ZmPAH1 and enhances maize thermotolerance.

Heat stress (HS) adversely impacts plant growth, development and grain yield. Heat shock factors (Hsf), especially HsfA2 subclass, play a pivotal role in the transcriptional regulation of genes in response to HS. In this study, the coding sequence of maize ZmHsf17 was cloned. ZmHsf17 contains conserved domains: DNA binding, oligomerization and transcriptional activation. The protein was nuclear localized and had transcription activation activity. Yeast two hybrid and split luciferase complementary assays confirmed the interaction of ZmHsf17 with members of the maize HsfA2 subclass. Overexpression of ZmHsf17 in maize significantly increased chlorophyll content and net photosynthesis rate of maize leaves, and enhanced the stability of cellular membranes. Through integrative analysis of ChIP-seq and RNA-seq datasets, ZmPAH1, encoding phosphatidic acid phosphohydrolase of lipid metabolic pathways, was identified as a target gene of ZmHsf17. The promoter fragment of ZmPAH1 was bound by ZmHsf17 in protein-DNA interaction experiments in vivo and in vitro. Lipidomic data also indicates that the overexpression of ZmHsf17 increased levels of some critical membrane lipid components of maize leaves under HS. This research provides new insights into the role of the ZmHsf17-ZmPAH1 module in regulating thermotolerance in maize.

Alleviating Effects of Methyl Jasmonate on Pepper (Capsicum annuum L.) Seedlings under Low-Temperature Combined with Low-Light Stress.

Low temperature combined with low light (LL) is an important factor limiting pepper quality and yield. 'Hang Jiao No. 2' were used as experimental materials, and different concentrations of MeJA (T1 (0 μM), T2 (100 μM), T3 (150 μM), T4 (200 μM), T5 (250 μM) and T6 (300 μM)) were sprayed under LL stress to explore the positive effect of exogenous methyl jasmonate (MeJA) on peppers under LL stress. The photosynthetic properties, osmoregulatory substance, reactive oxygen species, antioxidant enzyme activities, and related gene expressions of the peppers were measured. Our results demonstrated that 200 μM MeJA treatment significantly increased chlorophyll content, light quantum flux per active RC electron transfer (Eto/RC), maximum captured photonic flux per active RC (TRo/RC), energy flux for electron transfer in the excitation cross section (Eto/CSm), energy flux captured by absorption in the excitation cross section (TRo/CSm), soluble protein, and soluble sugar content. Moreover, it significantly improved the maximum photochemical efficiency of PSII (Fv/Fm) and performance index based on absorbed light energy (PI (abs)) by 56.77% and 67.00%, respectively, and significantly decreased malondialdehyde (MDA) content and relative conductivity by 30.55% and 28.17%, respectively. Additionally, antioxidant enzyme activities were elevated, and the expression of the related genes was activated in pepper seedlings under stress, leading to a significant reduction in reactive oxygen species content. In conclusion, our findings confirmed that 200 μM MeJA could reduce the injury of LL to pepper leaves to the photosynthetic organs of pepper leaves, protect the integrity of the cell membrane, and further improve the tolerance of pepper seedlings to LL.

Accumulation of plastid pigments in the leaves Triticum avestium L. under influence of composite recultivant Trevitan®

Aim. To investigate the efficiency of using composite recultivants TREVITAN® (RCT) according to the parameters of accumulation of the photosynthetic pigments in the leaves Triticum aestivum L. of the varieties Quintus and Licamero. Methods. The experiments were carried out on the plots of the agro-biolaboratory of Ternopil Volodymyr Hnatyuk National Pedagogical University in 4 variants (Control, TREVITAN® adjuvant, recultivants TREVITAN®, TREVITAN® adjuvant + recultivants TREVITAN®) and 3 repetitions. The content of chlorophylls a, b and carotenoids in flag leaves was defined by Welburn spectrometric method. Results. The highest content of chlorophylls was found in the leaves of both varieties of wheat in the phases of flowering and milk ripeness during autumn tillage, seeds before sowing and plants in the earing phase with recultivants TREVITAN®. Joint use of TREVITAN® adjuvant + recultivants TREVITAN® also significantly increased the content of chlorophyll in wheat leaves. Increase of carotenoids in the leaves of plants of all experimental variants on 4.2–14.6 % (variety Quintus) and on 43.2–59.5 % (variety Licamero) was defined in the phase of milk ripeness. Conclusions. The use of RCT in the technology of growing soft wheat had a significant impact on the accumulation of photosynthetic pigments in leaves during the generative phases of development.

Overexpression of Auxin/Indole-3-Acetic Acid Gene TrIAA27 Enhances Biomass, Drought, and Salt Tolerance in Arabidopsis thaliana

White clover (Trifolium repens L.) is an important forage and aesthetic plant species, but it is susceptible to drought and heat stress. The phytohormone auxin regulates several aspects of plant development and alleviates the effects of drought stress in plants, including white clover, by involving auxin/indole acetic acid (Aux/IAA) family genes. However, Aux/IAA genes and the underlying mechanism of auxin-mediated drought response remain elusive in white clover. To extend our understanding of the multiple functions of Aux/IAAs, the current study described the characterization of a member of the Aux/IAA family TrIAA27 of white clover. TrIAA27 protein had conserved the Aux/IAA family domain and shared high sequence similarity with the IAA27 gene of a closely related species and Arabidopsis. Expression of TrIAA27 was upregulated in response to heavy metal, drought, salt, NO, Ca2+, H2O2, Spm, ABA, and IAA treatments, while downregulated under cold stress in the roots and leaves of white clover. TrIAA27 protein was localized in the nucleus. Constitutive overexpression of TrIAA27 in Arabidopsis thaliana led to enhanced hypocotyl length, root length, plant height, leaf length and width, and fresh and dry weights under optimal and stress conditions. There was Improved photosynthesis activity, chlorophyll content, survival rate, relative water content, endogenous catalase (CAT), and peroxidase (POD) concentration with a significantly lower electrolyte leakage percentage, malondialdehyde (MDA) content, and hydrogen peroxide (H2O2) concentration in overexpression lines compared to wild-type Arabidopsis under drought and salt stress conditions. Exposure to stress conditions resulted in relatively weaker roots and above-ground plant growth inhibition, enhanced endogenous levels of major antioxidant enzymes, which correlated well with lower lipid peroxidation, lower levels of reactive oxygen species, and reduced cell death in overexpression lines. The data of the current study demonstrated that TrIAA27 is involved in positively regulating plant growth and development and could be considered a potential target gene for further use, including the breeding of white clover for higher biomass with improved root architecture and tolerance to abiotic stress.

The impact of roasting on oil and chlorophyll contents, bioactive components, antioxidant activity, phenolic and fatty acid component of rapeseeds

The impact of roasting on oil and chlorophyll contents, bioactive components, antioxidant activity, phenolic and fatty acid component of rapeseeds

Response of blueberry photosynthetic physiology to light intensity during different stages of fruit development.

To investigate the response of blueberry photosynthetic physiology to different light intensities during different stages of fruit development. In this study, four light intensity treatments (25%, 50%, 75% and 100% of full light) were set up to study the change rule of photosynthetic pigment content and photosynthetic characteristics of 'O'Neal' southern highbush blueberry leaves during the white fruiting stage (S1), purple fruiting stage (S2) and blue fruiting stage (S3) under different light intensity environments, and to explore the light demand and light adaptability of blueberry during different developmental stages of the fruit. The results showed that the chlorophyll and carotenoid contents of blueberry leaves showed an increasing trend with decreasing light intensity at all three stages of fruit development. The total chlorophyll content of blueberry leaves at 25% light intensity increased by 76.4% compared with CK during the blue fruiting stage; the maximum net photosynthetic rate (Pmax), light compensation point (LCP), light saturation point (LSP), rate of dark respirations (Rd), inter-cellular CO2 concentration (Ci), stomatal conductance (Gs), transpiration rate (Tr), net photosynthesis rate (Pn), and chlorophyll a/b showed a decreasing trend with decreasing light intensity. The Pn of blueberry leaves was highest under full light conditions at all three stages, and the Pn at 25% light intensity decreased by 68.5% compared with CK during the white fruiting stage Reflecting the fact that blueberries can adapt to low-light environments through increases in chlorophyll and carotenoids, but reduced light intensity significantly inhibited their photosynthesis. The photosynthetic physiology of blueberry showed a consistent pattern at all three stages, but there were some differences in the changes of photosynthetic parameters at different stages. The results of the study can provide theoretical references for the selection of sites and density regulation in blueberry production.

Bacillus velezensis GH1-13 enhances drought tolerance in rice by reducing the accumulation of reactive oxygen species.

Plant growth-promoting rhizobacteria colonize the rhizosphere through dynamic and intricate interactions with plants, thereby providing various benefits and contributing to plant growth. Moreover, increasing evidence suggests that plant growth-promoting rhizobacteria affect plant tolerance to abiotic stress, but the underlying molecular mechanisms remain largely unknown. In this study, we investigated the effect of Bacillus velezensis strain GH1-13 on drought stress tolerance in rice. Phenotypical analysis, including the measurement of chlorophyll content and survival rate, showed that B. velezensis GH1-13 enhances rice tolerance to drought stress. Additionally, visualizing ROS levels and quantifying the expression of ROS-scavenging genes revealed that GH1-13 treatment reduces ROS accumulation under drought stress by activating the expression of antioxidant genes. Furthermore, the GH1-13 treatment stimulated the jasmonic acid response, which is a key phytohormone that mediates plant stress tolerance. Together with the result that jasmonic acid treatment promotes the expression of antioxidant genes, these findings indicate that B. velezensis GH1-13 improves drought tolerance in rice by reducing ROS accumulation and suggest that activation of the jasmonic acid response is deeply involved in this process.

Genotype and Plant Biostimulant Treatments Influence Tuber Size and Quality of Potato Grown in the Pedoclimatic Conditions in Northern Apennines in Italy

AbstractIn marginal mountain areas, farm management presents challenges, particularly the sustainable improvement of yield and quality. To ensure this agronomic result, it is crucial to select appropriate varieties and apply sustainable agricultural practices, such as the use of plant biostimulants. To address these challenges a two-year field study was conducted using three potato varieties (Désirée, Kennebec and Spunta) in the Tuscan-Emilian Apennines. These varieties were treated with two plant biostimulants: one based on hydrolyzed proteins from animal epithelial tissue (Fitostim®) and another based on seaweed extracts (FitostimAlga®). Agronomic and biochemical traits were used to evaluate the development of plants, yield and tubers quality. Significant interactions among factors were found, resulting in higher or lower efficiency of the plant biostimulant treatment depending on weather conditions and potato genotype. Furthermore, results demonstrated that plant biostimulant treatments increased the leaf chlorophyll content (+ 11.5%), the number of leaves per plant (+ 13.3%) and the height of potato plants (+ 6.5%), while no effects were observed on yield. The Désirée variety achieved the highest yield (0.54 kg plant-1), whereas Kennebec was shown as the best variety to use for production of French fries due to a lower tuber quantity of reducing sugars, which were reduced also by plant biostimulants treatment (-18%). Moreover, Spunta tubers had the highest content of polyphenols, and the best value was achieved by Spunta variety treated with Fitostim® alga in the second year. Our finding have proven that plant biostimulant treatments can increase the quality of potato tuber without compromising yield.

Possibility of using industrial by-product combinations to remediate cadmium and arsenic contaminated soil

It is inevitable to produce by-products in industrial and mining production, and how to deal with these by-products has become a major environmental issue. Meanwhile, many studies have shown that applying soil amendments is a feasible measure for effectively controlling soil pollution. Finding low-cost and efficient soil passivators is an effective way to safely utilize polluted soil. This article provides a method of “treating contamination with waste”. Through spinach pot experiments, different proportions and doses of granite powder (A, quarry waste), market purchased conditioner (B), “granite powder+iron sulfate mineral (titanium powder industrial waste)” (C), and “granite powder+iron sulfate mineral+market purchased conditioner” (CB) were used to treat soil co-contaminated with cadmium (Cd) and arsenic (As). The results indicate that amendments affect the available Cd and As in soil by changing soil pH and cation exchange capacity. The amendment of A, B, C, and CB all has remarkable reduction rates of soil available Cd at 65.48 %, 57.02 %, 61.37 %, and 43.15 %, respectively, compared to the control. Both A and B increase the available As content in the soil and the As content in spinach. However, both C and CB reduced the available As content in the soil by 60.32 % and 12.48 %. CB treatment could simultaneously reduce the accumulation of Cd and As in spinach, increase chlorophyll content, and promote spinach growth. It was worth noting that the 3 % CB treatment has the best effect, with Cd and As content in spinach stems and leaves decreasing by 51.13 % - 69.62 % and 35.46 % - 59.53 %, respectively, and the repair cost being as low as 76.5 $ ton−1. Therefore, the combined application of granite powder, market purchased conditioner, and iron sulfate minerals for the remediation of Cd and As co-polluted soil was a cost-effective and environmentally friendly technology. However, applying these soil composite amendments also requires attention to adjusting with the soil type and with pollution type, which we are currently studying.

Integrated Phenotypic Physiology and Transcriptome Analysis Revealed the Molecular Genetic Basis of Anthocyanin Accumulation in Purple Pak-Choi

Purple Pak-choi is rich in anthocyanins, which have both ornamental and edible health functions, and has been used more and more widely in facility cultivation. In order to further clarify the molecular mechanism of purple Pak-choi, two Pak-choi inbred lines (‘PQC’ and ‘HYYTC’) were selected for the determination of pigment content and transcriptome analysis, and the key genes controlling the formation of purple character in leaves of Pak-choi were discovered. The results of pigment determination showed that the anthocyanin content of ‘PQC’ was 0.29 mg/g, which was about 100 times than ‘HYYTC’; The chlorophyll content of ‘HYYTC’ was 2.25 mg/g, while ‘PQC’ only contained 1.05 mg/g. A total of 20 structural genes related to anthocyanin biosynthesis and 28 transcriptional regulatory genes were identified by transcriptome analysis. Weighted gene co-expression network analysis (WGCNA) was used to construct the weight network analysis map of 14 genes. The results showed that the cinnamate hydroxylase gene (BraA04002213, BrC4H3), flavanone-3- hydroxylase (BraA09004531, BrF3H1), and chalcone synthetase (BraA10002265, BrCHS1) were the core genes involved in the anthocyanin synthesis pathway of purple Pak-choi. The results identified the key genes controlling the formation of purple leaf traits, which laid a foundation for further analysis of the molecular mechanism of anthocyanin accumulation in purple Pak-choi and provided a theoretical basis for leaf color regulation.

Effects of water level gradients on the physiological ecology of Potamogeton crispus

Water level is crucial to the growth and development of wetland plants, in order to study the physiological and ecological responses of Pomatogeton crispus under different water levels, in the study, P. crispus were placed under 50 cm (control) and 60–135 cm water levels following a 15 cm gap gradient for 60 days in a simulation experiment. The results showed that: (1) As the water level gradient increased, the plant height, leaf number and biomass of P. crispus showed a trend of increasing and then decreasing. (2) The concentrations of chlorophyll a (Chl-a), chlorophyll b (Chl-b), chlorophyll a + b (Chl a + b) and carotenoids (Car) showed a multi-peak increasing trend with increasing water level, with the maximum values occurring in the 135 cm water level group. (3) The antioxidant enzymes of P. crispus showed a fluctuating upward trend with increasing water level, and the higher the water level the greater the difference within the group, and rooting activity of P. crispus was significantly increased under elevated water level conditions. (4) The P. crispus grows best in the water level range of 105 ∼ 120 cm, and the growth indexes such as the number of leaves and biomass all reach higher values in the water level of 105 ∼ 120 cm, If the water level is too high or too low, it has an effect on the growth and development of P. crispus.

Can exogenous application of putrescine and priming modulate salinity stress in Camelina sativa L?

High salinity in soil significantly reduces growth and productivity; however, employing priming techniques and foliar spraying of putrescine can serve as an impressive method to reduce the impact of salt stress in saline soil. The current investigation intends to explore the effected of foliar spraying and priming methods on the growth, physiological, biochemical characteristics, and seed chemical compositions of salt-stressed Camelina sativa L. crop. A pot test was set up in a randomized complete block design by a factorial scheme with four replications. The experiment involved three factors: 1) salinity stress (0, 60, and 90 mM(, 2) priming techniques (no priming, hydro-priming, putrescine-priming (50 μmol L − 1), and 3) foliar application of putrescine at concentrations of 0, 100, and 200 μmol L−1. Camelina plants subjected to salinity stress showed decreased growth and performance, which correlated with lower chlorophyll levels, reduced photosynthesis maximum quantum efficiency, potassium concentration, and total soluble sugars and proline content. This decline was associated with increased lipid peroxidation (malondialdehyde content), sodium concentration, and electrical leakage, leading to diminished antioxidant enzyme activities. In contrast, under salt stress (60 mM), priming with putrescine led to an increase in grain yield (45 %), chlorophyll content (43 %), shoot length (54 %), maximum quantum efficiency (16 %), Superoxide dismutase (49 %), Catalase (58 %), Ascorbate peroxidase (47 %), linoleic acid (20 %), linolenic acid (38 %), oleic acid (27 %), eicosanoic acid (13 %) and shoot K+ ion (50 %) compared with non-treated plants. The application of 100 μmol L−1 putrescine through foliar application elicited the efficiency of camelina plants with increasing proline content, total soluble sugars, and antioxidant enzyme activities against salinity stress. In addition, the putrescine-priming method could improve photosynthetic efficiency and antioxidant enzyme activity under salt stress levels. Overall, our results supply an important outlook for the use of foliar putrescine spraying and putrescine-priming in modulating salinity tolerance in camelina crops.

Effects of foliar silicon and nitrogen applications on winter color retention and spring green-up of zoysia grass

Zoysia japonica Steud. (zoysia grass), with its high drought, shade, and salt tolerance, it is an excellent choice for green areas. However, in regions with subtropical climates, it goes into winter dormancy with a loss of green color and functionality, which is a main barrier to its widespread use. The application of silicon and nitrogen in fall was hypothesized to enhance winter color retention of Z. japonica. This study assessed the impact of fall (late-season) nitrogen (0, 2.5, or 5.0 g/m2 ammonium sulfate) and foliar silicon (0, 3, or 6 mL/L potassium silicate) applications on the winter color retention of Z. japonica grown in the field. The experiment was conducted over two consecutive growing seasons in Antalya, Türkiye. Turfgrass quality, color, chlorophyll content, shoot density, and winter dormancy were all improved by late-season nitrogen application. Overall, two sequential nitrogen applications at 5 g/m2 in fall provided 65% to 100% green coverage with acceptable turfgrass quality during fall and winter, indicating the possibility of maintaining the year-round green color of Z. japonica in subtropical climates. However, the silicon treatment did not affect the winter color retention of Z. japonica. The apparent lack of a beneficial response of Z. japonica to the silicon application might be due to the dose, application methods, and silicon source.

Multiple remotely sensed datasets and machine learning models to predict chlorophyll-a concentration in the Nakdong River, South Korea.

The Nakdong River is a crucial water resource in South Korea, supplying water for various purposes such as potable water, irrigation, and recreation. However, the river is vulnerable to algal blooms due to the inflow of pollutants from multiple points and non-point sources. Monitoring chlorophyll-a (Chl-a) concentrations, a proxy for algal biomass is essential for assessing the trophic status of the river and managing its ecological health. This study aimed to improve the accuracy and reliability of Chl-a estimation in the Nakdong River using machine learning models (MLMs) and simultaneous use of multiple remotely sensed datasets. This study compared the performances of four MLMs: multi-layer perceptron (MLP), support vector machine (SVM), random forest (RF), and eXetreme Gradient Boosting (XGB) using three different input datasets: (1) two remotely sensed datasets (Sentinel-2 and Landsat-8), (2) standalone Sentinel-2, and (3) standalone Landsat-8. The results showed that the MLP model with multiple remotely sensed datasets outperformed other MLMs with 0.43 - 0.86 greater in R2 and 0.36 - 5.88 lower in RMSE. The MLP model demonstrated the highest performance across the range of Chl-a concentrations and predicted peaks above 20 mg/m3 relatively well compared to other models. This was likely due to the capacity of MLP to handle imbalanced datasets. The predictive map of the spatial distribution of Chl-a generated by MLP well captured the areas with high and low Chl-a concentrations. This study pointed out the impacts of imbalanced Chl-a concentration observations (dominated by low Chl-a concentrations) on the performance of MLMs. The data imbalance likely led to MLMs poorly trained for high Chl-a values, producing low prediction accuracy. In conclusion, this study demonstrated the value of multiple remotely sensed datasets in enhancing the accuracy and reliability of Chl-a estimation, mainly when using the MLP model. These findings would provide valuable insights into utilizing MLMs effectively for Chl-a monitoring.

Performance Study of Betelvine (Piper betle Linn.) Cultivars under Varying Doses of Phytohormone-Triacontanol

Betel vine (Piper betle Linn.) belongs to the family Piperaceae. The experiment was carried out with two factorial randomized block design combining 3 replications and 18 no. of treatments. Adopted plant spacing was 50 cm x10 cm and plot to plot distance was 60 cm. Treatment Details: Factor 1: Triacontanol – 0.1% (T1), Triacontanol – 0.05% (T2), Triacontanol – 0% (T3), Factor 2: Cultivars: Utkal Sudam, Kali Bangla, Kotki, Simurali Bhabna, Simurali Gol Bhabna, Chalani local. Nutrients were applied as FYM (10 tonnes ha-1) and N:P:K::200:100:100 Kg ha-1year-1. Regarding the interaction effect of cultivar with the effect of Triacontanol, the cultivar Kotki treated with Triacontanol @ 0.1% (T1) recorded highest average vine elongation per month (32.83 cm). Whereas both the cultivar Kotki and Kali Bangla, when treated with Triacontanol @ 0.1% (T1) recorded maximum number of leaves per vine per year (4.60). The highest content of total Chlorophyll (3.89 mg/g) and essential oil (0.82%) was obtained from the cultivar Simurali Gole Bhabna treated with Triacontanol @ 0.1% (T1). The cultivar Utkal Sudam with Triacontanol @ 0.05% (T2) was observed highest Phenol content (142.58 mg GAE /100g). Maximum shelf life (18 days) was obtained from the cultivar Kali Bangla and Kotki treated with Triacontanol 0.1% (T1). From this experiment, highest benefit:cost ratio (3.03) was obtained from the cultivar Kali Bangla treated with Triacontanol @ 0.1%(T1) and lowest benefit:cost ratio (1.75) was recorded in cultivar Chalani local without the use of Triacontanol i.e. in control plot.

The seasonal variation of the inhibitory effect of bioactive extracts of a marine algae (Corallina officinalis) collected from the Algerian west coast

Algae are increasingly becoming the center for interest due to researchers for their composition of various important bioactive molecules. The objective of this study is to investigate the seasonal variations in the concentrations of flavonoids, polyphenols, chlorophyll a, chlorophyll b, and carotenoids, as well as the antimicrobial activity of methanolic extracts from the red alga Corallina officinalis collected from western Algeria. The results of the biochemical assays show that the best polyphenol contents are recorded by the summer extract with a concentration of 33.29 μgEqAG/mg. The recorded flavonoid contents are 967.33; 869; 239.66 and 156 µgEQ/mg for summer, autumn, spring and winter respectively. For chlorophyll a and b the winter extract recorded the highest values. The best results of antibacterial tests were noted for the summer season with diameters of 14.33 mm against the two-bacteria E. coli and Staphylococcus aureus resistant to methicillin (SARM). The autumn extract gave low activity against E. coli, Pseudomonas, SARM and Klebsiella. For the winter extract we noted resistance against B. cereus, Pseudomonas and B. subtilis while E. coli, SARM, Klebsiella and the yeast Candida albicans recorded low activity. For the spring extract, resistance was observed against all the bacteria tested except for the E. coli and Klebsiella strains. The extracts obtained can be used as an antibacterial due to their rich content of bioactive molecules. The best results of antibacterial tests are noted for the summer season.

Evaluating the efficacy of microalgal-bacterial granular sludge system in lake water remediation.

The microalgal-bacterial granular sludge (MBGS) process is attracting attention as a green wastewater treatment technology. However, research on the application of MBGS in lake water remediation is limited. Thus, this experiment investigated the feasibility and the efficacy of the MBGS process for the treatment of natural lake water in a continuous-flow tubular reactor. The averageremoval efficiencies of COD, NH4+-N, NO3--N, NO2--N, TN, PO43--P, TP, and turbidity by MBGS system in the day/night cycles were 50.10/61.39%, 63.52/75.23%, 43.37/73.57%, 90.72/93.48%, 78.30/80.02%, 71.13/74.62%, 65.08/70.57%, 92.32/89.84%, respectively. As the experiment progressed, the total chlorophyll content in MBGS decreased as the granule size increased, while the extracellular polymeric substances content increased, suggesting that thelake water contributed to bacterial growth and favored the stability of MBGS. Moreover, the eukaryotic microorganisms were dominated by Chlorophyta and Rotifera, and prokaryotic microorganisms were dominated by Proteobacteria in MBGS. By promoting the decomposition of various organic compounds in the lake water and inhibiting sludge expansion, these microorganisms helpthe MBGS system tomaintain excellent granular characteristics and performance. Overall, the MBGS system proved to be a feasible option for the remediation of natural lake waters.

Exploring the wild almond, Prunus arabica (Olivier), as a genetic source for almond breeding

During the process of almond (Prunus dulcis) domestication, essential traits, which gave plants the plasticity for facing unstable environmental conditions, were lost. In general, the domestication process often narrows the natural genetic diversity. Modern selections (i.e., breeding programs) dramatically accelerated this genetic bottleneck trend to a few successful almond cultivars, which are presently the founders of most commercial cultivars worldwide. The concept of utilizing wild species as a source for important traits and for the enrichment of the gene pool was deeply discussed in previous studies. However, in almonds and other Prunus species, deliberate utilization of wild species as a genetic resource for breeding programs is quite rare. To address these significant challenges, we generated an interspecific F1 population between the Israeli almond cultivar Um el Fahem (UEF) and a specimen of a local wild almond species, Prunus arabica (P. arabica), originating from the Judea desert. This interspecific F1 population possesses high phenotypic variability, and sixteen segregating traits were phenotyped. Among the segregating traits, we were able to genetically associate six agriculturally important traits, such as leaf chlorophyll content (LCC), flower size, and fruit size. The alleles for Self-Compatibility (SC) and kernel bitterness were previously mapped in almond and were reexamined on the background of the distinctive wild genetic material of P. arabica. Finally, phenotypic interactions between traits were suggested, such as rootstock perimeter and canopy area that were positively correlated with total yield in the F1 population. This study is a first step towards developing a well-characterized almond interspecies genetic population. The availability of such a genetic tool with detailed phenotypic analysis is crucial to address and explore the profound influence of almond wild species in Prunus genetic research and breeding. By using the interspecific population as the infrastructure, we show the advantages and importance of utilizing wild relatives.

CfSGR1 and CfSGR2 from Cryptomeria fortunei exhibit contrasting responses to hormones and abiotic stress in transgenic Arabidopsis

Stay-green (SGR) genes are pivotal regulatory genes in the context of plant chlorophyll metabolism, but few studies on SGR homologues in Cryptomeria fortunei have been previously reported. We cloned two CfSGR genes and overexpressed them in Arabidopsis to explore their functions. Full-length CfSGR1 and CfSGR2 are 1265 and 1197 bp, encompassing open reading frames (ORFs) encoding 274 and 276 amino acids, respectively. SGRs exhibited high conservation in higher plants, and phylogenetic analysis indicated that SGRs from monocots and gymnosperms cluster in a clade. The proteins localized to chloroplasts and showed no transcriptional activity in yeast cells. The CfSGR gene expressions were induced by abiotic stresses and hormones. Under conditions of darkness, abscisic acid (ABA), salt, drought, or freezing stress, CfSGR2-transgenic Arabidopsis exhibited a delay in leaf yellowing compared to the WT, which was attributed to increased chlorophyll content and enhanced photosynthetic capacity. These transgenic plants exhibited improved resistance to stress via upregulated expression of resistance-related genes, increased antioxidant enzyme activities, and reduced malondialdehyde content and electrolyte leakage rate. In contrast, CfSGR1-transgenic plants may accelerate leaf yellowing and exhibit reduced stress resistance. Our findings highlight potential divergence in the functions of CfSGR genes concerning plant growth and development and responses to abiotic stresses or hormones, providing a scientific foundation for future breeding of stress-resistant C. fortunei cultivars.