Biomedical subjects

Mei Ru Li

Publications and source records attributed to Mei Ru Li.

3 recordsLinked to original sources

PubMed2006

[Study on factors influencing Agrobacterium-mediated transformation of Jatropha curcas].

Susceptibility of explants to antibiotics and the transient expression of beta-glucuronidase (GUS) gene were studied to determine the optimal conditions for gene transformation of Jatropha curcas mediated by Agrobacterium Tumefaciens. The results showed that Jatropha curcas was insensitive to the antibiotic cefotaxime, which is used for suppressing the growth of Agrobacterium after cocultivation, while the plant was sensitive to kanamycin, hygromycin, phoshpinothrincin. All the three selective reagents synchronously suppressed the induction and the growth of callus, shoot organogenesis in a dose-dependent manner. The types of explants and the physiological state of the explants had strong influence on the transient expression efficiency of GUS. Hypocotyl, cotyledon petiole and cotyledon from 14-day-old seedling were more susceptible to Agrobacterium infection. Hygromycin-resistance calli from cotyledon explants were obtained and showed GUS staining.

Agrobacterium tumefaciens↗

PubMed2004

[Effect of methyl viologen on the Ca(2+)-ATPase activities of membrane vesicles in roots of rice seedlings].

The cold tolerance of rice (Oryza sativa L.) seedlings could be markedly improved by mild oxidative pretreatment (10 mumol/L methyl viologen (MV). The enhancement of chilling resistance induced by MV pretreatment could be inhibited by Ca(2+)-chelate ethyleneglycol-bis-(beta-aminoethylether) N,N-tetraacetic acid (EGTA, 10 mmol/L) and the calmodulin inhibitor chlorpromazine (CPZ, 0.5 mmol/L). The Ca(2+)-ATPase activity of root plasmolemma and tonoplast membrane as well as the Fe(CN)6(3-) reduction of plasmolemma were also enhanced by MV pretreatment. However, the above MV pretreatment effect could be inhibited by EGTA and CPZ, respectively. In vitro, Ca(2+)-ATPase activities in the two types of membrane vesicles were reduced by reactive oxygen species (H2O2, O2-., .OH). Results indicated that the enhancement of chilling resistance in rice seedlings with MV pretreatment was likely related to the effective activation of Ca(2+)-ATPase induced by calcium messenger of CaM, and the improved cold tolerance of the activities might be associated with the augmentation of cellular membrane protective ability caused by the MV pretreatment.

Calcium-Transporting ATPases↗

PubMed2003

[A simple and highly efficient Agrobacterium-mediated rice transformation system].

A simple and highly efficient rice transformation system was established based on the studying of factors influencing the Agrobacterium-mediated rice transformation. Embryogenic calli derived from mature embryos were infected and cocultivated with A. tumefaciens EHA101 harboring binary vectors: pHQ9, pHQ10, pHQT3. The highest transformation frequency was about 100 hygromycin resistance calli per gram of calli explants, and above 85% of these calli could be regenerated into plants. The putative transgenic plants were confirmed by GUS assay and southern-blot analysis. Hygromycin resistance tests indicated that the segregation of transgene in T1 progeny corresponded to the Mendelian ratio, 3:1. This system will benefit the functional genomic study of rice by using T-DNA insertion mutagenesis and gene targeting.

Agrobacterium tumefaciens↗