ABSTRACT
Bacillus cereus YN917, obtained from a rice leaf with remarkable antifungal activity against Magnaporthe oryzae, was reported in our previous study. The present study deciphered the possible biocontrol properties. YN917 strain exhibits multiple plant growth-promoting and disease prevention traits, including production of indole-3-acetic acid (IAA), ACC deaminase, siderophores, protease, amylase, cellulase, and ß-1,3-glucanase, and harboring mineral phosphate decomposition activity. The effects of the strain YN917 on growth promotion and disease prevention were further evaluated under detached leaf and greenhouse conditions. The results revealed that B. cereus YN917 can promote seed germination and seedling plant growth. The growth status of rice plants was measured from the aspects of rice plumule, radicle lengths, plant height, stem width, root lengths, fresh weights, dry weights, and root activity when YN917 was used as inoculants. YN917 significantly reduced rice blast severity under detached leaf and greenhouse conditions. Genome analysis revealed the presence of gene clusters for biosynthesis of plant promotion and antifungal compounds, such as IAA, tryptophan, siderophores, and phenazine. In summary, YN917 can not only be used as biocontrol agents to minimize the use of chemical substances in rice blast control, but also can be developed as bio-fertilizers to promote the rice plant growth.
ABSTRACT
OBJECTIVE: To examine the expression of cytokeratin-13 (CK-13) in oral squamous cell carcinoma (OSCC) and to discuss the effects of all-trans retinoic acid (ATRA) or arsenic trioxide (As2 O3) on the differentiation of human oral undifferentiated squamous cell carcinoma cell line KB cells. METHODS: The cultured KB cells were divided into three groups, ATRA group, As2 O3 group, and control. The expression of CK-13 in KB cells was detected using the immunofluorescence before and after KB cells were induced by ATRA or As2 O3. RESULTS: The expression rates of CK-13 in KB cells in the ATRA group and As2 O3 group were significantly higher than that in the control (P < 0.05), but there was no significant difference in the expression between ATRA and As2 O3 group(P > 0.05). CONCLUSIONS: ATRA and As2 O3 both have the ability to differentiate the KB cells, and the expression is associated with the degree of tumor differentiation. CK-13 may serve as a molecular marker to evaluate the effect of the differentiation treatment on OSCC.
