Shoot Development Research Articles

Inhibitory Effects of Garlic Extract on Hop Stunt Viroid in Micropropagated Grapevine Plantlets

Hop stunt viroid (HSVd) is a major pathogen that affects grapevine health and causes substantial economic losses in grape cultivation. Many studies have been conducted to control grapevine diseases, but effective control methods after plant infections remain lacking. This study aimed to assess the antiviral potential of garlic extract, a natural substance that inhibits HSVds in grapevine plants after micropropagation. Garlic extract was diluted 1,000-fold and applied to grapevine plants, and its effect on HSVd accumulation was evaluated using reverse transcription polymerase chain reaction and digital PCR. The results showed that HSVd accumulation was significantly reduced, with an inhibition rate of 74.45%; meanwhile, higher garlic extract concentrations resulted in contamination and plant damage. Nanopore sequencing confirmed that the integrity of the HSVd genome was compromised after treatment. Furthermore, garlic extract inhibited the HSVd and promoted plant growth by enhancing shoot and root development. Additionally, inhibition of the HSVd was sustained in regenerated grapevine plants. Moreover, the garlic extract showed inhibitory effects against HSVds in natural host cucumber plants. These results suggest that garlic extract could be a cost-effective and sustainable alternative for viroid control in grapevine cultivation, providing long-term protection and broader antiviral activity across plant species.

Genome-wide identification of MGT gene family in soybean (Glycine max) and their expression analyses under magnesium stress conditions

BackgroundMagnesium (Mg) is essential for plant growth and development and plays critical roles in physiological and biochemical processes. Mg deficiency adversely affects growth of plants by limiting shoot and root development, disturbing the structure and membranes of the grana, reducing photosynthesis efficiency, and lowering net CO2 assimilation. The MGT (Magnesium transporter) family is responsible for the absorption and transportation of magnesium in plants. Although the MGT family has been identified in different plant species, research regarding the soybean MGT genes is limited.ResultsIn the current study, a total of 39 MGT genes distributed on 17 different chromosomes were identified in soybean. Phylogenetic analysis classified GmMGTs into three subgroups, NIPA, MRS2/MGT, and CorA, which showed little homology with MGTs of Arabidopsis thaliana and Oryza sativa members and clustered tightly with GmMGTs. Gene structure and conserved motif analysis also confirmed similar grouping in GmMGTs. The expansion of the GmMGT members in NIPA and MRS2/MGT was predicted, while CorA was identified as the most conserved group in G. max. Segmental duplication under purifying selection pressure was identified as the major driving force in the expansion of MGTs in soybean. GmMGTs showed diverse tissue-specific and stress-response expression patterns due to the presence of stress-related cis-regulatory elements in their promoter regions. Under Mg-deficiency and surplus stress conditions, a decrease in root length, shoot length, and root and shoot fresh as well dry weight in susceptible genotypes showed the variegated expression of MGTs in soybean genotypes. Furthermore, the upregulation of GmMGT2 and GmMGT29 in tolerant genotypes in response to Mg-deficiency as well as surplus stress conditions in leaves suggested the essential role of GmMGT genes in the absorption and transportation of Mg in soybean leaves.ConclusionThis study presents a comprehensive analysis of the MGT gene family in soybean, providing insights into their evolutionary relationships, gene classification, protein structures, and expression patterns under both Mg deficiency and Mg surplus conditions.

Investigation of the Effects of Rooting Medium and IBA Concentration on Rooting and Shoot Development of Bougainvillea (Bougainvillea spp.) Cuttings

In this study, the effect of different rooting mediums (peat moss, peat + sand, peat + loam) and IBA (indole-3-butyric acid) concentration was investigated on hardwood cuttings taken from Bougainvillea glabra, Bougainvillea spectabilis, and Bougainvillea x buttiana species. The cuttings were treated with 0, 1000, 2000 and 3000 mg/l IBA. Statistical evaluation was performed according to a randomized block experimental design with three factors and three repetitions. The results showed that Bougainvillea x buttiana cuttings had the highest number of roots, root fresh weight, longest shoot length, and shoot fresh weight. Cuttings grown in 100% peat medium had the highest rooting percentage, root number, root dry weight, leaf number, and shoot fresh weight. Regarding IBA concentrations, the cuttings treated with 3000 ppm IBA had the highest number of roots, root length, and root fresh weight. Furthermore, in all of the Bougainvillea species, the highest rooting percentage and leaf number were observed in cuttings treated with 2000 ppm IBA. Notably, Bougainvillea x buttiana cuttings treated with 1000 ppm IBA dose and planted in peat medium provided the longest shoot length, highest shoot fresh weight, and shoot dry weight. In conclusion, the findings show that the growing medium has a statistically significant effect on the rooting and root quality of cuttings and that it would be useful to investigate various rooting hormones, dasages and rooting media to increase rooting and shoot development. Considering growing medium plays a crucial role in plant growth, it can be stated that further improvements in rooting and growth can be realized via utilizing the enhanced physical and chemical properties of peat-based mixtures.

Use of Hydroxyapatite Nanoparticles to Reduce Cd Contamination in Agricultural Soils: Effects on Growth and Development of Chenopodium quinoa Willd

Soil contamination and degradation have prompted extensive research into remediation techniques. A promising approach involves the use of nanoparticles, which can mitigate heavy metal contamination, such as cadmium (Cd), without adversely affecting crop development. This study evaluated the effects of hydroxyapatite nanoparticles (HANPs) on the growth of Chenopodium quinoa Willd. in soils contaminated with varying Cd contents (0, 5, 10, 25, and 50 mg/kg). The results indicated that HANPs enhanced early shoot development, particularly in soils with Cd concentrations ≥10 mg/kg, while significantly reducing Cd accumulation in plant tissues. HANPs also decreased Cd mobility in soil, retaining it in fractions less available for plant uptake. Germination rates differed between pot experiments and phytotoxicity assays, although the first demonstrated greater Cd immobilization in HANP-treated soils, resulting in reduced Cd translocation to quinoa shoots. These findings highlight the potential of HANPs as an effective tool for remediating Cd-contaminated soils, thereby improving soil pollution, crop safety, and quality for human consumption.

In vitro shoot regeneration of Cucumis melo “Meloncella fasciata” with the combined use of 6-benzylaminopurine and cefotaxime

Cucumis melo “Meloncella fasciata” is cultivated and appreciated locally for its unripe fruits. Seed production of these landraces rely on local farmers but heterogeneity limits rapid scalability of this crop. Plant micropropagation techniques may be an alternative method for propagation but their use is limited by genetic instability. We concentrated on organogenesis from cotyledonary nodes, applying the plant growth regulator 6-benzylaminopurine (BAP) combined with the antibiotic cefotaxime to reduce the negative effects of high cytokinin doses. It was observed that this antibiotic, in addition to limiting contamination, has a stimulatory effect on regeneration in several species including melon. Multiple shoot regeneration was achieved from explants within 30 days of cultivation. Explants regenerated adventitious shoots with all concentrations of BAP and cefotaxime, however efficiency varied significantly. Cefotaxime at a dose of 500 mg/L combined with BAP 0.5 mg/L induced an effect comparable to higher doses of BAP. Reducing BAP concentration was beneficial on shoot development, since excessive cytokinin concentrations can induce somaclonal variation. Thanks to the reduced quantity of BAP, no tetraploid cells could be observed in regenerated plants. We conclude that cefotaxime can be integrated in the propagation process providing multiple advantages including contamination control and reduced chromosomal instability.

In Vitro Regeneration of Bambusa Vulgaris Var. Striata Using Nodal Explants

The current study aimed to develop an effective micropropagation protocol for Bambusa vulgaris var. striata, through direct organogenesis using nodal explant. The maximum axillary bud break (84%) with the greatest number of shoots per explant (5.20 ± 0.37) was achieved using liquid MS medium containing 2.5 mg/l BAP and 1.5 mg/l TDZ, while the maximum length of shoots (7.12 ± 0.27 cm) was induced on 2.0 mg/l BAP. Shoots were multiplied in stirred liquid MS medium with 3.0 mg/l BAP, resulting in the highest number of shoots per culture (13.20 ± 0.58) with the shoot length of 7.32 ± 0.48 cm. BAP in combination with TDZ resulted in a feeble response to shoot proliferation; although in some cases, the presence of TDZ with BAP was inhibitory. The shoots progressively increased in number and length over the first four subculture cycles in the aforementioned medium, but declined in the 5th sub-culture cycle. Following the 4th sub-culture cycle, each culture produced 16.60 ± 0.60 shoots with an average length of 8.96 ± 0.61 cm. Adding 10% coconut water to the medium resulted in excellent shoot growth and development, with an average of 18.40 ± 1.44 shoots per culture, measuring 8.56 ± 0.79 cm. Half-strength MS medium with 3.0 mg/l IBA resulted in the highest rooting percentage (85%) and the most roots per culture (8.00 ± 0.71). Successful acclimatization of well-rooted clumps of 3-4 shoots was achieved in a mixture of soil, sand, and compost (2:1:1) with 85% survival rate. Bangladesh J. Bot. 53(4): 939-947, 2024 (December)

Tissue Culture and Rapid Micropropagation for Quercus suber L.

Quercus suber L. (Q. suber) is an evergreen tree species known for producing high-quality cork. Traditional seed propagation of Q. suber has low viability and is time-consuming. Therefore, we used young stem segments of 2~3-year-old seedlings as explants, and optimized protocols for tissue culture and rapid micropropagation of Q. suber. The best disinfection method was 0.10% HgCl2 (v/v) for 5 min. 0.50 g·L−1 Poly Vinyl Pyrrolidone (PVP) is the best anti-browning agent with a significant reduction in browning by nearly 1.76-fold (58.89% → 33.33%). Woody Plant Medium supplemented with micronutrients and vitamins from Murashige and Skoog Medium (WPMS) was found to be the most suitable for shoot formation. The optimal hormone ratio for development of shoots from axillary buds was 0.60 mg·L−1 6-benzyladenine (6-BA). Among the cytokinins tested, 0.50 mg·L−1 6-BA was the most suitable for development of shoots from axillary buds. In additon, the highest percentage of rooting explants (66.67%) and rooting number (3.03) was obtained on WPM basal medium supplemented 0.20 mg·L−1 IBA and 0.20 mg·L−1 NAA. In summary, we have established a set of protocols for tissue culture and rapid micropropagation of Q. suber. These findings lay the foundation for rapid micropropagation and genetic improvement.

Induction of shoot development of Stevia rebaudiana Morita II by vitamins and cysteine

Objective: The aim of this study was to evaluate the influence of B vitamins and cysteine on the formation and development of shoots in Stevia rebaudiana (S. rebaudiana) Morita II, without the addition of plant growth regulators. Design/methodology/approach: The starting material consisted of nodal segments, subjected to eight different vitamin treatments. The results were analyzed using mean comparisons and Tukey's test to identify statistical differences. Results: The most effective treatment was treatment number two, which yielded an average of 7.5 shoots per explant, demonstrating its efficiency for multiplication. For explant elongation, treatment five proved to be the most effective. Limitations of the study/implications: This study aims to establish a multiplication protocol with enhanced efficiency; however, a limitation is the transferability of the results to temporary immersion bioreactors. Findings/conclusions: Thiamine and cysteine are two organic compounds that induce multiple sprouting, while nicotinic acid and pyridoxine promote the elongation of Stevia explants. This research represents a significant step towards transferring this knowledge to grassroots technological enterprises.

The effect controlled release fertilizer on growth, flowering, and leaf morphology of Pulsatilla species

The effect of 14N-6.2P-11.6K controlled release fertilizer (CRF) on growth, flowering, and leaf morphology during vegetative growth of Pulsatilla tongkangensis and P. cernua var. koreana (P. koreana) were investigated. Pulsatilla tongkangensis flowered earlier (26 to 28 days) than P. koreana (50 to 51 days) after natural low-temperature treatment. The highest number of flowers was observed in P. koreana (3.6 flowers) and P. tongkangensis (1.7 flowers) with 0.9–1.2 g of CRF treatment. The formation of a third rachis and leaflet is a unique characteristic observed in P. koreana. Two morphological types of P. tongkangensis seedlings, with either long or short petioles, suggests that seedlings with long petioles are considered putative hybrids between P. tongkangensis and P. koreana. The development of axillary shoots in P. koreana seedlings before overwintering, when seedlings received more than 0.6 g of CRF, suggests that the seedlings undergo a phase change from juvenile vegetative growth to mature plants. This is the first detailed report describing morphology of leaves and plants during growth of seedlings and development of Pulsatilla.

The Effect of Cadmium Salts on the In Vitro Growth and Development of Sorghum (Sorghum)

Purpose. To determine the effect of different concentrations of cadmium salt on the growth and development of shoots of different sorghum species in vitro and to select tolerant forms for developing breeding genotypes resistant to abiotic factors. Methods. The study involved different sorghum species: grain, broomcorn, Sudan grass, and soryz. Sorghum bicolor cultivar 'Stepovyi 8' was used as a control. Nutrient media were prepared using the standard Murashige and Skoog (MS) formulation. Sorghum seeds were sterilized with a solution of Bilyzna (bleach). Clonal micropropagation was conducted through direct selection with the addition of cadmium chloride (CdCl₂) and cadmium sulfate (CdSO₄) at concentrations ranging from 1.0 to 45.0 mg/L. The resulting shoots were evaluated on days 3 and 7 for the percentage of viable, necrotic, and dead shoots, as well as their biometric parameters. Results. The tolerance levels of sorghum plants varied depending on the species, the type of cadmium salt, and the salt concentration. Sudan grass exhibited the highest tolerance, whereas broomcorn was the most sensitive. This trend was consistent for both cadmium chloride and cadmium sulfate. At a concentration of 10.0 mg/L CdCl₂, shoot viability remained high in all treatments (82–95%). Increasing the concentration to 15.0 mg/L reduced viability to 70–87%, while at a concentration of 20.0 mg/L, it dropped to 44–54%. Concentrations of 30.0 mg/L and higher were critical, reducing shoot viability to 2–12%. The maximum toxic concentration (45.0 mg/L) caused the death of broomcorn shoots. In comparison, CdSO₄ demonstrated lower toxicity under similar conditions. At a concentration of 10.0 mg/L, shoot viability was 90–98%, while at a concentration of 15.0 mg/L, it was 80–95%. Even at higher concentrations (20.0–25.0 mg/L), viability remained higher compared to CdCl₂, and the maximum concentrations provided survival of a small proportion of viable shoots (up to 6%). Necrotic shoots began to appear at CdCl₂ concentrations as low as 7.5 mg/L, with the highest percentage of necrosis recorded in broomcorn plants. CdSO₄ caused less necrosis, even at higher concentrations (10.0–17.5 mg/L), indicating its reduced toxicity. At low cadmium salt concentrations (1.0–5.0 mg/L), the number of newly formed shoots was high in all treatments. CdSO₄ promoted greater shoot formation compared to CdCl₂. At 1.0 mg/L, the number of new shoots ranged from 7 to 18, while at 15.0 mg/L, this number decreased to 2–10. Conclusions. CdSO₄ is a less toxic alternative to obtain viable sorghum shoots in cadmium-containing media. The best results were observed at concentrations up to 10.0 mg/L, particularly for Sudan grass and soryz. Breeding programs should consider the species-specific tolerance of sorghum to heavy metals, with special attention to Sudan grass as the most tolerant species.

Plant growth promoting properties of Methylobacterium brachiatum B0021T and its influence on the growth and short-term thermal stress resistance of Lactuca sativa L

Abstract The paper describes the investigation of the effect of inoculation by Methylobacterium brachiatum B0021T on both the growth lettuce plants and their resistance to short-term thermal stress which was made for the first time. The ability of strain B0021T to synthesize indole derivatives, siderophores, to solubilize insoluble phosphates was revealed. It was shown that inoculation of lettuce plants by strain B0021T improved of shoot growth and development, formation of the root system. It had a positive effect on the work of the photosynthetic apparatus, and also increased resistance to short-term temperature stress in vegetation experiments. The obtained results indicate the potential of using the studied strain to improve the yield of agricultural crops, as well as to protect plants from unfavorable environmental conditions.

Blackthorn (Prunus spinosa L.): ecological features of promising forms and the value of the nutrient composition of their fruits for the production of functional products

Background.The relevance of the research is determined by a constant striving to increase the possibilities of using rare fruit and berry crops, e.g. blackthorn, in plant bree­ding and the production of healthy food products. It can be achieved by scientifically based selection and evaluation of fruit taking into account their physiological, phyto­pathological and biochemical parameters. The purpose of the research is to expand the morphological diversity of blackthorn that combines high productivity and quality for further breeding. Materials and Methods. Morphological characteristics and biological properties of the new forms of blackthorn as well as their biochemical parameters constitute the material for this research. A plethora of methods was applied: field, phenological, biometric, physiological and statistical ones. Results. The study presents original data on the morphology and economic charac­teristics of various blackthorn forms (Prunus spinosa L.) obtained as a result of selection in semiarid lands of the northern, central and western parts of Ukraine. The paper highlights morphological and biological properties of the selected forms of blackthorn, biochemical parameters of fruits, including the content of polyphenolic substances as a source of antioxidants. The study revealed that the selected forms of blackthorn have high drought resistance and winter hardiness, in addition to resistance to low temperatures during the flowering phase. Phenological observations of plants of different forms of Prunus spinosa L. allowed establishing the time of onset of the ontogenesis phases: the development of vegetative and generative buds, budding and flowering, appearance of leaves, intensity of shoot growth, formation and development of ovaries, and fruit ripening, which is a significant scientific achievement for the prospective selection in the fruit gardening system. The forms of blackthorn were differentiated by plant height, growth strength, thorniness, fruit size and weight and their potential use in the processing and manufacturing of functional foods. Biochemical analysis of the fruits, particularly the determination of polyphenols, allowed ascertaining their suitability for processing and manufacturing of healthy food products. Conclusions. The obtained data on selected new forms of blackthorn is a potential source of material for prospective breeding. Moreover, technologies for the production of blended juices and syrups from the fruits of the best samples of blackthorn were developed regarding their biochemical properties and technological indicators.

Variability of secondary metabolism and morphogenesis of Ligustrum vulgare L. under different growing conditions in an urban environment

Abstract Assessing the condition of plants in an urban landscaping is a necessary component of monitoring urban ecosystems. Studying how the sensitivity of plants to stressful conditions and the influence of many factors on their growth and development is important for determining the suitability of using plants for urban improvement. The purpose of this study was to identify the impact of stress factors on the growth and development of Ligustrum vulgare L. (commonly called privet). The research was conducted in the city of Kyiv, where the plants are affected by significant vehicle traffic, intense insolation or excessive shade, and mechanical traumatization of plants due to plant trimming. Shoots of Ligustrum vulgare L. of different ages and under different growing conditions were used for the analysis. The research used methods of morphometry, chromatographic profiling of secondary metabolites, and statistical data processing. To analyze the morphogenesis of annual shoots, the Gaussian model was used, which accurately (R2 > 0.90) describes their growth processes. The model coefficients were used for a comparative assessment of the growth dynamics of Ligustrum vulgare L. shoots depending on the growing conditions and plant care. Correlation analysis also allowed for the identification of potential connections between the growth model coefficients and certain phenolic synthesis products. It was found that the plant trimming leads to an increase in the length of the shoots and accelerated growth of the side shoots. The obtained results may indicate that phenolic compounds, in particular chlorogenic acid, directly or indirectly affect the regulation of growth and development of shoots of Ligustrum vulgare L. in response to stress factors, such as mechanical injury. The content of chlorogenic acid positively correlates with the increase in the length of internodes, which indicates its possible role in morphogenesis. It has been established that the profiles of phenolic substances allow identification of Ligustrum plants at the species level. Principal component analysis (PCA) and cluster analyses showed that the phenolic profiles of plants depend on their growing conditions and the urban environment. The study confirms the importance of plant trimming for stimulating plant growth. The significant adaptation potential of Ligustrum vulgare L. plants confirmed the suitability of their use in urban environments.

Efficient micropropagation protocol and assessment of genetic fidelity of micropropagated plantlets of Pueraria tuberosa

The aim of this study was to develop an efficient micropropagation protocol for Pueraria tuberosa, a medicinally valuable woody liana species. The nodal explants derived from in vitro-grown seedlings were cultured on Murashige and Skoog (MS) medium containing various combinations of 6-benzylaminopurine (BAP), thidiazuron (TDZ), indole-3-acetic acid (IAA), and indole-3-butyric acid (IBA). These combinations led to the substantial development of multiple shoots. The combination of TDZ (0.57 µM/L) and IBA (0.12 µM/L) resulted in the highest regeneration rate (85%), maximum number of shoots (5.52 ± 0.67), and best shoot length (4.96 ± 0.33 cm). The most effective in vitro rooting treatment consisted of half-strength MS medium accompanied by 2.46 µM/L IBA and a 10-minute pulse treatment with the same concentration of IBA. This treatment resulted in the highest root formation (100%) and maximum roots per shoot (16.72 ± 1.81), with the highest root length (3.58 ± 0.54 cm) among all treatments tested. After four weeks under field conditions, hardened in vitro plantlets showed an 88.2% survival rate. The genetic fidelity of regenerated plants was assessed using inter-simple sequence repeat (ISSR) and random amplified polymorphic DNA (RAPD) markers, which produced monomorphic bands, demonstrating the genetic homogeneity of regeneration and reliability of the in vitro propagation method.

Tannins and copper sulphate as antimicrobial agents to prevent contamination of Posidonia oceanica seedling culture for restoration purposes.

Seed-based restoration methods are increasingly recognized as a relevant tool contributing to halt and reverse the loss of seagrass meadows while providing genetic and evolutionary benefit for the conservation of these habitats. Ad-hoc protocols aimed at maximizing the survival of plantlets obtained from seeds in cultivation systems are therefore required. Previous trials of seedling culture of Posidonia oceanica, the dominant seagrass of the Mediterranean Sea, recorded up to 40% loss due to mould development. In this study we aim to (i) identify the putative causal agents of seed decay and (ii) test the efficacy of copper sulphate (0.2 and 2 ppm) and of tannin-based products derived from chestnut, tara and quebracho in reducing seed and seedling decay, while assessing possible phytotoxic effects on plant development. Halophytophthora lusitanica, H. thermoambigua and a putative new Halophytophtora species were identified as possible causal agents of seed loss. The antimicrobial agents (copper and tannins) reduced seed contamination by 20%, although copper sulphate at 2 ppm strongly inhibited the root growth. Among tannins, chestnut and tara reduced seeds germination by up to 75% and decreased shoot and root development, while quebracho showed a less severe phytotoxic effect. The use of copper sulphate at 0.2 ppm is therefore recommended to prevent P. oceanica seedling loss in culture facilities since it reduces seed contamination with no phytotoxic effects. Our results contribute to improving the seedling culture of one the key species of the Mediterranean Sea, increasing propagule availability for restoration purposes.

Stem Cutting, Rooting, and Shoot Growth Potentials of Some Hedge Plant Species as Influenced by Number of Nodes

Root and shoot initiation, as well as seedling growth after planting a stem cutting, is critical for ensuring seedling establishment. This study was carried out at the Department of Horticulture Nursery, Federal University of Agriculture Abeokuta, Nigeria, to examine early rooting and shoot development of landscape hedge plants during propagation with respect to the number of nodes per cutting. Species used were Duranta repense Linn., Duranta erecta Linn., Variegated Duranta erecta Linn., Ficus retusa Linn., Ixora coccinea Linn., Acalypha inferno Linn., Acalypha wilkesiana Mull. Arg. Hamelia patense Jacq., Boungainvillea glabra Wild. and Alternanthra dentata Scheygr. Stem cuttings of each of the ten species with 2, 3 and 5 nodes constituted the treatments arranged in Completely Randomized Design with three replicates. Time of root and shoot emergence, rooting percentage observed daily from one day after planting (DAP), number of leaves, seedling height, number of sprouted cuttings were measured weekly from 2 weeks after planting (WAP) and stem girth (at 15cm seedling height) 4 WAP. Fresh root and fresh shoot biomass were measured at 16 WAP. The result revealed that the number of nodes per cutting and the plant species had significant effects on the time to root, shoot initiation, cutting height, and number of leaves, stem girth, fresh root and shoot biomass. Duranta species performed best for all of these parameters while Bougainvillea glabra produced the lowest shoot biomass. Days to shoot initiation was not significantly different (p≤0.05) across the number of nodes for all species, ranging between 8 and 10 days after planting (DAP). Time to root was also similar regardless of the number of nodes across species with all species rooting at a range of 14-28 DAP. All the species used in this study, except Ficus retusa can be classified as easy to propagate because of their early root formation and relatively fast shoot initiation, indicating their potential suitability for use as hedge plants.

Tomato HAIRY MERISTEM4, expressed in the phloem, is required for proper shoot and fruit development

Tomato HAIRY MERISTEM4, expressed in the phloem, is required for proper shoot and fruit development

Revealing the formation mechanisms of key flavor components during the fermentation of bamboo shoots by combining flavoromics and metagenomics

Microbial metabolism plays a critical role in the flavor development of Guangxi fermented bamboo shoots (GFBS). To clarify the role of microorganisms in flavor formation and predict the metabolic pathways of key characteristic flavor compounds, this study employed metabolomics, Odor Activity Value (OAV), and Taste Activity Value (TAV) calculations, integrated with Partial Least Squares Discriminant Analysis (PLS-DA), to investigate changes in GFBS flavors—represented by volatile flavor compounds, organic acids, and free amino acids—across a 30-day fermentation period. Metagenomic datasets were used to identify taxonomic and functional changes in the microbial community. As a result, 26 characteristic flavor compounds (OAV or TAV > 1) were identified in mature GFBS, and 23 differential flavor compounds were identified at different fermentation stages using PLS-DA (VIP > 1.2). The top 10 microbial genera associated with these characteristic flavor compounds were identified, including Acinetobacter, Enterobacter, Raoultella, Enterococcus, Klebsiella, Lactococcus, Leuconostoc, Weissella, Lactiplantibacillus and Limosilactobacillus. Based on these findings, a predictive metabolic network of key flavor compounds in GFBS was constructed, providing a comprehensive understanding of the diverse metabolic roles of microorganisms during fermentation. This work lays a theoretical foundation for the standardized production and quality control of GFBS flavor.

In vitro Propagation Techniques for 'Ferragnes' and 'Ferraduel' Almond Cultivars: Concentration Optimization and Rooting Success

In this study, an appropriate in vitro propagation technique was determined for 'Ferragnes' and 'Ferraduel' almond varieties, which are used in almond orchards for various reasons. To facilitate shoot and proliferation development in the culture medium, 1 mg L-1 and 2 mg L-1 concentrations of BAP were added to the MS medium. For the 'Ferragnes' variety, it was found that 1.0 mg L-1 BAP concentration was more suitable, resulting in a higher number of leaves. When the BAP concentration was 2 mg L-1, the explants exhibited greater length. Explants started to grow on nutrient medium containing 1.0 and 2.0 mg L-1 BAP by the fifth day and 73% of the explants reached a size suitable for subculturing by the end of the third week. The study found that varying the concentrations of IBA did not affect rooting rates. In the rooting medium containing 0.1 mg L-1 NAA, rooting success averaged 23.07% with 2.6 roots per plant for 'Ferragnes' and 62.50% rooting success with an average of 2 roots per plant for 'Ferraduel’.

Physiological Effects and Mechanisms of Chlorella vulgaris as a Biostimulant on the Growth and Drought Tolerance of Arabidopsis thaliana.

Microalgae have demonstrated biostimulant potential owing to their ability to produce various plant growth-promoting substances, such as amino acids, phytohormones, polysaccharides, and vitamins. Most previous studies have primarily focused on the effects of microalgal biostimulants on plant growth. While biomass extracts are commonly used as biostimulants, research on the use of culture supernatant, a byproduct of microalgal culture, is scarce. In this study, we aimed to evaluate the potential of Chlorella vulgaris culture as a biostimulant and assess its effects on the growth and drought tolerance of Arabidopsis thaliana, addressing the gap in current knowledge. Our results demonstrated that the Chlorella cell-free supernatant (CFS) significantly enhanced root growth and shoot development in both seedlings and mature Arabidopsis plants, suggesting the presence of specific growth-promoting compounds in CFS. Notably, CFS appeared to improve drought tolerance in Arabidopsis plants by increasing glucosinolate biosynthesis, inducing stomatal closure, and reducing water loss. Gene expression analysis revealed considerable changes in the expression of drought-responsive genes, such as IAA5, which is involved in auxin signaling, as well as glucosinolate biosynthetic genes, including WRKY63, MYB28, and MYB29. Overall, C. vulgaris culture-derived CFS could serve as a biostimulant alternative to chemical products, enhancing plant growth and drought tolerance.