ABSTRACT
The genus Musa sp. contains commercially important fleshy fruit-producing plants, including plantains and bananas, with a strong potential for providing food security and sources of revenue to farmers. Concerns with the quality of vegetative tissues along with the possibility of the transmission of phytopathogens makes the availability of healthy plantlets limited for farmers. Micropropagation of plantains offers an alternative to producing large numbers of plantlets. However, conventional methods of micropropagation have high production costs and are labor-intensive. Recently, the temporary immersion bioreactor (TIB) has emerged as an alternative to conventional micropropagation (CM) methods. Our work utilized SEM microscopy (scanning electron microscope) and molecular and biochemical tools (qRT-PCR and ICP-OES) to characterize and compare the morphological properties, elemental composition, and photosynthetic gene expression of plantains cultured on TIB. Additionally, morphological features of growth and propagation rates were analyzed to compare outputs obtained from TIB and CM. Results showed higher growth and multiplication rates for plantlets cultivated in TIB. Gene expression analysis of selected photosynthetic genes demonstrated high transcript abundance of phosphoenolpyruvate carboxylase (PEPC) in plantain tissues obtained by TIB. Elemental composition analysis showed higher content of iron in plantains grown in TIB, suggesting a potential correlation with PEPC expression. These results demonstrate that micropropagation of Musa sp. via the liquid medium in TIB is an efficient and low-cost approach in comparison with solid media in CM.
ABSTRACT
We report the development of in vitro propagation protocols through an adventitious shoot induction pathway for a rare and medicinal Scutellaria havanensis. In vitro propagation studies using nodal explants showed MS medium supplemented with 10 µM 6-Benzylaminopurine induced the highest number of adventitious shoots in a time-dependent manner. A ten-day incubation was optimum for shoot bud induction as longer exposures resulted in hyperhydricity of the explants and shoots induced. We also report preliminary evidence of Agrobacterium tumefaciens EHA105-mediated gene transfer transiently expressing the green fluorescent protein in this species. Transformation studies exhibited amenability of various explant tissues, internode being the most receptive. As the plant has medicinal value, research was carried out to evaluate its potential antioxidant capacity and the efficacy of methanolic leaf extracts in curbing the viability of human colorectal cancer cell line HCT116. Comparative total polyphenol and flavonoid content measurement of fresh and air-dried leaf extract revealed that the fresh leaf extracts contain higher total polyphenol and flavonoid content. The HCT 116 cell viability was assessed by colorimetric assay using a 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide, showed a steady growth inhibition after 24 h of incubation. Scanning electron microscopy of leaf surface revealed a high density of glandular and non-glandular trichomes. This research provides a basis for the conservation of this rare plant and future phytochemical screening and clinical research.
