MicroRNAs (miRNAs) play essential regulatory roles in the development of eukaryotes. Methods based on deep-sequencing have provided a powerful high-throughput strategy for identifying novel miRNAs and have previously been used to identify over 100 novel miRNAs from rice. Most of these reports are related to studies of rice development, tissue differentiation, or abiotic stress, but novel rice miRNAs related to viral infection have rarely been identified. In previous work, we constructed and pyrosequenced the small RNA (sRNA) libraries of rice infected with Rice stripe virus and described the character of the small interfering RNAs (siRNA) derived from the RSV RNA genome. We now report the identification of novel miRNAs from the abundant sRNAs (with a minimum of 100 sequencing reads) in the sRNA library of RSV-infected rice. 7 putative novel miRNAs (pn-miRNAs) whose precursor sequences have not previously been described were identified and could be detected by Northern blot or RT-PCR, and were recognized as novel miRNAs (n-miRNAs). Further analysis showed that 5 of the 7 n-miRNAs were up-expressed while the other 2 n-miRNAs were down-expressed in RSV-infected rice. In addition, 23 pn-miRNAs that were newly produced from 19 known miRNA precursors were also identified. This is first report of novel rice miRNAs produced from new precursors related to RSV infection.
MicroRNAs (miRNAs) play key roles in plant development and defense against pathogens. To establish the function of individual miRNAs, gain-of-function analysis is usually done by overexpressing a specific miRNA in transgenic plants and has proved very effective. Loss-of-function analysis by the target mimic method is now also increasingly being used. The mimics expressed in the transgenic plants sequester a specific miRNA and lead to changed phenotypes that elucidate miRNA function. However, it takes time to obtain the transgenic plants. To avoid using transgenic plants, we have developed a virus-based miRNA suppression system (VbMS) based on a Tobacco rattle virus vector. The target mimic sequences of miR156, miR319, or miR164 were introduced into the viral genomic RNA, which was then inoculated to Arabidopsis thaliana plants. The resulting phenotypes were consistent with previous reports from transgenic plants, and the expression of targets of the miRNAs was also increased showing that the activity of the miRNAs had been inhibited. VbMS developed here is validated for loss-of-function analysis of miRNA in plants. Moreover, since only simple agroinfiltration rather than transformation is needed, VbMS is suitable for large-scale approaches to miRNA function analysis in plants.
Context Tocilizumab (TCZ), an interleukin-6 (IL-6) receptor antagonist, has been approved for use in rheumatoid arthritis and cytokine storm syndrome (CSS) associated with chimeric antigen receptor T cells treatment. Although TCZ is currently utilized in the treatment of critically ill coronavirus 2019 (COVID-19) patients, data on survival impact is minimal. Objectives To assess the mortality rate of patients presenting with COVID-19 who received TCZ for suspected CSS. Methods This retrospective cohort study was conducted at Henry Ford Health System between March 10, 2020 and May 18, 2020. Data collection began in May 2020 and was completed in June 2020. Patients included in the study required hospital admission and had positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction on nasopharyngeal swab. Eligibility criteria to receive TCZ, per hospital protocol, included any of the following: persistent fever, defined as 38.0 °C for at least 6 hours; a diagnosis of the acute respiratory distress syndrome (ARDS); serum ferritin ≥1,000 (ng/mL) or doubling within 24 hours; D-Dimer ≥ 5 (mg/L); serum lactate dehydrogenase ≥500 (IU/L); or interlukin-6 level ≥5 times the upper limit of normal. Dosing was initially determined by weight, then changed to a fixed 400 mg per hospital protocol. A comparator cohort was created from patients with COVID-19 and ARDS who did not receive TCZ. Patient survival was analyzed using the Kaplan–Meier method and compared by log rank test. A multivariable cox regression was applied to evaluate the association between TCZ and mortality. Results One hundred and thirty patients were evaluated in the study, 54 (41.5%) of whom received TCZ. Patients who received TCZ were younger (mean age, 63.8 vs. 69.4 years; p=0.0083) and had higher body mass indices (mean, 33.9 vs. 30.4; p=0.005). Of the comorbid conditions evaluated, heart disease was more common in the comparator group than the TCZ group (27 patients [35.5%] vs. 10 patients [18.5%]; p=0.034). A Kaplan–Meier survival curve demonstrated no difference in survival between TCZ and comparator patients (log rank p=0.495). In the multivariable Cox regression model for mortality at 30 days, treatment with TCZ was not associated with decreased mortality (hazard ratio, 1.1; 95% confidence interval, 0.53–2.3; p=0.77). Lower mean C-reactive protein (CRP) levels were demonstrated within 48 hours of disposition in the TCZ group (mean TCZ, 4.9 vs. mean comparator, 13.0; p=<0.0001). Conclusions In this cohort study, no difference in survival was observed in critically ill patients treated with TCZ.
Characterization of drought-tolerance mechanisms during the jointing stage in foxtail millet under water-limited conditions is essential for improving the grain yield of this C4 crop species. In this trial, two drought-tolerant and two drought-sensitive cultivars were examined using transcriptomic dissections of three tissues (root, stem, and leaf) under naturally occurring water-limited conditions. We detected a total of 32,170 expressed genes and characterized 13,552 differentially expressed genes (DEGs) correlated with drought treatment. The majority of DEGs were identified in the root tissue, followed by leaf and stem tissues, and the number of DEGs identified in the stems of drought-sensitive cultivars was about two times higher than the drought-tolerant ones. A total of 127 differentially expressed transcription factors (DETFs) with different drought-responsive patterns were identified between drought-tolerant and drought-sensitive genotypes (including MYB, b-ZIP, ERF, and WRKY). Furthermore, a total of 34 modules were constructed for all expressed genes using a weighted gene co-expression network analysis (WGCNA), and seven modules were closely related to the drought treatment. A total of 1,343 hub genes (including RAB18, LEA14, and RD22) were detected in the drought-related module, and cell cycle and DNA replication-related transcriptional pathways were identified as vital regulators of drought tolerance in foxtail millet. The results of this study provide a comprehensive overview of how Setaria italica copes with drought-inflicted environments during the jointing stage through transcriptional regulating strategies in different organs and lays a foundation for the improvement of drought-tolerant cereal cultivars through genomic editing approaches in the future.
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