Pigment Content Research Articles

Effects of different karst fissures and rainfall distribution on the biomass, mineral nutrient elements, antioxidant substances, and photosynthesis of two coniferous seedlings

BackgroundStudying the physiological growth status of Pinus yunnanensis Franch and Pinus elliottii Engelm. seedlings under different karst fissure thicknesses and rainfall distributions is of great significance for the management, vegetation restoration, and tree species selection in karst rocky desertification areas. In this study, we used a two-factor block experiment and set different rainfall durations, namely reduced rainfall duration (I3d), natural rainfall duration (I6d), and extended rainfall duration (I9d); Different karst small habitats, i.e., stone-free soil (S0), less stone and more soil (S1/4), and half stone and half soil (S1/2), are simulated at these three levels. Analyze the changes in physiological growth and photosynthetic characteristics in two coniferous seedlings under different treatments with different karst thicknesses.ResultsThe results showed that with the increase of karst thickness, the growth volumes of height and diameter of P. yunnanensis seedlings, the biomass of various organs, and the accumulation of K+, Ca2+, Na+, and Mg2+ showed a significant change pattern of first increasing and then decreasing (P < 0.05); P. elliottii seedlings show a gradually decreasing trend (except for Ca2+). The biomass accumulation of each organ in two coniferous seedlings showed that leaves > stems > roots. The K+, Ca2+, and Mg2+ content in various organs of P. yunnanensis seedlings showed that leaves > roots > stems, while Na+ shows the order of roots > leaves > stems. The accumulation of mineral elements in various organs of P. elliottii seedlings is manifested as roots > stems > leaves and the accumulation of mineral elements in both coniferous seedlings is manifested as Ca2+ > Mg2+ > K+ > Na+. Root length, root volume, root surface area, root diameter, SOD, POD, SP, photosynthetic pigment content, fluorescence parameters, and gas exchange parameters of P. yunnanensis seedlings gradually increase with the increase of karst thickness (except for the 9-day rainfall duration), while those of P. elliottii seedlings gradually decrease. The light saturation point of P. yunnanensis seedlings is highest under the I6dS1/2 treatment, while that of P. elliottii is highest under the I3dS0 treatment.ConclusionsIn summary, prolonging rainfall duration has an inhibitory effect on the growth of two types of coniferous seedlings. Increasing karst thickness inhibits the growth of P. elliottii seedlings, and to some extent, promotes the growth and development of P. yunnanensis seedlings. I6dS1/4 and I3dS0 treatments have the best growth effects on P. yunnanensis and P. elliottii seedlings. Therefore, we give priority to P. yunnanensis as the tree species for vegetation restoration or rocky desertification management in karst areas. Our study reveals the role of limestone-filled different karst fissures in mitigating the effects of drought as “containers” for plant growth. These findings help us understand the response of plants to drought stress and provide valuable insights for vegetation restoration in karst environments affected by global climate change. Therefore, further experiments with various karst fissure sizes are necessary to test the universality of the reactions of various plants under different karst fissures.

Photosynthetic characteristics and genetic mapping of a yellow-green leaf mutant jym165 in soybean

BackgroundLeaves are important sites for photosynthesis and can convert inorganic substances into organic matter. Photosynthetic performance is an important factor affecting crop yield. Leaf colour is closely related to photosynthesis, and leaf colour mutants are considered an ideal material for studying photosynthesis.ResultsWe obtained a yellow-green leaf mutant jym165, using ethyl methane sulfonate (EMS) mutagenesis. Physiological and biochemical analyses indicated that the contents of chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll in the jym165 mutant decreased significantly compared with those in Jiyu47 (JY47). The abnormal chloroplast development of jym165 led to a decrease in net photosynthetic rate and starch content compared with that of JY47. However, quality traits analysis showed that the sum of oil and protein contents in jym165 was higher than that in JY47. In addition, the regional yield (seed spacing: 5 cm) of jym165 increased by 2.42% compared with that of JY47 under high planting density. Comparative transcriptome analysis showed that the yellow-green leaf phenotype was closely related to photosynthesis and starch and sugar metabolism pathways. Genetic analysis suggests that the yellow-green leaf phenotype is controlled by a single recessive nuclear gene. Using Mutmap sequencing, the candidate regions related of leaf colour was narrowed to 3.44 Mb on Chr 10.ConclusionsAbnormal chloroplast development in yellow-green mutants leads to a decrease in the photosynthetic pigment content and net photosynthetic rate, which affects the soybean photosynthesis pathway and starch and sugar metabolism pathways. Moreover, it has the potentiality to increase soybean yield under dense planting conditions. This study provides a useful reference for studying the molecular mechanisms underlying photosynthesis in soybean.

Effects of combined application of phosphorus and zinc on growth and physiological characteristics of apple rootstock M9-T337 seedlings (Malus domestica Borkh.)

BackgroundBalancing nutrient application is crucial for plant growth. However, excessive fertilizer use, especially imbalanced applications of macronutrients such as phosphate (P), can hinder plant uptake of micronutrients. Balanced P and zinc (Zn) are vital for apple yield and quality, and apple trees are highly sensitive to deficiencies in these nutrients. Therefore, this study was conducted in May 2022, employed a sand culture experiment to investigate the effects of varying P and Zn levels on the growth phenotype, photosynthetic capacity, antioxidant enzyme activity, sugar composition, endogenous hormone levels, and nutrient absorption and utilization of M9-T337 seedlings. Three levels of P (low, medium, high) and three levels of Zn (low, medium, high) were combined to create a total of nine distinct treatment.ResultsThe results indicate that combined P and Zn fertilization at various levels exerts either synergistic or antagonistic effects on the growth, nutrient absorption, and utilization of M9-T337 seedlings. Compared to low and medium levels of P, a combination of high P (4 mmol·L−1) and an adequate amount of Zn significantly enhanced plant growth, root system development, and the microstructure of leaves. Notably, seedlings treated with high P and low Zn (HPLZn) reached a height 1.54 times that of the medium P and medium Zn (MPMZn, control). Physiological indicators under HP conditions revealed significant increases in antioxidant enzyme activity, leaf water retention, photosynthetic pigment concentration, osmotic adjustment substances, and the contents of glucose, sucrose, fructose, endogenous hormones, as well as P and Zn accumulation in the leaves, compared to the control. However, an increase in Zn application led to a declining trend in these parameters. Specifically, the HPLZn treatment exhibited substantial increases in Net photosynthetic rate (Pn), Total chlorophyll (Chl a + b), glucose, fructose, sucrose, and Auxin(IAA), with increments of 7.12%, 27.32%, 11.40%, 23.20%, 16.67%, and 55.11%, respectively, compared to the control.ConclusionBased on the comprehensive ranking from principal component analysis, the combination of HP ( 4 mmol·L−1) and LZn (0.5 µmol·L−1) was found to be the most effective in enhancing the antioxidant capacity, sugar accumulation, osmotic regulation ability, photosynthetic capacity, endogenous hormone levels, as well as P and Zn nutrient absorption and utilization in M9-T337 seedlings.

Assessment of the adaptive ability of regenerant and original oat genotypes to soil stressors

The aim of the research is a comparative analysis of the response to soil stressors according to the biochemical and productive characteristics of the initial genotypes of oats (line 2h15) and regenerative forms (RA, RAAl, RAMn, RACd) in the framework of evaluating the effectiveness of applied cell selection schemes. In the vegetation experiment, the effect of soil stressors on plants was studied – increased acidity (pH = 4.3), toxicity of manganese ions (65.2 mg/kg, pH = 5.2) and cadmium (2.87 mg/kg, pH = 5.2). The Arkhan variety was used as a standard. The control was soil with a neutral pH (7.2). Regenerants were previously obtained in vitro on artificial media without stress (RA) and with selective agents: alumina acid (RAAl), increased Mn2+ (RAMn) and Cd2+ (RACd). On soil with stressors, the pigment content in regenerant leaves exceeded the baseline values by 1.4…1.6 times. In control, the differences between RA and the baseline are unreliable. All regenerative lines, regardless of growing conditions, were characterized by significantly lower levels of polyphenols in grain (11.2…12.4 mg/g dry weight), compared with the baseline and the standard by 1.2…1.3 times. On backgrounds with artificial addition of metals, an excess of the manganese level in the grain was noted: 1.7 times in RAMn (256.1 mg/kg), compared with the baseline, and there were no differences between them in the cadmium content in RACd (1.82…1.67 mg/kg). On the control background, RA and the baseline significantly lagged behind the standard in terms of grain weight from the plant: in regenerants – 1.29 g; baseline – 1.38 g; standard – 1.65 g. With increased acidity and cadmium, all genotypes decreased productivity relative to the control, but to a lesser extent regenerants (1.6 and 1.4 times, respectively), the baseline – 2.8 and 2 times, the standard – 2.4 and 1.9 times.

Photosystems functioning, the content of chemical elements, flavonoids and brassinosteroids in leaves of chimera Cornus controversa

he formation of chimera is a well-known phenomenon in variegated ornamental and wild plants, but the biochemical peculiarities of this phenomenon are not well studied. The purpose of this work was to conduct a comparative study of the photosynthetic apparatus functioning, the content of macro-, microelements, flavonoids and brassinosteroids in the variegated and green leaves of the periclinal chimera Cornus controversa plant grown in the collection of M. M. Gryshko National Botanical Garden of the NAS of Ukraine. Sampling was made during the period from June to October 2022. The content of photosynthetic pigments and brassinosteroids was measured spectrophotometrically, autofluorescence of leaf tissues was studied using an inverted microscope with a multi-channel fluorescence imaging system, Normalized difference vegetation index (NDVI) – using GreenSeeker devices and fluorimeter, the level of macro- and microelements – using plasma emission spectrometer. Phenolic secondary metabolites were separated by HPTLC. To assess the protective capacity of flavonoids, a bioassay on the germination of radish seeds Raphanus in the presence of AlCl3 was used. It was shown that green leaves of C. controversa chimera, compared to variegated ones, had a twice as high NDVI index, maintained photosynthetic function longer in autumn, and had higher content of macronutrients (Mg, Ca and S) but lower concentration of toxic metals (Al, Cu, Fe, Zn, Ti). Instead, variegated leaves accumulated more brassinosteroids and phenolic metabolites, which were found not only to reduce the toxic effect of aluminum but also to have a growth-stimulating effect on the roots of radish seedlings. Such specialization of green and variegated leaves may contribute to better plant chimeras adaptation to environmental pollution. Keywords: brassinosteroids, Cornus controversa, macroelements, microelements, NDVI index, periclinal chimera, phenolic metabolites, photosynthetic pigments, tissue autofluorescence

Comparative study of the photosynthetic efficiency and leaf structure of four Cotoneaster species

Plants belonging to the genus Cotoneaster can be valuable sources of phytochemicals with potential therapeutic properties. The natural habitats of most of these species are situated in Asia, Africa and southern Europe. Introducing them into other climatic conditions could expose them to abiotic and biotic stresses, affecting their bioactive properties. The aim of this study was to assess and compare the performance of four non-native Cotoneaster species (C. roseus, C. hissaricus, C. hsingshangensis, C. nebrodensis) grown in eastern Poland in terms of leaf morphology, anatomy, and efficiency of the photosynthetic apparatus in relation to lipid peroxidation level, being an indicator of oxidative stress. Photosynthetic pigments concentration and chlorophyll a fluorescence parameters were used to evaluate the photosynthetic capacity. The morphological and anatomical analysis of leaves did not show any anomalies or stress symptoms. Cotoneaster roseus was characterized by the highest chlorophyll concentration, viability index (Rfd) and a moderate lipid peroxidation level. On the other hand, the lowest values of photochemical quenching (qP), maximum fluorescence (Fm), Rfd, and quantum yield of the photosystem II (QY) observed for C. nebrodensis might indicate an inferior efficiency of the photosynthetic apparatus in this species; however, it demonstrated the lowest lipid peroxidation level. Nevertheless, the content and proportion of the photosynthetic pigments as well as overall chlorophyll a fluorescence parameters and lipid peroxidation levels indicate a good physiological condition of all examined plants. The observed differences between the species may be rather species specific and genetically established and not indicate their sensitivity to non-native growth conditions. This is the first report about the physiological parameters of the four Cotoneaster species, proving they are well adapted to growth in the climatic conditions of central Europe providing thus a raw material with potential for pharmaceutical applications.

Effect of Bacillus subtilis – based microbiological preparations on the numerical composition of cultured forms of endophytic bacteria, content of mineral nutrition elements, photosynthetic pigments, as well as on chlorophyll fluorescence indices in leaves of columnar apple trees

The results of agrochemical field experiments conducted in an orchard of columnar apple tree (Malus domestica Borkh.) in the Moscow Oblast during the period of 2021–2022 are presented. The research objects were the ‘Valuta’, ‘Triumph’, and ‘President’ varieties. The effect of foliar treatments of plants with Bacillus subtilis (strain V167) and Bacillus subtilis (strain V417) strains, as well as Bacillus subtilis – based microbiological preparations “Extrasol” (strain Ch13) and “Phytosporin-M” (strain 26D) on such indicators as the microbiological and chemical composition of leaves, the content of photosynthetic pigments in leaves, and chlorophyll fluorescence indices was studied. Plant samples were analyzed using standard methodology. When applying strains and microbiological preparations based on Bacillus subtilis, the taxonomic composition of endophytic bacterial forms cultured on dense nutrient media and isolated from leaves was represented by the Bacillus genus. For comparison, when treating plants with Bacillus subtilis strain V417 and “Phytosporin-M”, the Pseudomonas genus was also detected. The number of cultivated forms of endophytic bacteria in the treated plants was consistently growing, having reached the maximum value of 406800 CFU/g in the “Extrasol” variant. Notably, the content of photosynthetic pigments in leaves depended on both the plant variety and the strain used. High values of maximal efficiency of PSII photochemistry (Fv/Fm) were observed both in experimental and control variants. A consistent increase in leaf N content was detected when applying “Extrasol”. In this respect, the ‘President’ variety showed the greatest response, i.e., a 16.1 % increase compared to the control. The ‘President’ and ‘Triumph’ varieties demonstrated an increase in leaf K content under the influence of foliar treatment of plants with the studied strains and microbiological preparations. The greatest effect of 17.2 % above the control was observed in the ‘Triumph’ variety when treated with “Extrasol”. Foliar treatments of ‘President’ and ‘Valuta’ plants with microbiological preparations contributed to increased, compared to the control, Mg contents in their leaves.

Activity of photosynthetic pigments and the antioxidant system in sunflower under drought stress

Background. The study is of particular importance in view of the increasing pace of global climate aridization. The article highlights the results of an experiment on the effect of drought on the physiological status of seedlings of cv. ‘Poseidon 625’ representing an important food crop – sunflower (Helianthus annuus L.). Materials and methods. The experiment included a group of control samples grown with sufficient moisture and four impact groups subjected to osmotic stress. The intensity of accumulation of lipid peroxidation products (LPP) was measured by the reaction of malondialdehyde (MDA) with thiobarbeturic acid; catalase activity was assessed by a photocolorimetric method based on the interaction between hydrogen peroxide and potassium iodide; the content of pigments (Chl a, Chl b, Сar) was calculated spectrophotometrically in acetone extract. Results. The degree of POL accumulation in the impact groups of the experiment was found to be many times higher than the values in the control samples, which was confirmed by a rapid increase in the MDA concentration in response to a growing water shortage. The accumulation of oxygen free radicals triggered the mechanisms of antioxidant protection of seedlings by synthesizing catalase, the concentration of which increased proportionally to the accumulation of POL. At the same time, the rapid accumulation of POL in the absence of irrigation and under osmotic stress of 3 and 5 atm led to a suppression of low-molecular-weight components of protection (carotenoids) and activation of their synthesis only when critical values of osmotic stress were reached. Conclusion. As a result of the experiment, catalase was identified as the main component of antioxidant protection in sunflower seedlings. Due to the activation of its synthesis, the concentrations of Chl a and Chl b decreased, attesting to the activation of the mechanisms protecting the photosynthetic activity in seedlings, and their antioxidant status.

Transcriptomic Analysis Reveals the Mechanism of Color Formation in the Peel of an Evergreen Pomegranate Cultivar 'Danruo No.1' During Fruit Development.

Pomegranate (Punica granatum L.) is an ancient fruit crop that has been cultivated worldwide and is known for its attractive appearance and functional metabolites. Fruit color is an important index of fruit quality, but the color formation pattern in the peel of evergreen pomegranate and the relevant molecular mechanism is still unknown. In this study, the contents of pigments including anthocyanins, carotenoids, and chlorophyll in the peel of 'Danruo No. 1' pomegranate fruit during three developmental stages were measured, and RNA-seq was conducted to screen key genes regulating fruit color formation. The results show that pomegranate fruit turned from green to red during development, with a dramatic increase in a* value, indicating redness and anthocyanins concentration, and a decrease of chlorophyll content. Moreover, carotenoids exhibited a decrease-increase accumulation pattern. Through RNA-seq, totals of 30, 18, and 17 structural genes related to anthocyanin biosynthesis, carotenoid biosynthesis and chlorophyll metabolism were identified from differentially expressed genes (DEGs), respectively. Transcription factors (TFs) such as MYB, bHLH, WRKY and AP2/ERF were identified as key candidates regulating pigment metabolism by K-means analysis and weighted gene co-expression network analysis (WGCNA). The results provide an insight into the theory of peel color formation in evergreen pomegranate fruit.

Optimizing micropropagation of Miscanthus sinensis ‘Gold Bar’ by shortening the production cycle and reducing acclimation stress through the use of selected growth regulators

Miscanthus, with its decorative qualities and low cultivation requirements in terms of soil fertility and temperature, is the most popular grass in gardens and urban areas. For years, micropropagation has been regarded as an effective method of its production. However, in order to meet the demands of customers and provide adequate quantities of high-quality planting materials, it is necessary to develop more efficient methods of Miscanthus production. The present study evaluated the influence of different media on Miscanthus sinensis (Thunb.) Andersson (silver grass) multiplication as well as assessing the effect of different concentrations of selected cytokinins and auxins on multiplication and rhizogenesis. To shorten the production cycle and reduce costs, ex vitro rooting was combined with acclimatization, and selected growth regulators were used to decrease stress associated with external conditions. Biochemical analyses were conducted at each stage to determine the content of basic organic compounds, hydrogen peroxide (H2O2) and catalase activity. Stomatal function was assessed at the acclimatization stage. The obtained results allowed for the production cycle of plants propagated in tissue culture to be shortened by simultaneous rooting and acclimatization of microcuttings sprayed with abscisic acid (ABA). This regulator has been shown to effectively reduce plant stress associated with acclimatization by reducing H2O2 concentration and increasing assimilation pigment content. Growth regulators reduced the number of stomata that developed on the leaves of silver grass and led to lower stomatal conductance. H2O2 should be considered not only a stress marker but a vital signaling molecule.

Foliar application of esculin and digitoxin improve the yield quality of salt-stressed flax by improving the antioxidant defense system

BackgroundSecondary metabolites of several plants, including esculin and digitoxin, which are cardiac glycosides, were previously employed for their therapeutic effects. The current study aims to investigate the functions of the main Na+ /K+ transport inhibitor digitoxin and the antioxidant esculin for enhancing flax plant growth and production under salinity.MethodologyFlax plants were irrigated with distilled water supplemented with 0.0 and 5000 mg/L salt solution starting from 15 DAS from sowing. Then exogenous treatment with digitoxin and esculin with 50 mg L− 1 and 100 mg L− 1 were used for this work.ResultsAccording to the results of this work, foliar spraying of esculin or digitoxin increased the salinity tolerance of flax plants.The foliar application of either esculin or digitoxin induced an elevation in the contents of photosynthetic pigments, osmolytes including soluble sugar and proline as well as the total phenols in salt-stressed flax plants. Moreover, esculin and digitoxin in particular counteract oxidative stress by increasing the activity of antioxidant enzymes including superoxide dismutase, catalase, peroxidase, phenylalanine ammonia-lyase, and tyrosine ammonia lyase, leading to a decrease in reactive oxygen species and lipid peroxidation levels and electrolyte leakage. The efficiency of esculin and digitoxin to sustain ion homeostasis by inhibiting Na+ absorption and increasing potassium, calcium, and phosphorus in flax plants may be the reason for their protective actions towards salinity.As a consequence, esculin and digitoxin increased yield quantity and quality as shown by increases in all investigated yield criteriaas shoot height, root length, their fresh and dry weights as well asseed yield/plant (g), and 1000 seeds weight, especially those that improved the desired oil properties.ConclusionIn conclusion, this study concluded that digitoxin was more effective in inhibiting Na+ build-up and increasing flax salinity tolerance, particularly at the high investigated dose as compared to esculin. In this study, we reported the recent findings of exogenousapplication of either digitoxin or esculin glycosides which are new investigated salt alleviators never used before for improving the salt tolerance in flax plants.

A decade of rain exclusion in a Mediterranean forest reveals trade-offs of leaf chemical defenses and drought legacy effects

Increasing aridity in the Mediterranean region will result in longer and recurrent drought. These changes could strongly modify plant defenses, endangering tree survival. We investigate the response of chemical defenses from central and specialized metabolism in Quercus pubescens Willd. to future Mediterranean drought using a long-term drought experiment in natura where trees have been submitted to amplified drought (~ –30% annual precipitation) since April 2012. We focused on leaf metabolites including chlorophylls and carotenoids (central metabolism) and flavonols (specialized metabolism). Measurements were performed in summer from 2016 to 2022. Amplified drought led to higher concentrations of total photosynthetic pigments over the 2016–2022 period. However, it also led to lower AZ/VAZ and flavonol concentrations. Additionally, chemical defenses of Q. pubescens responded to previous precipitation where low precipitation 1 year and/or 2 years preceding sampling was associated to low concentrations of VAZ, flavonol and high neoxanthin concentrations. Our study indicates that the decline of flavonol concentration under long-term drought is counterbalanced by a higher production of several central metabolites. Such results are potentially due to an adjustment in tree metabolism, highlighting the importance of performing long-term experimental studies in natura for assessing drought legacy effects and thus forest adaptation to climate change.

Polypropylene Packaged Ten Days Cold Stored Rose Cut Flowers cv. Bordeaux Influenced by Different Pulsing Solution

The study included different pulsing solution viz., water, HQC 200mg/l, sucrose 50g/l + HQC 200 mg/l, citric acid 200mg/l, α-lipoic acid 200mg/l, GA3 100 mg/l and BA 100mg/l to study the effect on flower quality and vase life of PP (polypropylene) packaged cold storage (at 2°C) rose cv. Bordeaux, for the period of 10 days. Pre-storage pulsing of GA3 100mg/l solution treatment showed highly promising results in extending flowers vase life along with maintained flower quality just after storage and at 4th DAS in vase life. Further, GA3 100mg/l solution treatment recorded significantly higher water up take (175.65 ml), change in fresh weight (10.50%) at 4th DAS, total dissolve solids (8.85 °brix, 8.05 °brix and 6.75 °brix) and membrane stability index (81.97 %, 65.97 % and 37.88 %) at 2nd, 4th and 6th DAS. Moreover, it was evident from the results that same treatment recoded significantly higher total soluble sugar (59.65 mg/g fresh weight), Estimated protein (18.79 mg/g fresh weight), catalase activity (20.42 µ mol H2O2 min-1 g-1 protein), peroxidation activity (40.30 µ mol H2O2 min-1 g-1 protein), pigment content (15.82 mg/g fresh weight) anthocyanin content in the petals at 4th DAS. Whereas, GA3 100 mg/l pulsing solution treated PP packaged cold stored rose cut flowers cv. Bordeaux recorded significantly higher vase life (6.88 days) which was at par with treatment P2 (Sucrose 50 g/l + HQC 200 mg/l).

Carotenoids dispersed in gypsum rock as a result of algae adaptation to the extreme conditions of the Atacama Desert

The high-altitude pre-Andean region of the Atacama Desert is characterized by its stark volcanic rock formations and unique hydrothermal gypsum outcrops (gypcrete) that it hosts. This study delves into the biomolecular composition of the endolithic phototrophic microbes that thrive within these gypcretes. Using advanced Raman spectroscopy techniques, including Raman imaging (complemented by microscopic and 3D microscopic observations), herein we unveil new insights into the adaptive strategies of these gypsum-inhabiting algae. Our Raman imaging results provide a detailed chemical map of carotenoids associated with microbial colonization. This map reveals a significant gradient in pigment content, highlighting a critical survival mechanism for algae and cyanobacteria in this polyextreme environment. Intriguingly, we detected signals for carotenoids not only in the algae-colonized layer, but also deeper within the gypsum matrix - indicating pigment migration following cell disruption. In addition, we conducted an in-depth analysis of individual algal cells from the Trebouxiaceae family, noting their color variations from green to orange, plus describing the spectral differences in detail. This investigation identified in-vivo pigments (carotenoids, chlorophyll) and lipids at the cellular level, offering a comprehensive view of the molecular adaptations enabling life in one of the Earth’s most extreme habitats.

Effect of Paenibacillus favisporus CHP14 inoculation on selenium accumulation and tolerance of Pakchoi (Brassica chinensis L.) under exogenous selenite treatments

The effects of Paenibacillus favisporus CHP14 inoculation on selenium (Se) accumulation and Se tolerance of Pakchoi were studied by a pot experiment conducted in greenhouse. The results revealed that the growth traits such as plant height, root length, and biomass were significantly elevated during CHP14 treatment at 0 ∼ 8.0 mg·kg−1 Se(IV) levels. CHP14-inoculated plants accumulated more Se in root and shoot, which were 24.1%∼57.3% and 7.5%∼50.9% higher than those of non-inoculated plants. The contents of leaf nitrogen (N), phosphorus (P), magnesium (Mg), and iron (Fe), as well as the ratio of indoleacetic acid and abscisic acid contents (IAA/ABA) were increased by CHP14 inoculation, and positively associated with photosynthetic pigment contents (p < 0.05). At ≥ 4.0 mg·kg−1 Se(IV) levels, superoxide dismutase, peroxidase, and glutathione peroxidase activities of Pakchoi roots were increased with CHP14 inoculation, by 9.9%∼17.1%, 28.4%∼40.7%, and 7.4%∼15.3%, respectively. Moreover, CHP14 inoculation enhanced ascorbate-glutathione (AsA-GSH) metabolism in roots by upregulating the related enzymes activities and antioxidant contents under excess Se(IV) stress. These findings suggest that CHP14 is beneficial to improve plant growth and enhance Se(IV) resistance of Pakchoi, and can be exploited as potential inoculants for phytoremediation process in Se contaminated soil.

Studying the Influence of Salt Concentrations on Betalain and Selected Physical and Chemical Properties in the Lactic Acid Fermentation Process of Red Beetroot

This study emphasizes the significance of optimizing salt content during the fermentation of red beetroot to produce healthier and high-quality fermented products. It investigates the impact of different salt levels on fermentation, analyzing various parameters such as pH levels, dry matter content, total acidity, salt content, color changes, pigment content, and lactic acid bacteria count. This study identifies the most favorable salt concentration for bacterial growth during fermentation and storage as 2–3%. It was evaluated that salt levels fluctuated significantly during fermentation, with nearly 50% of the added salt absorbed by the beetroot tissues, mainly when lower salt concentrations were used. The fermentation process had a negative effect on the content of betalain pigments, as well as yellow pigments, including vulgaxanthin-I. It was also found that fermentation and storage affected the proportions of red pigments, with betacyanins proving to be more stable than betaxanthins, and that salt addition affected negatively pH and total acidity while causing an increase in yellow color. The pH was negatively correlated with the duration of the process, the amount of red pigment, and bacterial count. The results indicate that lower salt levels can lead to favorable physicochemical and microbiological parameters, allowing for the production of fermented red beetroot with reduced salt content without compromising quality.

Alleviative effect of iron chlorin e6 on isoproturon phytotoxicity to wheat

Abstract Isoproturon phytotoxicity to wheat (Triticum aestivum L.) is a worry for many farmers in chemical control of weeds in wheat fields, especially in subzero weather conditions. Iron chlorin e6 (ICe6), a new plant growth regulator, has been reported to enhance crop stress resistance to alleviate damage caused by stress; however, it is not clear whether ICe6 has an alleviative effect on isoproturon phytotoxicity to wheat. We determined the alleviative effect of ICe6 on isoproturon phytotoxicity to wheat, and 0.018 g ai ha−1 was the optimal dose. Meanwhile, we also studied the photosynthetic pigment content, photosynthetic parameters, oxidative stress indicators, and antioxidant enzyme activity of wheat treated with the three different treatments. We found that the photosynthetic pigment content, antioxidant enzyme activity, and photosynthesis of wheat damaged by isoproturon were significantly lower than those of the control, and the hydrogen peroxide (H2O2) and malondialdehyde (MDA) content increased. These results indicate that isoproturon stress significantly weakened the photosynthetic and antioxidant capacity of wheat. The photosynthetic pigment content, photosynthetic parameters (excluding intercellular CO2 concentration), and antioxidant enzyme activity of isoproturon+ICe6– treated wheat were significantly higher than those of isoproturon-treated wheat. The H2O2 and MDA content was significantly lower than that of isoproturon-treated wheat. These results indicate that ICe6 treatment maintained the photosynthetic pigment content of wheat and relatively improved photosynthetic capacity, allowing photosynthesis to proceed normally. ICe6 treatment also limits the decrease in antioxidant enzyme activity, effectively clearing excess reactive oxygen species and ultimately alleviating membrane lipid peroxidation damage. In summary, ICe6 not only enhances stress resistance and increases yield in crops such as soybean [Glycine max (L.) Merr.] and canola (Brassica napus L.), but also has an alleviating effect on the isoproturon phytotoxicity to wheat, which is manifested by the improvement of photosynthetic and antioxidant abilities, ultimately leading to an increase in wheat shoot height and shoot fresh weight.

Effect of different concentrations of soil and foliar applied zinc, boron and iron fertilizers on seedling growth, chlorophyll content and productivity of chickpea seedlings under semi-arid environment

The effectiveness of zinc (Zn), boron (B), and iron (Fe) is reduced in semi-arid regions, which can lead to a deficiency of these nutrients and inhibit chickpea productivity. In this work, three field experiments were executed over two years where soil and foliar applications of Zn, B, and Fe were carried out, including controls (Zn0, B0, and F0), soil application at 4.125 kg/ha (Zn-1, B1, and F1) and 8.25 kg/ha (Zn-2, B2, and F2), and foliar spay at 0.3% at flowering initiating (Zn-3, B3, and F3) and one week after flowering initiation (Zn-4, B4, and F4, respectively). The results indicate that the deficiency of these nutrients inhibited chickpea growth and yield, leading to a reduction in the pigment contents. Nonetheless, soil and foliar application of Zn, B, and Fe significantly improved growth, chlorophyll contents, and yield, showing a dose-dependent effect. The best results were recorded for Zn-3, B2, and F2 treatments which significantly (P&lt;0.05) increased shoot length (20.96-85.19%), root length (42.85-93.65%), shoot fresh (23-76%) and root fresh weight (45-90.32%), compared with the control treatment. Chlorophyll parameters, including chlorophyll a and b contents, showed similar trends. Zn-3, B2, and F2 treatments significantly increased biological and grain yields, which were associated with higher values of the number of pods per plant and the number of seeds per pod. In a nutshell, we suggest that Zn foliar application at 0.3% at flowering initiation and soil application of B and Fe at 25 kg/ha are beneficial for improving the growth, pigment content, and overall productivity of chickpea.

Chlorophyll and Carotenoid Metabolism Varies with Growth Temperatures among Tea Genotypes with Different Leaf Colors in Camellia sinensis

The phenotype of albino tea plants (ATPs) is significantly influenced by temperature regimes and light conditions, which alter certain components of the tea leaves leading to corresponding phenotypic changes. However, the regulatory mechanism of temperature-dependent changes in photosynthetic pigment contents and the resultant leaf colors remain unclear. Here, we examined the chloroplast microstructure, shoot phenotype, photosynthetic pigment content, and the expression of pigment synthesis-related genes in three tea genotypes with different leaf colors under different temperature conditions. The electron microscopy results revealed that all varieties experienced the most severe chloroplast damage at 15 °C, particularly in albino cultivar Baiye 1 (BY), where chloroplast basal lamellae were loosely arranged, and some chloroplasts were even empty. In contrast, the chloroplast basal lamellae at 35 °C and 25 °C were neatly arranged and well-developed, outperforming those observed at 20 °C and 15 °C. Chlorophyll and carotenoid measurements revealed a significant reduction in chlorophyll content under low temperature treatment, peaking at ambient temperature followed by high temperatures. Interestingly, BY showed remarkable tolerance to high temperatures, maintaining relatively high chlorophyll content, indicating its sensitivity primarily to low temperatures. Furthermore, the trends in gene expression related to chlorophyll and carotenoid metabolism were largely consistent with the pigment content. Correlation analysis identified key genes responsible for temperature-induced changes in these pigments, suggesting that changes in their expression likely contribute to temperature-dependent leaf color variations.

Structure–Function Relationships and Health-Promoting Properties of the Main Nutraceuticals of the Cactus Pear (Opuntia spp.) Cladodes: A Review

Over the past decade, several studies have established a direct link between functional foods, nutraceuticals, and a reduced risk of oxidative-stress-related diseases. Nutraceuticals, which encompass a variety of bioactive molecules, exhibit both nutritional and therapeutic properties. The cactus pear (Opuntia spp.) is a plant genus with many species recognized as functional foods, largely attributed to their high content of nutraceuticals, including polyphenols, fatty acids, vitamins, amino acids, pigments, and phytosterols. These compounds of different structures and functions possess different biological activities, contributing to the health-promoting properties of cactus pear. This makes cactus pears a valuable plant for the food, cosmetic, and pharmaceutical industries. While extensive research has focused on the nutritional profile of cactus pear fruits, the cladodes have received comparatively limited attention. Notably, the nutritional composition of cladodes can exhibit considerable variability, influenced by species and growing conditions. Furthermore, although various bioactive compounds have been identified in cladodes, studies elucidating their mechanisms of action, health benefits, and potential therapeutic applications remain insufficient. Addressing these gaps is crucial for enhancing the understanding and utilization of cactus pear cladodes. This paper provides a comprehensive overview of the structure–function relationships of the main nutraceuticals found in cactus pear cladodes. It synthesizes data from recent and relevant literature to elucidate the content of these compounds in relation to species and geographical origin, while also detailing the main biological activities and health-promoting benefits associated with cactus pear cladodes.