Effects of different factors on adventitious bud induction from stem explants of Ludisia discolor

In this study, the stem explants of Ludisia discolor were used as experimental materials to investigate the effects of 6-BA, NAA, Cu2+ and Ag+ on the induction of adventitious bud regeneration, and to analyze the most suitable culture conditions for stem explants regeneration. The results showed that when the medium was supplemented with 1.0 mg/L 6-BA, 0.75 mg/L NAA, 0.25 mg/L CuSO4, or 6.4 mg/L AgCl, the best regeneration effects would be gained, respectively. And the adventitious bud regeneration rate reached the maximum, which were 61.67%, 83.67%, 80.95% and 87.63%, respectively. The results of this study provided a theoretical basis for tissue culture and rapid propagation of L. discolor.

IN VITRO BREEDING AND NURSING TAQUA BANANA IN TRA VINH PROVINCE

The goal of this study is to determine in vitro propagation media of Taqua banana. The results showed that: the optimal medium for banana bud regeneration was MS medium (Murashine & Skoog 1962) supplemented 0.1 mg/l NAA, 100 mg/l adenine sulfate, 30g/l sucrose, 8 g/l Agar, 5 mg/l BAP, 10% volume coconut juice and kept in completely dark condition. The medium, which is similar to bud generation media except for supplementing BAP 7 mg/l, was also good for bud replication with 6,33 shoots per sample after 4 weeks. (2)The medium, which is similar to bud generation media except for non-added BAP and an increase of NAA from 0.1 to 1 mg/l, was the best for the banana rooting.

SIS-ECM Laden with GMSC-Derived Exosomes Promote Taste Bud Regeneration

Oral cancer has a high annual incidence rate all over the world, and the tongue is the most frequently affected anatomic structure. The current standard care is ablative surgery of malignant neoplasm, followed by tongue reconstruction with free flap. However, such reconstructive modalities with postsurgery radiotherapy or chemotherapy can hardly support the functional recovery of the tongue—particularly, functional taste bud regeneration—in reconstructed areas, thus seriously affecting patients’ prognosis and life quality. Using a critical-sized tongue defect model in rats, we show that combinatory transplantation of small intestinal submucosa–extracellular matrix (SIS-ECM) with gingival mesenchymal stem cells (GMSCs) or their derivative exosomes promoted tongue lingual papillae recovery and taste bud regeneration as evidenced by increased expression of CK14, CK8, and markers for type I, II, and III taste bud cells (NTPdase 2, PLC-β2, and AADC, respectively). In addition, our results indicate that GMSCs or their derivative exosomes could increase BDNF expression, a growth factor that plays an important role in the proliferation and differentiation of epithelial basal progenitor cells into taste bud cells. Meanwhile, we showed an elevated expression level of Shh—which is essential for development, homeostasis, and maintenance of the taste bud organ—in wounded areas of the tongue among animals treated with GMSC/SIS-ECM or exosome/SIS-ECM as compared with SIS-ECM control. Moreover, our data show that GMSCs or their derivative exosomes promoted innervation of regenerated taste buds, as evidenced by elevated expressions of neurofilament and P2X3 at the injury areas. Together, our findings indicate that GMSC/SIS-ECM and exosome/SIS-ECM constructs can facilitate taste bud regeneration and reinnervation with promising potential application in postsurgery tongue reconstruction of patients with tongue cancer.

Medium pH between 5.5 and 7.5 has Minimal Effects on Tissue Culture of Apple

Medium pH is generally adjusted to 5.8 to 6.0 for plant tissue culture. Our research indicated that pH generally falls between 5.5 and 7.5 in an ordinarily made medium which can be directly used for apple tissue culture without adjusting pH. Repeated adjustment of pH by adding NaOH and HCl leads to the increase in Na+ and Cl− concentration and decrease in Mg2+ and Ca2+ concentration in the medium due to precipitation. To determine the pros, cons, and necessity of pH levels while making medium in plant tissue culture, subculture proliferation, adventitious root induction, and organ regeneration, the apple cultivars Fuji, Golden Delicious, Jonagold, and Gala were used and hardness of the medium and the ion content of Na+, Cl−, Mg2+, and Ca2+ in the medium under different pH were measured. In the lower pH range of 5.0–5.5, plantlets could be subcultured and grew normally; however, the medium did not solidify or solidified poorly resulting in problems associated with handling. No significant difference was found among the treatments when pH ranged 6.0–8.0 in terms of proliferation, adventitious root induction, and adventitious bud regeneration from leaves, except a slight decrease in shoot number proliferation in ‘Jonagold’ and in adventitious bud regeneration from leaves in ‘Fuji’ and ‘Golden Delicious’ at pH above 7.5. The hardness of the medium increased with the increased pH. The superfluous Cl− and Na+ generated during the process of overadjusting pH to 7.0 by adding NaOH and then readjusting to 6.0 by adding HCl significantly affected the proliferation, rooting, and organ regeneration of apple plantlets. A relative broad range of medium pH (5.5–7.5) is suitable for apple tissue culture. We suggest that it is not necessary to always adjust medium pH to 5.8–6.0 in apple tissue culture; especially the repeated adjustment should be avoided.