Somatic Embryogenesis of Anthurium andraeanum Linden., -A Tropical Florists' Plant.

The global floriculture market is expected to reach US$41.1 billion by 2027 at a CAGR of 5% over the analysis period 2020-2027; on the year 2020, the recorded market value in this trade was US$29.2 billion. The florists mainly use Anthurium andraeanum flowers in fashionable bouquets and floral arrangements because of their beautiful, attractive bright colored eye-catching spathe, candle-like spadix, prolonged vase life, etc. The cut flower industry always seeks elite cultivars and new hybrids of A. andraeanum, that in turn depend on the availability of large numbers of clonal planting propagules. In vitro somatic embryogenesis is an important technique for large-scale clonal propagation, development of transgenic plants, creation of new variety by somaclonal variation, mutagenesis on in vitro plants, and germplasm preservation for future use. Here, we describe the protocol of somatic embryogenesis of Anthurium andraeanum cv. Cancan, an important commercial cultivated variety. The protocol has been optimized by using 4 different types of culture media which are used during embryogenic callus induction, multiplication of callus, induction of somatic embryogenesis, and maturation plus conversion of embryos into plantlets. The protocol outlines the detailed methods from mother plant procurement to hardening of micro plants that is ready to transfer in the field and it can be used for large-scale commercial propagation.

Transformation of Long-Lived Albino Epipremnum aureum 'Golden Pothos' and Restoring Chloroplast Development.

Chloroplasts are organelles responsible for chlorophyll biosynthesis, photosynthesis, and biosynthesis of many metabolites, which are one of key targets for crop improvement. Elucidating and engineering genes involved in chloroplast development are important approaches for studying chloroplast functions as well as developing new crops. In this study, we report a long-lived albino mutant derived from a popular ornamental plant Epipremnum aureum 'Golden Pothos' which could be used as a model for analyzing the function of genes involved in chloroplast development and generating colorful plants. Albino mutant plants were isolated from regenerated populations of variegated 'Golden Pothos' whose albino phenotype was previously found to be due to impaired expression of EaZIP, encoding Mg-protoporphyrin IX monomethyl ester cyclase. Using petioles of the mutant plants as explants with a traceable sGFP gene, an efficient transformation system was developed. Expressing Arabidopsis CHL27 (a homolog of EaZIP) but not EaZIP in albino plants restored green color and chloroplast development. Interestingly, in addition to the occurrence of plants with solid green color, plants with variegated leaves and pale-yellow leaves were also obtained in the regenerated populations. Nevertheless, our study shows that these long-lived albino plants along with the established efficient transformation system could be used for creating colorful ornamental plants. This system could also potentially be used for investigating physiological processes associated with chlorophyll levels and chloroplast development as well as certain biological activities, which are difficult to achieve using green plants.

An Effective Way of Producing Fully Assembled Antibody in Transgenic Tobacco Plants by Linking Heavy and Light Chains via a Self-Cleaving 2A Peptide.

Therapeutic monoclonal antibodies (mAbs) have evolved into an important class of effective medicine in treatment of various diseases. Since the antibody molecule consists of two identical heavy chains (HC) and two light chains (LC), each chain encoded by two different genes, their expressions at similar levels are critical for efficient assembly of functional recombinant mAbs. Although the plant-based expression system has been tested to produce fully assembled recombinant mAbs, coordinately expressing HC and LC at similar levels in a transgenic plant remains a challenge. A sequence coding for a foot-and-mouth disease virus (FMDV) 2A peptide has been successfully used to link two or more genes, which enable the translated polyprotein to be "self-cleaved" into individual protein in various genetically modified organisms. In the present study, we exploited the usage of F2A in Ebola virus monoclonal antibody (EBOV mAb) production. We found that transgenic tobacco plants carrying a transcription unit containing HC and LC linked by 2A not only produced similar levels of HC and LC but also rendered a higher yield of fully assembled EBOV mAb compared to those expressing HC and LC in two independent transcription units. Purified EBOV mAb bound to an Ebola epitope peptide with apparent Kd -values of 90.13-149.2 nM, indicating its proper assembly and high affinity binding to Ebola epitope peptide. To our knowledge, this is the first report showing mAb production by overexpressing a single transcription unit consisting of HC, LC and 2A in stable transformed tobacco plants.