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The rocoto (Capsicum pubescens Ruiz & Pav.) (Solanaceae) is an endemic herbaceous chili pepper from Peru. Low yields of rocoto production are due to the low availability of certified seeds or the production of superior plant seedlings. Therefore, the present study aimed to establish an in vitro protocol for the regeneration and multiplication of rocoto shoots. The multiplication was carried out on shoot tips excised from rocoto seedlings germinated under in vitro conditions, and then the explants were placed on Murashigue and Skoog (MS) medium supplemented with different concentrations of 6-benzylaminopurine (BAP) and Kinetin: 0.5, 1.0, 1.5 and 2.0 mg/L. For rooting, shoots were obtained from the multiplication phase and placed under different treatments made up of MS medium supplemented with different concentrations of indole butyric acid (IBA) and naphthalene acetic acid (NAA): 0.5, 1.0, 1.5 and 2.0 mg/L. In the multiplication phase, the best results were observed with MS medium supplemented with 1.0 mg/L BAP, with 82.22% shoot development, 2.93 shoots per explant and 2.75 cm shoot length. In the rooting phase, the best results were observed with MS medium supplemented with 1.5 mg/L IBA, with 91.11% root development, 9.73 roots per explant and 6.79 cm root length. Here, we show the first evidence and tool for the in vitro regeneration and multiplication of rocoto chili pepper, which could be used for the multiplication of superior genotypes, germplasm in vitro conservation and its use in plant breeding programs. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polygonatum cyrtonema Hua (family Asparagaceae) is an endemic plant in China that is valuable for its edible and medicinal uses. Plant growth regulators (PGRs) are natural or synthetic compounds that can regulate plant development and metabolism effectively. To explore potential applications of PGRs for improving the yield and bioactivity of this plant, four PGRs, including gibberellic acid (GA3), 6-benzylaminopurine (6-BA), naphthaleneacetic acid (NAA) and 24-epibrassinolide (EBL), were used in this study and sprayed on the growing seedlings of P. cyrtonema. All of these PGRs did not significantly affect the growth rate of P. cyrtonema, but they had varying effects on the polysaccharide and saponin content in the rhizome. NAA and 6-BA positively affected the polysaccharide content, while most PGR treatments negatively affected the saponin content. Widely targeted metabolomic analysis based on UPLC-MS/MS was conducted and revealed 101 differential metabolites in response to 6-BA, most of which were flavonoids, steroids and lipids. Most of the significantly changed flavonoids decreased under the 6-BA treatment. The study provides insights into the potential use of PGRs for improving the quality of P. cyrtonema, particularly in regulating the content of bioactive compounds. [ABSTRACT FROM AUTHOR]

The cultivation of snap beans (Phaseolus vulgaris L.) in subtropical regions faces environmental challenges leading to potential declines in yield. This study explores the efficacy of biostimulants as a solution, specifically investigating spraying treatments with 6-benzylaminopurine (6-BA), chitosan (Ch), triacontanol (TRIA), and potassium silicate (KSi) on the snap bean cv. Paulista. Over two growing seasons with late sowing and elevated summer temperatures, the research assesses growth, flowering, yield, and quality. Notably, 5 ppm TRIA demonstrates the most significant impact on plant growth and leaf nutrient content. Treatments with 40 ppm 6-BA, 5 ppm TRIA, or 200 ppm KSi exhibit notable effects on inflorescence flower count and flowers per plant. These treatments prove most effective for crucial green pod yield measures, including the number and weight of marketable pods. Moreover, 40 ppm 6-BA or 5 ppm TRIA significantly enhances pod characteristics, such as length, diameter, and weight, consistently improving over both seasons. Particularly, 5 ppm TRIA outperforms in enhancing the chemical quality of pods throughout the study. Overall, the findings suggest that the application of 5 ppm TRIA offers the most favorable enhancements for the growth, flowering, productivity, and quality of snap bean plants in subtropical field conditions.

[Objective] Achieving a rapid, sensitive, and visual detection of 6-benzylaminopurine （6-BA） residues in vegetables. [Methods] Based on the peroxidase-like activity and specific recognition of Fe3O4 magnetic molecularly imprinted nanoparticles （Fe3O4 MMIP NPs）, a simple, rapid and highly selective colorimetric method was established to detect 6-BA residues in vegetables. [Results] Fe3O4 MMIP NPs exhibits optimal peroxidase-like catalytic activity at pH 4.0, 0.02 mol/L TMB, 0.02 mol/L H2O2 and a reaction time of 5 min. 6-BA showed a good linear relationship with the difference between the blank and the sample absorbance value in the mass concentration range of 1~300 ng/mL with a limit of detection at 0.697 ng/mL. The method was successfully applied to the detection of 6-BA residues in vegetables （cucumber, tomato, bean sprouts, mung bean sprouts）. The recovery rate was 83.47%~106.76%, with a relative standard deviation of 0.37%~5.66%. In addition, Fe3O4 MMIP NPs could still maintain good catalytic activity after 60 days of storage at 4 ℃. [Conclusion] The colorimetric method for the detection of 6-BA based on Fe3O4 MMIP NPs has the advantages of simplicity, rapidity, economy, and can be used for the detection of 6-BA residues in vegetables, which has certain reliability and practicability.

Soil salinization severely hinders crop growth and decreases crop yield, and is increasingly an obstacle for the sustainability of agriculture. In this paper, different concentrations of NaCl (0, 50, 100, 150 mmol/L) and 6-benzyladenine (6-BA) (0, 1, 3, 5, 7 mg/L) were mixed together for investigating the mitigative effects of 6-BA on soybean (variety of Zhonghuang 13) germination stage under salt stress. Moreover, in order to quickly monitor the degree of salt stress on soybean, the low-field nuclear magnetic resonance (LF-NMR) technology was applied to assay the bonding water content and the dormancy of soybean seedling, and to establish the stress level prediction models of back propagation neural network (BPNN), resilient back propagation with backtracking neural network (RPROP-WBNN), resilient back propagation without backtracking neural network (RPROP-OBNN), and global learning resilient back propagation neural network (GRPROPNN), and thus obtaining the optimal model. The results showed that (1) soybean exhibited strong bound water relaxation peaks under salt stress, thus enhancing their water storage capacity and overall survival; (2) the 6-BA could break the physiological dormancy of soybean seeds and promote germ elongation; (3) the RPROP-WBNN index values, including Precision (87.36 %), Recall (87.34 %), Accuracy (93.80 %), and F1-score (0.88) were outperformed the values of all other models. Overall, it could be concluded that the 3 mg/L 6-BA had the best effect on alleviating salt stress in soybean, and the RPROP-WBNN was more conducive to predicting accurately the salt stress level of soybean seeds with LF-NMR technology and neural network. Therefore, this paper could provide the theoretical support and data reference for the study of the response effects of 6-BA to salt stress during soybean seed germination stage with rapid non-destructive monitoring.

The limited availability of water due to agricultural, industrial, technological, and urban expansion requires a greater effort to make its use more efficient and achieve substantial savings in ornamental productions without affecting the commercial value quality, and final presentation of flowers and plants. Water stress is an environmental factor that causes physiological effects in plants and accelerates the senescence of leaves and flowers on cut stems. Considering crop evapotranspiration (ETc), an alternative way to reducing water consumption in intensive crops is the use of controlled, restricted irrigation, coupled with the application of phytohormones in pre-harvest to mitigate the effects of water stress, i.e. 6- Benzylaminopurine (6-BAP). The objective of this study was to determine the quality and vase life of Lilium stems under restricted irrigation combined with phytohormones application. An experiment with four treatments was designed, concerning normal (NI, 100% ETc) or restricted irrigation (RI, 35% ETc) and with or without application of 6-BAP (300 ppm). A completely randomized ANOVA design with 6 repetitions per treatment was used. The vase life of cut Lilium flowers was not significantly affected (13.9 vs. 12.5 days under NI and RI respectively). The application of 6-BAP had no influence on vase life, but delayed the foliage yellowing and therefore reduced the rate of deterioration of the floral stem. Restricted irrigation and the application of phytohormones can be useful tools to improve the water use efficiency in lily crops.

This study uses inflorescence stalk node as explants to establish an efficient and quick Phalaenopsis orchids cloning procedure for the most significant monopodial orchid in floriculture, without callus formation. The current study aimed to develop a rapid and easy regeneration process utilizing flower stalk nodes as explants, while also evaluating the clonal fidelity of the in vitro micropropagated plants through the analysis of RAPD markers. The tissue-cultured plantlets were grown on a solidified half-strength Murashig and Skoog (MS) base medium enriched with 15% coconut water (CW), 150 mg L−1 activated charcoal, and a mixture of 6-benzylaminopurine, BAP (cytokinins) and α-napthalene acetic acid, NAA and indole 3-butyric acid, IBA (auxins). After 14 weeks of growth, the early production of shoot bud was reported in ½ MS medium enriched with 2.5 mg L−1 BAP alone. Maximum shoot bud multiplication was observed in ½ MS fortified with BAP (2.5 mg L−1) + NAA (1.0 mg L−1), while the lowest was observed in 1.5 mg L−1 BAP + 0.5 mg L−1 IBA after 4 months of culturing. In this investigation, roots emerged simultaneously with shoot elongation from the axil, indicating the absence of a distinct rooting stage. The largest number of roots (3.25) was produced by BAP (2.5 mg L−1) + IBA (1.0 mg L−1) compared to NAA. Control, on the other hand, displayed no signs of root growth. Tissue cultured plantlets with well developed root systems while planted in a potting mixture of brick and charcoal (1: 1) resulted in a 70% survival rate during hardening. The clonal faithfulness of in vitro regenerated crop plantlets to the mother plant was demonstrated by the DNA extraction method with ten micropropagated plants’ young leaves as well as the mother plant using random amplification of a polymorphic DNA marker. [ABSTRACT FROM AUTHOR]

Camelina is an oil seed crop that is enjoying increasing interest because it has a particularly valuable fatty acid profile, is modest regarding its water and nutrient requirements, and is comparatively resilient to abiotic and biotic stress factors. The regeneration of plants from cells accessible to genetic manipulation is an essential prerequisite for the generation of genetically engineered plants, be it by transgenesis or genome editing. Here, immature embryos were used on the assumption that their incomplete differentiation was associated with totipotency. In culture, regenerative structures appeared adventitiously at the embryos' hypocotyls. For this, the application of auxin- or cytokinin-type growth regulators was essential. The formation of regenerative structures was most efficient when indole-3-acetic acid was added to the induction medium at 1 mg/L, zygotic embryos of the medium walking stick stage were used, and their hypocotyls were stimulated by pricking to a wound response. Histological examinations revealed that the formation of adventitious shoots was initiated by locally activated cell division and proliferation in the epidermis and the outer cortex of the hypocotyl. While the regeneration of plants was established in principle using the experimental line Cam139, the method proved to be similarly applicable to the current cultivar Ligena, and hence it constitutes a vital basis for future genetic engineering approaches. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Effective protocols for in vitro rooting for woody fruit trees are still a challenge for in vitro seedling production, especially when there is a need to insert new cultivars or rootstocks. These protocols are essential to accelerate studies in plant breeding programs and for seedling distribution. This study evaluated the use of 6-Benzylaminopurine (IBA) in in vitro rooting of Pyrus comunnis rootstocks, clones 'OHxF87' and Pyrodwarf. Explant exposure times (0, 24, 48, 72, and 96 hours) to 20 mg L-1 IBA were tested for in vitro rooting. The exposure to IBA resulted in rooting rates above 80%, surpassing some results reported in the literature. The 24-hour treatment provided 81,81% survival, leading to an average growth of five roots with 19 mm length, for 'OHxF87' rootstock. The same exposure time resulted in the highest survival rate (75%) and the highest mean root number, seven roots per plant with 10 mm length, for 'PDW' rootstock. Root formation did not occur in the absence of synthetic auxin. Therefore, it can be concluded that a 24-hour exposure at 20 mg L-1 IBA was sufficient to promote in vitro rooting in 'OHxF87' and Pyrodwarf rootstocks'. [ABSTRACT FROM AUTHOR]

Cryopreservation is considered to be one of the most effective methods for long-term storage of plant genetic resources, particularly for ornamental species. However, there is a very little research on cryopreservation of lilacs. In this study, for the first time the cryopreservation protocol (a variation of a pregrowth-dehydration method) was successfully applied to two cultivars of Syringa vulgaris: ‘Aucubaefolia’ and ‘Polina Osipenko’. Explants of both cultivars were able to withstand the different steps of the protocol, and high survival and regrowth percentages were obtained after exposure to liquid nitrogen (67–100% and 63–88%, respectively). The current study is mainly focused on the preculture conditions of the applied method. Based on our results, we propose the use of paclobutrazol (PBZ) with the combination of 6-benzylaminopurine (BAP) and thidiazuron (TDZ) in the preculture medium for increasing explant tolerance to subsequent dehydration and freezing. During post-LN recovery, the explants appeared morphologically normal, and after 12–16 weeks after thawing, they were propagated and cultured as normal plantlets. Therefore, the reported method is effective for long-term storage of lilac meristems and could be used to create a cryobank of achievements in lilac breeding.

This study uses inflorescence stalk node as explants to establish an efficient and quick Phalaenopsis orchids cloning procedure for the most significant monopodial orchid in floriculture, without callus formation. The current study aimed to develop a rapid and easy regeneration process utilizing flower stalk nodes as explants, while also evaluating the clonal fidelity of the in vitro micropropagated plants through the analysis of RAPD markers. The tissue-cultured plantlets were grown on a solidified half-strength Murashig and Skoog (MS) base medium enriched with 15% coconut water (CW), 150 mg L−1 activated charcoal, and a mixture of 6-benzylaminopurine, BAP (cytokinins) and α-napthalene acetic acid, NAA and indole 3-butyric acid, IBA (auxins). After 14 weeks of growth, the early production of shoot bud was reported in ½ MS medium enriched with 2.5 mg L−1 BAP alone. Maximum shoot bud multiplication was observed in ½ MS fortified with BAP (2.5 mg L−1) + NAA (1.0 mg L−1), while the lowest was observed in 1.5 mg L−1 BAP + 0.5 mg L−1 IBA after 4 months of culturing. In this investigation, roots emerged simultaneously with shoot elongation from the axil, indicating the absence of a distinct rooting stage. The largest number of roots (3.25) was produced by BAP (2.5 mg L−1) + IBA (1.0 mg L−1) compared to NAA. Control, on the other hand, displayed no signs of root growth. Tissue cultured plantlets with well developed root systems while planted in a potting mixture of brick and charcoal (1: 1) resulted in a 70% survival rate during hardening. The clonal faithfulness of in vitro regenerated crop plantlets to the mother plant was demonstrated by the DNA extraction method with ten micropropagated plants’ young leaves as well as the mother plant using random amplification of a polymorphic DNA marker.

Given the importance of olive sprouts, it is crucial to explore their potential as an innovative source of bioactive and nutritive compounds through research. Here, we aimed at investigating the potential role of benzylaminopurine (BAP) in improving the tissue chemical composition and bioactivity of olive sprouts. To this end, seeds of two olive varieties (Olea europaea L. vr. Kroniaki and Coratina) were primed with BAP at 25 µM. A substantial enhancement was observed in biomass accumulation by 35% and 30% in Kroniaki and Coratina varieties, respectively. Likewise, the photosynthetic pigments (total chlorophyll, α- and β-carotene, lutein and β-cryptoxanthin) in both varieties were increased, mainly in Coratina. At primary metabolic level, BAP priming improved sprout lipid composition, particularly in Coratina variety. At antioxidant level, BAP priming improved lipid antioxidants (α-, β- and γ-tocopherols) and water-soluble antioxidants (phenols, flavonoids, ascorbate, glutathione and anthocyanins) in both olive varieties. At the anthocyanins level, their precursors (phenylalanine, cinnamic acid, coumaric acid and naringenin) and key biosynthetic enzyme activity (phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), coenzyme A ligase (4CL) and cinnamate 4-hydroxylase (C4H)) were improved in olive varieties, but to a greater extent in Coratina variety. Overall, the sprouts of BAP-primed olive seeds could potentially enhance their nutritional value, suggesting that the sprouts of BAP-primed olive seeds can be used as a food ingredient and additives. [ABSTRACT FROM AUTHOR]

Cryopreservation is considered to be one of the most effective methods for long-term storage of plant genetic resources, particularly for ornamental species. However, there is a very little research on cryopreservation of lilacs. In this study, for the first time the cryopreservation protocol (a variation of a pregrowth-dehydration method) was successfully applied to two cultivars of Syringa vulgaris: 'Aucubaefolia' and 'Polina Osipenko'. Explants of both cultivars were able to withstand the different steps of the protocol, and high survival and regrowth percentages were obtained after exposure to liquid nitrogen (67-100% and 63-88%, respectively). The current study is mainly focused on the preculture conditions of the applied method. Based on our results, we propose the use of paclobutrazol (PBZ) with the combination of 6-benzylaminopurine (BAP) and thidiazuron (TDZ) in the preculture medium for increasing explant tolerance to subsequent dehydration and freezing. During post-LN recovery, the explants appeared morphologically normal, and after 12-16 weeks after thawing, they were propagated and cultured as normal plantlets. Therefore, the reported method is effective for long-term storage of lilac meristems and could be used to create a cryobank of achievements in lilac breeding. [ABSTRACT FROM AUTHOR]

Polygonatum cyrtonema Hua (family Asparagaceae) is an endemic plant in China that is valuable for its edible and medicinal uses. Plant growth regulators (PGRs) are natural or synthetic compounds that can regulate plant development and metabolism effectively. To explore potential applications of PGRs for improving the yield and bioactivity of this plant, four PGRs, including gibberellic acid (GA3), 6-benzylaminopurine (6-BA), naphthaleneacetic acid (NAA) and 24-epibrassinolide (EBL), were used in this study and sprayed on the growing seedlings of P. cyrtonema. All of these PGRs did not significantly affect the growth rate of P. cyrtonema, but they had varying effects on the polysaccharide and saponin content in the rhizome. NAA and 6-BA positively affected the polysaccharide content, while most PGR treatments negatively affected the saponin content. Widely targeted metabolomic analysis based on UPLC-MS/MS was conducted and revealed 101 differential metabolites in response to 6-BA, most of which were flavonoids, steroids and lipids. Most of the significantly changed flavonoids decreased under the 6-BA treatment. The study provides insights into the potential use of PGRs for improving the quality of P. cyrtonema, particularly in regulating the content of bioactive compounds.

Aloe vera [Aloe vera (L.) Burm. f.] is considered a valuable medicinal plant worldwide due to its remarkable beneficial effects on human health. However, challenges in A. vera propagation hinder meeting the increasing demand in the health and beauty sectors. As an alternative method, in vitro propagation is crucial for the mass production of Aloe plants, which is a rapid method as well. Therefore, the present study aimed to establish an efficient micropropagation protocol for A. vera by in vitro optimization of the effect of different plant growth regulators (PGRs). For shoot proliferation, sterilized explants were inoculated on the Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (BAP) and thidiazuron (0.5, 1.0, 2.0, and 4.0 mg/l) in combination with 0.5 mg/l naphthaleneacetic acid (NAA). Subsequently, indole-3-butyric acid (IBA) (1.0, 2.0, and 3.0 mg/l) was used for root induction. It was found that the explants cultured on the MS medium supplemented with 4.0 mg/l BAP + 0.5 mg/l NAA showed the highest percentage of response (90±1.29) for shoot induction within the minimum number of days (5±0.33). The highest number of shoots (2.7±0.36) and length of shoots (4.7±0.42 cm) per explant were also observed with the same concentration of PGRs. However, the highest number of roots (3.2±0.57), length of roots (5.67±0.21 cm), and root induction (80±1.97 %) were noticed within the minimum number of days (11±0.79) on the MS medium supplemented with 1.0 mg/l IBA. Thus, the proposed method is a quick and effective approach for the mass propagation of A. vera with appropriate dosages of auxins and cytokinins, which may allow meeting the increasing commercial demand.

Delayed or incomplete recovery of gas exchange after water stress relief limits assimilation in the post-drought period and can thus negatively affect the processes of post-drought recovery. Abscisic acid (ABA) accumulation and antagonistic action between ABA and cytokinins (CKs) play an important role in regulation of stomatal conductance under water deficit. Specifically, in pine species, sustained ABA accumulation is thought to be the main cause of delayed post-drought gas exchange recovery, although the role of CKs is not yet known. Therefore, we aimed to study the effects of ABA and CKs on recovery of stomatal conductance in greenhouse-grown 3-year-old Scots pine saplings recovering from water stress. We analysed both changes in endogenous ABA and CK contents and the effects of treatment with exogenous CK on stomatal conductance. Drought stress suppressed stomatal conductance, and post-drought stomatal conductance remained suppressed for 2 weeks after plant rewatering. ABA accumulated during water stress, but ABA levels decreased rapidly after rewatering. Additionally, trans-zeatin/ABA and isopentenyladenine/ABA ratios, which were decreased in water-stressed plants, recovered rapidly in rewatered plants. Spraying plants with 6-benzylaminopurine (0.1–100 µM) did not influence recovery of either stomatal conductance or needle water status. It can be concluded that the delayed recovery of stomatal conductance in Scots pine needles was not due to sustained ABA accumulation or a sustained decrease in the CK/ABA ratio, and CK supplementation was unable to overcome this delayed recovery. [ABSTRACT FROM AUTHOR]

With a very diverse structure and small molecules, phytohormones are regulators of plant growth and development. Despite the fact that they are synthesized by plants in small quantities, they are highly active physiologically. According to their action, phytohormones can be divided into two categories, as either activators of plant growth and development or as inhibitors, with auxins and cytokinins belonging to the former group. Auxins are synthesized by plants in the apical meristems of shoots, but also in young leaves, seeds, and fruits. They stimulate the elongation growth of shoots and initiate the production of adventitious and lateral roots. Cytokinins, in turn, are formed in root tips and in unripe fruits and seeds. These hormones are responsible for stimulating the growth of lateral shoots, they also stimulate cytokinesis and, consequently, cell division. The aim of this review paper is to present the progress of the research on the effect of selected auxins and cytokinins on crops, considering the prospect of using them in plant growing methods. [ABSTRACT FROM AUTHOR]

The present study introduced an in vitro shoot organogenesis protocol for the medicinal plant Scutellaria araxensis (Lamiaceae). Stem, leaf, and petiole explants were cultured in half-strength Murashige and Skoog (MS) medium containing different concentrations of 6-benzylaminopurine (BAP) alone or in combination with thidiazuron (TDZ), indole-3-butyric acid (IBA), or α-naphthalene acetic acid. Callus formation occurred from stem and petiole explants in most cultures; however, in leaf explants, it was observed only in cultures containing 0.5 mg/l BAP supplemented with TDZ at all concentrations. The highest frequency of indirect shoot induction (100 and 90%) with an average of 20.33 and 12 shoots per explant was observed in stem-derived calli cultured on half-strength MS medium containing 2.0 mg/l BAP plus 0.5 and 1.5 mg/l TDZ, respectively. The best direct shoot organogenesis (40%) was observed in stem explants cultured on half-strength MS medium containing 0.5 mg/l BAP and 0.5 mg/l IBA with a mean of 18 shoots per stem explant. The regenerated micro-shoots were elongated on a medium fortified with 0.5 mg/l gibberellic acid and then successfully rooted in half-strength MS medium supplemented with 0.5 mg/l IBA. The obtained plantlets were acclimatized in a growth chamber with a survival rate of 100%. This study is the first report of a simple and efficient in vitro shoot organogenesis and regeneration protocol for S. araxensis by using stem explants, which could be useful for the conservation, genetic manipulation, and exploitation of biological molecules of this valuable genetic source.

Camelina is an oil seed crop that is enjoying increasing interest because it has a particularly valuable fatty acid profile, is modest regarding its water and nutrient requirements, and is comparatively resilient to abiotic and biotic stress factors. The regeneration of plants from cells accessible to genetic manipulation is an essential prerequisite for the generation of genetically engineered plants, be it by transgenesis or genome editing. Here, immature embryos were used on the assumption that their incomplete differentiation was associated with totipotency. In culture, regenerative structures appeared adventitiously at the embryos’ hypocotyls. For this, the application of auxin- or cytokinin-type growth regulators was essential. The formation of regenerative structures was most efficient when indole-3-acetic acid was added to the induction medium at 1 mg/L, zygotic embryos of the medium walking stick stage were used, and their hypocotyls were stimulated by pricking to a wound response. Histological examinations revealed that the formation of adventitious shoots was initiated by locally activated cell division and proliferation in the epidermis and the outer cortex of the hypocotyl. While the regeneration of plants was established in principle using the experimental line Cam139, the method proved to be similarly applicable to the current cultivar Ligena, and hence it constitutes a vital basis for future genetic engineering approaches.

Increasing shoot branch numbers of Chrysanthemum morifolium Ramat cv. Hangbaiju (Hangbaiju) is crucial for producing high flower yields. Pot experiments were designed to evaluate the effects of foliar application of 6-benzylaminopurine (6-BA) combined with prohexadione-Ca (Pro-Ca) on the yield and quality of Hangbaiju flowers. Foliar application of 6-BA combined with Pro-Ca typically increased leaf chlorophyll content and decreased leaf soluble sugar and soluble protein contents throughout the floral organ growth phase. At the bud formation phenophase stage (August), the contents of gibberellin (GA), indole-3-acetic acid (IAA), and zeatin (ZA) decreased (except for GA content in the 10 mg L−1 6-BA combined with 100 mg L−1 Pro-Ca treatment), but abscisic acid (ABA) content increased. The yield of Hangbaiju flowers was found higher in plants treated with foliar application of 6-BA combined with Pro-Ca. Higher yields were found in the 6-BA5 + Ca100 and 6-BA10 + Ca100 treatments than in the 6-BA5 + Ca50 and 6-BA10 + Ca50 treatments, and the highest yield was observed in the 6-Ba5 + Ca100 treatment both in 2019 and 2020. Nutritional indices such as soluble sugar, soluble protein, total amino acid, and water extract increased, and medicinal indices such as flavonoid, total phenolics, chlorogenic acid, cynaroside, and 3,5-dicaffeoyl quinic acid slightly decreased after foliar application of 6-BA combined with Pro-Ca; however, they were all higher than the standards recorded in the Chinese Pharmacopeia. Overall, foliar application of 6-BA combined with Pro-Ca could increase the yield and nutritional quality of Hangbaiju flowers, enhancing its tea quality. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) plants were treated with synthetic cytokinins - 6-benzylaminopurine (BAP) and 6-furfurylaminopurine, or kinetin (KIN) - during the grain filling stage in a field experiment performed in 2020 in Sadovo, central Bulgaria. The objective was to study their effect on plant productivity and seedling viability of maize after cold storage. The morpho-physiological parameters of the leaves assessed 15 days after cytokinin priming showed an increase in biosynthetic processes compared to control plants. Analysis of yield parameters at harvesting revealed improved productivity of cytokinin-treated plants, which was evidenced as 10 mg L-1 KIN, and BAP priming resulted in, respectively, 18% and 16% higher grain mass compared to untreated plants (control). The produced seeds were exposed to cold storage (-18°C) for 12 months and afterwards physiological parameters of 5-day-old seedlings were measured to evaluate exogenous cytokinins' impact upon stress alleviation. The seedlings developed from cytokinin-treated plants accumulated significantly lower amounts of oxidative stress markers (hydrogen peroxide and malondialdehyde) after cold storage. In a laboratory experiment, maize seeds were subjected to artificially induced senescence (AIS) test for 72 h at 41°C temperature and were subsequently soaked in cytokinin solutions. Cytokinins had a positive effect on both physiological parameters of seedlings of field-grown plants after cold storage and improved the performance of seedlings after AIS test through increased oxidative stress protection and enhanced reactive oxygen species (ROS) detoxification. [ABSTRACT FROM AUTHOR]

Micropropagation is an effective way to preserve the gene pool of threatened plants. This study is devoted to the mathematical modeling of nutrient media and the study of the effect of mT (meta-topoline) on the multiplication of shoots of Hedysarum grandiflorum, Hyssopus cretaceus, and Matthiola fragrans in vitro in comparison with benzylaminopurine (BAP) and kinetin (KT). Initiation was performed on an MS medium with 0.5 mg/L BAP. For shoots multiplication, MS, B5, and WPM media were used with the addition of mT, BAP, KT. For H. grandiflorum, the multiplication coefficient of shoots was highest on medium B5 with the addition of mT at a concentration of 1 mg/L—2.90 shoots per plant, for H. cretaceus—B5 + 0.5 mg/L mT, and for M. fragrans—B5 + 1 mg/L KT. A positive effect of mT on H. grandiflorum and M. fragrans in vitro was found. The efficiency of using KT for H. cretaceus shoot multiplication is shown. The effectiveness of the B5 nutrient medium for H. grandiflorum and M. fragrans was determined. The positive effect of WPM for H. cretaceus micropropagation has been demonstrated. It is not recommended to use the MS media for micropropagation of these plant species. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work was to establish an efficient protocol for the in vitro organogenesis of Dalbergia nigra. For this purpose, 30-day-old seedlings were sectioned at their cotyledonary nodes and nodal segments. These materials were cultivated in a medium with different combinations of the 6-benzylaminopurine and thidiazuron cytokinins. After 60 days in a growth chamber set at 27°C and a 16-hour photoperiod, growth characteristics were analyzed. Explants from the cotyledonary nodes show a greater morphogenetic potential, regardless of the addition of cytokinins. Cotyledonary nodes in the medium supplemented with 2.22 µmol L-1 BAP show the best combination for the in vitro propagation of D. nigra.

Papaya is a heterozygous plant commonly cultivated by seed but, unfortunately, they are not true to type. Moreover, the hybrid seed varieties like the Red Lady are very highly expensive. Hence, tissue culture techniques offer an alternative method to produce a million clones within a short period and a reasonable price. Thus, the current study aimed to optimize the shoot multiplication rate of papaya (Carica papaya L. cv. Red Lady) in vitro. Five concentrations of sucrose (10, 20, 30, 40, and 50 g.L-1) were applied for the papaya shoot proliferation. Results demonstrated that the 30 g.L-1 sucrose was significantly superior in the rate of shoot numbers (4.1 shoots. explant-1), shoot length (0.90 cm), (2.7 leaves. shoot-1), leaf area (1.40 cm2) and fresh weight (0.192 g) in compared with other sucrose treatments. Whereas, the 40 g.L-1 sucrose treatment was significantly superior in dry weight of shoot compared to the other treatments, which recorded 0.058 g. While the treatment of 10 g.L-1 sucrose recorded the lowest values in shoot numbers, length, and dry weight. Current study conclude that the 30 g.L-1 sucrose is the best concentration treatment that must be used in papaya micropropagation, where it gives the maximum rate of shoot numbers and other morphological traits.

Given the importance of olive sprouts, it is crucial to explore their potential as an innovative source of bioactive and nutritive compounds through research. Here, we aimed at investigating the potential role of benzylaminopurine (BAP) in improving the tissue chemical composition and bioactivity of olive sprouts. To this end, seeds of two olive varieties (Olea europaea L. vr. Kroniaki and Coratina) were primed with BAP at 25 µM. A substantial enhancement was observed in biomass accumulation by 35% and 30% in Kroniaki and Coratina varieties, respectively. Likewise, the photosynthetic pigments (total chlorophyll, α- and β-carotene, lutein and β-cryptoxanthin) in both varieties were increased, mainly in Coratina. At primary metabolic level, BAP priming improved sprout lipid composition, particularly in Coratina variety. At antioxidant level, BAP priming improved lipid antioxidants (α-, β- and γ-tocopherols) and water-soluble antioxidants (phenols, flavonoids, ascorbate, glutathione and anthocyanins) in both olive varieties. At the anthocyanins level, their precursors (phenylalanine, cinnamic acid, coumaric acid and naringenin) and key biosynthetic enzyme activity (phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), coenzyme A ligase (4CL) and cinnamate 4-hydroxylase (C4H)) were improved in olive varieties, but to a greater extent in Coratina variety. Overall, the sprouts of BAP-primed olive seeds could potentially enhance their nutritional value, suggesting that the sprouts of BAP-primed olive seeds can be used as a food ingredient and additives.

Embryo rescue refers to an in vitro technology have been used for propagating plants under in vitro from poorly developed embryos by avoiding embryo abortion. The aim of the present study was to in vitro regeneration of a medicinally wild tree species Buchanania lanzan through embryo rescue method. Isolated immature poorly developed embryo dissected out from de-coded seeds collected from 15 years old trees were cultured an Woody Plant Medium (WPM) was used to test in vitro germination. 100% embryo germination were recorded when the embryos inoculated on the medium supplemented with 1.5 mg/L-1 6-benzylaminopurine (BAP) and 50 mg/L-1 adenine sulphate (AS). Further, a week-old seedling derived explants viz embryo axis and cotyledonary node were selected to study in vitro clonal propagation. On medium augmented with 1.5 mg/L-1 6-benzylaminopurine (BAP) showed maximum mean shoots numbers (4.2±1.80) with 4.0±0.98 cm shoot height were achieved in cotyledonary node. Compare to Kinetin (Kn) BAP was to be better in shooting response and multiple shoot induction. Healthy regenerated shoots was separated from multiple shoots cluster and transferred to a rooting medium containing half strength WP medium fortified with Indole-3-butyric acid (IBA). IBA at 0.5 mg/L-1 showed 90% rooting response and maximum mean roots (4.9±0.98) per shootlet was obtained. The rooted in vitro plantlets were transferred to polythene bags containing autoclaved humus, red soil and farmyard manure (1:1:1 ratio) for acclimation at 25 ± 2 ᵒC. Later, these plantlets were gradually transferred to field condition. About 70% survival rate was recorded after three months period. The protocol developed in the present study was to restore the viable embryos from poorly developed immature embryos and rapid multiplication can help to ex situ conservation of this threatened tree B. lanzan. [ABSTRACT FROM AUTHOR]

Vetiveria zizanioides is ideal in maintaining soil and water, and is widely used for remediation of soil contaminated by heavy metals. However, it is affected by high-temperature stress. In this study, Vetiveria zizanioides plants were sprayed with 6-BA and ABA in a growth chamber 1 d before heat stress treatment, then the plants were subjected to high-temperature conditions. Relative water content, relative electrical conductivity, contents of ascorbic acid (AsA) and reduced glutathione (GSH) as the antioxidative substances, and content of malondiadehyde (MDA) were determined. Also, the antioxidative enzyme activities and the osmoprotectants levels were detected. Diaminobenzidine (DAB) staining of leaves and roots in Vetiveria zizanioides was observed for determination of hydrogen peroxide accumulation. The results showed that relative water content was decreased, relative electrical conductivity and MDA content were increased by the heat stress treatment. Under high-temperature conditions, relative water content was increased and relative electrical conductivity was decreased by 6-BA and ABA treatments. At the middle and the late stages of the heat stress treatment, activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the contents of ASA and GSH in leaves of the 6-BA-treated and ABA-treated plants were significantly higher, whereas the MDA content was significantly lower than those in the high-temperature controls. Hydrogen peroxide accumulation levels in the 6-BA-treated and ABA-treated leaves and roots were lower than in the high-temperature controls. Contents of soluble sugar, sucrose, and glucose in the 6-BA-treated and ABA-treated leaves were significantly higher than those in the high-temperature controls. Proline content in the 6-BA-treated and ABA-treated leaves was stable. The results suggested that the enhancement of the heat resistance by 6-BA and ABA treatments was correlated with the activation of the antioxidant system, as well as the sugar-based osmoprotectant.

In vivo and in vitro grown plants of Hibiscus coddii subsp. barnardii were used as explant source for establishment of in vitro cultures. Nodal shoot explants derived from in vivo grown plants, both naturally and under controlled environmental conditions, showed high sensitivity to the surface disinfection treatment and poor survival in in vitro culture. In vitro grown seedlings proved successful as aseptic source of apical and basal shoot explants to establish contamination-free in vitro cultures. Sprouting of axillary buds was observed on 90% of apical shoot explants after four weeks of culture on full strength, plant growth regulator (PGR)-free Murashige and Skoog (MS) medium. However, further proliferation of short shoots, limited to the bud sprout at the explant base, occurred on only 50% of these explants. In contrast, all basal shoot explants attained 3-5 single primary axillary shoots (30-40 mm in length) while a clump of short (5-10 mm) shoots also formed at the base in 60% of these explants. In both explant types, addition of 0.25-1 mg L-1 6-Benzylaminopurine (BAP) to the MS medium resulted in a low frequency (10%-60%) of explants with short shoots (5-10 mm) that showed no further elongation. Moreover, explants cultured in the presence of BAP showed a high frequency of callus formation (up to 90%) and low survival (20%-60%). A lower frequency of callus formation (30%-40%) and higher survival (90%-100%) of both explant types occurred on BAP-free medium. Further subculturing of primary and secondary axillary shoots onto fresh MS medium (with and without BAP) did not improve shoot multiplication. Regenerated plantlets from PGR-free MS medium were successfully acclimatized and hardened-off.

Phyto-hormones play a key role in regulating plant responses to stress. Cytokines are a type of phyto-hormones involved in the regulation of many important biological processes related to growth, development, and response to environmental variables. The exogenous application of cytokines increases the possibility of delaying senescence; however, this is a physiological process, and, under certain conditions, degradation processes may be triggered. The effect of 6-bencilaminopurine application and the endogenous hormonal changes involved in lilies floral stalks after their cutting were studied. In order to improve vase life and quality of Lilium longiflorum ‘Brindisi’ flower stalks, they were sprayed with 6-BAP, at a concentration of 300 ppm at pre-harvest, post-harvest, and pre- and postharvest stages. After that, they were compared to non-sprayed control stalks. The application of 6-BAP caused endogenous hormonal changes in abscisic acid and cytokinin levels, and the most effective treatment was pre-harvest spraying. This treatment proved to be an appropriate method to improve the stalk tolerance to post-harvest stress as it delayed the appearance of senescence symptoms and reduced the speed of chlorophyll degradation with differences of up to 10% with respect to untreated stalks. In addition, the opening of flowers was delayed by up to 2 days, although there were no significant differences in total vase life.

6-BA is a common plant growth regulator, but its safety has not been conclusive. The heart is one of the most important organs of living organisms, and the cardiogenesis process of zebrafish is similar to that of humans. Therefore, based on wild-type and transgenic zebrafish, we explored the development of zebrafish heart under 6-BA exposure and its mechanism. We found that 6-BA affected larval cardiogenesis, inducing defective expression of key genes for cardiac development (myl7, vmhc, and myh6) and AVC differentiation (bmp4, tbx2b, and notch1b), ultimately leading to weakened cardiac function (heart rate, diastolic speed, systolic speed). Acridine orange staining showed that the degree of apoptosis in zebrafish hearts was significantly increased under 6-BA, and the expression of cell-cycle-related genes was also changed. In addition, HPA axis assays revealed abnormally expressed mRNA levels of genes and significantly increased cortisol contents, which was also consistent with the observed anxiety behavior in zebrafish at 3 dpf. Transcriptional abnormalities of pro- and anti-inflammatory factors in immune signaling pathways were also detected in qPCR experiments. Collectively, we found that 6-BA induced cardiotoxicity in zebrafish, which may be related to altered HPA axis activity and the onset of inflammatory responses under 6-BA treatment. [ABSTRACT FROM AUTHOR]

Large cardamom is one of the most important spices that can significantly contribute to the economical farming in the country of Nepal. It is grown in Nepal and north-eastern states of India which provide suitable agroclimatic growing conditions of high humidity, ambient temperature and high rainfall. Meeting the demand for high quality plants and yield of cardamom is challenging with traditional methods of propagation. The present study has used the plant tissue culture technique to produce high quality plants. In this regard, MS media with three different hormonal combinations were used for the development protocol for 8 weeks. Shoot length, root length, shoot number and root number were assessed at intervals. The best protocol for growth was MS media with 1 mg/L BAP + 0.5 mg/L IBA for the Ramsey variety, with no significant difference for Golsai, Dambarsai, or Sikkimae varieties. Similarly, the acclimatization and field transfer study was done. The use of any substrate composition in ratio of coco peat: soil 1:2; moss: coco peat 1:2 and sawdust: coco peat 1:2 enables transfer of healthy plants to the field. The results indicate that the varieties respond differently to the micropropagation process and to hormone concentrations indicated by differing root and shoot production. The protocol of 1mg/L BAP and 0.5mg/L IBA could be used for the Ramsai while optimal shoot production for Golsai and Sikkimae should be at 0.5mg/L and 5mg/L for shoot production. All varieties showed optimal root production at 0mg/L BAP and 0.5mg/L IBA. This study sheds light on the different responsiveness of varieties to tissue culture and hormone concentrations for both root and shoot development in micropropagation. [ABSTRACT FROM AUTHOR]

Aloe vera [Aloe vera (L.) Burm. f.] is considered a valuable medicinal plant worldwide due to its remarkable beneficial effects on human health. However, challenges in A. vera propagation hinder meeting the increasing demand in the health and beauty sectors. As an alternative method, in vitro propagation is crucial for the mass production of Aloe plants, which is a rapid method as well. Therefore, the present study aimed to establish an efficient micropropagation protocol for A. vera by in vitro optimization of the effect of different plant growth regulators (PGRs). For shoot proliferation, sterilized explants were inoculated on the Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (BAP) and thidiazuron (0.5, 1.0, 2.0, and 4.0 mg/l) in combination with 0.5 mg/l naphthaleneacetic acid (NAA). Subsequently, indole-3-butyric acid (IBA) (1.0, 2.0, and 3.0 mg/l) was used for root induction. It was found that the explants cultured on the MS medium supplemented with 4.0 mg/l BAP + 0.5 mg/l NAA showed the highest percentage of response (90 ± 1.29) for shoot induction within the minimum number of days (5 ± 0.33). The highest number of shoots (2.7 ± 0.36) and length of shoots (4.7 ± 0.42 cm) per explant were also observed with the same concentration of PGRs. However, the highest number of roots (3.2 ± 0.57), length of roots (5.67 ± 0.21 cm), and root induction (80 ± 1.97 %) were noticed within the minimum number of days (11 ± 0.79) on the MS medium supplemented with 1.0 mg/l IBA. Thus, the proposed method is a quick and effective approach for the mass propagation of A. vera with appropriate dosages of auxins and cytokinins, which may allow meeting the increasing commercial demand. [ABSTRACT FROM AUTHOR]

Azadirachta indica is a tree with high medicinal value that is conventionally propagated by seed while exhibiting heterozygosity. The aim of this research was to determine the best culture media and plant growth regulators for the micropropagation of Neem. Lateral and terminal buds of A. indica were sterilized with 0.15% and 0.2% mercuric chloride for 10,11,12, and 13 min, followed by washing with sterilized double-distilled water three times. At the proliferation and elongation stage, WPM and MS media were tested with different concentrations of BAP either alone or in combination with 0.01 mg L-1 IBA. LS and MS media containing four different levels of IBA (0, 0.5,1.0, and 2.0 mg L-1) were used for the rooting stage. Pulsing technique with different IBA concentrations was investigated at the rooting stage. Hardening of rooted plantlets was done in potting soil containing peat and perlite (2:1), at 23-24 °C prior to transfer into the natural environment. Maximum survival percentage (70.83%) with minimum browning (10.42%) was achieved by sterilizing the explant with 0.15% of mercuric chloride at all times. The longest shoots (3.66 cm) were observed in the media containing BAP (0.5 mg L-1). Furthermore, the highest number of leaves (14.2 leaves per plant) was recorded in MS medium. Additionally, the MS media containing BAP hormone alone at 0.7 mg L-1 produced the highest number of shoots (3.6 shoots per treatment). LS medium supplemented with IBA (4.0 mg L-1) using the pulsing technique gave the best result at the rooting stage. [ABSTRACT FROM AUTHOR]

Rapid propagation of plants by tissue culture is of great significance for large-scale production, molecular genetics research, and breeding. Currently, a rapid and high-efficient tissue culture protocol for Euonymus bungeanus is needed. To develop a propagation system for this species, we established a new regeneration system from leaves. Callus formation was induced on Murashige and Skoog (MS) medium supplemented with 0.5 mg dm-3 6-benzylaminopurine (6-BA) and 0.5 mg dm-3 α-naphthalene acetic acid (NAA) and the induction rate almost reached 100 % under red radiation within 21 d. The medium for proliferation of adventitious buds comprised of MS medium with 1.0 mg dm-3 6-BA and 0.5 mg dm-3 NAA, and the induction rate within 20 d nearly reached 100 %. When, the adventitious buds were transferred to the rooting medium containing 1/2MS, 2.0 mg dm-3 indole-3-butyric acid (IBA), and 0.05 mg dm-3 NAA, adventitious root formation was achieved within 20 d. Collectively, the rapid and high-efficient regeneration system from E. bungeanus leaves was established, providing useful references for effective mass propagation and it could serve as an enabling technology for future genetic engineering.

An efficient protocol for in vitro regeneration of Strychnos potatorum L. f. through indirect organogenesis was developed using mature leaf disc explants. The explants were selected from twenty years old tree. Cultured on Murashige and Skoog's medium supplemented with 2,4-dichloro phenoxy acetic acid (2,4-D) was used for the induction of organogenic calli. A pale yellow coloured friable callus developed at 2 mg/L-1 2,4-D where showed higher morphogenic potential. Further denovo shoots formation and multiplication in optimal concentrations of cytokinins with different combinations of auxins. An average mean shoots number (14.2±0.42) and shoots height (3.5±0.27cm) was obtained from piece of calli in 6-benzylaminopurine (BAP) 1 mg/L-1 with 0.5 mg/L-1 a-naphthalene acetic acid (NAA). BAP in combinations with NAA was found to be superior to shoot development than other combination used. The well developed shoots were transferred to root induction medium for effective rooting. The rooting medium consisted of in half-strength MS medium augmented with 0.5 mg/L-1 NAA was used. The maximal mean number of roots per shoots 6.5±0.53 was recorded in 4 weeks. The rooted plantlets were removed from the culture tubes, gently washed with sterile double distilled water to remove agar adhering on the plant surface. The regenerated plants were transferred to plastic cups filled with a potting mixture containing sterile sand and soilrite (1:1 ratio) and allowed to grow in the greenhouse. The slowly acclimatized plants were further transferred to substrate containing red soil and farmyard manure (1:1) for effective hardening. 75% survival rate was recorded. This protocol can be useful for the ex-situ conservation and rehabilitation of this vulnerable medicinal tree S. potatorum. [ABSTRACT FROM AUTHOR]

In this study, we aimed to clarify the distribution and dynamics of water in the Xudou 20 soybean cultivar post-germination after culturing plants with various concentrations of 6-benzylaminopurine (6-BA). Low-field nuclear magnetic resonance and magnetic resonance imaging (LF-NMR/MRI), as well as principal component analysis (PCA), were used for the investigation. Results showed that low concentrations of 6-BA promoted soybean germination and high concentrations inhibited soybean germination, with 5 mg/l of 6-BA producing the most optimal conditions for growth. Moreover, the T 22 determination of weakly bound water increased with increasing 6-BA concentration, and the PCA effectively distinguished soybeans cultured at different 6-BA concentrations. This study provides a method for the rapid detection of 6-BA concentration in bean sprouts and provides theoretical support and bean sprout quality assessment. [ABSTRACT FROM AUTHOR]

The present study introduced an in vitro shoot organogenesis protocol for the medicinal plant Scutellaria araxensis (Lamiaceae). Stem, leaf, and petiole explants were cultured in half-strength Murashige and Skoog (MS) medium containing different concentrations of 6-benzylaminopurine (BAP) alone or in combination with thidiazuron (TDZ), indole-3-butyric acid (IBA), or a-naphthalene acetic acid. Callus formation occurred from stem and petiole explants in most cultures; however, in leaf explants, it was observed only in cultures containing 0.5 mg/l BAP supplemented with TDZ at all concentrations. The highest frequency of indirect shoot induction (100 and 90%) with an average of 20.33 and 12 shoots per explant was observed in stem-derived calli cultured on halfstrength MS medium containing 2.0 mg/l BAP plus 0.5 and 1.5 mg/l TDZ, respectively. The best direct shoot organogenesis (40%) was observed in stem explants cultured on half-strength MS medium containing 0.5 mg/l BAP and 0.5 mg/l IBA with a mean of 18 shoots per stem explant. The regenerated micro-shoots were elongated on a medium fortified with 0.5 mg/l gibberellic acid and then successfully rooted in half-strength MS medium supplemented with 0.5 mg/l IBA. The obtained plantlets were acclimatized in a growth chamber with a survival rate of 100%. This study is the first report of a simple and efficient in vitro shoot organogenesis and regeneration protocol for S. araxensis by using stem explants, which could be useful for the conservation, genetic manipulation, and exploitation of biological molecules of this valuable genetic source. [ABSTRACT FROM AUTHOR]

Propagation of S. rebaudiana Bert. can be cultivated by seed germination and stem cutting however, seed germination of this plant is not efficient due to low fertility and produce a heterogeneous population, thus producing unstable sweetening level. Thus, micropropagation can overcome these problems by producing large number of clone plantlets within a short time. In this research, the objective is to study the effect of different concentrations of plant growth regulators; auxin and cytokinin on in vitro responses of S. rebaudiana Bert. The nodal segments used as explant and inoculated onto full strength of Murashige and Skoog (MS) media. The medium supplemented with five concentrations of 6-benzylaminopurine (BAP); 0, 1, 2, 3 and 4 mg/L and also indole-3-butyric acid (IBA); 0, 0.5, 1.0, 1.5 and 2.0 mg/L. After six weeks of culture, number and length of shoots, number and length of roots and callus percentage were recorded. The results showed that 3.0 mg/L BAP produced the highest number of shoots per explant and for rooting, the best treatment that can be used was 1.5 mg/L IBA without cytokinin. [Fundam Appl Agric 2020; 5(2.000): 243-247]

In this study, we aimed to clarify the distribution and dynamics of water in the Xudou 20 soybean cultivar post-germination after culturing plants with various concentrations of 6-benzylaminopurine (6-BA). Low-field nuclear magnetic resonance and magnetic resonance imaging (LF-NMR/MRI), as well as principal component analysis (PCA), were used for the investigation. Results showed that low concentrations of 6-BA promoted soybean germination and high concentrations inhibited soybean germination, with 5 mg/l of 6-BA producing the most optimal conditions for growth. Moreover, the T22 determination of weakly bound water increased with increasing 6-BA concentration, and the PCA effectively distinguished soybeans cultured at different 6-BA concentrations. This study provides a method for the rapid detection of 6-BA concentration in bean sprouts and provides theoretical support and bean sprout quality assessment.

Queñoais a forest species of great importance and its propagation in a conventional way is a limitation when it is desired to produce it on a large scale, for which the micropropagation technique was used, with the objective of evaluating the effect of the combination of auxin and cytokinin in the rooting of Polylepis rugulosaBitter buds, establishing 12 treatments with different concentrations of IBA and BAP, likewise during acclimatization, the influence of four types of substrates based on ground, peat and cow manure in different proportions was tested, where seedlings weretransplanted rooted, which were subjected to greenhouse conditions. The best response in the rooting percentage was 98%, this result was obtained with the concentration of 0.5 μM AIB + 0.05 μM BAP, which presented 1.9 roots and an average root length of 7mm. A survival percentage of 87.5% was reached during acclimatization; cow manure-basedtreatments showed higher values regarding the variable’sseedling height, number of leaves and root length. Therefore, the result will make it possible to mass produce plants and initiate conservation and recovery programs.

With a very diverse structure and small molecules, phytohormones are regulators of plant growth and development. Despite the fact that they are synthesized by plants in small quantities, they are highly active physiologically. According to their action, phytohormones can be divided into two categories, as either activators of plant growth and development or as inhibitors, with auxins and cytokinins belonging to the former group. Auxins are synthesized by plants in the apical meristems of shoots, but also in young leaves, seeds, and fruits. They stimulate the elongation growth of shoots and initiate the production of adventitious and lateral roots. Cytokinins, in turn, are formed in root tips and in unripe fruits and seeds. These hormones are responsible for stimulating the growth of lateral shoots, they also stimulate cytokinesis and, consequently, cell division. The aim of this review paper is to present the progress of the research on the effect of selected auxins and cytokinins on crops, considering the prospect of using them in plant growing methods.

Orchids have a long period of production and need to be under the right conditions. Therefore, in vitro propagation is an alternative to reduce production time. This study aimed to determine the optimal in vitro propagation conditions in two species of orchids, Cattleya maxima Lindl. and Phalaenopsis amabilis (L.) Blume. For this goal, two experiments were carried out: multiplication and rooting, for both species. In the multiplication experiment, the treatments were differentiated according to the complement of MS (Murashige and Skoog medium), banana flour, kinetin or 6-Benzylaminopurine (BAP). Meanwhile, in the rooting experiment, the complements were banana flour, Indol-3-butiric acid (IBA), Naphthaleneacetic acid (NAA) or 2,4-Dichlorophenoxyacetic acid (2,4-D). According to the results, banana flour (50 g.L-1) increased the plantlet height in C. maxima (multiplication) and P. amabilis (rooting). Kinetin (0.003 g.L-1) and BAP (0.005 g.L-1) increased the number of shoots and leaves in C. maxima, in multiplication experiment. In rooting experiment, NAA (0.003 g.L-1) increased significantly the number of leaves in C. maxima. The root formation was notably stimulated by banana flour in both species. Likewise, 2,4-D (0.003 g.L-1) can cause phytotoxic effects and inhibit root formation. In conclusion, C. maxima was more robust than P. amabilis since in all studied variables the former presented the highest values. Furthermore, C. maxima responds adequately to application of kinetin and BAP to increase the aerial part of the plant, however, they inhibit the root formation. In contrast, kinetin and BAP do not limit root growth in P. amabilis.

The coordination between phytohormones regulation, stomatal behaviour (stomatal index and opening/closing) and gas exchange are potent determinants of plant survival under drought stress. However, we found a knowledge gap in the mechanism regulating the fine-tuning of these features during drought. In order to address this we evaluated gas exchange, stomatal behaviour and endogenous phytohormones content in two cotton varieties (LRA-5166 and NBRI-67) differing in drought sensitivity during water deficit conditions. Variety specific differences were recorded in net photosynthesis rate (A), transpiration rate (E) and stomatal conductance (gs) with significantly less decrease in drought tolerant LRA-5166 than drought sensitive NBRI-67. The abscisic acid (ABA) accumulation was significantly increased in LRA-5166 while reduced in NBRI-67 under water deficit, which was accompanied by relatively less reduced 6-benzylaminopurine (6-BAP) level in LRA-5166 than NBRI-67. Thus, improved ABA/6-BAP ratio was observed in both the varieties of cotton. Critically, LRA-5166 has reduced stomatal index, aperture size and significantly higher A and intrinsic water use efficiency (WUEi), thus higher drought tolerance than NBRI-67. Furthermore, we found that endogenous ABA predominantly maintains the stomatal behaviour and regulates its physiology either by antagonizing 6-BAP or alone to coordinate with water deficit signals. Overall, our findings describe a new insight as to how drought modulates endogenous ABA and 6-BAP homeostasis in cotton leaf and the mechanism of stomatal regulation by ABA and 6-BAP in cotton. [ABSTRACT FROM AUTHOR]

Orchids have a long period of production and need to be under the right conditions. Therefore, in vitro propagation is an alternative to reduce production time. This study aimed to determine the optimal in vitro propagation conditions in two species of orchids, Cattleya maxima Lindl. and Phalaenopsis amabilis (L.) Blume. For this goal, two experiments were carried out: multiplication and rooting, for both species. In the multiplication experiment, the treatments were differentiated according to the complement of MS (Murashige and Skoog medium), banana flour, kinetin or 6-Benzylaminopurine (BAP). Meanwhile, in the rooting experiment, the complements were banana flour, Indol-3-butiric acid (IBA), Naphthaleneacetic acid (NAA) or 2,4-Dichlorophenoxyacetic acid (2,4-D). According to the results, banana flour (50 g.L-1 ) increased the plantlet height in C. maxima (multiplication) and P. amabilis (rooting). Kinetin (0.003 g.L-1 ) and BAP (0.005 g.L-1 ) increased the number of shoots and leaves in C. maxima, in multiplication experiment. In rooting experiment, NAA (0.003 g.L-1 ) increased significantly the number of leaves in C. maxima. The root formation was notably stimulated by banana flour in both species. Likewise, 2,4- D (0.003 g.L-1 ) can cause phytotoxic effects and inhibit root formation. In conclusion, C. maxima was more robust than P. amabilis since in all studied variables the former presented the highest values. Furthermore, C. maxima responds adequately to application of kinetin and BAP to increase the aerial part of the plant, however, they inhibit the root formation. In contrast, kinetin and BAP do not limit root growth in P. amabilis. [ABSTRACT FROM AUTHOR]

Increasing shoot branch numbers of Chrysanthemum morifolium Ramat cv. Hangbaiju (Hangbaiju) is crucial for producing high flower yields. Pot experiments were designed to evaluate the effects of foliar application of 6-benzylaminopurine (6-BA) combined with prohexadione-Ca (Pro-Ca) on the yield and quality of Hangbaiju flowers. Foliar application of 6-BA combined with Pro-Ca typically increased leaf chlorophyll content and decreased leaf soluble sugar and soluble protein contents throughout the floral organ growth phase. At the bud formation phenophase stage (August), the contents of gibberellin (GA), indole-3-acetic acid (IAA), and zeatin (ZA) decreased (except for GA content in the 10 mg L−1 6-BA combined with 100 mg L−1 Pro-Ca treatment), but abscisic acid (ABA) content increased. The yield of Hangbaiju flowers was found higher in plants treated with foliar application of 6-BA combined with Pro-Ca. Higher yields were found in the 6-BA5 + Ca100 and 6-BA10 + Ca100 treatments than in the 6-BA5 + Ca50 and 6-BA10 + Ca50 treatments, and the highest yield was observed in the 6-Ba5 + Ca100 treatment both in 2019 and 2020. Nutritional indices such as soluble sugar, soluble protein, total amino acid, and water extract increased, and medicinal indices such as flavonoid, total phenolics, chlorogenic acid, cynaroside, and 3,5-dicaffeoyl quinic acid slightly decreased after foliar application of 6-BA combined with Pro-Ca; however, they were all higher than the standards recorded in the Chinese Pharmacopeia. Overall, foliar application of 6-BA combined with Pro-Ca could increase the yield and nutritional quality of Hangbaiju flowers, enhancing its tea quality.

Micropropagation is an effective way to preserve the gene pool of threatened plants. This study is devoted to the mathematical modeling of nutrient media and the study of the effect of mT (meta-topoline) on the multiplication of shoots of Hedysarum grandiflorum, Hyssopus cretaceus, and Matthiola fragrans in vitro in comparison with benzylaminopurine (BAP) and kinetin (KT). Initiation was performed on an MS medium with 0.5 mg/L BAP. For shoots multiplication, MS, B5, and WPM media were used with the addition of mT, BAP, KT. For H. grandiflorum, the multiplication coefficient of shoots was highest on medium B5 with the addition of mT at a concentration of 1 mg/L—2.90 shoots per plant, for H. cretaceus—B5 + 0.5 mg/L mT, and for M. fragrans—B5 + 1 mg/L KT. A positive effect of mT on H. grandiflorum and M. fragrans in vitro was found. The efficiency of using KT for H. cretaceus shoot multiplication is shown. The effectiveness of the B5 nutrient medium for H. grandiflorum and M. fragrans was determined. The positive effect of WPM for H. cretaceus micropropagation has been demonstrated. It is not recommended to use the MS media for micropropagation of these plant species.

As a highly effective plant hormone, the overuse of 6-benzylaminopurine (6-BA) may pose potential threats to organisms and the environment. Melatonin is widely known for its regulation of sleep rhythm, and it also shows a beneficial effect in a variety of adverse situations. In order to investigate the harm of 6-BA to vertebrates and whether melatonin can reverse the toxicity induced by 6-BA, we analyzed the circadian rhythm and cardiovascular system of zebrafish, and further clarified the role of the thyroid endocrine system. The exposure of well-developed embryos started at 2 hpf, then 6-BA and/or melatonin were carried out. The results indicated that 6-BA disturbed the rhythmic activities of the larvae, increased wakefulness, correspondingly reduced their rest, and induced disrupted clock gene expression. Video analysis and qRT-PCR data found that zebrafish under 6-BA exposure showed obvious cardiovascular morphological abnormalities and dysfunction, and the mRNA levels of cardiovascular-related genes (nkx2.5, gata4, myl7, vegfaa and vegfab) were significantly down-regulated. In addition, altered thyroid hormone content and hypothalamus-pituitary-thyroid (HPT) axis-related gene expression were also clearly observed. 1umol/L of melatonin had little effect on zebrafish, but its addition could significantly alleviate the circadian disturbance and cardiovascular toxicity caused by 6-BA, and simultaneously played a regulatory role in thyroid system. Our research revealed the adverse effects of 6-BA on zebrafish larvae and the protective role of melatonin in circadian rhythm, cardiovascular and thyroid systems.