ABSTRACT
Endophytic fungi are promising sources for the production of podophyllotoxin-an important anticancer compound, replacing depleted medical plants. In this study, the endophytes associated with Dysosma difformis-an ethnomedicinal plant species were isolated to explore novel sources of podophyllotoxin. Fifty-three endophytic fungi were isolated and identified by morphological observation and ITS-based rDNA sequencing, assigning them to 27 genera in 3 divisions. Fusarium was found the most prevalent genus with a colonization frequency of 11.11%, followed by Trametes (9.26%) and Penicillium (7.41%). Phylogenetic trees were constructed for the endophytic fungi community in two collection sites, Ha Giang and Lai Chau, revealing the adaptation of the species to the specific tissues and habitats. Cytotoxic activity of endophytic fungal extracts was investigated on cancer cell lines such as SK-LU-1, HL-60, and HepG2, demonstrating strong anti-cancer activity of six isolates belonging to Penicillium, Trametes, Purpureocillium, Aspergillus, and Ganoderma with IC50 value of lower than 10 µg/mL. The presence of podophyllotoxin was indicated in Penicillium, Trametes, Aspergillus and for the first time in Purpureocillium and Ganoderma via high-performance liquid chromatography, which implied them as a potential source of this anti-cancer compound.
ABSTRACT
<b>Background and Objective:</b> Plant genetic resources provide the raw material for crop improvement and plant breeding program largely depends on it. Therefore, the evaluation of plant genetic resources plays a critical role in crop improvement and also in conserving valuable genetic resources for the future. In this study, the genetic diversity of 16 <i>Lactuca indica</i> L. accessions collected in Vietnam was investigated by using ISSR and RAPD markers. <b>Materials and Methods:</b> Genetic diversity of 16 <i>Lactuca sativa</i> L. genotypes collected in Vietnam were evaluated using Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeat (ISSR) molecular markers. <b>Results:</b> In this study, 42 RAPD and ISSR primers were initially used, of which 12 and 9 primers, respectively were finally selected as they produced scorable patterns. RAPD markers produced a total of 113 loci, out of which 52 loci (45.96%) were polymorphic. The average percentage of the polymorphic band for RAPD primer is 45.96% and the genetic similarity based on simple matching coefficient ranged from 69.0-94.7%. ISSR analysis detected a total of 60 loci, out of which 22 loci (36.32%) were polymorphic and the genetic similarity ranged from 56.7-95.0%. In general, ISSR markers amplified fewer loci and showed lower variation in the percentage of polymorphism compares to the RAPD assay. <b>Conclusion:</b> These results indicate that the 16 collected Indian lettuce genotypes are genetically diverse. Because of these genetic diversities, the collected genotypes could be used for preserving or crossing programs to improve this precious medicinal plant in Vietnam.
