Genetic Authentication of Gardenia jasminoides Ellis var. grandiflora Nakai by Improved RAPD-Derived DNA Markers

Overexpression of an endogenous raw starch digesting mesophilic α-amylase gene in Bacillus amyloliquefaciens Z3 by in vitro methylation protocol

BACKGROUND

Mesophilic α-amylases function effectively at low temperatures with high rates of catalysis and require less energy for starch hydrolysis. Bacillus amyloliquefaciens is an essential producer of mesophilic α-amylases. However, because of the existence of the restriction-modification system, introducing exogenous DNAs into wild-type B. amyloliquefaciens is especially tricky.

RESULTS

α-Amylase producer B. amyloliquefaciens strain Z3 was screened and used as host for endogenous α-amylase gene expression. In vitro methylation was performed in recombinant plasmid pWB980-amyZ3. With the in vitro methylation, the transformation efficiency was increased to 0.96 × 10² colony-forming units μg^-1 plasmid DNA. A positive transformant BAZ3-16 with the highest α-amylase secreting capacity was chosen for further experiments. The α-amylase activity of strain BAZ3-16 reached 288.70 ± 16.15 U mL^-1 in the flask and 386.03 ± 16.25 U mL^-1 in the 5-L stirred-tank fermenter, respectively. The Bacillus amyloliquefaciens Z3 expression system shows excellent genetic stability and high-level extracellular production of the target protein. Moreover, the synergistic interaction of AmyZ3 with amyloglucosidase was determined during the hydrolysis of raw starch. The hydrolysis degree reached 92.34 ± 3.41% for 100 g L^-1 raw corn starch and 81.30 ± 2.92% for 100 g L^-1 raw cassava starch after 24 h, respectively.

CONCLUSION

Methylation of the plasmid DNA removes a substantial barrier for transformation of B. amyloliquefaciens strain Z3. Furthermore, the exceptional ability to hydrolyze starch makes α-amylase AmyZ3 and strain BAZ3-16 valuable in the starch industry. © 2020 Society of Chemical Industry.

Development of an In Vitro Propagation Protocol and a Sequence Characterized Amplified Region (SCAR) Marker of Viola serpens Wall. ex Ging

An efficient protocol of plant regeneration through indirect organogenesis in Viola serpens was developed in the present study. Culture of leaf explants on MS (Murashige and Skoog) medium supplemented with 2.0 mg/L 6-benzyladenine and 0.13 mg/L 2,4-dichloro phenoxy acetic acid. Adventitious shoot formation was observed when calli were transferred on to MS medium containing 0.5 mg/L α-naphthalene acetic acid and 2.25 mg/L kinetin, which showed the maximum 86% shoot regeneration frequency. The highest root frequency (80.92%) with the 5.6 roots per explant and 1.87 cm root length was observed on MS medium supplemented with 2 mg/L indole-3-butyric acid. The plantlets were transferred to the mixture of sand, coffee husk and soil in the ratio of 1:2:1 in a pot, and placed under 80% shade net for one month. It was then transferred to 30% shade net for another one month, prior to transplantation in the field. These plantlets successfully acclimatized under field conditions. A Sequence Characterized Amplified Region (SCAR) marker was also developed using a 1135 bp amplicon that was obtained from RAPD (Random Amplification of Polymorphic DNA) analysis of six accessions of V. serpens. Testing of several market samples of V. serpens using the SCAR marker revealed successful identification of the genuine samples of V. serpens. This study, therefore, provides a proficient in vitro propagation protocol of V. serpens using leaf explants and a SCAR marker for the authentic identification of V. serpens. This study will be helpful for conservation of authentic V. serpens.

Development of diagnostic SCAR markers for genomic DNA amplifications in breast carcinoma by DNA cloning of high-GC RAMP-PCR fragments

Cancer is genetically heterogeneous regarding to molecular genetic characteristics and pathogenic pathways. A wide spectrum of biomarkers, including DNA markers, is used in determining genomic instability, molecular subtype determination and disease prognosis, and estimating sensitivity to different drugs in clinical practice. In a previous study, we developed highly effective DNA markers using improved random amplified polymorphic DNA (RAPD) with high-GC primers, which is a valuable approach for the genetic authentication of medicinal plants. In this study, we applied this effective DNA marker technique to generate genetic fingerprints that detect genomic alterations in human breast cancer tissues and then developed sequence-characterized amplified region (SCAR) markers. Three SCAR markers (BC10-1, BC13-4 and BC31-2) had high levels of genomic DNA amplification in breast cancer. The PHKG2 and RNF40 genes are either overlapping or close to the sequences of SCAR marker BC13-4, while SCAR marker BC10-1 is in the intron and overlap the DPEP1 gene, suggesting that alterations in the expression of these genes could contribute to cancer progression. Screening of breast cancer cell lines showed that the mRNA expression levels for the PHKG2 and DPEP1 were lower in non-tumorigenic mammary epithelial cell MCF10A, but elevated in other cell lines. The DPEP1 mRNA level in invasive ductal carcinoma specimens was significantly higher than that of the adjacent normal tissues in women. Taken together, high-GC RAMP-PCR provides greater efficacy in measuring genomic DNA amplifications, deletion or copy number variations. Furthermore, SCAR markers BC10-1 and BC13-4 might be useful diagnostic markers for breast cancer carcinomas.