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In the sixteenth and seventeenth centuries, the trade in and cultivation of exotic plant life proliferated at a rapid rate. Horticulturalists analogized plant acclimatization to human travel and acculturation, arguing that transplantation could ameliorate both species. Despite anxieties surrounding the influence of foreign environments, unfamiliar soil was thought to bring about "civility" and provoke both plants and humans to shed their "ill qualit[ies]." As I show, horticulturalists, such as John Parkinson and John Evelyn, distinguish plants that embody this myth from those that resist foreign soil, attributing their decline to their affective dispositions, their "peevish" or "impatient" temperaments, for example. Not only does this anthropomorphic impulse ignore the harsh climatological conditions to which plants were exposed, but it also contributes to an emerging racial discourse that differentiates human populations by their perceived cultivability, whether or not they can become more "civil." I argue that English polemicists, writing on the supposed savagery of the Irish, reappropriate this fantasy to authorize subjugation and forcible displacement. In drawing attention to the horticultural rhetoric that justified these imperial ventures, this essay proffers new avenues for examining the ideologies that underwrote colonial violence in Africa, the Indian subcontinent, and the Americas. [R.B.] [ABSTRACT FROM AUTHOR]

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile 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.)

Asparagus (Asparagus officinalis L.) is an important vegetable crop in southern Ontario, Canada, where winter air and soil temperatures below 0°C are common. Consequently, cultivars growing in this area must possess winterhardiness and freezing tolerance for survival. Asparagus acquires freezing tolerance in the fall through cold acclimation and loses freezing tolerance in the spring through deacclimation. To understand the molecular bases of these processes, transcriptomic analysis (RNA-Seq) was conducted on two cultivars, one adapted, 'Guelph Millennium' (GM), and one unadapted, 'UC157' (UC), to the winter conditions of southern Ontario. RNA extracted from bud and rhizome tissues, sampled on three dates during early spring and late fall, was subjected to sequencing. In the fall, the numbers of differentially expressed (DE) genes at the second and third harvests increased, relative to the first harvest, in dormant buds and rhizomes as freezing tolerance of cultivars increased, and the majority of DE genes were downregulated. In spring, freezing tolerance decreased as plants deacclimated and most genes DE at second and third harvests were upregulated in both cultivars. GM had lower LT50 (lethal temperature at which 50% of plants die) values and hence higher freezing tolerance than UC on specific sampling dates during both spring and fall, and expression patterns of specific genes were correlated with LT50 differences. Functional analysis revealed that these genes were involved in carbohydrate metabolic process, plant hormone signal transduction (auxin and gibberellin), proline metabolism, biosynthesis of secondary metabolites, circadian rhythm, and late embryogenesis abundant proteins and could be associated with cold acclimation and deacclimation processes. These findings will help researchers understand the molecular mechanisms of freezing tolerance in asparagus, leading to breeding and genetic strategies to improve the trait. [ABSTRACT FROM AUTHOR]

Summary Arabidopsis PSEUDORESPONSE REGULATOR7 (PRR7) is a core component of the circadian oscillator which also plays a crucial role in freezing tolerance. PRR7 undergoes proteasome‐dependent degradation to discretely phase maximal expression in early evening. While its repressive activity on downstream genes is integral to cold regulation, the mechanism of the conditional regulation of the PRR7 abundance is unknown. We used mutant analysis, protein interaction and ubiquitylation assays to establish that the ubiquitin ligase adaptor, HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 15 (HOS15), controls the protein accumulation pattern of PRR7 through direct protein–protein interactions at low temperatures. Freezing tolerance and electrolyte leakage assays show that PRR7 enhances cold temperature sensitivity, supported by ChIP‐qPCR at C‐REPEAT BINDING FACTOR1 (CBF1) and COLD‐REGULATED 15A (COR15A) promoters where PRR7 levels were higher in hos15 mutants. HOS15 mediates PRR7 turnover through enhanced ubiquitylation at low temperature in the dark. Under the same conditions, increased PRR7 association with the promoters of CBFs and COR15A in hos15 correlates with decreased CBF1 and COR15A transcription and enhanced freezing sensitivity. We propose a novel mechanism whereby HOS15‐mediated degradation of PRR7 provides an intersection between the circadian system and other cold acclimation pathways that lead to increased freezing tolerance. [ABSTRACT FROM AUTHOR]

Micropropagation of fig is playing an interesting role in the rapid multiplication of varieties with important characters and the regeneration of virus-free plants. FMD (Fig Mosaic Disease) is the viral disorder the most spread all over the world and considered as a serious problem for healthy fig plant propagation and high fig production. During the last four decades, many efficient protocols have been established for in vitro large-scale propagation of female figs and caprifigs for plant material sanitation. Successful micropropagation of figs using meristematic tissues (nodal segments or apical buds) is dependant to several external and internal factors including in vitro conditions (media components essentially) and ex vitro (genotype and physiological state, etc.). Specific requirements during all steps of plant regeneration, such as the initiation of in vitro cultures, shoot multiplication, plantlet rooting and acclimatization are summarized in this review. The efficacy of meristem and tip culture in the eradication of viruses from fig vitroplants is also reported. New approaches for the improvement of shoot multiplication and fig vitroplant quality (bioreactors, Arbuscular mycorrhizal fungi, etc.) and the genetic stability and conformity of micropropagated plantlets are discussed. [ABSTRACT FROM AUTHOR]

This document is an editorial summarizing a special issue of the International Journal of Molecular Sciences focused on abiotic stresses in plants. The issue includes 20 original research articles and 4 comprehensive reviews that cover a range of topics related to plant responses to environmental stressors such as heavy metals, waterlogging, salt stress, and UV light. The articles provide insights into the molecular mechanisms underlying these responses and offer potential solutions for improving crop resilience in the face of global climate challenges. The editor expresses gratitude to the contributors and hopes that the articles are useful and inspirational to readers in the field. [Extracted from the article]

Petiole segments of an economically ornamental plant Oxalis triangularis A.st.-Hil have been used in the present study for rapid, reliable and systematic in vitro propagation. The morphogenic effect of a-Naphthalene acetic acid (NAA) at various concentrations (0.5 - 3.0 mg/L) was studied individually or in combination with 6-benzylaminopurine (BAP). Superior multiplication rates were achieved on Murashige and Skoog (MS) medium supplemented with 0.5 mg/L NAA and 1.0 mg/L BAP. Of the tested combinations, maximum shoot regeneration (100.00 %), mean shoot number (14.60 ± 0.37 shoots per segment), and shoot length (18.11 ± 0.30 mm) were recorded on MS medium supplemented with 0.5 mg/L NAA and 1.0 mg/L BAP after 6 weeks of incubation. Half-strength MS medium augmented with 1.0 mg/L indole-3-butyric acid (IBA) was the optimal medium for in vitro root induction, (24.60 ± 0.37 roots per shoot with 9.10 ± 0.32 mm in length) after 6 weeks of incubation. The regenerated plantlets showed 100 % survival success during acclimatization and exhibited normal growth characteristics and morphology. This optimized protocol is cost-effective and highly efficient for the rapid mass propagation of Oxalis triangularis A.st.-Hil. [ABSTRACT FROM AUTHOR]

Plants have evolved various mechanisms to adapt to the ever‐changing external environment. Autophagy is one such mechanism and has been suggested to play a key role in responding to and adapting to abiotic stresses in plants. However, the role of autophagy in adaptation to cold and freezing stresses remains to be characterized in detail. Here, we investigated the role of autophagy in the low‐temperature response of Arabidopsis using atg mutants. Both the atg5‐1 and atg10‐1 mutants exhibited normal freezing tolerance, regardless of cold acclimation. A comparison of fresh weights indicated that the difference in growth between the wild‐type and atg plants under cold conditions was rather small compared with that under normal conditions. Analysis of COLD‐REGULATED gene expression showed no significant differences between the atg mutants and wild type. Treatment with 3‐methyladenine, an inhibitor of autophagy, did not impair the induction of COR15Apro::LUC expression upon exposure to low temperature. Evaluation of autophagic activity using transgenic plants expressing RBCS‐mRFP demonstrated that autophagy was rarely induced by cold exposure, even in the dark. Taken together, these data suggest that autophagy is suppressed by low temperatures and is dispensable for cold acclimation and freezing tolerance in Arabidopsis. [ABSTRACT FROM AUTHOR]

Up-flow sand filtration is an excellent alternative to point-of-use treatment for rural water supply. However, the sites and interval of microorganism growth in filter beds and the effect on bioclogging remain unknown. This study aimed to assess microorganism growth based on biological activity levels using Dissolved Oxygen (DO) consumption and Field Emission Scanning Electron Microscopy (FE-SEM) imaging in various zones of the filter bed. Additionally, pressure drop was monitored to evaluate bio-clogging. The results showed that microorganism activities differed within the 0.50 m up-flow sand filter bed during 8 weeks of acclimatization. Exponential growth started after day 35, and DO levels declined to a minimum of 2 mg/L at 0.10 m bed height (measured from the bottom) after day 46. At 0.30 m and 0.50 m height, the DO decreased to 0.8 mg/L and 0.3 mg/L after days 35 and 46, respectively. FE-SEM images confirmed microorganism growth on samples from 0.1 m after 4 weeks of acclimatization. Substantial growth was seen on samples of 0.10 and 0.30 m height at 8 weeks, while lesser growth was observed on samples of 0.50 m. The pressure drop showed no significant increase, signifying that clogging did not occur during the 135-day operational period. In conclusion, the up-flow configuration prevented bio-clogging in sand filters, reducing maintenance requirements. [ABSTRACT FROM AUTHOR]

Micropropagation facilitates the rapid production of roses. Nevertheless, in vitro rhizogenesis of essential oil roses has presented significant challenges, primarily attributed to low rates of rooting and poorer acclimatization compared to ornamental rose varieties. This study reports the optimization of in vitro rooting of Al-Taif rose (Rosa damascena f. trigintipetala (Diek) R. Keller) microshoots with the aim of increasing survival rate during acclimatization. We also investigated the effects of various parameters, including type and concentration of auxin (i.e., 2,4-Dichlorophenoxyacetic acid (2,4-D), indole acetic acid (IAA), indole butyric acid (IBA), and naphthaleneacetic acid (NAA) at concentrations of 0, 0.05, 0.1, 0.2, and 0.4 mg/L), salt strength (i.e., full- and half-strength Murashige and Skoog (MS) medium), sucrose concentration (i.e., 20, 30, 40, 60, and 80 g/L), light spectra (a 2:1 or 1:2 blue/red spectral ratio, cool or warm white light at a 1:1 ratio, and fluorescent light), light intensity (photosynthetic photon flux density (PPFD) values of 25, 50, and 100 µmol·m−2·s−1), and activated charcoal (i.e., 0 and 0.5 g/L) on the rooting and growth of in vitro regenerated Al-Taif rose axillary shoots. We found that half-strength MS medium supplemented with 0.2 mg/L NAA, 80 g/L sucrose, 0.5 g/L activated charcoal, and 50 μmol·m−2·s−1 PPFD were the optimal conditions for 100% induction of adventitious roots. Next, micropropagated Al-Taif rose plantlets were successfully transferred to a potting medium containing perlite/peatmoss (in a 1:1 ratio). We found that 98% of plants survived ex vitro conditions. The genetic fidelity of micropropagated Al-Taif rose clones along with their mother plant was tested using the inter-simple sequence repeats (ISSR) molecular marker. The genetic similarity between the micropropagated plantlets and the mother plant of Al-Taif rose plants was 98.8%, revealing high uniformity and true-to-type regenerated plants. These findings may therefore contribute toward the commercial micropropagation of Al-Taif roses. [ABSTRACT FROM AUTHOR]

Despite traditional beliefs of orthologous genes maintaining similar functions across species, growing evidence points to their potential for functional divergence. C-repeat binding factors/dehydration-responsive element binding protein 1s (CBFs/DREB1s) are critical in cold acclimation, with their overexpression enhancing stress tolerance but often constraining plant growth. In contrast, a recent study unveiled a distinctive role of rice OsDREB1C in elevating nitrogen use efficiency (NUE), photosynthesis, and grain yield, implying functional divergence within the CBF/DREB1 orthologs across species. Here, we delve into divergent molecular mechanisms of OsDREB1C and AtCBF2/3/1 by exploring their evolutionary trajectories across rice and Arabidopsis genomes, regulatomes, and transcriptomes. Evolutionary scrutiny shows discrete clades for OsDREB1C and AtCBF2/3/1 , with the Poaceae-specific DREB1C clade mediated by a transposon event. Genome-wide binding profiles highlight OsDREB1C's preference for GCCGAC compared to AtCBF2/3/1's preference for A/GCCGAC, a distinction determined by R12 in the OsDREB1C AP2/ERF domain. Cross-species multiomic analyses reveal shared gene orthogroups (OGs) and underscore numerous specific OGs uniquely bound and regulated by OsDREB1C, implicated in NUE, photosynthesis, and early flowering, or by AtCBF2/3/1, engaged in hormone and stress responses. This divergence arises from gene gains/losses (∼16.7% to 25.6%) and expression reprogramming (∼62.3% to 66.2%) of OsDREB1C- and AtCBF2/3/1-regulated OGs during the extensive evolution following the rice– Arabidopsis split. Our findings illustrate the regulatory evolution of OsDREB1C and AtCBF2/3/1 at a genomic scale, providing insights on the functional divergence of orthologous transcription factors following gene duplications across species. [ABSTRACT FROM AUTHOR]

Halophytes are species able to grow and complete their life cycle under NaCl concentrations above 0.2 M. In a context of growing population and uncertain agricultural food sustainability, there is an interest on halophytes as potential source of food and fodder. However, scarce research has addressed in vitro propagation of halophytes as a tool for study, conservation, and propagation of elite germplasm. In this study, an efficient method for micropropagation of the succulent and salt accumulator halophyte Arthrocaulon macrostachyum has been established for the first time, using shoot tips from in vitro-germinated plant material. During shoot multiplication stage, superior genotypes were selected from explants grown in high strength and NaCl content medium and subsequently rooted and acclimatized to ex vitro conditions. A comprehensive characterization including determination of oxidative stress, photosynthesis performance, and mineral nutrient contents was done. This research gains insight into the physiological and biochemical characterization of halophytes during micropropagation and provides a solid platform for the production of elite A. macrostachyum germplasm for ulterior uses. [ABSTRACT FROM AUTHOR]

Research conducted at the Plant Breeding and Acclimatization Institute—NIR in Poland in 2020–2022 assessed the commercial quality of potato tubers depending on the production system (organic, conventional), variety, and weather conditions prevailing in the years of research. The tuber size distribution and the share of tuber defects was assessed. It was found that all tested factors influenced the commercial quality of the yield but to different extents. The production system had the greatest influence on most of the examined features, followed by weather conditions and the least influential factor being the variety. The production system had the greatest impact on such features as: tuber size distribution (all fractions), pest damage, scab infection, tuber deformations, and share of green tubers. Weather conditions had the greatest impact on scab infection, pest damage, deformation, cracks and share of large tubers. The variety factor had the greatest influence on such features as: deformations, cracks, green tubers, black scarf, and share of the smallest (non-commercial) tubers. In the conventional system, a significantly better tuber yield distribution was found. The share of tuber defects varied depending on the production system. In the organic system, a greater share of defects such as scab (68.3 and 41.3) and pest damage was found (6.8 and 0.2), while in the conventional system, a greater share of deformations (9.2 and 4.9), cracks (5.4 and 2.4), and rust spots (0.61 and 0.06) occurred. [ABSTRACT FROM AUTHOR]

SUMMARY: The development of photosynthetically competent seedlings requires both light and retrograde biogenic signaling pathways. The transcription factor GLK1 functions at the interface between these pathways and receives input from the biogenic signal integrator GUN1. BBX14 was previously identified, together with GLK1, in a core module that mediates the response to high light (HL) levels and biogenic signals, which was studied by using inhibitors of chloroplast development. Our chromatin immunoprecipitation‐Seq experiments revealed that BBX14 is a direct target of GLK1, and RNA‐Seq analysis suggests that BBX14 may function as a regulator of the circadian clock. In addition, BBX14 plays a role in chlorophyll biosynthesis during early onset of light. Knockout of BBX14 results in a long hypocotyl phenotype dependent on a retrograde signal. Furthermore, the expression of BBX14 and BBX15 during biogenic signaling requires GUN1. Investigation of the role of BBX14 and BBX15 in GUN‐type biogenic (gun) signaling showed that the overexpression of BBX14 or BBX15 caused de‐repression of CA1 mRNA levels, when seedlings were grown on norflurazon. Notably, transcripts of the LHCB1.2 marker are not de‐repressed. Furthermore, BBX14 is required to acclimate plants to HL stress. We propose that BBX14 is an integrator of biogenic signals and that BBX14 is a nuclear target of retrograde signals downstream of the GUN1/GLK1 module. However, we do not classify BBX14 or BBX15 overexpressors as gun mutants based on a critical evaluation of our results and those reported in the literature. Finally, we discuss a classification system necessary for the declaration of new gun mutants. Significance Statement: A picture is emerging in which BBX proteins have multifaceted functions in plant development, acting as receivers of chloroplast signals as well as playing a role in responses to acute stress. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Forestry Research is the property of Indonesian Journal of Forestry Research 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.)

The intensification of warming-induced mass-mortalities in invertebrate populations including in temperate regions is a critical global issue. Mesophotic zones (30–150 m depth) have been suggested as potential refuges from climate change for gorgonian populations, offering hope for reseeding damaged shallow populations. Using a proteomic approach, we investigated the responses and acclimatization ability of the yellow gorgonian Eunicella cavolini along an environmental gradient following reciprocal transplantations between shallow (20 m) and mesophotic (70 m) zones. Our findings indicate that yellow gorgonians from mesophotic waters exhibit a greater plasticity when transplanted to shallow waters, compared to shallow gorgonians transplanted to the mesophotic zone at 70 m. Transplanted colonies from mesophotic to shallow waters showed an increasing level of proteins involved in immune response but displayed no signs of necrosis or apoptosis, highlighting the acclimation potential of mesophotic populations. These results suggest that Eunicella cavolini populations may exhibit physiological plasticity in response to future climate change, allowing natural colonization from mesophotic populations. This analysis offers valuable insights into gorgonians' cellular and molecular responses to environmental changes. [ABSTRACT FROM AUTHOR]

Although Thymbra spicata is not a native Egyptian plant, a freshly picked twig was discovered in the tomb of Tutankhamun. Such a plant could have been cultivated in Egypt by "the state," or by a foreigner sojourning in Egypt. The twig is an example of plant acclimatization, such as plants brought by Hatshepsut's mission to Punt and those collected during Thutmose III's expedition in Retjenu depicted on the walls of Amun's temple in Karnak. The maximal span of elapsed time between the Battle of Megiddo and the death of Tutankhamun is less than 150 years (at most four or five generations). A study of a family of royal gardeners suggests that T. spicata was cultivated in Egypt during the Eighteenth Dynasty and the twig found in Tutankhamun's tomb was a progeny of such an introduction. Eventually its cultivation failed, and the plant vanished from Egypt. [ABSTRACT FROM AUTHOR]

Lower winter temperatures may negatively affect winter survival by preventing maximum cold acclimation before freezing temperatures. The process of cold acclimation requires adaptation to both light and low temperatures, depending on the duration of exposure. Accordingly, research is needed to identify strategies to promote cold acclimation and increase freezing tolerance. Therefore, this experiment was conducted to investigate whether a shorter or more extended preconditioning cold treatment can improve the cold hardiness of hollyhock and its threshold of winter hardiness. The results showed that both 14 (CP1) and 28 days of Cold Preconditioning (CP2) decreased electrolyte loss, increased the activity of SOD, CAT, and APX enzymes, inhibited accumulation of Hydrogen peroxide (H2O2), and delayed the increase of Malondialdehyde (MDA) content, while non-acclimated plants experienced a decrease in MDA. No difference was observed in antioxidant activity and photosynthetic parameters between CP1 and CP2. Although proline and water-soluble sugar contents were higher in plants subjected to 28 days of cold preconditioning than in those treated for 14 days, no significant difference was found in survival percentage. Low temperatures decreased photosynthetic parameters, while increasing leaf contents of Abscisic Acid (ABA) and phenolic. The results suggested that 14-day cold preconditioning could be used to increase cold tolerance for non-acclimated hollyhocks to grow in the field at -4°C. [ABSTRACT FROM AUTHOR]

Protected agriculture is especially useful for crop production in regions where climatic conditions are unsuitable for outdoor or open field production. By controlling the temperature, humidity and amount of light of the internal environment, these structures allow plants to grow and flower at any time of the year. Likewise, They also make possible the establishment of seedbeds to obtain seedlings and their subsequent transplanting to the field, as well as the production of pathogen-free and high quality fruits and seeds,, also reducing the need for pesticides and other toxic chemicals. Due to the great success of this technology in horticultural and fruit agriculture, research into other factors that can affect crops and also cause production losses has been encouraged. Genetic improvement to increase yields and resistance to pests and diseases, production management with or without soil, during the acclimatization phase of plants from in vitro propagation, among others, are some of the works that are frequently published and report an increase in the effectiveness of protected agriculture. In the following work, the generalities of protected agriculture, the benefits and uses that this technology offers are socialized; as well as its support for research and seed production. [ABSTRACT FROM AUTHOR]

In vitro propagation, cold preservation, and cryopreservation are three essential approaches to preserve the genetic resources of red-listed plants, including English yew (Taxus baccata L.). Different concentrations of plant growth regulators (PGRs) and different pre-treatments of cold preservation and cryopreservation are the prerequisites of these three approaches. Apical bud as explant and Murashige and Skoog (MS) as the culture medium for all three sections of the research, kinetin (Kin) and indole-3-butyric acid (IBA) as PGRs for the micropropagation section, and encapsulation-dehydration as pre-treatment for the sections of cold preservation and cryopreservation were used. The results of the micropropagation section indicated that the highest number of shoots (5.40 per explant) and roots (5.98 per explant) were obtained from the culture of the explants on the media containing 1 mg L-1 IBA together with 1 and 2 mg L-1 Kin, respectively. The results of the cold preservation section revealed that the highest percentage of survival of germplasms (100%) after storage in the refrigerator was observed in the apical buds pre-treated by dehydration of encapsulated explants with 0.75 M sucrose for two hours, followed by dehydration under a laminar airflow cabinet for two hours. The results of the cryopreservation section demonstrated that the highest percentage of survival of germplasms (100%) after storage in liquid nitrogen was obtained in the apical buds pre-treated by encapsulation-dehydration under a laminar airflow cabinet for two hours. At the acclimatization stage, 100% of the plantlets acclimatized suitably with ex vitro conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) 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.)

Eryngium foetidum L., a biennial herb with diverse applications in food and traditional medicine, holds economic and pharmacological significance. Given its growing commercial interest, implementing biotechnological approaches like plant tissue culture is vital for sustainable propagation and metabolite production. In this study, we investigated the in vitro photoautotrophic potential of Eryngium foetidum, examining growth, chlorophyll a fluorescence, photosynthetic pigments, and anatomical features under sucrose concentrations (0 and 30 g L−1) and gas exchange rate (14 and 25 μL L−1 s−1 CO2). Acclimatization and survival rates of plants after ex vitro transfer were also assessed. Eryngium foetidum exhibited robust growth in both photoautotrophic and photomixotrophic conditions, with natural ventilation significantly enhancing plant development. Chlorophyll a fluorescence and photosynthetic performance were influenced by sucrose and gas exchange, highlighting the importance of these factors in plant micropropagation. Moreover, the species demonstrated remarkable plasticity during acclimatization, with high survival rates and rapid inflorescence development. The research provides valuable insights into optimizing in vitro cultivation conditions for Eryngium foetidum, emphasizing the potential for large-scale clonal propagation and exploring secondary metabolites. The observed phenotypic plasticity underscores the adaptability of the species to diverse environments. These biotechnological strategies open avenues for future studies, including the application of elicitors for enhanced secondary metabolite production. [ABSTRACT FROM AUTHOR]

This study comprehensively explored the micropropagation and rooting capabilities of four distinct lavender genotypes, utilizing culture media with and without 2 g/L of activated charcoal. A systematic examination of varying concentrations of BAP for micropropagation and IBA for rooting identified an optimal concentration of 1 mg/L for both BAP and IBA, resulting in excellent outcomes. Following robust root development, the acclimatization of plants to external conditions achieved a 100% survival rate across all genotypes. In addition to the conventional techniques employed, integrating machine learning (ML) methodologies holds promise for further enhancing the efficiency of lavender propagation protocols. Using cutting-edge computational tools, including MLP, RBF, XGBoost, and GP algorithms, our findings were rigorously examined and forecast using three performance measures (RMSE, R2, and MAE). Notably, the comparative evaluation of different machine learning models revealed distinct R2 rates for plant characteristics, with MLP, RBF, XGBoost, and GP demonstrating varying degrees of effectiveness. Future studies may leverage ML models, such as XGBoost, MLP, RBF, and GP, to fine-tune specific variables, including culture media composition and growth regulator treatments. The adaptability and ability of ML techniques to analyze complex biological processes can provide valuable insights into optimizing lavender micropropagation on a broader scale. This collaborative approach, combining traditional in vitro techniques with machine learning, validates the success of current micropropagation and rooting protocols and paves the way for continuous improvement. By embracing ML in lavender propagation studies, researchers can contribute to advancing sustainable and efficient plant propagation techniques, thereby fostering the preservation and exploitation of genetic resources for conservation and agriculture. [ABSTRACT FROM AUTHOR]

Monstera deliciosa Liebm. 'Thai Constellation' is a variegated variety of M. deliciosa belonging to the family Araceae, which has become a new favorite in the foliage plant market. However, limited studies exist on its propagation, and growers have difficulties in achieving large-scale production. This study aimed at developing an efficient protocol for the micropropagation of M. deliciosa using SETIS™ temporary immersion bioreactors. Furthermore, we aimed at evaluating the role of a novel biostimulant (IQ Forte) in the acclimatization of M. deliciosa. Significant differences were observed among the different treatments, showing higher multiplication rates under TIS conditions as compared to the semi-solid control. Adjusting immersion parameters also showed benefits in improving multiplication rates. The novel biostimulant (IQ Forte) did not provide significant gains in growth of M. deliciosa 'Thai Constellation' during acclimatization. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciencia y Tecnología Agropecuaria is the property of Agrosavia 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.)

This document, published in the International Journal of Molecular Sciences, discusses the impact of biotic and abiotic stress factors on plant specialized metabolites. It highlights the importance of plants' chemical adaptations and defense mechanisms against harmful environmental conditions and predators. The document emphasizes the mutualistic bio-chemical interactions of plants with various organisms and agents in the environment. It also mentions the relevance of studying plant interactions with stress factors in various scientific fields. The document concludes by mentioning the publication of six original articles in this Special Issue, which contribute to the understanding of the effects of stress on specialized plant metabolism. [Extracted from the article]

Summary: Induction of high photosynthetic capacity is a key acclimation response to high light (HL) for many herbaceous dicot plants; however, the signaling pathways that control this response remain largely unknown. Here, a systems biology approach was utilized to characterize the induction of high photosynthetic capacity in strongly and weakly acclimating Arabidopsis thaliana accessions.Plants were grown for 5 wk in a low light (LL) regime, and time‐resolved photosynthetic physiological, metabolomic, and transcriptomic responses were measured during subsequent exposure to HL.The induction of high nitrogen (N) assimilation rates early in the HL shift was strongly predictive of the induction of photosynthetic capacity later in the HL shift. Accelerated N assimilation rates depended on the mobilization of existing organic acid (OA) reserves and increased de novo OA synthesis during the induction of high photosynthetic capacity. Enhanced sucrose biosynthesis capacity increased in tandem with the induction of high photosynthetic capacity, and increased starch biosynthetic capacity was balanced by increased starch catabolism.This systems analysis supports a model in which the efficient induction of N assimilation early in the HL shift begins the cascade of events necessary for the induction of high photosynthetic capacity acclimation in HL. [ABSTRACT FROM AUTHOR]

Cold is a major environmental factor that restrains potato production. Abscisic acid (ABA) can enhance freezing tolerance in many plant species, but powerful evidence of the ABA‐mediated signalling pathway related to freezing tolerance is still in deficiency. In the present study, cold acclimation capacity of the potato genotypes was enhanced alongside with improved endogenous content of ABA. Further exogenous application of ABA and its inhibitor (NDGA) could enhance and reduce potato freezing tolerance, respectively. Moreover, expression pattern of downstream genes in ABA signalling pathway was analysed and only ScAREB4 was identified with specifically upregulate in S. commersonii (CMM5) after cold and ABA treatments. Transgenic assay with overexpression of ScAREB4 showed that ScAREB4 promoted freezing tolerance. Global transcriptome profiling indicated that overexpression of ScAREB4 induced expression of TPS9 (trehalose‐6‐phosphate synthase) and GSTU8 (glutathione transferase), in accordance with improved TPS activity, trehalose content, higher GST activity and accumulated dramatically less H2O2 in the ScAREB4 overexpressed transgenic lines. Taken together, the current results indicate that increased endogenous content of ABA is related to freezing tolerance in potato. Moreover, ScAREB4 functions as a downstream transcription factor of ABA signalling to promote cold tolerance, which is associated with increased trehalose content and antioxidant capacity. Summary Statement: The cold acclimation capacity of the potato genotypes was enhanced alongside with improved endogenous content of ABA and ScAREB4 was identified to promotes potato constitutive and acclimated freezing tolerance. [ABSTRACT FROM AUTHOR]

This article, published in the Journal of Experimental Botany, explores the role of light quality in the photosynthetic acclimation of Ostreococcus, a small green algae found in the ocean. The study focuses on two ecotypes of Ostreococcus, one habituated in shallow water and the other in deep water, and examines their genetic and physiological responses to different light conditions. The findings suggest that genetic modifications play a role in an organism's ability to adapt to environmental niches, and provide insights into the molecular mechanisms of photosynthetic acclimation in Ostreococcus. The study also identifies differentially expressed genes that may contribute to photosynthetic acclimation in Ostreococcus, but further research is needed to fully understand the process. Overall, this research contributes to our understanding of plant evolution, photosynthetic acclimations, and the conservation of marine ecosystems. [Extracted from the article]

Metal homeostasis has evolved to tightly modulate the availability of metals within the cell, avoiding cytotoxic interactions due to excess and protein inactivity due to deficiency. Even in the presence of homeostatic processes, however, low bioavailability of these essential metal nutrients in soils can negatively impact crop health and yield. While research has largely focused on how plants assimilate metals, acclimation to metal-limited environments requires a suite of strategies that are not necessarily involved in metal transport across membranes. The identification of these mechanisms provides a new opportunity to improve metal-use efficiency and develop plant foodstuffs with increased concentrations of bioavailable metal nutrients. Here, we investigate the function of two distinct subfamilies of the nucleotidedependent metallochaperones (NMCs), named ZNG1 and ZNG2, that are found in plants, using Arabidopsis thaliana as a reference organism. AtZNG1 (AT1G26520) is an ortholog of human and fungal ZNG1, and like its previously characterized eukaryotic relatives, localizes to the cytosol and physically interacts with methionine aminopeptidase type I (AtMAP1A). Analysis of AtZNG1, AtMAP1A, AtMAP2A, and AtMAP2B transgenic mutants are consistent with the role of Arabidopsis ZNG1 as a Zn transferase for AtMAP1A, as previously described in yeast and zebrafish. Structural modeling reveals a flexible cysteinerich loop that we hypothesize enables direct transfer of Zn from AtZNG1 to AtMAP1A during GTP hydrolysis. Based on proteomics and transcriptomics, loss of this ancient and conserved mechanism has pleiotropic consequences impacting the expression of hundreds of genes, including those involved in photosynthesis and vesicle transport. Members of the plant-specific family of NMCs, ZNG2A1 (AT1G80480) and ZNG2A2 (AT1G15730), are also required during Zn deficiency, but their target protein(s) remain to be discovered. RNA-seq analyses reveal wide-ranging impacts across the cell when the genes encoding these plastid-localized NMCs are disrupted. [ABSTRACT FROM AUTHOR]

Natural selection for plant species in heterogeneous environments creates genetic variation for traits such as cold tolerance. While physiological or molecular analyses have been used to evaluate stress tolerance adaptations, combining these approaches may provide deeper insight. Acacia koa (koa) occurs from sea level to 2300 m in Hawaiʻi, USA. At high elevations, natural koa populations have declined due to deforestation, and freeze tolerance is a limiting factor for tree regeneration. We used physiology and molecular analyses to evaluate cold tolerance of koa populations from low (300–750 m), middle (750–1500 m), and high elevations (1500–2100 m). Half of the seedlings were cold acclimated by exposure to progressively lowered air temperatures for eight weeks (from 25.6/22.2°C to 8/4°C, day/night). Using the whole plant physiology‐freezing test and koa C‐repeat Binding Factor CBF genes, our results indicated that koa can be cold‐acclimated when exposed to low, non‐freezing temperatures. Seedlings from high elevations had consistently higher expression of Koa CBF genes associated with cold tolerance, helping to explain variation in cold‐hardy phenotypes. Evaluation of the genetic background of 22 koa families across the elevations with low coverage RNA sequencing indicated that high elevation koa had relatively low values of heterozygosity, suggesting that adaptation is more likely to arise in the middle and low elevation sources. This physiology and molecular data for cold tolerance of koa across the elevation gradient of the Hawaiian Islands provides insights into natural selection processes and may help to support guidelines for conservation and seed transfer in forest restoration efforts. [ABSTRACT FROM AUTHOR]

Cold acclimation is a crucial biological process that enables conifers to overwinter safely. The late embryogenesis abundant (LEA) protein family plays a pivotal role in enhancing freezing tolerance during this process. Despite its importance, the identification, molecular functions and regulatory networks of the LEA protein family have not been extensively studied in conifers or gymnosperms. Pinus tabuliformis , a conifer with high ecological and economic values and with high-quality genome sequence, is an ideal candidate for such studies. Here, a total of 104 LEA genes were identified from P. tabuliformis , and we renamed them according to their subfamily group: PtLEA1 – PtLEA92 (group LEA1–LEA6), PtSMP1 – PtSMP6 (group seed maturation protein) and PtDHN1 – PtDHN6 (group Dehydrin). While the sequence structure of P. tabuliformis   LEA genes are conserved, their physicochemical properties exhibit unique characteristics within different subfamily groupings. Notably, the abundance of low-temperature responsive elements in PtLEA genes was observed. Using annual rhythm and temperature gradient transcriptome data, PtLEA22 was identified as a key gene that responds to low-temperature induction while conforming to the annual cycle of cold acclimation. Overexpression of PtLEA22 enhanced Arabidopsis freezing tolerance. Furthermore, several transcription factors potentially co-expressed with PtLEA22 were validated using yeast one-hybrid and dual-luciferase assays, revealing that PtDREB1 could directly bind PtLEA22 promoter to positively regulate its expression. These findings reveal the genome-wide characterization of P. tabuliformis   LEA genes and their importance in the cold acclimation, while providing a theoretical basis for studying the molecular mechanisms of cold acclimation in conifers. [ABSTRACT FROM AUTHOR]

Cannabis sativa L., subsp. ruderalis Janish., 'Finola' is a dioecious cultivar of Finnish origin. This cultivar is very interesting because its cultivation cycle lasts less than 3 months. The aim of this study was to define an efficient micropropagation protocol to ensure in vitro multiplication and rooting and in vivo acclimatization. Two different explant sources were tested: seed-derived in vitro explants and nodal segments containing axillary buds from selected mother plants. Shoot proliferation was tested on different growth media enriched with cytokinin alone or cytokinin in combination with auxins. Among all combinations, the best results were obtained by combining the Basal Medium (BM—a Murashige and Skoog modified medium) with sucrose (20 g L−1), thidiazuron (TDZ 0.4 mg L−1), and 1-naphthalenacetic acid (NAA 0.2 mg L−1). Regarding rooting induction, the plants developed an extensive root system under red/blue lights on BM enriched with sucrose (30 g L−1) and indol-3 butyric acid (0.1 mg L−1), which allowed the survival of more than 90 percent of the plantlets once transplanted into the climate-controlled greenhouse. [ABSTRACT FROM AUTHOR]

Striped Bass are economically important, migratory fishes, which occur across a wide range of latitudes. Given their wide-ranging nature, Striped Bass can cope with a broad range of environmental temperatures, yet the mechanisms underlying this ability have not been thoroughly described. Heat shock proteins (HSPs) are inducible molecular chaperones, which help mitigate protein damage resulting from increased temperatures. The importance of HSPs has been demonstrated in a number of fish species, but their role in Striped Bass is poorly understood. This study characterizes changes in gene expression in juvenile Striped Bass, following acute and chronic temperature change. Fish were acclimated to one of three temperatures (15, 25 or 30°C) and sampled at one of two treatments (control or after CTmax), following which we assessed differential gene expression and gene ontology in muscle. It is clear from our differential expression analyses that acclimation to warm temperatures elicits more robust changes to gene expression, compared to acute temperature increases. Our differential expression analyses also revealed induction of many different heat shock proteins, including hsp70, hsp90, hsp40 and other small HSPs, after both acute and chronic temperature increase in white muscle. Furthermore, the most consistent gene ontology pattern that emerged following both acclimation and CTmax was upregulation of transcripts involved in "protein folding", which also include heat shock proteins. Gene ontology analyses also suggest changes to other processes after acclimation, including decreased growth pathways and changes to DNA methylation. Overall, these data suggest that HSPs likely play a major role in the Striped Bass's ability to tolerate warm waters. [ABSTRACT FROM AUTHOR]

Cold stress is a major abiotic stress that adversely affects plant growth and crop productivity. The C‐REPEAT BINDING FACTOR/DRE BINDING FACTOR 1 (CBF/DREB1) transcriptional regulatory cascade plays a key role in regulating cold acclimation and freezing tolerance in Arabidopsis (Arabidopsis thaliana). Here, we show that max (more axillary growth) mutants deficient in strigolactone biosynthesis and signaling display hypersensitivity to freezing stress. Exogenous application of GR245DS, a strigolactone analog, enhances freezing tolerance in wild‐type plants and strigolactone‐deficient mutants and promotes the cold‐induced expression of CBF genes. Biochemical analysis showed that the transcription factor WRKY41 serves as a substrate for the F‐box E3 ligase MAX2. WRKY41 directly binds to the W‐box in the promoters of CBF genes and represses their expression, negatively regulating cold acclimation and freezing tolerance. MAX2 ubiquitinates WRKY41, thus marking it for cold‐induced degradation and thereby alleviating the repression of CBF expression. In addition, SL‐mediated degradation of SMXLs also contributes to enhanced plant freezing tolerance by promoting anthocyanin biosynthesis. Taken together, our study reveals the molecular mechanism underlying strigolactones promote the cold stress response in Arabidopsis. Synopsis: Plants respond to extreme cold stress by synthesizing strigolactones; however, how this class of plant hormones promotes freezing tolerance is still poorly understood. Here, cold‐induced strigolactones are shown to promote plant survival in sub‐zero temperatures by enhancing expression of freezing tolerance regulators DREB1/CBF.Strigolactones positively regulate plant freezing tolerance via a CBF‐dependent pathway.The E3 ligase MAX2 interacts with and ubiquitinates the transcription factor WRKY41, mediating its cold‐induced degradation.WRKY41 represses the cold‐induced expression of CBFs by directly binding to their promoters.SLs‐mediated degradation of SMXLs also contributes to enhanced freezing tolerance by accumulating anthocyanin. [ABSTRACT FROM AUTHOR]

This study aimed to determine a sainfoin variety best suited to the soil and weather conditions of the Great Lake Basin region inUlaangom soum of Uvs aimag (province). We carried out studies into five varieties of sainfoin, including Peschany 1251, Tashyl 3, Novosibirsky 1284, Shortandisky 83, and Mikhailovsky-5, which were compared with each other without irrigation trial. Sainfoin has a high resistance to cold winter conditions, high temperatures and and dry drought conditions. Sainfoin varieties growing in Mongolia are highly palatable perennial leguminous plants. According to the result of our research, sainfoin is well acclimatized to Uvs province's soil and weather conditions. The variety with the highest performance showing is Taskhyl 3, which was generated atthe Plant Research Center of Khakassia, a republic of Russia located in southern Siberia. [ABSTRACT FROM AUTHOR]

Agastache aurantiaca 'Sunset Yellow' and A. mexicana 'Sangria' are aromatic plants with edible flowers characterized with good flavors, nutritional values and pleasant aromas. The aim of this study was to establish a successful protocol to ensure fast shoot propagation, rooting and in vivo acclimatization to obtain many vigorous plants for edible flower production. Micropropagation was tested with an agarized Murashige and Skoog (MS) medium enriched with different 6-benzylamino purine (BAP) levels. In vitro rooting trials were carried out using a half-strength MS medium comparing the traditional jar method with an agarized medium and the temporary immersion system (TIS) bioreactor with a liquid medium. After acclimatization in a greenhouse, the survival of plants and their development were recorded. Microscopical analyses were performed on both in-jar and in-TIS leaves at rooting stages and compared with in vivo leaves. In both species, the greatest number of new shoots was noted at 2.22 µM and 3.33 µM of BAP. In TIS, rooting started earlier, resulting in larger plants with more roots and longer roots than in the jar substrate. Any anatomical difference was observed in leaves collected from the jar and TIS during the rooting stage. The best acclimatization performances were recorded in plants coming from the TIS bioreactor. [ABSTRACT FROM AUTHOR]

Fluctuating light intensity challenges fluent photosynthetic electron transport in plants, inducing photoprotection while diminishing carbon assimilation and growth, and also influencing photosynthetic signaling for regulation of gene expression. Here, we employed in vivo chlorophyll‐a fluorescence and P700 difference absorption measurements to demonstrate the enhancement of photoprotective energy dissipation of both photosystems in wild‐type Arabidopsis thaliana after 6 h exposure to fluctuating light as compared with constant light conditions. This acclimation response to fluctuating light was hampered in a triple mutant lacking the thylakoid ion transport proteins KEA3, VCCN1, and CLCe, leading to photoinhibition of photosystem I. Transcriptome analysis revealed upregulation of genes involved in biotic stress and defense responses in both genotypes after exposure to fluctuating as compared with constant light, yet these responses were demonstrated to be largely upregulated in triple mutant already under constant light conditions compared with wild type. The current study illustrates the rapid acclimation of plants to fluctuating light, including photosynthetic, transcriptomic, and metabolic adjustments, and highlights the connection among thylakoid ion transport, photosynthetic energy balance, and cell signaling. [ABSTRACT FROM AUTHOR]

Beaucarnea hookeri is a species endemic to Mexico and is listed as threatened in NOM-059-SEMARNAT-2010. In order to micropropagate this species, an experiment was established at the Montecillo Campus, College of Postgraduates in 2022, where the response of the shoots during in vitro multiplication with different concentrations of benzylaminopurine (BAP) and their capacity for ex-vitro rooting during acclimatization were evaluated. An experiment was established with three subsequent subcultures (SC3, SC4, SC4-1); in SC3, shoots generated with 0.5 mg L-1 BAP (SC2) were used; in SC4, healthy shoots generated from SC3; and SC4-1 with shoots from SC3 but with initial hyperhydration (IHH). In SC3, 0.5, 1, 1.5, 2, and 2.5 mg L-1 BAP were evaluated. In SC4, 0 and 0.5 mg L-1 BAP and in SC4-1, concentrations of 0, 0.5, and 1 mg L-1 BAP. During acclimatization, four treatments of Radix® 10 000 (0, 1 000, 2 000, and 4 000 mg kg-1) were evaluated, and shoots from SC2 were used. During multiplication, the number of shoots (NS) was recorded, and SC3 generated 6.35 shoots with the concentration of 1.5 mg L-1 BAP, with the presence of IHH. On average, 9.7 shoots were obtained in SC4, and 5.3 shoots in SC4-1, both subcultures with 0.5 mg L-1 BAP. In addition, there was a recovery of IHH in SC4-1. In rooting, there were no significant differences between treatments, and the control generated 73.3% of shoots with roots (SSR) 80 days after transplantation. Only the shoots of the control treatment in multiplication presented roots, which allowed complete plants to be obtained in 30 days. [ABSTRACT FROM AUTHOR]

As a typical warm-season grass, bermudagrass growth and turf quality begin to decrease when the environmental temperature drops below 20 °C. The current study investigated the differential responses of three bermudagrass genotypes to chilling stress (8/4 °C) for 15 days and then freezing stress (2/−2 °C) for 2 days. The three genotypes exhibited significant variation in chilling and freezing tolerance, and Chuannong-3, common bermudagrass 001, and Tifdwarf were ranked as cold-tolerant, -intermediate, and -sensitive genotypes based on evaluations of chlorophyll content, the photochemical efficiency of photosystem II, oxidative damage, and cell membrane stability, respectively. Chuannong-3 achieved better tolerance through enhancing the antioxidant defense system to stabilize cell membrane and reactive oxygen species homeostasis after being subjected to chilling and freezing stresses. Chuannong-3 also downregulated the ethylene signaling pathway by improving CdCTR1 expression and suppressing the transcript levels of CdEIN3-1 and CdEIN3-2; however, it upregulated the hydrogen sulfide signaling pathway via an increase in CdISCS expression under cold stress. In addition, the molecular basis of cold tolerance could be associated with the mediation of key genes in the heat shock pathway (CdHSFA-2b, CdHSBP-1, CdHSP22, and CdHSP40) and the CdOSMOTIN in Chuannong-3 because the accumulation of stress-defensive proteins, including heat shock proteins and osmotin, plays a positive role in osmoprotection, osmotic adjustment, or the repair of denatured proteins as molecular chaperones under cold stress. The current findings give an insight into the physiological and molecular mechanisms of cold tolerance in the new cultivar Chuannong-3, which provides valuable information for turfgrass breeders and practitioners. [ABSTRACT FROM AUTHOR]

Light-emitting diodes (LEDs) are currently being used as a light source for in vitro regeneration or the growth of plants in a controlled environment. However, it is crucial to define the target system's sensitivity to light quality before LEDs may be employed as the exclusive source of light. The objective of the present work was to investigate the influence of red (R), blue (B), white (W), and a combination of red plus blue (1:1) and red, blue, and green (1:1:1) LEDs on Gerbera jamesonii cv. 'Shy Pink' during in vitro regeneration. It was observed that LED lighting had a substantial impact on the process of shoot regeneration, shoot growth, and rooting of the shoots. When compared to other light treatments, red plus blue (1:1) LED had the greatest impact on the regeneration of shoots, growth of shoots, and root regeneration from shoot and root growth. Length of shoots, height of plantlets, and petiole length were affected by a red LED, and leaf length, width, and area were affected by a blue LED. The content of photosynthetic pigments (Chl a, Chl b, total chlorophyll, and carotenoids) was higher with acclimatized plants upon transplantation, which were regenerated under blue LEDs. In acclimatized plants, photosynthetic efficiency was calculated. Higher internal CO2 concentrations (Ci), photosynthetic rates (Pn), stomatal conductance (Gs), and transpiration rates (Tr) were seen in plants that were grown under red plus blue (1:1) LED. However, the plants that were grown under white LEDs had higher chlorophyll fluorescence (Fv/Fm). Collectively, the current results suggest that red and blue LED is suitable for in vitro regeneration of Gerbera jamesonii cv. 'Shy Pink' plants compared to red, blue, and white LEDs. [ABSTRACT FROM AUTHOR]

Oriented movement (phototaxis) is an efficient way to optimize light‐driven processes and to avoid photodamage for motile algae. In Chlamydomonas the receptors for phototaxis are the channelrhodopsins ChR1 and ChR2. Both are directly light‐gated, plasma membrane‐localized cation channels. To optimally adjust its overall light‐dependent responses, Chlamydomonas must tightly control the ChRs cellular abundance and integrate their activities into its general photoprotective network. How this is achieved is largely unknown. Here we show that the ChR1 protein level decreases upon illumination in a light‐intensity and quality‐dependent manner, whereas it is stable in prolonged darkness. Analysis of knockout strains of six major photoreceptors absorbing in the blue–violet range, which is most effective in evoking ChR1 degradation, revealed that only phototropin (PHOT) is involved. Notably, ChR2 degradation was normal in a ΔPHOT strain. Further, our results indicate that a COP1‐SPA1 E3 ubiquitin ligase, the transcription factor Hy5 as well as changes in the cellular redox poise and cyclic nucleotide levels are additional components involved in this light acclimation response of Chlamydomonas. Our data highlight the presence of an adaptive framework connecting phototaxis with general photoprotective mechanisms via the use of overlapping signaling components already at the level of the primary photoreceptor. Summary Statement: How Chlamydomonas controls the level of ChR1, the main photoreceptor for its movement responses, is largely unknown. Here we show that regulatory elements involved in photoprotective gene expression are parts of this cascade(s), supporting an integrating link between phototaxis and photoprotection. [ABSTRACT FROM AUTHOR]

Securidaca longepedunculata Fresen. is an overexploited forest species in the Lubumbashi region (south-eastern DR Congo), as its roots are highly valued in traditional medicine. Conventional propagation of this species is affected by seed dormancy and a high mortality rate during early seedling development. To improve on existing methods, we developed an in vitro seed germination protocol. After observing the germination rates, the effects of different doses (0.5, 1, 1.5, and 2 mg/L) of cytokinins (6-benzylaminopurine, kinetin, and meta-topolin) on S. longepedunculata seedling development were compared. Our results showed that soaking for 10 min in NaOCl (10%) followed by 5 min in ethanol (70%) effectively reduced the death rate of seeds while increasing the germination rate to almost 77%. The addition of cytokinins improved plantlet growth: a 12.2× increase in the number of plantlets was obtained with 1.5 mg/L meta-topolin, while only a single stem was obtained from the control. The effects of different auxin types on rhizogenesis did not differ significantly. The best recovery and rooting were noted with microcuttings from the basal parts of S. longepedunculata plantlets. Finally, the seedlings produced survived during the acclimatisation phase regardless of the type of substrate used. The established protocol provides a means for large-scale production of S. longepedunculata plantlets for the restoration of degraded landscapes and agroforestry. [ABSTRACT FROM AUTHOR]

Somatic embryogenesis (SE) is an excellent example of mass plant propagation. Due to its genetic variability and low somaclonal variation, coffee SE has become a model for in vitro propagation of woody species, as well as for large-scale production of vigorous plants that are advantageous to modern agriculture. The success of the large-scale propagation of an embryogenic system is dependent on the development, optimization, and transfer of complementary system technologies. In this study, two successful SE systems were combined with a SETIS™ bioreactor immersion system to develop an efficient and cost-effective approach for the in vitro development of somatic embryos of Coffea spp. This study used an efficient protocol for obtaining somatic embryos, utilizing direct and indirect SE for both C. canephora and C. arabica. Embryos in the cotyledonary stage were deposited in a bioreactor to complete their stage of development from embryo to plant with minimal manipulation. Following ten weeks of cultivation in the bioreactor, complete and vigorous plants were obtained. Different parameters such as fresh weight, length, number of leaves, and root length, as well as stomatal index and relative water content, were recorded. In addition, the survival rate and ex vitro development of plantlets during acclimatization was assessed. The best substrate combination was garden soil (GS), peat moss (PM), and agrolite (A) in a 1:1:0.5 ratio, in which the bioreactor-regenerated plants showed an acclimatization rate greater than 90%. This is the first report on the use of SETIS™ bioreactors for the in vitro development of somatic embryos in Coffea spp., providing a technology that could be utilized for the commercial in vitro propagation of coffee plants. A link between research and innovation is necessary to establish means of communication that facilitate technology transfer. This protocol can serve as a basis for the generation and scaling of different species of agroeconomic importance. However, other bottlenecks in the production chains and the field must be addressed. [ABSTRACT FROM AUTHOR]

• MEL (Melatonin) regulates the physiological and biochemical signaling pathways in plants. • Under stress conditions MEL upregulates the downstream signaling. • MEL cross-talks with different phytohormones perform different development functions. • MEL-based genetic engineering could be utilized to unfold the stress tolerance mechanism. • Regulatory pathways of MEL need to be more accurate clarification in future. Melatonin is a derivative of tryptophan and consists of a conserved domain present ubiquitously from bacteria to higher organisms. Melatonin is an emerging pleiotropic plant growth hormone that is pivotal in coping with various biotic and abiotic stress conditions. It regulates downstream signaling transduction that modulates plants' physiological and biochemical pathways. Melatonin can be externally applied and could strengthen the stress tolerance mechanism of plants by enhancing ROS-scavenging enzymatic and non-enzymatic antioxidant defense systems. Which consequently exhibits lower lipid peroxidation, MDA content, greater enzyme activity, metabolic pool, ion homeostasis, and plasma membrane integrity under stress conditions. In addition, melatonin protects photosynthetic machinery by maintaining cell membrane stability and chlorophyll recovery. It also stimulates the electron transport chain during photosynthesis and D1 protein biosynthesis and maximizes the photochemistry efficiency (Fv/Fm) of photosystem II and photochemical quenching. Besides abiotic stress, melatonin plays a significant role in biotic stress tolerance. This review emphasizes Melatonin as a stress protectant under biotic and abiotic stress. Further, we have highlighted integrating advanced biotechnology tools with recent information for the possible application of melatonin in the current scenario of changing climate. [ABSTRACT FROM AUTHOR]