Regulatory networks of senescence-associated gene-transcription factors promote degradation in Moso bamboo shoots.

Bamboo cultivation, particularly Moso bamboo (Phyllostachys edulis), holds significant economic importance in various regions worldwide. Bamboo shoot degradation (BSD) severely affects productivity and economic viability. However, despite its agricultural consequences, the molecular mechanisms underlying BSD remain unclear. Consequently, we explored the dynamic changes of BSD through anatomy, physiology and the transcriptome. Our findings reveal ruptured protoxylem cells, reduced cell wall thickness and the accumulation of sucrose and reactive oxygen species (ROS) during BSD. Transcriptomic analysis underscored the importance of genes related to plant hormone signal transduction, sugar metabolism and ROS homoeostasis in this process. Furthermore, BSD appears to be driven by the coexpression regulatory network of senescence-associated gene transcription factors (SAG-TFs), specifically PeSAG39, PeWRKY22 and PeWRKY75, primarily located in the protoxylem of vascular bundles. Yeast one-hybrid and dual-luciferase assays demonstrated that PeWRKY22 and PeWRKY75 activate PeSAG39 expression by binding to its promoter. This study advanced our understanding of the molecular regulatory mechanisms governing BSD, offering a valuable reference for enhancing Moso bamboo forest productivity.

Improving transformation and regeneration efficiency in medicinal plants: Insights from other recalcitrant species.

Medicinal plants are integral to traditional medicine systems world-wide, being pivotal for human health. Harvesting plant material from natural environments, however, has led to species scarcity, prompting action to develop cultivation solutions that also aid conservation efforts. Biotechnological tools, specifically plant tissue culture and genetic transformation, offer solutions for sustainable, large-scale production and enhanced yield of valuable biomolecules. While these techniques are instrumental to the development of the medicinal plant industry, the challenge of inherent regeneration recalcitrance in some species to in vitro cultivation hampers these efforts. This review examines the strategies for overcoming recalcitrance in medicinal plants using a holistic approach, emphasising the meticulous choice of explants, e.g. embryonic/meristematic tissues; plant growth regulators, e.g. synthetic cytokinins; and use of novel regeneration-enabling methods to deliver morphogenic genes e.g. GRF/GIF chimeras and nanoparticles, which have been shown to contribute to overcoming recalcitrance barriers in agriculture crops. Furthermore, it highlights the benefit of cost-effective genomic technologies that enable precise genome editing and the value of integrating data-driven models to address genotype-specific challenges in medicinal plant research. These advances mark a progressive step towards a future where medicinal plant cultivation is not only more efficient and predictable but also inherently sustainable, ensuring the continued availability and exploitation of these important plants for current and future generations.

Silver nanoparticle-induced in vitro flowering in Dendrocalamus strictus (Roxb.) nees and genetic fidelity assessment of regenerants using molecular markers.

BACKGROUND: Dendrocalamus strictus (Roxb.) Nees, generally referred to as 'Male bamboo,' is a globally prevalent and highly significant species of bamboo. It is a versatile species and possesses notable industrial significance. However, despite its numerous applications, the production of this plant is insufficient to fulfill the worldwide demand. The challenges that impede the dissemination of D. strictus encompass the unpredictable blooming pattern (30-70 years), low seed production, and limited seed viability. Therefore, tissue culture presents a reliable and effective option for the mass production of standardized planting material. METHODOLOGY AND RESULTS: This study investigated the effects of silver nanoparticles (AgNPs) at a concentration of 6.0 mg L- 1 in the Murashige and Skoog (MS) nutrient medium fortified with pre-optimized plant growth regulators (3.0 mg L- 1 6-benzylaminopurine + 0.5 mg L- 1 α-naphthalene acetic acid) on the induction of flowering in a controlled environment in D. strictus. The use of AgNPs in the media induced a maximum of 14 inflorescences per culture vessel, 9 flowers per inflorescence, and improved the performance of the micropropagated plantlets during acclimatization in the greenhouse and field. The ISSR and SCoT amplified polymorphic DNA analysis of the regenerants resulted in the formation of 49 bands (300 to 2000 bp size) and 36 scorable bands (350 to 2000 bp) respectively. All the PCR amplicons produced by SCoT and ISSR were monomorphic confirming the genetic uniformity of the tissue cultured plants of D. strictus with the mother plant. CONCLUSIONS: It can be inferred that the incorporation of AgNPs during the shoot proliferation phase has the potential to stimulate in vitro flowering in D. strictus. This finding could provide valuable insights into innovative strategies for enhancing crop productivity and genetic manipulation for accelerated breeding and agricultural advancement.

Sulfonyl-acetohydrazide derivatives as juvenile hormone mimics to be insect growth regulators.

The need for targeted pest control strategies has led to the development of juvenile hormone (JH) mimics that selectively disrupt the life cycles of harmful insect species. Present study focuses on the synthesis, characterization and evaluation of sulfonyl-acetohydrazide derivatives (H1-H8) as novel JH mimics on two different insect species, with an emphasis on their insect-specific action. The yellow fever mosquito, Aedes aegypti and cabbage leaf borer, Spodoptera litura, were selected for this investigation. Our results indicate that while these compounds exhibit negligible effects on the development of Aedes aegypti, they demonstrate a potent and specific action against Spodoptera litura. The sulfonyl-acetohydrazide derivatives induced significant developmental abnormalities and increased mortality rates in Spodoptera litura larvae, leading to a marked disruption in their life cycle. Additionally, Density Functional Theory methods were employed to elucidate the electronic structure and corelate the reactivity of the synthesized compounds with the insect growth regulating activity (IGR). The DNA-binding study of synthesized JH analogs has been carried out using UV-vis spectroscopy for toxicity assessment against biomolecule DNA. All the synthesized JH analogs (H1-H8) show IGR action and exhibit better reactivity and reduced toxicity as compared to the commercial in use IGR, pyriproxyfen.

Modeling insect growth regulators for pest management.

Insect growth regulators (IGRs) have been developed as effective control measures against harmful insect pests to disrupt their normal development. This study is to propose a mathematical model to evaluate the cost-effectiveness of IGRs for pest management. The key features of the model include the temperature-dependent growth of insects and realistic impulsive IGRs releasing strategies. The impulsive releases are carefully modeled by counting the number of implements during an insect's temperature-dependent development duration, which introduces a surviving probability determined by a product of terms corresponding to each release. Dynamical behavior of the model is illustrated through dynamical system analysis and a threshold-type result is established in terms of the net reproduction number. Further numerical simulations are performed to quantitatively evaluate the effectiveness of IGRs to control populations of harmful insect pests. It is interesting to observe that the time-changing environment plays an important role in determining an optimal pest control scheme with appropriate release frequencies and time instants.

Scaffold hopping approach to the novel hexacyclic pyrazol-3-amide derivatives as potential multi-target insect growth regulators candidates.

Ecdysone receptor (EcR) and three insect chitinases (OfChtI, OfChtII, and OfChi-h) are considered as attractive targets for the development of novel insect growth regulators (IGRs) since they are closely related to the insect molting. In this study, to develop potent multi-target IGRs, a series of hexacyclic pyrazol-3-amide derivatives were rationally designed by utilizing the scaffold hopping strategy with the previously reported compound 6j (N-(4-bromobenzyl)-2-phenyl-4,5,6,7-tetrahydro-2H-indazole-5-carboxamide) as a lead compound. The bioassay results indicated that most of the target compounds exhibited obvious insecticidal activity. Especially, compounds a5 and a21 displayed excellent insecticidal activities against P. xylostella with LC50 values of 82.29 and 69.45 mg/L, respectively, exceeding that of 6j (263.78 mg/L). Compounds a5 and a21 also dramatically disturbed the growth and development of O. furnacalis larvae, and their LC50 values were 124.71 and 127.54 mg/L, respectively, superior to the lead 6j (267.33 mg/L). The action mechanism study revealed that the most active compound a21 could act simultaneously on EcR (21.4 % binding activity at 8 mg/L), OfChtI (94.9 % inhibitory at 10 µM), OfChtII (23.1 % inhibitory at 10 µM), and OfChi-h (94.3 % inhibitory at 10 µM), significantly higher than that of the lead compound 6j. The result of molecular docking indicated that transferring the carboxamide group from pyrazole position 5 to 3 enhanced the interactions of a21 with the key amino acid residues of the OfChtI, OfChtII, and OfChi-h, resulting in stronger affinity to the three targets than 6j. The present work offers a useful guidance for the further development of novel multi-target IGRs.

The immunosuppressive, growth-hindering, hepatotoxic, and oxidative stress and immune related-gene expressions-altering effects of gibberellic acid in Oreochromis niloticus: A mitigation trial using alpha-lipoic acid.

This study aimed to examine the effects of gibberellic acid (GBA) on growth, hemato-biochemical parameters related to liver functions, digestive enzymes, and immunological response in Oreochromis niloticus. Besides, the probable underlying mechanisms were explored by assessing antioxidant, apoptotic, and immune-related gene expression. Furthermore, the likelihood of restoration following alpha-lipoic acid (LIP) dietary supplementation was explored. The fish (average initial weight 30.75 ± 0.46) were equally classified into four groups: the control group, the LIP group (fed on a basal diet plus 600 mg/kg of LIP), the GBA group (exposed to 150 mg GBA/L), and the GBA + LIP group (exposed to 150 mg GBA/L and fed a diet containing LIP and GBA) for 60 days. The study findings showed that LIP supplementation significantly reduced GBA's harmful effects on survival rate, growth, feed intake, digestive enzymes, and antioxidant balance. Moreover, the GBA exposure significantly increased liver enzymes, stress markers, cholesterol, and triglyceride levels, all of which were effectively mitigated by the supplementation of LIP. Additionally, LIP addition to fish diets significantly minimized the histopathological alterations in the livers of GBA-treated fish, including fatty change, sharply clear cytoplasm with nuclear displacement to the cell periphery, single-cell necrosis, vascular congestion, and intralobular hemorrhages. The GBA-induced reduction in lysozyme activity, complement C3, and nitric oxide levels, together with the downregulation of antioxidant genes (cat and sod), was significantly restored by dietary LIP. Meanwhile, adding LIP to the GBA-exposed fish diets significantly corrected the aberrant expression of hsp70, caspase- 3, P53, pcna, tnf-a, and il-1ß in O. niloticus liver. Conclusively, dietary LIP supplementation could mitigate the harmful effects of GBA exposure on fish growth and performance, physiological conditions, innate immunity, antioxidant capability, inflammatory response, and cell apoptosis.

Genome-Wide Association Studies Reveal That the Abietane Diterpene Isopimaric Acid Promotes Rice Growth through Inhibition of Defense Pathways.

Plants are an important source for the discovery of novel natural growth regulators. We used activity screening to demonstrate that treatment of Nipponbare seeds with 25 µg/mL isopimaric acid significantly increased the resulting shoot length, root length, and shoot weight of rice seedlings by 11.37 ± 5.05%, 12.96 ± 7.63%, and 27.98 ± 10.88% and that it has a higher activity than Gibberellin A3 (GA3) at the same concentration. A total of 213 inbred lines of different rice lineages were screened, and we found that isopimaric acid had different growth promotional activities on rice seedlings of different varieties. After induction with 25 µg/mL isopimaric acid, 15.02% of the rice varieties tested showed increased growth, while 15.96% of the varieties showed decreased growth; the growth of the remaining 69.02% did not show any significant change from the control. In the rice varieties showing an increase in growth, the shoot length and shoot weight significantly increased, accounting for 21.88% and 31.25%. The root length and weight significantly increased, accounting for 6.25% and 3.13%. Using genome-wide association studies (GWASs), linkage disequilibrium block, and gene haplotype significance analysis, we identified single nucleotide polymorphism (SNP) signals that were significantly associated with the length and weight of shoots on chromosomes 2 and 8, respectively. After that, we obtained 17 candidate genes related to the length of shoots and 4 candidate genes related to the weight of shoots. Finally, from the gene annotation data and gene tissue-specific expression; two genes related to this isopimaric acid regulation phenotype were identified as OsASC1 (LOC_Os02g37080) on chromosome 2 and OsBUD13 (LOC_Os08g08080) on chromosome 8. Subcellular localization analysis indicated that OsASC1 was expressed in the plasma membrane and the nuclear membrane, while OsBUD13 was expressed in the nucleus. Further RT-qPCR analysis showed that the relative expression levels of the resistance gene OsASC1 and the antibody protein gene OsBUD13 decreased significantly following treatment with 25 µg/mL isopimaric acid. These results suggest that isopimaric acid may inhibit defense pathways in order to promote the growth of rice seedlings.

Method development, multi-residue determination, and dietary exposure risk assessment of plant growth regulators in homologous materials of medicine and food.

Residues of plant growth regulators (PGRs) in homologous materials of medicine and food threaten public health. This study aimed to develop a rapid, sensitive, and high-throughput method for simultaneously determining 16 PGR residues in homologous materials of medicine and food. Furthermore, the established method was applied to actual samples to assess the potential exposure risk of multi-PGR residues. A modified high-throughput quick, easy, cheap, effective, rugged, and safe (QuEChERS) method coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and validated. The extraction solvent, type of extraction method, and subsequent purification techniques were investigated to achieve a better analysis of the target. Risk assessment was based on chronic dietary risk assessment. Ultrasonic extraction with 1% formic acid-acetonitrile was employed, and MgSO4 + NaAc was selected as the clean-up sorbent. The 16 PGRs showed a good linear relationship in the range of 1 ~ 200 µg/L (r ≥ 0.9960), with detection limits ranging from 0.3 to approximately 3 µg/kg. The recovery rate ranged from 65 to 109%, with RSD from 0.01 to 10% (n = 6). The total detection rate of 16 PGRs in the samples was 87%. The risk assessment indicated that the multi-residues of PGRs in homologous materials of medicine and food would not pose a potential risk to human health. This work provides a valuable reference for the monitoring of multiple PGRs. It has also improved our understanding of the possible exposure risk of PGR residues in homologous materials of medicine and food.

On the biosynthesis and evolution of apocarotenoid plant growth regulators.

Carotenoids are an important source of metabolites with regulatory function, which include the plant hormones abscisic acid (ABA) and strigolactones (SLs), and several recently identified growth regulators and signaling molecules. These carotenoid-derivatives originate from oxidative breakdown of double bonds in the carotenoid polyene, a common metabolic process that gives rise to diverse carbonyl cleavage-products known as apocarotenoids. Apocarotenoids exert biologically important functions in all taxa. In plants, they are a major regulator of plant growth, development and response to biotic and abiotic environmental stimuli, and mediate plant's communication with surrounding organisms. In this article, we provide a general overview on the biology of plant apocarotenoids, focusing on ABA, SLs, and recently identified apocarotenoid growth regulators. Following an introduction on carotenoids, we describe plant apocarotenoid biosynthesis, signal transduction, and evolution and summarize their biological functions. Moreover, we discuss the evolution of these intriguing metabolites, which has not been adequately addressed in the literature.

Effect of plant growth regulators DA-6 and COS on drought tolerance of pineapple through bromelain and oxidative stress.

BACKGROUND: Due to global warming, drought climates frequently occur on land, and despite being drought resistant, pineapples are still subjected to varying degrees of drought stress. Plant growth regulators can regulate the stress tolerance of plants through hormonal effects. This experiment aims to investigate the regulatory effects of different plant growth regulators on Tainong- 16 and MD-2 Pineapple when subjected to drought stress. RESULTS: In this experiment, we examined the regulatory effects of two different plant growth regulators, sprayed on two pineapple varieties: MD-2 Pineapple and Tainong-16. The main component of T1 was diethyl aminoethyl hexanoate (DA-6) and that of T2 is chitosan oligosaccharide (COS). An environment similar to a natural drought was simulated in the drought stress treatments. Then, pineapples at different periods were sampled and a series of indicators were measured. The experimental results showed that the drought treatments treated with T1 and T2 plant growth regulators had a decrease in malondialdehyde, an increase in bromelain and antioxidant enzyme indicators, and an increase in phenotypic and yield indicators. CONCLUSION: This experiment demonstrated that DA-6 and COS can enhance the drought resistance of pineapple plants to a certain extent through bromelain and oxidative stress. Therefore, DA-6 and COS have potential applications and this experiment lays the foundation for further research.

Flowering and fruit-set in cassava under extended red-light photoperiod supplemented with plant-growth regulators and pruning.

BACKGROUND: Cassava (Manihot esculenta Crantz) is staple food and major source of calories for over 500 million people in sub-Saharan Africa. The crop is also a source of income for smallholder farmers, and has increasing potential for industrial utilization. However, breeding efforts to match the increasing demand of cassava are impeded by its inability to flower, delayed or unsynchronized flowering, low proportion of female flowers and high fruit abortions. To overcome these sexual reproductive bottlenecks, this study investigated the effectiveness of using red lights to extend the photoperiod (RLE), as a gateway to enhancing flowering and fruit set under field conditions. MATERIALS AND METHODS: Panels of cassava genotypes, with non- or late and early flowering response, 10 in each case, were subjected to RLE from dusk to dawn. RLE was further evaluated at low (LL), medium (ML) and high (HL) red light intensities, at ~ ≤ 0.5; 1.0 and 1.5PFD (Photon Flux Density) in µmol m-2 s-1 respectively. Additionally, the effect of a cytokinin and anti-ethylene as plant growth regulators (PGR) and pruning under RLE treatment were examined. RESULTS: RLE stimulated earlier flower initiation in all genotypes, by up to 2 months in the late-flowering genotypes. Height and number of nodes at first branching, particularly in the late-flowering genotypes were also reduced, by over 50%. Number and proportion of pistillate flowers more than doubled, while number of fruits and seeds also increased. Number of branching levels during the crop season also increased by about three. Earlier flowering in many genotypes was most elicited at LL to ML intensities. Additive effects on flower numbers were detected between RLE, PGR and pruning applications. PGR and pruning treatments further increased number and proportion of pistillate flowers and fruits. Plants subjected to PGR and pruning, developed bisexual flowers and exhibited feminization of staminate flowers. Pruning at first branching resulted in higher pistillate flower induction than at second branching. CONCLUSIONS: These results indicate that RLE improves flowering in cassava, and its effectiveness is enhanced when PGR and pruning are applied. Thus, deployment of these technologies in breeding programs could significantly enhance cassava hybridizations and thus cassava breeding efficiency and impact.

In vitro propagation of Codonopsis pilosula (Franch.) Nannf. using apical shoot segments and phytochemical assessments of the maternal and regenerated plants.

BACKGROUND: Codonopsis pilosula (Franch.) Nannf. is a medicinal plant traditionally used in China, Korea, and Japan to treat many diseases including poor gastrointestinal function, low immunity, gastric ulcers, and chronic gastritis. The increasing therapeutic and preventive use of C. pilosula has subsequently led to depletion of the natural populations of this species thus necessitating propagation of this important medicinal plant. Here, we developed an efficient and effective in vitro propagation protocol for C. pilosula using apical shoot segments. We tested various plant tissue culture media for the growth of C. pilosula and evaluated the effects of plant growth regulators on the shoot proliferation and rooting of regenerated C. pilosula plants. Furthermore, the tissues (roots and shoots) of maternal and in vitro-regenerated C. pilosula plants were subjected to Fourier-transform near-infrared (FT-NIR) spectrometry, Gas chromatography-mass spectrometry (GC-MS), and their total flavonoids, phenolics, and antioxidant capacity were determined and compared. RESULTS: Full-strength Murashige and Skoog (MS) medium augmented with vitamins and benzylaminopurine (1.5 mg·L-1) regenerated the highest shoot number (12 ± 0.46) per explant. MS medium augmented with indole-3-acetic acid (1.0 mg·L-1) produced the highest root number (9 ± 0.89) and maximum root length (20.88 ± 1.48 mm) from regenerated C. pilosula shoots. The survival rate of in vitro-regenerated C. pilosula plants was 94.00% after acclimatization. The maternal and in vitro-regenerated C. pilosula plant tissues showed similar FT-NIR spectra, total phenolics, total flavonoids, phytochemical composition, and antioxidant activity. Randomly amplified polymorphic DNA (RAPD) test confirmed the genetic fidelity of regenerated C. pilosula plants. CONCLUSIONS: The proposed in vitro propagation protocol may be useful for the rapid mass multiplication and production of high quality C. pilosula as well as for germplasm preservation to ensure sustainable supply amidst the ever-increasing demand.

Recent advances in application and progress of advanced materials as adsorbents in sample preparation for plant growth regulators.

Plant growth regulators are a class of physiologically active substances that could modify or regulate basic physiological processes in the plant and defense against abiotic and biotic stresses, including natural plant growth regulators and synthetic ones. Different from natural plant growth regulators with low content and high cost of extraction in plants, synthetic ones can be produced in large-scale production and widely used in agriculture for increasing and securing yield and quality of the harvested produce. However, like pesticides, the abuse of plant growth regulators will have negative impacts on human beings. Therefore, it is important to monitor plant growth regulators residues. Due to the low concentration of plant growth regulators and complex matrices of food, it is necessary to isolate and extract plant growth regulators by appropriate adsorbents in sample preparation for obtaining satisfactory results. In the last decade, several advanced materials as adsorbents have shown superiority in sample preparation. This review briefly introduces the recent application and progress of advanced materials as adsorbents in sample preparation for extraction of plant growth regulators from the complex matrix. In the end, the challenge and outlook about the extraction of plant growth regulators of these advanced adsorbents in sample preparation are presented.

Regionality in vector control: effect of fluctuating temperature in the susceptibility of Aedes aegypti (Diptera: Culicidae) larvae to Pyriproxyfen.

Using Pyriproxyfen in controlling Aedes aegypti shows great potential considering its high competence in low dosages. As an endocrine disruptor, temperature can interfere with its efficiency, related to a decrease in larval emergence inhibition in hotter environments. However, previous studies have been performed at constant temperatures in the laboratory, which may not precisely reflect the environmental conditions in the field. The aim of this study was to assess the effect of the fluctuating temperatures in Pyriproxyfen efficiency on controlling Aedes aegypti larvae. We selected maximum and minimum temperatures from the Brazilian Meteorological Institute database from September to April for cities grouped by five regions. Five fluctuating temperatures (17-26; 20-28.5; 23-32.5; 23-30.5; 19.5-31 °C) were applied to bioassays assessing Pyriproxyfen efficiency in preventing adult emergence in Aedes aegypti larvae in five concentrations. In the lowest temperatures, the most diluted Pyriproxyfen treatment (0.0025 mg/L) was efficient in preventing the emergence of almost thrice the larvae than in the hottest temperatures (61% and 21%, respectively, p value = 0.00015). The concentration that inhibits the emergence of 50% of the population was lower than that preconized by the World Health Organization (0.01 mg/L) in all treatments, except for the hottest temperatures, for which we estimated 0.010 mg/L. We concluded that fluctuating temperatures in laboratory bioassays can provide a more realistic result to integrate the strategies in vector surveillance. For a country with continental proportions such as Brazil, considering regionalities is crucial to the rational use of insecticides.

Effects of 24-Epibrassinolide, melatonin and their combined effect on cadmium tolerance in Primula forbesii Franch.

This study aimed to investigate the interaction between 24-Epibrassinolide (EBR) and melatonin (MT) and their effects on cadmium (Cd)-stressed Primula forbesii Franch. P. forbesii seedlings were hydroponically acclimatized at 6-7 weeks, then treated with Cd (200 µmol L-1), 24-EBR (0.1 µmol L-1), and MT (100 µmol L-1) after two weeks. Cd stress significantly reduced crown width, shoot, root length, shoot fresh weight, and fresh and dry root weights. Herein, 24-EBR, MT, and 24-EBR+MT treatments attenuated the growth inhibition caused by Cd stress and improved the morphology, growth indexes, and ornamental characteristics of P. forbesii under Cd stress. 24-EBR had the best effect by effectively alleviating Cd stress and promoting plant growth and development. 24-EBR significantly increased all growth parameters compared to Cd treatment. In addition, 24-EBR significantly improved the gas exchange parameters, activities of antioxidant enzymes, and the cycle efficiency of AsA-GSH. Furthermore, 24-EBR increased the activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) by 127.29%, 61.31%, 61.22%, and 51.04%, respectively, compared with the Cd treatment. Therefore, 24-EBR removed the reactive oxygen species produced by stress, thus protecting plants against stress damage. These results indicate that 24-EBR can effectively enhance the tolerance of P. forbesii to Cd stress.

Reproductive and developmental toxicity of plant growth regulators in humans and animals.

Plant growth regulators (PGRs) are currently one of the widely used pesticides, as being considered to have relatively low toxicity compared with other pesticides. However, widespread use may lead to overexposure from multiple sources. Exposure to PGRs is associated with different toxicity that affects many organs in our body, such as the toxicity to testis, ovaries, liver, kidneys and brain. In addition, some PGRs are considered potential endocrine disrupting chemicals. Evidence exists for development and reproductive toxicity associated with prenatal and postnatal exposure in both animals and humans. PGRs can affect the synthesis and secretion of sex hormones, destroy the structure and function of the reproductive system, and harm the growth and development of offspring, which may be related to germ cell cycle disorders, apoptosis and oxidative stress. This review summaries the reproductive and developmental toxicity data available about PGRs in mammals. In the future, conducting comprehensive epidemiological studies will be crucial for assessing the reproductive and developmental toxicity resulting from a mixture of various PGRs, with a particular emphasis on understanding the underlying molecular mechanisms.

Low-Temperature Cleanup Followed by Dispersive Solid-Phase Extraction for Determination of Nine Polar Plant Growth Regulators in Herbal Matrices Using Liquid Chromatography-Tandem Mass Spectrometry.

Polar plant growth regulators, used alone or doped in fertilizers, are most effective and widely utilized plant growth regulators (PGRs) in agriculture, which play important roles in mediating the yield and quality of crops and foodstuffs. The application scope has been extended to herbal medicines in the past 2 decades and relevant study is inadequate. The aim of this study is to establish a QuPPe-based extraction method containing low-temperature and d-SPE cleanup procedure followed by the detection on a selective multiresidue ultrahigh-performance liquid chromatography - triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS) in three herbal matrices. This simple, accurate, versatile and robust method was verified according to the validation criteria of the SANTE/12682/2019 guideline document. The analytical range was from 2.5 to 200 µg/L, and the average recoveries were in the range of 64.6-117.8% (n = 6). The optimized method was applied to 135 herbal medicines thereof. Result showed that the detection frequency of chlormequat was the highest in the investigated PGRs, with the positive rate of 15.6%. Improvement of the detection method for polar PGRs will enrich the coverage of PGRs, which is conducive to safeguard public health and ensure drug safety. Supplementary Information: The online version contains supplementary material available at 10.1007/s10337-023-04254-3.

Seeds of Stevia rebaudiana Bertoni as a Source of Plant Growth-Promoting Endophytic Bacteria with the Potential to Synthesize Rebaudioside A.

In this study, a new strain of Pantoea vagans, SRS89, was isolated from surface-sterilized stevia seeds. The isolate was evaluated using morphological, molecular, and biochemical methods. The bacterium was 1.5 µm long, yellowish in color, and classified as Gram-negative. Whole genome sequencing of our strain revealed the presence of a 4,610,019 bp chromosome, and genome annotation resulted in the detection of 4283 genes encoding 4204 putative coding sequences. Phylogenic analysis classified the genome of our strain close to the MP7 and LMG 24199 strains of P. vagans. Functional analysis showed that the highest number of genes within the analyzed bacterium genome were involved in transcription, amino acid transport and metabolism, and carbohydrate transport and metabolism. We also identified genes for enzymes involved in the biosynthesis of carotenoids and terpenoids. Furthermore, we showed the presence of growth regulators, with the highest amount noted for gibberellic acid A3, indole-3-acetic acid, and benzoic acid. However, the most promising property of this strain is its ability to synthesize rebaudioside A; the estimated amount quantified using reversed-phase (RP)-HPLC was 4.39 mg/g of the dry weight of the bacteria culture. The isolated endophytic bacterium may be an interesting new approach to the production of this valuable metabolite.

Transcriptomic Profiling of Embryogenic and Non-Embryogenic Callus Provides New Insight into the Nature of Recalcitrance in Cannabis.

Differential gene expression profiles of various cannabis calli including non-embryogenic and embryogenic (i.e., rooty and embryonic callus) were examined in this study to enhance our understanding of callus development in cannabis and facilitate the development of improved strategies for plant regeneration and biotechnological applications in this economically valuable crop. A total of 6118 genes displayed significant differential expression, with 1850 genes downregulated and 1873 genes upregulated in embryogenic callus compared to non-embryogenic callus. Notably, 196 phytohormone-related genes exhibited distinctly different expression patterns in the calli types, highlighting the crucial role of plant growth regulator (PGRs) signaling in callus development. Furthermore, 42 classes of transcription factors demonstrated differential expressions among the callus types, suggesting their involvement in the regulation of callus development. The evaluation of epigenetic-related genes revealed the differential expression of 247 genes in all callus types. Notably, histone deacetylases, chromatin remodeling factors, and EMBRYONIC FLOWER 2 emerged as key epigenetic-related genes, displaying upregulation in embryogenic calli compared to non-embryogenic calli. Their upregulation correlated with the repression of embryogenesis-related genes, including LEC2, AGL15, and BBM, presumably inhibiting the transition from embryogenic callus to somatic embryogenesis. These findings underscore the significance of epigenetic regulation in determining the developmental fate of cannabis callus. Generally, our results provide comprehensive insights into gene expression dynamics and molecular mechanisms underlying the development of diverse cannabis calli. The observed repression of auxin-dependent pathway-related genes may contribute to the recalcitrant nature of cannabis, shedding light on the challenges associated with efficient cannabis tissue culture and regeneration protocols.