OsFKBP20-1b interacts with the splicing factor OsSR45 and participates in the environmental stress response at the post-transcriptional level in rice.

Sessile plants have evolved distinct mechanisms to respond and adapt to adverse environmental conditions through diverse mechanisms including RNA processing. While the role of RNA processing in the stress response is well understood for Arabidopsis thaliana, limited information is available for rice (Oryza sativa). Here, we show that OsFKBP20-1b, belonging to the immunophilin family, interacts with the splicing factor OsSR45 in both nuclear speckles and cytoplasmic foci, and plays an essential role in post-transcriptional regulation of abiotic stress response. The expression of OsFKBP20-1b was highly upregulated under various abiotic stresses. Moreover genetic analysis revealed that OsFKBP20-1b positively affected transcription and pre-mRNA splicing of stress-responsive genes under abiotic stress conditions. In osfkbp20-1b loss-of-function mutants, the expression of stress-responsive genes was downregulated, while that of their splicing variants was increased. Conversely, in plants overexpressing OsFKBP20-1b, the expression of the same stress-responsive genes was strikingly upregulated under abiotic stress. In vivo experiments demonstrated that OsFKBP20-1b directly maintains protein stability of OsSR45 splicing factor. Furthermore, we found that the plant-specific OsFKBP20-1b gene has uniquely evolved as a paralogue only in some Poaceae species. Together, our findings suggest that OsFKBP20-1b-mediated RNA processing contributes to stress adaptation in rice.

Dissipation, persistence, and risk assessment of fluxapyroxad and penthiopyrad residues in perilla leaf (Perilla frutescens var. japonica Hara).

The objective of this study was to determine the residual characteristics and to calculate the persistence of the fungicides fluxapyroxad (15.3% suspension concentrate) and penthiopyrad (20% emulsifiable concentrate) on the leaves of greenhouse-cultivated perilla (Perilla frutescens var. japonica Hara). Fluxapyroxad was diluted 2,000-fold and penthiopyrad was diluted 4,000-fold. Each solution was sprayed 3 times onto crops at 7-d intervals before harvest. Leaf samples were collected at 3 h (0 d), 1, 3, 5 and 7 d after the third and final treatment. The recovery ranges of fluxapyroxad and penthiopyrad and their metabolites were 74.2%-104.1%. Pesticide residue analyses indicated that fluxapyroxad and penthiopyrad residues in perilla leaves dissipated over time. The persistence of fluxapyroxad and penthiopyrad residues 7 d after the final spray were 50.0% ± 4.9% and 44.2% ± 2.8% of those measured 3 h (0 d) after the final spray, respectively. The percent acceptable daily intake (%ADI)-which was assessed according to the daily food intake by Koreans according to age-was < 7.3%. Therefore, it was determined that the health risk was low. The perception that residual pesticides are present in large amounts in perilla leaf has led to consumer concern. However, in this study, the amounts of pesticide in perilla leaf decreased over time. Although it has been hypothesized that the risk of pesticide intake would be higher in younger children, the results actually suggest the opposite. Therefore, the pesticides in question are considered to be safe for use on perilla leaves.

Risk of dermal and inhalation exposure to chlorantraniliprole assessed by using whole-body dosimetry in Korea.

BACKGROUND: We determined the characteristics and evaluated associated risks of sprayed pesticide exposure among workers cultivating Korean cabbage. The test pesticide, a mixture of 3% chlorantraniliprole and 4% indoxacarb wettable granules diluted 2000 times, was sprayed on Korean cabbage within a 3000 m2 area in Goesan, Korea. Dermal exposures were measured using a whole-body dosimetry method. RESULTS: Exposure to chlorantraniliprole was observed among ten individuals, ranging from 140.4 to 4234.0 µg person-1 . The legs were the most prominent exposure area (86.35%), with the face being the least exposed (0.06%). Exposure risk was assessed by calculating the margin of safety (MOS) on the exposure amount for each body part. The MOS based on dermal and inhalation exposure doses ranged from 59 to 1765. CONCLUSION: Exposure was the greatest for the legs, probably as a result of the low height of the crop and the use of a long-wand sprayer. An MOS value >1 indicates a low risk for applicators using this method of application. However, with tall crops, exposure level and MOS values can vary widely, as MOS increases or decreases based on exposure dose. Therefore, future research is needed to better understand appropriate safety precautions when working with potent pesticides. © 2018 Society of Chemical Industry.