Investigation Into Environmental Selenium and Arsenic Levels and Arseniasis Prevalence in an Arsenic-Affected Coal-Burning Area.

This study aims to explore whether selenium (Se) concentration correlates with arseniasis in a high-arsenic coal area in the southern Shaanxi Province, China. Herein, an epidemiological investigation was conducted among 100 arsenic (As)-poisoned patients in Ziyang County, an area with high soil As and Se levels. Fifty healthy subjects were selected from areas without endemic As poisoning. The subjects in the high-As coal area were diagnosed with either normal, suspicious, mild, moderate, or severe As poisoning. Local coal, water, soil, corn, and pepper samples, as well as hair, blood, and urine samples of subjects and patients were collected and analyzed for their As and Se contents. The contents of As and Se in coal, soil, corn, pepper, and hair samples from Ziyang County were significantly higher than those in the control area. The As content of hair in Ziyang County positively correlated with As poisoning, whereas the Se content of hair and urine negatively correlated with As poisoning. The Se content in the body was negatively correlated with the degree of As poisoning, indicating that Se may accelerate the metabolism and decumulation of As and antagonize As toxicity.

Biotype Characterization, Developmental Profiling, Insecticide Response and Binding Property of Bemisia tabaci Chemosensory Proteins: Role of CSP in Insect Defense.

Chemosensory proteins (CSPs) are believed to play a key role in the chemosensory process in insects. Sequencing genomic DNA and RNA encoding CSP1, CSP2 and CSP3 in the sweet potato whitefly Bemisia tabaci showed strong variation between B and Q biotypes. Analyzing CSP-RNA levels showed not only biotype, but also age and developmental stage-specific expression. Interestingly, applying neonicotinoid thiamethoxam insecticide using twenty-five different dose/time treatments in B and Q young adults showed that Bemisia CSP1, CSP2 and CSP3 were also differentially regulated over insecticide exposure. In our study one of the adult-specific gene (CSP1) was shown to be significantly up-regulated by the insecticide in Q, the most highly resistant form of B. tabaci. Correlatively, competitive binding assays using tryptophan fluorescence spectroscopy and molecular docking demonstrated that CSP1 protein preferentially bound to linoleic acid, while CSP2 and CSP3 proteins rather associated to another completely different type of chemical, i.e. α-pentyl-cinnamaldehyde (jasminaldehyde). This might indicate that some CSPs in whiteflies are crucial to facilitate the transport of fatty acids thus regulating some metabolic pathways of the insect immune response, while some others are tuned to much more volatile chemicals known not only for their pleasant odor scent, but also for their potent toxic insecticide activity.

Overexpression of a phytochrome-regulated tandem zinc finger protein gene, OsTZF1, confers hypersensitivity to ABA and hyposensitivity to red light and far-red light in rice seedlings.

UNLABELLED: Tandem zinc finger proteins (TZFs) in plants are involved in gene regulation, developmental responses, and hormone-mediated environmental responses in Arabidopsis. However, little information about the functions of the TZF family in monocots has been reported. Here, we investigated a cytoplasmic TZF protein, OsTZF1, which is involved in photomorphogenesis and ABA responses in rice seedlings. The OsTZF1 gene was expressed at relatively high levels in leaves and shoots, although its transcripts were detected in various organs. Red light (R)- and far-red light (FR)-mediated repression of OsTZF1 gene expression was attributed to phytochrome B (phyB) and phytochrome C (phyC), respectively. In addition, OsTZF1 expression was regulated by salt, PEG, and ABA. Overexpression of OsTZF1 caused a long leaf sheath relative to wild type (WT) under R and FR, suggesting that OsTZF1 probably acts as a negative regulator of photomorphogenesis in rice seedlings. Moreover, ABA-induced growth inhibition of rice seedlings was marked in the OsTZF1-overexpression lines compared with WT, suggesting the positive regulation of OsTZF1 to ABA responses. Genome-wide expression analysis further revealed that OsTZF1 also functions in other hormone or stress responses. Our findings supply new evidence on the functions of monocot TZF proteins in phytochrome-mediated light and hormone responses. KEY MESSAGE: OsTZF1 encodes a cytoplasm-localized tandem zinc finger protein and is regulated by both ABA and phytochrome-mediated light signaling. OsTZF1 functions in phytochrome-mediated light and ABA responses in rice.