De novo transcriptome analysis of tobacco seedlings and identification of the early response gene network under low-potassium stress.

Tobacco is an economically important crop, and its potassium content can greatly affect the quality of tobacco leaves. However, the molecular mechanism involved in potassium starvation in tobacco has not been elucidated to date. In this study, Illumina (Solexa) sequencing technology was used to analyze the transcriptome of tobacco seedlings under low-potassium stress for 6, 12, and 24 h. After analysis, 107,824 assembled unigenes were categorized into 57 GO functional groups, and 31,379 unigenes (29.08%) were clustered into 25 COG categories. A total of 9945 genes were classified into 233 KEGG pathways, and 15,209 SSRs were found among the 107,824 unigenes. Between the two samples, 1034 genes were differentially expressed. Twelve randomly selected gene expression levels were analyzed by quantitative RT-PCR, and the results were highly consistent with those obtained by Solexa sequencing. Our results provide a comprehensive analysis of the gene-regulatory network of tobacco seedlings under low-potassium stress.

Upregulation of salivary α2 macroglobulin in patients with type 2 diabetes mellitus.

We investigated the expression of salivary α2-macroglobulin (α2-MG) in patients with type 2 diabetes mellitus (T2DM) to investigate its value for predicting damage to the salivary glands. A total of 116 patients with T2DM and 60 patients with impaired fasting glucose (IFG) were included in this study. Sixty health volunteers were enrolled as a control group. Unstimulated saliva was collected at 8 a.m. prior to breakfast. Expression of α2-MG was determined using an enzyme-linked immunosorbent assay. The correlation between salivary α2-MG, serum α2-MG, and concentration of fasting glucose was analyzed using Pearson correlation analysis. No significant difference was observed in the expression of serum α2-MG in the T2DM group, IFG group, and control group (P > 0.05). Compared with the control group and IFG group, a statistical difference was observed in the salivary α2-MG in the T2DM group (P < 0.01). No statistical difference was observed in the salivary α2-MG in the IFG group compared with the control group (P > 0.05). In the patients with T2DM, a close correlation was identified in the expression of serum α2-MG and salivary α2-MG (r = 0.52, P < 0.01). A poor correlation was identified between salivary α2-MG and blood sugar level (r = -0.12, P = 0.199). The expression of salivary α2-MG showed a remarkable increase in T2DM patients, which may be associated with functional disorders of the salivary gland.