Fulvic acid affects proliferation and maturation phases in Abies cephalonica embryogenic cells

Morphological and Physiological Indicators for Screening Cell Lines with High Potential for Somatic Embryo Maturation at an Early Stage of Somatic Embryogenesis in Pinus Koraiensis

Many cell lines in the embryogenic callus cannot produce somatic embryos (SEs) even if they meet the optimal SE maturation culture conditions during conifer somatic embryogenesis. This phenomenon hinders the progress of the industrial-scale reproduction of conifers. Therefore, there is an urgent need to obtain morphological and physiological markers to screen embryogenic calli in response to SE maturation conditions. To detect cell lines with high somatic embryogenesis potential during the proliferation process, we counted the number of pro-embryos and early SEs (ESEs) in different cell lines and storage substances, endogenous hormones, and polyamine contents. The results showed that the yield of P. koraiensis SEs was heavily dependent on genotype (p = 0.001). There were high levels of PE III (pro-embryo III) number, ESE number, and soluble protein content, in the response cell lines (R cell lines), which were 1.6-, 3-, and 1.1-fold those of the obstructive cell lines (B cell lines), respectively. The B cell line had high levels of starch, auxin (IAA), Put, Spd, and putrescine: spermine (Put: Spm) compared to the R cell line. In addition, the numbers of PE III, ESEs, and soluble protein content were significantly positively correlated with SE yield. In contrast, the contents of starch, abscisic acid (ABA), Put, Spm, and Spd were significantly negatively correlated with SE yield. To ensure the accuracy of the results, we used nine cell lines to test the results. The PE III and ESE numbers and the Spm and Spd contents were positively correlated with SE yield, while the levels of starch, ABA, IAA, Put: Spd, and Put: Spm were negatively correlated with SE yield. Thus, we recommend using high PE III and ESEs as morphological indicators and low levels of starch, IAA, ABA, and Put: Spm as physiological markers to screen cell lines with a high somatic embryogenesis potential. In addition, we also found that the relationship between Spd, Spm, and SE yield was opposite in the two experimental results. Therefore, we speculate that the differences in Spd and Spm content are mainly affected by genotype. In conclusion, this study obtained the morphological and physiological markers of some high-somatic embryogenic cell lines by comparing the differences between nine somatic embryogenic cell lines. Our results can guide the improvement of conifer somatic embryogenesis technology and can provide a theoretical basis for accelerating the application of biotechnology in large-scale artificial breeding.

Physiological and Structural Aspects of In Vitro Somatic Embryogenesis in Abies alba Mill

Initiation of somatic embryogenesis from immature zygotic embryos, long-term maintenance of embryogenic tissue in vitro or by cryopreservation, as well as maturation, of somatic embryos of Abies alba Mill. are reported in this study. For the initiation of embryogenic tissues, a DCR medium containing different types of cytokinins (1 mg.L−1) were tested. During three consecutive years, 61 cell lines were initiated out of 1308 explants, with initiation frequencies ranging between 0.83 and 13.33%. The type of cytokinin had no profound effect on the initiation frequency within one given year. Microscopic observations revealed presence of bipolar somatic embryos in all initiated embryogenic tissues. Besides the typical bipolar somatic embryos, huge polyembryonal complexes, as well as “twin” embryos, were observed. Maturation of somatic embryos occurred on a DCR medium supplemented by abscisic acid (10 mg.L−1), polyethylene glycol (PEG-4000, 7.5%) and 3% maltose. The maturation capacity was cell-line dependent. All of the four tested cell lines produced cotyledonary somatic embryos, though at different quantities, of 16 to 252 per g of fresh weight. After germination, seedlings developed, but their further growth soon stopped after the formation of a resting bud. Altogether, seven cell lines were cryopreserved, using the slow-freezing technique. After rewarming, all tested cell lines showed regrowth rates between 81.8 and 100%.

Effects of Dietary Supplementation of Humic Acid Sodium and Zinc Oxide on Growth Performance, Immune Status and Antioxidant Capacity of Weaned Piglets

Simple Summary

Weaning of piglets can destroy the piglet’s intestinal health and immune function, leading to diarrhea and a reduction in growth rate eventually. Considering drug resistance and residues, new alternatives, such as sodium humate (HNa), have attracted considerable research interest over recent decades. Our study was designed to explore the effect of HNa on the growth performance, diarrhea rate, antioxidative, inflammation, and immunity of weaned piglets and the possibility of HNa replacing antibiotics and zinc oxide. The obtained results indicate that HNa reduces stress, protects the intestinal barrier, and improves the performance of weaned piglets.

Abstract

At present, the widespread use of high-dose zinc oxide and antibiotics to prevent post-weaning diarrhea (PWD) in piglets has caused serious environmental problems. To solve this problem, we studied the effect of HNa as a substitute for zinc oxide (ZnO) and antibiotics on the growth performance, immune status, and antioxidant capacity of piglets. Seventy-two weaned piglets (body weight = 7.42 ± 0.85 kg, 26-d-old) were distributed in a randomized 2 × 3 factorial design (two sexes and three treatments) with six replicates of four piglets each. The three treatments were the control diet (basic diet), HNa diet (basic diet + 2000 mg/kg sodium humate), and ZoA group (basic diet + 1600 mg/kg zinc oxide + 1000 mg/kg oxytetracycline calcium). ANOVA and Chi-square tests were applied to compare the means (p < 0.05) between treatments. The results showed that body weight at 16 and 30 d and the average daily gain of piglets fed with HNa or ZoA were significantly higher (p < 0.05) than the control group. Supplementing HNa or ZoA significantly increased (p < 0.05) the level of immunoglobulin M and G, and reduced (p < 0.05) the concentration of inflammatory factors such as tumor necrosis factor-alpha (TNF-α), interleukins IL-6 and IL-1β, myeloperoxidase (MPO), and diamine oxidase (DAO). Furthermore, dietary HNa or ZnO significantly reduced (p < 0.05) the level of total antioxidant capacity (T-AOC) and malondialdehyde (MDA) compared with the control group. ZoA treatment showed an upward trend of IgA level and a downward trend of the concentration of lipopolysaccharide (LPS) and catalase (CAT). Overall, the study demonstrated that the addition of HNa in the diet partially replaced antibiotics and ZnO to improve the growth performance, immune function, and antioxidant capacity of weaned piglets, and maintained a good preventive effect on piglet diarrhea.

Foliar antitranspirant and soil superabsorbent hydrogel affect photosynthetic gas exchange and water use efficiency of maize grown under low rainfall conditions

BACKGROUND

Two lysimeter experiments with maize plants were conducted to investigate the effect of combined superabsorbent polymer (SAP) and fulvic acid (FA) application on photosynthetic gas exchange and water use efficiency (WUE) under deficit irrigation conditions. Soil SAP (45 kg hm^-2 ) was applied while sowing, and FA solution (2 g L^-1 ) was sprayed onto the crop canopy three times at later plant growth periods.

RESULTS

Combining SAP and FA application significantly improved plant photosynthesis, chlorophyll contents and instantaneous WUE while maintaining optimal leaf stomatal transpiration. The effect of using the combined chemicals on photosynthesis and leaf instantaneous WUE was superior to the effects of their individual applications. Compared with plots not treated with chemicals, soil SAP significantly improved the yield by 12% and grain WUE by 10% when averaged across the two experiments, whereas foliar FA application did not affect yield and grain WUE. In contrast, the combined use of the two chemicals significantly increased the yield by 20% and grain WUE by 26%, largely attributed to the increase in grain number.

CONCLUSION

Soil SAP and foliar FA use under low rainfall conditions had little influence on crop water consumption but improved plant WUE by enhancing photosynthesis and increasing kernel number. © 2018 Society of Chemical Industry.

Somatic Embryogenesis of Abies cephalonica Loud

Greek fir (Abies cephalonica Loudon) belongs to the Mediterranean fir species and is widely distributed in the mountains of Central and Southern Greece. Considering a climatic scenario, infestation by pathogens or insects and fire episodes, it has been proposed that Mediterranean firs could be in danger in some parts of their present range but, on the other hand, could also replace other species in more northern zones with temperate humid climates (e.g., silver fir, Abies alba Mill.). As fir species are generally highly productive and therefore important for commercial forestry, they have traditionally been involved in conventional tree improvement programs. A lot of effort has been put into the development of vegetative propagation methods for firs, in order to rapidly gain the benefits of traditional breeding to be utilized in reforestation. The present paper provides up to date information on protocols for somatic embryogenesis (i.e., the most promising in vitro method for vegetative propagation) of Greek fir. Moreover, the protocols for cryopreservation and long-term storage of embryogenic material are described as well.

Structure-Property-Function Relationship in Humic Substances to Explain the Biological Activity in Plants

Knowledge of the structure-property-function relationship of humic substances (HSs) is key for understanding their role in soil. Despite progress, studies on this topic are still under discussion. We analyzed 37 humic fractions with respect to their isotopic composition, structural characteristics, and properties responsible for stimulating plant root parameters. We showed that regardless of the source of origin of the carbon (C₃ or C₄), soil-extracted HSs and humic acids (HAs) are structurally similar to each other. The more labile and functionalized HS fraction is responsible for root emission, whereas the more recalcitrant and less functionalized HA fraction is related to root growth. Labile structures promote root stimulation at lower concentrations, while recalcitrant structures require higher concentrations to promote a similar stimulus. These findings show that lability and recalcitrance, which are derived properties of humic fractions, are related to the type and intensity of their bioactivity. In summary, the comparison of humic fractions allowed a better understanding of the relationship between the source of origin of plant carbon and the structure, properties, and type and intensity of the bioactivity of HSs in plants. In this study, scientific concepts are unified and the basis for the agronomic use of HSs is established.

Studies on the binding of fulvic acid with transferrin by spectroscopic analysis

Transferrin has shown potential in the delivery of anticancer drugs into primarily proliferating cancer cells that over-express transferrin receptors. Fulvic acid has a wide range of biological and pharmacological activities which caused widespread concerns, the interaction of fulvic acid with human serum transferrin (Tf) has great significance for gaining a deeper insight about anticancer activities of fulvic acid. In this study, the mechanism of interaction between fulvic acid and Tf, has been investigated by using fluorescence quenching, thermodynamics, synchronous fluorescence and circular dichroism (CD) under physiological condition. Our results have shown that fulvic acid binds to Tf and form a new complex, and the calculated apparent association constants are 5.04×10(8) M(-1), 5.48×10(7) M(-1), 7.38×10(6) M(-1) from the fluorescence quenching at 288 K, 298 K, and 310 K. The thermodynamic parameters indicate that hydrogen bonding and weak van der Waals are involved in the interaction between fulvic acid and Tf. The binding of fulvic acid to Tf causes the α-helix structure content of the protein to reduce, and resulting that peptide chains of Tf become more stretched. Our results have indicated a mechanism of the interaction between fulvic acid and Tf, which may provide information for possible design of methods to deliver drug molecules via transferrin to target tissues and cells effectively.

Changes in ATP, glucose-6-phosphate and NAD(P)H cellular levels during the proliferation and maturation phases of Abies alba Mill. embryogenic cultures

The aim of the present study was to evaluate the adenosine triphospate (ATP), glucose-6-phosphate (glu-6P) and reduced form of nicotinamide adenine dinucleotide phosphate (NAD(P)H) cellular levels during the proliferation and maturation phases of Abies alba Mill. somatic embryos. For a better understanding of the dynamics of these parameters during the proliferation cycle, four embryonic cell lines were tested. During the maturation period, three independent experiments were conducted, focused on the effects of PEG-4000 (5 or 10% (w/v)) and abscisic acid (16, 32 or 64 μM) applied together (Experiments A and B) or with addition of gibberellic acid (Experiment C) on the dynamics of bio-energetic molecules and on the mean number of cotyledonary somatic embryos. Our results demonstrated that the cellular levels of bio-energetic molecules strongly depended on the composition of maturation media. Generally, the higher the number of cotyledonary embryos produced, the higher the level of ATP observed after a 2-week maturation period. The cellular level of ATP, glu-6P and NAD(P)H increased, particularly after the transition from the proliferation to the maturation phase when the differentiation and growth of somatic embryos occurred.

Molecular properties of a fermented manure preparation used as field spray in biodynamic agriculture

Manure products fermented underground in cow horns and commonly used as field spray (preparation 500) in the biodynamic farming system, were characterized for molecular composition by solid-state nuclear magnetic resonance [(13) C cross-polarization magic-angle-spinning NMR ((13) C-CPMAS-NMR)] spectroscopy and offline tetramethylammonium hydroxide thermochemolysis gas chromatography-mass spectrometry. Both thermochemolysis and NMR spectroscopy revealed a complex molecular structure, with lignin aromatic derivatives, polysaccharides, and alkyl compounds as the predominant components. CPMAS-NMR spectra of biodynamic preparations showed a carbon distribution with an overall low hydrophobic character and significant contribution of lignocellulosic derivatives. The results of thermochemolysis confirmed the characteristic highlighted by NMR spectroscopy, revealing a molecular composition based on alkyl components of plant and microbial origin and the stable incorporation of lignin derivatives. The presence of biolabile components and of undecomposed lignin compounds in the preparation 500 should be accounted to its particularly slow maturation process, as compared to common composting procedures. Our results provide, for the first time, a scientific characterization of an essential product in biodynamic agriculture, and show that biodynamic products appear to be enriched of biolabile components and, therefore, potentially conducive to plant growth stimulation.