Photosynthesis and metabolite responses of Isatis indigotica Fortune to elevated [CO 2 ]

Investigating the Endophyte Actinomycetota sp. JW0824 Strain as a Potential Bioinoculant to Enhance the Yield, Nutritive Value, and Chemical Composition of Different Cultivars of Anise (Pimpinella anisum L.) Seeds

Anise (Pimpinella anisum L.) seeds have various nutritional and therapeutic benefits and are thus considered a valuable addition to animal and human health. Hence, in this study, we aimed to induce the nutritive and biological value of anise seeds. To this end, the potential biofortification effect of the endophytic Actinomycetota sp. JW0824 strain, isolated during the fall of 2023 from the medicinal plant Achyranthes aspera, exhibiting natural distribution in the Jazan region of Saudi Arabia, was investigated in four varieties of anise seeds from Egypt, Tunisia, Syria, and Morocco. Results revealed significant increments (p < 0.05) in the seed dry weight percentage (DW%) and oil yields. In line with increased biomass accumulation, the metabolism of the primary and secondary metabolites was increased. There were differential increases in proteins, sugars, flavonoids, alkaloids, phenols, vitamins (e.g., β-carotene, ascorbic acid), and essential oil components (e.g., phenylpropanoids and monoterpenes), along with their precursor phenylalanine. Consistently, the activity of L-phenylalanine aminolyase (PAL) was increased in the Egyptian and Tunisian varieties at 83.88% and 77.19%, respectively, while 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS) activity increased in all varieties, with a significant 179.31% rise in the Egyptian variety. These findings highlight the beneficial effects of Actinomycetota sp. JW0824 as a bioinoculant for anise seeds, suggesting its potential application in agricultural practices to improve seed yield and quality. Further field trials are recommended to assess the commercial viability of this endophyte for enhancing anise seed production and potentially benefiting other plant species.

Selenium nanoparticles induce coumarin metabolism and essential oil production in Trachyspermum ammi under future climate CO2 conditions

Research on nanoparticles (NPs) and future elevated CO2 (eCO2) is extensive, but the effects of SeNPs on plant growth and secondary metabolism under eCO2 remain uncertain. In this study, we explored the impact of SeNPs and/or eCO2 on the growth, physiology, chemical composition (primary metabolites, coumarins, and essential oils), and antioxidant capacity of Trachyspermum (T.) ammi. The treatment with SeNPs notably improved the biomass and photosynthesis of T. ammi plants, particularly under eCO2 conditions. Plant fresh and dry weights were improved by about 19, 33 and 36% in groups treated by SeNPs, eCO2, and SeNPs + eCO2, respectively. SeNPs + eCO2 induced photosynthesis, consequently enhancing sugar and amino acid levels. Similar to the increase in total sugars, amino acids showed variable enhancements ranging from 6 to 42% upon treatment with SeNPs + eCO2. At the level of the secondary metabolites, SeNPs + eCO2 substantially augmented coumarin biosynthesis and essential oil accumulation. Consistently, there were increases in coumarins and essential oil precursors (shikimic and cinnamic acids) and their biosynthetic enzymes. The enhanced accumulation of coumarins and essential oils resulted in increased overall antioxidant activity, as evidenced by improvements in FRAP, ORAC, TBARS, conjugated dienes, and inhibition % of hemolysis. Conclusively, the application of SeNPs demonstrates significant enhancements in plant growth and metabolism under future CO2 conditions, notably concerning coumarin metabolism and essential oil production of T. ammi.

Rapeseed plant: biostimulation effects of plant growth-promoting Actinobacteria on metabolites and antioxidant defense system under elevated CO2 conditions

BACKGROUND

The present study set out to evaluate the potential of plant growth-promoting Actinobacteria (PGPB) in improving some physiological and molecular parameters of rapeseed (Brassica napus L.) plants under ambient and elevated CO2 conditions by assessing some nitrogen- and sulfur-containing metabolites, antioxidant defense system and antimicrobial activity. With this aim, a pot experiment was conducted where the rapeseed plants were treated with Actinobacterium sp. strain NCO2 (OQ451136) and were grown under two levels of air CO2 concentrations: ambient CO2 (aCO2 , 410 μmol CO2  mol-1 ); and elevated CO2 (eCO2 , 710 μmol CO2  mol-1 ).

RESULTS

There was an increase in the photosynthetic pigments (+35-80%) and photosynthesis rate (+20-34%) in PGPB-treated plants under eCO2 compared to control plants, resulting in further growth and biomass production (+53-294%). These results were associated with an enhancement in the content of total antioxidant capacity (+15-128%), polyphenols (+21-126%) and α-tocopherols (+20-138%) under both eCO2 and PGPB application (in combination or individual application), while only the combined treatment (eCO2  + PGPB) led to a significantly higher accumulation of antioxidant enzymes (+88-197%), β-tocopherols (+177%) and flavonoids (+155%). Moreover, nitrogen- and sulfur-containing metabolites (glucosinolates and amino acids) were improved by PGPB treatment and/or CO2 levels, in which PGPB increased the amino acid-derived glucosinolate induction by eCO2 with low levels of effective sulforaphane.

CONCLUSIONS

Therefore, the interaction effects of beneficial Actinobacteria and eCO2 are expected to boost the level of antioxidant molecules and to have a helpful role in improving plant biomass and adaptability to complicated climate changes in the future. © 2023 Society of Chemical Industry.

Elevated CO2 differentially attenuates beryllium-induced oxidative stress in oat and alfalfa

Elevated CO2 (eCO2 ) is one of the climate changes that may benefit plant growth under emerging soil contaminants such as heavy metals. In this regard, the morpho-physiological mechanisms underlying the mitigating impact of eCO2 on beryllium (Be) phytotoxicity are poorly known. Hence, we investigated eCO2 and Be interactive effects on the growth and metabolism of two species from different groups: cereal (oat) and legume (alfalfa). Be stress significantly reduced the growth and photosynthetic attributes in both species, but alfalfa was more susceptible to Be toxicity. Be stress induced reactive oxygen species (ROS) accumulation by increasing photorespiration, subsequently resulting in increased lipid and protein oxidation. However, the growth inhibition and oxidative stress induced by Be stress were mitigated by eCO2 . This could be explained, at least partially, by the increase in organic acids (e.g., citric acid) released into the soil, which subsequently reduced Be uptake. Additionally, eCO2 reduced cellular oxidative damage by reducing photorespiration, which was more significant in alfalfa plants. Furthermore, eCO2 improved the redox status and detoxification processes, including phytochelatins, total glutathione and metallothioneins levels, and glutathione-S-transferase activity in both species, but to a greater extend in alfalfa. In this context, eCO2 also stimulated anthocyanin biosynthesis by accumulating its precursors (phenylalanine, coumaric acid, cinnamic acid, and naringenin) and key biosynthetic enzymes (phenylalanine ammonia-lyase, cinnamate hydroxylase, and coumarate:CoA ligase) mainly in alfalfa plants. Overall, this study explored the mechanistic approach by which eCO2 alleviates the harmful effects of Be. Alfalfa was more sensitive to Be stress than oats; however, the alleviating impact of eCO2 on Be stress was more pronounced in alfalfa.

Physiological and transcriptome analysis of response of soybean (Glycine max) to cadmium stress under elevated CO2 concentration

The continuous accumulation of Cd has long-lasting detrimental effects on plant growth and food safety. Although elevated CO₂ concentration (EC) has been reported to reduce Cd accumulation and toxicity in plants, evidence on the functions of elevated CO₂ concentration and its mechanisms in the possible alleviation of Cd toxicity in soybean are limited. Here, we used physiological and biochemical methods together with transcriptomic comparison to explore the effects of EC on Cd-stressed soybean. Under Cd stress, EC significantly increased the weight of roots and leaves, promoted the accumulations of proline, soluble sugars, and flavonoid. In addition, the enhancement of GSH activity and GST gene expressions promoted Cd detoxification. These defensive mechanisms reduced the contents of Cd²⁺, MDA, and H₂O₂ in soybean leaves. The up-regulation of genes encoding phytochelatin synthase, MTPs, NRAMP, and vacuoles protein storage might play vital roles in the transportation and compartmentalization process of Cd. The MAPK and some transcription factors such as bHLH, AP2/ERF, and WRKY showed changed expressions and might be engaged in mediation of stress response. These findings provide a boarder view on the regulatory mechanism of EC on Cd stress and provide numerous potential target genes for future engineering of Cd-tolerant cultivars in soybean breeding programs under climate changes scenarios.

An optimistic future of C4 crop broomcorn millet (Panicum miliaceum L.) for food security under increasing atmospheric CO2 concentrations

Broomcorn millet, a C₄ cereal, has better tolerance to environmental stresses. Although elevated atmospheric CO₂ concentration has led to grain nutrition reduction in most staple crops, studies evaluating its effects on broomcorn millet are still scarce. The yield, nutritional quality and metabolites of broomcorn millet were investigated under ambient CO₂ (aCO₂, 400 µmol mol^-1) and elevated CO₂ (eCO₂, aCO₂+ 200 µmol mol^-1) for three years using open-top chambers (OTC). The results showed that the yield of broomcorn millet was markedly increased under eCO₂ compared with aCO₂. On average, eCO₂ significantly increased the concentration of Mg (27.3%), Mn (14.6%), and B (21.2%) over three years, whereas it did not affect the concentration of P, K, Fe, Ca, Cu or Zn. Protein content was significantly decreased, whereas starch and oil concentrations were not changed by eCO₂. With the greater increase in grain yield, eCO₂ induced increase in the grain accumulations of P (23.87%), K (29.5%), Mn (40.08%), Ca (22.58%), Mg (51.31%), Zn (40.95%), B (48.54%), starch (16.96%) and oil (28.37%) on average for three years. Flavonoids such as kaempferol, apigenin, eriodictyol, luteolin, and chrysoeriol were accumulated under eCO₂. The reduction in L-glutamine and L-lysine metabolites, which were the most representative amino acid in grain proteins, led to a reduction of protein concentration under eCO₂. Broomcorn millet has more desirable nutritional traits for combating hidden hunger. This may potentially be useful for breeding more nutritious plants in the era of climate change.

Increasing atmospheric CO2 differentially supports arsenite stress mitigating impact of arbuscular mycorrhizal fungi in wheat and soybean plants

Arbuscular mycorrhizal fungi (AMF) are beneficial for the plant growth under heavy metal stress. Such beneficial effect is improved by elevated CO2 (eCO2). However, the mechanisms by which eCO2 improves AMF symbiotic associations under arsenite (AsIII) toxicity are hardly studied. Herein, we compared these regulatory mechanisms in species from two agronomical important plant families - grasses (wheat) and legumes (soybean). AsIII decreased plant growth (i.e., 53.75 and 60.29% of wheat and soybean, respectively) and photosynthesis. It also increased photorespiration and oxidative injury in both species, but soybean was more sensitive to oxidative stress as indicated by higher H2O2 accumulation and oxidation of protein and lipid. eCO2 significantly improved AMF colonization by increasing auxin levels, which induced high carotenoid cleavage dioxygenase (CCDs) activity, particularly in soybean roots. The improved sugar metabolism in plant shoots by co-application of eCO2 and AsIII allocated more sugars to roots sequentially. Sugar accumulation in plant roots is further induced by AMF, resulting in more C skeletons to produce organic acids, which are effectively exudated into the soil to reduce AsIII uptake. Exposure to eCO2 reduced oxidative damage and this mitigation was stronger in soybean. This could be attributed to a greater reduction in photorespiration as well as a stronger antioxidant and detoxification defence systems. The grass/legume-specificity was supported by principal component analysis, which revealed that soybean was more affected by AsIII stress and more responsive to AMF and eCO2. This study provided a mechanistic understanding of the impact of AMF, eCO2 and their interaction on As-stressed grass and legume plants, allowing better practical strategies to mitigate AsIII phytotoxicity.

Laser Light Treatment Improves the Mineral Composition, Essential Oil Production and Antimicrobial Activity of Mycorrhizal Treated Pelargoniumgraveolens

Pelargonium graveolens, rose-scented geranium, is commonly used in the perfume industry. P. graveolens is enriched with essential oils, phenolics, flavonoids, which account for its tremendous biological activities. Laser light treatment and arbuscular mycorrhizal fungi (AMF) inoculation can further enhance the phytochemical content in a significant manner. In this study, we aimed to explore the synergistic impact of these two factors on P. graveolens. For this, we used four groups of surface-sterilized seeds: (1) control group1 (non-irradiated; non-colonized group); (2) control group2 (mycorrhizal colonized group); (3) helium-neon (He-Ne) laser-irradiated group; (4) mycorrhizal colonization coupled with He-Ne laser-irradiation group. Treated seeds were growing in artificial soil inculcated with Rhizophagus irregularis MUCL 41833, in a climate-controlled chamber. After 6 weeks, P. graveolens plants were checked for their phytochemical content and antibacterial potential. Laser light application improved the mycorrhizal colonization in P. graveolens plants which subsequently increased biomass accumulation, minerals uptake, and biological value of P. graveolens. The increase in the biological value was evident by the increase in the essential oils production. The concomitant application of laser light and mycorrhizal colonization also boosted the antimicrobial activity of P. graveolens. These results suggest that AMF co-treatment with laser light could be used as a promising approach to enhance the metabolic content and yield of P. graveolens for industrial and pharmaceutical use.

Influence of Combined NPK and Manure on Improving Growth, Photosynthetic Characteristic and Yield of Justicia gendarussa Burm. F

&lt;b&gt;Background and Objective:&lt;/b&gt; &lt;i&gt;Justicia gendarussa &lt;/i&gt;(family &lt;i&gt;Acanthaceae&lt;/i&gt;) is regarded as a medicinal plant valued for its beneficial pharmacological activities. A polybag experiment has been conducted at Bogor (Indonesia) to determine the effects on growth, photosynthetic and yield of various NPK ratios and manure fertilizer application in &lt;i&gt;J. gendarussa&lt;/i&gt;. &lt;b&gt;Materials and Methods:&lt;/b&gt; Six treatments (control: 50 g/plant manure, NPK (1.1 g/plant N:0.7 g/plant P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; and 0.6 g/plant K), 50+50%/plant (manure+NPK), 10+50%/plant (manure+NPK) and 50+10%/plant (manure+NPK) were performed in a randomized complete block design. Data of individual plants were extracted from various treatments: plant height, number of leaves, number of branches, chlorophyll content, photosynthetic parameters, yield and sugar content were collected. &lt;b&gt;Results:&lt;/b&gt; The plant treated with 10+50%/plant (manure+NPK) demonstrated a statistically significant increase in plant height, number of leaves and number of branches with the value of 59.00 cm, 85.00 per plant and 9.50 per plant, respectively. Chlorophyll a (0.538 mg g&lt;sup&gt;1&lt;/sup&gt; FW), chlorophyll b (0.192 mg g&lt;sup&gt;1&lt;/sup&gt; FW) and total chlorophyll (0.730 mg g&lt;sup&gt;1&lt;/sup&gt; FW) were significantly improved by the treatment of NPK fertilizer. The application of manure and NPK at (50+50%) and (50+10%) was significantly increased stomatal conductance and transpiration rate, respectively. Leaves yield (9 g/plant DW) was improved by the application of 10+50%/plant (manure+NPK) fertilizer. The highest sugar content was obtained from &lt;i&gt;J. gendarussa&lt;/i&gt; growth with 50+50%/plant (manure+NPK) followed by 10+50% plant (manure+NPK) fertilizer. &lt;b&gt;Conclusion:&lt;/b&gt; The &lt;i&gt;J. gendarussa&lt;/i&gt; plants could benefit from combined manure and NPK fertilizer application in growth, stomatal conductance, intercellular CO&lt;sub&gt;2&lt;/sub&gt; concentration, transpiration rate, leaves yield and sugar content.

Developmental Stages-Specific Response of Anise Plants to Laser-Induced Growth, Nutrients Accumulation, and Essential Oil Metabolism

Compared to seeds and mature tissues, sprouts are well known for their higher nutritive and biological values. Fruits of Pimpinella anisum (anise) are extensively consumed as food additives; however, the sprouting-induced changes in their nutritious metabolites are hardly studied. Herein, we investigated the bioactive metabolites, phytochemicals, and antioxidant properties of fruits, sprouts (9-day-old), and mature tissue (5-week-old) of anise under laser irradiation treatment (He-Ne laser, 632 nm). Laser treatment increased biomass accumulation of both anise sprouts and mature plants. Bioactive primary (e.g., proteins and sugars) and secondary metabolites (e.g., phenolic compounds), as well as mineral levels, were significantly enhanced by sprouting and/or laser light treatment. Meanwhile, laser light has improved the levels of essential oils and their related precursors (e.g., phenylalanine), as well as enzyme activities [e.g., O-methyltransferase and 3-Deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS)] in mature tissues. Moreover, laser light induced higher levels of antioxidant and anti-lipidemic activities in sprouts as compared to fruits and mature tissues. Particularly at the sprouting stage, anise was more responsive to laser light treatment than mature plants.

Effect of Elevated CO2 on Biomolecules' Accumulation in Caraway (Carum carvi L.) Plants at Different Developmental Stages

Caraway plants have been known as a rich source of phytochemicals, such as flavonoids, monoterpenoid glucosides and alkaloids. In this regard, the application of elevated CO₂ (eCO₂) as a bio-enhancer for increasing plant growth and phytochemical content has been the focus of many studies; however, the interaction between eCO₂ and plants at different developmental stages has not been extensively explored. Thus, the present study aimed at investigating the changes in growth, photosynthesis and phytochemicals of caraway plants at two developmental stages (sprouts and mature tissues) under control and increased CO₂ conditions (ambient CO₂ (a CO₂, 400 ± 27 μmol CO₂ mol^-1 air) and eCO₂, 620 ± 42 μmol CO₂ mol^-1 air ppm). Moreover, we evaluated the impact of eCO₂-induced changes in plant metabolites on the antioxidant and antibacterial activities of caraway sprouts and mature plants. CO₂ enrichment increased photosynthesis and biomass accumulation of both caraway stages. Regarding their phytochemical contents, caraway plants interacted differently with eCO₂, depending on their developmental stages. High levels of CO₂ enhanced the production of total nutrients, i.e., carbohydrates, proteins, fats and crude fibers, as well as organic and amino acids, in an equal pattern in both caraway sprouts and mature plants. Interestingly, the eCO₂-induced effect on minerals, vitamins and phenolics was more pronounced in caraway sprouts than the mature tissues. Furthermore, the antioxidant and antibacterial activities of caraway plants were enhanced under eCO₂ treatment, particularly at the mature stage. Overall, eCO₂ provoked changes in the phytochemical contents of caraway plants, particularly at the sprouting stage and, hence, improved their nutritive and health-promoting properties.

Drought and Elevated CO2 Impacts Photosynthesis and Biochemicals of Basil (Ocimum basilicum L.)

Drought-induced reduction in crop growth and productivity can be compensated by increasing atmospheric carbon dioxide (CO2), a significant contributor to climate change. Drought stress (DS) affects crops worldwide due to dwindling water resources and irregular rainfall patterns. The experiment was set up under a randomized complete block design within a three-by-two factorial arrangement. Six SPAR chambers represent three blocks (10 replications each), where each chamber has 30 pots in three rows. Each chamber was maintained with 30/22 (day/night) °C temperature, with either ambient (aCO2; 420 ppm) or elevated CO2 (eCO2; 720 ppm) concentrations. This experiment was designed to address the impact of DS on the physiological and biochemical attributes and study how the eCO2 helps alleviate the adversity of DS in basil. The study demonstrated that DS + eCO2 application highly accelerated the decrease in all forms of carotene and xanthophylls. eCO2 positively influenced and increased anthocyanin (Antho) and chlorophyll (LChl). eCO2 supplementation increased LChl content in basil under DS. Furthermore, DS significantly impeded the photosynthetic system in plants by decreasing CO2 availability and causing stomatal closure. Although eCO2 did not increase net photosynthesis (Pn) activity, it decreased stomatal conductance (gs) and leaf transpiration rate (E) under DS, showing that eCO2 can improve plant water use efficiency by lowering E and gs. Peroxidase and ascorbate activity were higher due to the eCO2 supply to acclimate the basil under the DS condition. This study suggests that the combination of eCO2 during DS positively impacts basil’s photosynthetic parameters and biochemical traits than aCO2.

Effect of Laser Light on Growth, Physiology, Accumulation of Phytochemicals, and Biological Activities of Sprouts of Three Brassica Cultivars

Brassica sprouts are known as a good source of antimicrobial bioactive compounds such as phenolics and glucosinolates (GLs). We aim at understanding how He-Ne laser light treatment (632 nm, 5 mW) improves sprout growth and physiology and stimulates the accumulation of bioactive metabolites in three Brassica spp., i.e., mustard, cauliflower, and turnip. Moreover, how these changes consequently promote their biological activities. Laser light improved growth, photosynthesis, and respiration, which induced the accumulation of primary and secondary metabolites. Laser light boosted the levels of pigments, phenolics, and indole and aromatic precursors of GLs, which resulted in increased total GLs and glucoraphanin contents. Moreover, laser light induced the myrosinase activity to provoke GLs hydrolysis to bioactive sulforaphane. Interestingly, laser light also reduced the anti-nutrient content and enhanced the overall biological activities of treated sprouts including antioxidant, antibacterial, anti-inflammatory, and anticancer activities. Accordingly, laser light is a promising approach for boosting the accumulation of beneficial metabolites in Brassica sprouts and, subsequently, their biological activities.

Elevated CO2 improves the nutritive value, antibacterial, anti-inflammatory, antioxidant and hypocholestecolemic activities of lemongrass sprouts

Sprouts have been regarded as a big store for bioactive compounds with a wide range of biological activities. Elevated CO2 (eCO2, 620 μmol mol-1)was employed to enhance the nutritive and health promoting values of sprouts of two species of lemongrass, i.e. Cymbopogon citratus and Cymbopogon proximus. eCO2 improved the biomass production of sprouts, and their levels of primary metabolites e.g., amino acids and oils and active secondary metabolites e.g., phenolic compounds. As a result, eCO2 increased total antioxidant capacity, cytotoxicity against several human cancer cell lines, and antibacterial activities of Cymbopogon sprouts. We also recorded a significant increase in hypocholesterolaemic potential and anti-inflammatory activities of eCO2-treated sprouts, as indicated by inhibition of cholesterol micellar solubility and pancreatic lipase activity, as well as lipoxygenase and cyclooxygenase activities, respectively. Thus, the present investigation supports the use of eCO2 as a promising approach to produce lemongrass sprouts with effective phytochemicals and enhanced biological activities.

The combined effects of elevated atmospheric CO2 and cadmium exposure on flavonoids in the leaves of Robinia pseudoacacia L. seedlings

Flavonoids participate in several plant processes such as growth and physiological protection in adverse environments. In this study, we investigated the combined effects of eCO₂ and cadmium (Cd)-contaminated soils on the total flavonoid and monomer contents in the leaves of Robinia pseudoacacia L. seedlings. Elevated CO₂, Cd, and eCO₂+ Cd increased the total flavonoids in the leaves relative to the control, and eCO₂ mostly increased (p < 0.05) the total flavonoid content under Cd exposure. Elevated CO₂ increased (p < 0.05) robinin, rutin, and acacetin contents in the leaves of 45-day seedlings and decreased (p < 0.05) the content of robinin and acacetin at 90 and 135 d under Cd exposure except for robinin at day 45 under Cd1 and acacetin on day 135 under Cd1. Quercetin content decreased (p < 0.05) under the combined conditions relative to Cd alone. Kaempferol in the leaves was only detected under eCO₂ on day 135. The responses of total chlorophyll, total soluble sugars, starch, C, N, S, and the C/N ratio in the leaves to eCO₂ significantly affected the synthesis of total flavonoids and monomers under Cd exposure. Overall, rutin was more sensitive to eCO₂+ Cd than the other flavonoids. Cadmium, CO_2, and time had significant interactive effects on the synthesis of flavonoids in the leaves of R. pseudoacacia L. seedlings. Elevated CO₂ may improve the protection and defense system of seedlings grown in Cd-contaminated soils by promoting the synthesis of total flavonoids, although robinin, rutin, quercetin, and acacetin yields may reduce with time. Additionally, increased Cd in the leaves suggested that eCO₂ could improve the phytoremediation of Cd-contaminated soils.

Laser light as a promising approach to improve the nutritional value, antioxidant capacity and anti-inflammatory activity of flavonoid-rich buckwheat sprouts

Buckwheat sprouts are rich in several nutrients such as antioxidant flavonoids that have a positive impact on human health. Although there are several studies reported the positive impact of laser light on crop plants, no studies have applied laser light to enhance the nutritive values of buckwheat sprouts. Herein, the contents of health-promoting minerals, metabolites and enzymes as well as the antioxidant and anti-inflammatory activities were determined in laser-treated (He-Ne laser, 632 nm, 5 mW) common buckwheat (CBW) and tartarybuckwheat (TBW) sprouts. Out of 49 targeted minerals, vitamins, pigments and antioxidants, more than 35 parameters were significantly increased in CBW and/or TBW sprouts by laser light treatment. Also, laser light boosted the antioxidant capacity and anti-inflammatory activities through inhibiting cyclooxygenase-2 and lipoxygenase activities, particularly in TBW sprouts. Accordingly, laser light could be recommended as a promising method to improve the nutritional and health-promoting values of buckwheat sprouts.

Influence of elevated CO2 on nutritive value and health-promoting prospective of three genotypes of Alfalfa sprouts (Medicago Sativa)

Alfalfa sprouts are well known for their nutritive values. Although there are several studies reported the positive impact of elevated CO₂ (eCO₂) on plants, there are no in-depth, comprehensive studies on how eCO₂ could improve the sprouting of plant seeds. Herein, the production of health-promoting metabolites was determined in eCO₂ (620 ppm)-treated Alfalfa sprout cultivars (Giza 1, Nubaria and Ismailia 1). eCO₂ increased the photosynthetic process and pigment contents, which consequently induced carbohydrates, proteins, fats and fiber accumulation. eCO₂ also boosted the levels of vitamins, phenolics, flavonoids and mineral individuals and enhanced the antioxidant capacity of alfalfa sprouts. Interestingly, eCO₂ reduced the antinutritional factor l-canavanine content in Ismailia 1 cultivar and improved the anti-inflammatory activities through inhibiting cyclooxygenase-2 and lipoxygenase activity. Therefore, eCO₂ is a promising approach to improve the health-promoting prospective of alfalfa sprouts to be a valuable source of nutritious and bioactive compounds in our daily diet.

Elevated CO2 improves glucosinolate metabolism and stimulates anticancer and anti-inflammatory properties of broccoli sprouts

Sprouting process enhances plant bioactive compounds. Broccoli (Brassica oleracea L) sprouts are well known for their high levels of glucosinolates (GLs), amino acids, and antioxidants, which offer outstanding biological activities with positive impacts on plant metabolism. Elevated CO₂ (eCO₂, 620 ppm) was applied for 9 days to further improve nutritive and health-promoting values of three cultivars of broccoli sprouts i.e., Southern star, Prominence and Monotop. eCO₂ improved sprouts growth and induced GLs accumulation e.g., glucoraphanin, possibly through amino acids production e.g., high methionine and tryptophan. There were increases in myrosinase activity, which stimulated GLs hydrolysis to yield health-promoting sulforaphane. Interestingly, low levels of ineffective sulforaphane nitrile were detected and positively correlated with reduced epithiospecifier protein after eCO₂ treatment. High glucoraphanin and sulforaphane levels in eCO₂ treated sprouts improved the anticarcinogenic and anti-inflammatory properties of their extracts. In conclusion, eCO₂ treatment enriches broccoli sprouts with health-promoting metabolites and bioactivities.

CO2 enrichment can enhance the nutritional and health benefits of parsley (Petroselinum crispum L.) and dill (Anethum graveolens L.)

The functional food value of herbal plants is greatly related to their contents of valuable phytochemicals. Regarding its impact on primary and secondary plant metabolism, CO₂ enrichment could be a candidate strategy to modulate the levels of nutritionally and medicinally interesting phytochemicals in herbal plants. Herein, the concentrations of 81 metabolites and minerals were evaluated in shoot tissues of parsley and dill grown under two levels of CO₂, ambient (378 ± 25 µmole CO₂ mole^-1 air, aCO₂) and elevated (627 ± 24 µmole CO₂ mole^-1 air, eCO₂). Regardless of the plant species, eCO₂ improved the levels of soluble sugars, starch, organic acids, some EAAs, most of USFA, total phenolics, total flavonoids and vitamins A and E. However, notable variations in the metabolites responsiveness to eCO₂ were recorded among the tested plant species. Moreover, considerable improvements in the total antioxidant capacity, antiprotozoal, antibacterial and anticancer activities were recorded for parsley and dill in response to eCO₂.

Elevated CO2 induces a global metabolic change in basil (Ocimum basilicum L.) and peppermint (Mentha piperita L.) and improves their biological activity

Many studies have discussed the influence of elevated carbon dioxide (eCO₂) on modeling and crop plants. However, much less effort has been dedicated to herbal plants. In this study, a robust monitoring for the levels of 94 primary and secondary metabolites and minerals in two medicinal herbs, basil (Ocimum basilicum L.) and peppermint (Mentha piperita L.), grwon under both ambient (aCO₂, 360 ppm) and eCO₂ (620 ppm) was performed. We also assessed how the changes in herbal tissue chemistry affected their biological activity. Elevated CO₂ significantly increased herbal biomass, improved the rates of photosynthesis and dark respiration, and altered the tissue chemistry. Principal Component Analysis of the full data set revealed that eCO₂ induced a global change in the metabolomes of the two plants. Moreover, Hierarchical Clustering Analyses showed quantitative differences in the metabolic profiles of the two plants and in their responsiveness to eCO₂. Out of 94 metabolites, 38 and 31 significantly increased in basil and peppermint, respectively, as affected by eCO₂. Regardless of the plant species, the levels of non-structural carbohydrates, fumarate, glutamine, glutathione, ascorbate, phylloquinone (vitamin K1), anthocyanins and a majority of flavonoids and minerals were significantly improved by eCO₂. However, some metabolites tended to show species specificity. Interestingly, eCO₂ caused enhancement in antioxidant, antiprotozoal, anti-bacterial and anticancer (against urinary bladder carcinoma; T24P) activities in both plants, which was consequent with improvement in the levels of antioxidant metabolites such as glutathione, ascorbate and flavonoids. Therefore, this study suggests that the metabolic changes triggered by eCO₂ in the target herbal plants improved their biological activities.