Plant Cell, Tissue and Organ Culture最新文献

Crocanthemum canadense (L.) Britt. (Cistaceae), Rockrose, is a small perennial herb found in Eastern North America sand barrens. It is classified as critically imperiled in Nova Scotia under the Nova Scotia Endangered Species Act. Nova Scotia C. canadense populations continue to decline; recent counts estimate only 5000–5500 plants remain. To better understand C. canadense conservation, we completed ex-situ in vitro germination and propagation trials using seed collected from native Nova Scotia populations at 14 Wing Canadian Forces Base, Greenwood, Nova Scotia. Concurrently, soil was collected from the same locations to analyze belowground endomycorrhizal symbionts, arbuscular mycorrhizal fungi (AMF). Recent research has documented the presence of AMF within C. canadense roots, however, this is the first study to successfully identify AMF species present in-situ using single spore rDNA barcoding. C. canadense successfully germinated in vitro with high germination rates (average 86.6%) for one population (SB000147) maintained at room temperature with a 16-hour photoperiod. Successful vigor continued to be monitored with regular multiplication and transfers. Eight AMF spores were identified, all members of the genus Rhizophagus. Seven spores identified as Rhizophagus clarus and one as Rhizophagus irregularis. R. clarus are commonly found in many semi-arid environments now including sand barrens. This research will aid in the conservation and restoration of this critically imperiled species by further understanding beneficial soil fungi, an understudied component of the declining sand barrens habitat.

Medicinal plants are invaluable sources of bioactive natural products. To further access plant’s biosynthetic and biotechnological potential, plant tissue culture has become a standard practice. Plant biotechnology might offer selected cell lines with higher metabolic production and allow a more controlled environment for plant development and optimized metabolic flux for the biosynthesis of specific compounds. In this work, we established the in vitro growth of Melia azedarach through micropropagation and evaluated its biosynthetic potential. LC-MS-based metabolic profiling investigation was applied to generate information on natural products composition. A set of computational tools including spectral library matching and in silico prediction of molecular structures and chemical classes were employed to annotate M. azedarach’s plantlets chemical space. Our findings indicate salannin- and nimbolinin-type limonoid production and a series of glycosylated flavonoids and lignan-related phenylpropanoids. This is the first time nimbolinin-related limonoids have been produced in vitro, opening a venue for biotechnological applications of such compounds.

Iris pallida LAM., which has characterized the economy of small and medium-sized Tuscan farms for decades, is one of the most typical rustic species of the Mediterranean landscape. I. pallida essence is widely used in the perfumery sector for the indicative smell of violet caused by its high content of irones, ketone compounds accumulated inside the rhizome during their storage phase. One of the main critical aspects of its cultivation is the vegetative propagation method, traditionally carried out by rhizome transplanting, which does not allow obtaining a sufficient number of plants to encourage its cultivation. The state of the art indicates the micropropagation of I. pallida via somatic embryogenesis as the most effective propagation method, using immature flower components as starting tissue; however, there are no studies aimed at comparing the responses of different ecotypes of I. pallida to this technique. In this study, I. pallida clones of HE, VIC and BA ecotypes were obtained via somatic embryogenesis, starting from bud (young and immature) and leaf explants, monitoring all the development steps from callus to plantlets production, and testing clones adaptation to field conditions, using a modified acclimatization protocol. The results highlighted the different responses of the ecotypes to the in vitro protocol and demonstrated the effectiveness of somatic embryogenesis in producing I. pallida plantlets with a chromatographic profile overlapping with the donor plant; this alternative propagation method could allow to produce plantlets without sacrificing sealable rhizome.

The influence of the temperature and different light qualities emitted by light-emitting diodes (LEDs) and fluorescent lamps (Fl) on the micropropagation of the tree fern Cyathea delgadii was evaluated. The most efficient somatic embryo production was obtained on internode explants at 22 °C. The optimal temperature range for obtaining well-developed plants was 24–28 °C. This stimulated the elongation and development of the first leaf and the formation of the next leaf and roots primordia. Temperatures lower than 24 °C and higher than 28 °C inhibited the formation of young sporophyte organs and delayed their development. The RBUV (35% red, 15% blue, and 50% UV) and B (100% blue) lights and Fl light were beneficial for the sporophyte production on internode explants. However, plants obtained under RBUV light were undeveloped. The white LED light stimulated the number of explants capable of gametophyte production and development. The RB light (70% red and 30% blue) enhanced the number of roots of newly-formed plants. Most of the LED lights tested had a good impact on root elongation compared to Fl light and constant darkness. The R light (100% red) benefits leaf development and elongation. Research shows that temperature and LED lightning play a significant role in the process of morphogenesis in C. delgadii, significantly affecting the embryogenic competence of somatic cells and the development of sporophytes.

Cryopreservation has emerged as one of the most viable methods for the long-term conservation of plant species, but many plants are still recalcitrant to the stresses imposed by cryogenic processes, and robust cryopreservation protocols are lacking for some plant species. High-throughput omics-based approaches are being used to understand the molecular mechanisms governing the response to cryopreservation and associated stresses, but there are limited studies exploring the gene expression mechanisms and regulation governing survival and recovery post cryopreservation. Evidence, although scarce, has emerged that the energy metabolism and oxidative homeostasis pathways are most affected during the osmotic and dehydration stresses and up/down regulation of genes resulting in altered expression of their corresponding proteins has been observed in cryo-tolerant plant cells. Understanding the specific genes and proteins that determine cryo-tolerance or susceptibility can help develop conservation strategies for difficult to conserve species and overcome the challenges to their long-term conservation. The genes and proteins that are dynamically regulated during cryopreservation are the key to successful cryopreservation and plant regrowth. By characterizing these specific genes and proteins, researchers can better understand the mechanisms underlying cryo-tolerance and susceptibility and develop more effective and widely applicable conservation strategies for plant species.

Abstract

Blueberries are a fruit with an increasing global demand due to their phytochemical and bioactive compounds content. They are promoted worldwide because of their health benefits. For optimal growth and productivity, blueberry crops need acidic soil pH, specific chilling hours, and an adequate atmospheric temperature. This delicate production equilibrium is under severe threat from climate change, potentially leading to reduced yields and increased cultivation costs unless new cultivars are developed for each edafoclimatic zone. Therefore, considering varietal replacements with more productive cultivars offering higher quality and better adaptability to local conditions is imperative. In this study, we employ polyploidization and in vitro tissue culture to promote variability and lay the foundation for new cultivar development. We report the successful induction of octoploids in three blueberry cultivars, namely ‘Biloxi’, ‘Legacy’, and ‘Duke’, through whole-genome duplication. Leaves and microstem explants were exposed to 0.1% colchicine for 24 and 48 hours in in vitro culture. After analyzing the polyploid level of 160 regenerated shoots using DNA flow cytometry, we obtained a total of 18 mutants, consisting of 8 mixoploids and 10 octoploids. The number of chloroplasts in the stomata was analyzed by fluorescence microscopy, revealing the duplication of these organelles in the induced octoploid plants. To our knowledge, this represents the first successful induction of octoploids in three blueberry cultivars -‘Biloxi,’ ‘Legacy,’ and ‘Duke’- achieved by exposing leaves and microstem explants to colchicine in in vitro culture. This technique holds promise as a valuable tool for the development of improved blueberry cultivars.

Key message

This study presents the first successful induction of octoploids of three blueberry cultivars ‘Biloxi’, ‘Legacy’, and ‘Duke’ by inducing polyploidization exposing leaves and microstems explants to colchicine in in vitro culture.

In vitro propagation, is becoming the predominant method for blackberry propagation due to its advantages compared to agamic traditional propagation methods. Synthetic seed technology represents a promising approach to further enhance the productivity of in vitro propagation facilitating the exchange of plant materials among laboratories and contributing to germplasm conservation efforts. This study aimed to establish an optimal protocol for the storage and sowing of synthetic blackberry seeds obtained through the encapsulation of clump bases. The synthetic seeds were sown without storage (Control) and after storage periods of 30, 60, and 120 days at 4 °C and 25 °C in the dark, in three different substrates (agarised, perlite, and potting). After forty-five days from sowing viability, regeneration rate, shoot and root numbers and lengths, as well as fresh and dry weights of the plantlets, were assessed. Results indicated that agarised substrate consistently exhibited favourable outcomes, with sustained regeneration rates and robust plantlet development even after prolonged storage at 4 °C. Synthetic seeds sown in perlite and potting substrates demonstrated enhanced regeneration rates following storage at 4 °C for 60 and 120 days. On the contrary, storage at 25 °C resulted in a notable decline in regeneration rate, highlighting its inadequacy for blackberry synthetic seed conservation purposes. These findings underscore the importance of sowing substrate selection and storage temperature in optimizing the storage and sowing protocols for synthetic blackberry seeds.

Climate change has made plants more vulnerable to various stresses, which presents a significant threat to the world’s food supply. Despite several efforts deployed over the last three decades in plant breeding and genetic engineering, there is still a lot to be done for crop improvement. CRISPR/Cas is a naturally occurring genome editing tool adopted from the bacterial adaptive immune defense system. Gene editing has undergone a revolutionary change since the discovery of CRISPR/Cas-based genome engineering. This emerging technology recently implemented, has enabled targeted mutagenesis with unprecedented simplicity and accuracy, making it suitable to edit DNA sequences at site-specific targets with ultimate precision. Currently, this cutting-edge technology has been extensively used and incessantly improved at several orders of magnitude to contribute as a robust approach for studying gene function with a variety of applications that can accelerate basic and applied research toward crop improvement. This mini-review briefly describes some of the major achievements in genome editing tools and highlights future outlooks for these technologies in functional genomics and applied plant biotechnology.

Gene editing tools for banana crop improvement necessitates efficient embryogenic cell suspensions, which are derived through embryogenic calli (EC). Although many factors are known to influence EC formation, the roles of seasonal effects and environmental factors in EC induction of banana remain unclear. We therefore examined the formation of EC from immature male flower buds (IMFB) collected in each month of the years 2020 and 2022. Among 12 batches examined, IMFB initiated between January and April produced the highest percentage of EC in both years. In 2020, the percent of EC ranges from 8.22 to 12.14, whereas in 2022 the EC percentage ranges from 2.50 to 4.47. IMFB initiated from May to August produced moderate response and those initiated between September and December gave the lowest percentage of EC in both the years. Plants that generated highest percentage of EC underwent transition from vegetative to reproductive phase in autumn and flowered in winter. During this period, environmental factors such as global radiation, relative humidity and temperature were relatively low compared to summer. In contrast, plants that underwent vegetative–reproductive transition under extreme summer conditions and flowered at the end of summer and autumn yielded lowest percentage of EC. Exposure to high temperature and radiation during this period might have altered inflorescence development. Our results indicate that seasonal alterations in environmental factors influence the rate of EC induction.

The addition of precursors, like tyrosine (Tyr), can increase the biomass and specialized metabolite production in plant cell suspensions. There is a need for natural compounds with inhibitory activity against α-amylase and α-glucosidase to decrease the intestinal absorption of simple carbohydrates. It has been previously reported that soluble melanins from the Randia echinocarpa fruit inhibit the enzymatic activity of α-glucosidase. Thus, the objective of this study was to analyze the metabolomic profiles of R. echinocarpa cell suspensions when treated with different concentrations of Tyr and to assess the inhibitory activities of the cell extracts against α-amylase and α-glucosidase. Methanolic extracts (1 mg/mL) of R. echinocarpa cell suspensions inhibited the activity of α-amylase similarly to acarbose at 50 µM. Nevertheless, no inhibition of α-glucosidase by the extracts was observed. Further purification of the methanolic extracts is required to prevent antagonist effects of the compounds. Four specific chemical profiles were determined by Hierarchical Cluster and Principal Components Analysis. Galactose metabolism and starch/sucrose metabolism were among the main modulated metabolic pathways. Molecular docking showed that compounds Tyr_100 and 200 treatments had an estimated free binding energy of -2.4 to -5.6 kcal/mol and can interact with key amino acids involved with the catalytic activity of α-amylase. The addition of Tyr to the cell suspensions of R. echinocarpa can be used to produce α-amylase inhibitory extracts.