CRISPR/Cas9-mediated mutation of OsSWEET14 in rice cv. Zhonghua11 confers resistance to Xanthomonas oryzae pv. oryzae without yield penalty.

BACKGROUND: Bacterial blight of rice, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a devastating rice disease in Southeast Asia and West Africa. OsSWEET14, encoding a sugar transporter, is known to be a major susceptible gene of bacterial blight targeted by four different transcription activator-like (TAL) effectors from either Asian or African Xoo strains. However, the OsSWEET14 single knockout or promoter mutants in the Kitaake background are moderately resistant or even susceptible to African Xoo strains. Therefore, in this study, we knocked out OsSWEET14 in rice cv. Zhonghua 11 background for disease assessment. RESULTS: In this study, CRISPR/Cas9 was utilized to disrupt the function of OsSWEET14 by modifying its corresponding coding region in the genome of rice cv. Zhonghua 11 (CR-S14). In total, we obtained nine different OsSWEET14-mutant alleles. Besides conferring broad-spectrum resistance to Asian Xoo strains, tested mutant alleles also showed strong resistance to African Xoo strain AXO1947. Moreover, the expression of OsSWEET14 was detected in vascular tissues, including the stem, leaf sheath, leaf blade and root. The disruption of OsSWEET14 led to increased plant height without a reduction in yield. CONCLUSIONS: Disruption of OsSWEET14 in the Zhonghua 11 background is able to confer strong resistance to African Xoo strain AXO1947 and Asian Xoo strain PXO86. CR-S14 has normal reproductive growth and enhanced plant height under normal growth conditions. These results imply that CR-S14 may serve as a better tester line than sweet14 single-knockout mutant in the Kitaake background for the diagnostic kit for rice blight resistance. The genetic background and increased plant height need to be taken into consideration when utilizing OsSWEET14 for resistant rice breeding.

Antioxidant and anticancer effection of the volatile oil from various habitats of Selaginella doederleinii Hieron.

This research aimed to compare antioxidant and anticancer activities of the essential oil from various habitats of Selaginella doederleinii Hieron. The results showed that antioxidative activities of the essential oil were the best from Guizhou province in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical scavenging, ferric reducing and ferric reducing antioxidant power (FRAP), while those of the essential oil from Sichuan province were the weakest among different habitats. The anticancer results showed that antitumor effects of the essential oil from Guizhou province were the best against A549 cell line and 7721 cell line, while those of the essential oil from Sichuan province were the weakest among different habitats. Proliferative and antioxidant activities were correlated. The correlation coefficients (R2) between antioxidant and anticancer capacities varied from 0.71 to 0.94. The results of tests indicated that the antioxidant and anticancer activities of the essential oil from various habitats were great differences that might be affected by environmental variation, harvest seasons and so on. Investigation in vitro revealed that the essential oil of S. doederleinii were found to be effective in suppressing the oxidative activity and proliferation of cancer cells. This experiment provides scientific foundation for further utilization of S. doederleinii.

Development and validation of a new HPV genotyping assay based on next-generation sequencing.

OBJECTIVES: We developed a new human papillomavirus (HPV) genotyping assay based on multiplex polymerase chain reaction and next-generation sequencing (NGS) methods for large-scale cervical cancer screening. METHODS: We first trained the assay on 1,170 self-collected samples, balancing the cutoff points for high-risk types. Then using 4,262 separate self-collected specimens, we compared concordance, sensitivity, and specificity for cervical intraepithelial neoplasia type 2 (CIN2) or higher and CIN type 3 (CIN3) or higher of the HPV sequencing assay with that of Hybrid Capture 2 (HC2) direct samples and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry assay self-samples. RESULTS: All assays had a good agreement. The sensitivity for CIN2 or higher and CIN3 or higher of the self-sampling specimens tested with the sequencing assay run on both MiSeq and Ion Torrent Personal Genome Machine sequencer was similar to that of direct-sampling specimens tested with HC2 (P > .05), but the specificity of the sequencing assay for CIN2 or higher and CIN3 or higher was significantly higher than that of HC2 (P < .01). CONCLUSIONS: This population-based study has demonstrated the applicability of a new NGS high-risk HPV assay for primary cervical cancer screening based on self-collection.