Rice responds to Spodoptera frugiperda infestation via epigenetic regulation of H3K9ac in the jasmonic acid signaling and phenylpropanoid biosynthesis pathways.

KEY MESSAGE: This study provided important insights into the complex epigenetic regulatory of H3K9ac-modified genes involved in the jasmonic acid signaling and phenylpropanoid biosynthesis pathways of rice in response to Spodoptera frugiperda infestation. Physiological and molecular mechanisms underlying plant responses to insect herbivores have been well studied, while epigenetic modifications such as histone acetylation and their potential regulation at the genomic level of hidden genes remain largely unknown. Histone 3 lysine 9 acetylation (H3K9ac) is an epigenetic marker widely distributed in plants that can activate gene transcription. In this study, we provided the genome-wide profiles of H3K9ac in rice (Oryza sativa) infested by fall armyworm (Spodoptera frugiperda, FAW) using CUT&Tag-seq and RNA-seq. There were 3269 and 4609 up-regulated genes identified in plants infested by FAW larvae for 3 h and 12 h, respectively, which were mainly enriched in alpha-linolenic acid and phenylpropanoid pathways according to transcriptomic analysis. In addition, CUT&Tag-seq analysis revealed increased H3K9ac in FAW-infested plants, and there were 422 and 543 up-regulated genes enriched with H3K9ac observed at 3 h and 12 h after FAW feeding, respectively. Genes with increased H3K9ac were mainly enriched in the transcription start site (TSS), suggesting that H3K9ac is related to gene transcription. Integrative analysis of both RNA-seq and CUT&Tag-seq data showed that up-expressed genes with H3K9ac enrichment were mainly involved in the jasmonic acid (JA) and phenylpropanoid pathways. Particularly, two spermidine hydroxycinnamoyl transferase genes SHT1 and SHT2 involved in phenolamide biosynthesis were highly modified by H3K9ac in FAW-infested plants. Furthermore, the Ossht1 and Ossht2 transgenic lines exhibited decreased resistance against FAW larvae. Our findings suggest that rice responds to insect herbivory via H3K9ac epigenetic regulation in the JA signaling and phenolamide biosynthesis pathways.

Staging liver fibrosis by a continuous-time random-walk diffusion model.

PURPOSE: Noninvasive assessment of liver fibrosis holds significant clinical importance. We aimed to evaluate the clinical potential of using a continuous-time random-walk diffusion model (CTRW) for staging liver fibrosis. METHODS: This prospective study included 52 patients suspected of liver disease and scheduled for liver biopsy. All patients underwent multi-b value diffusion-weighted imaging (DWI) using a 1.5 T MR scanner to derive the anomalous diffusion coefficient (D) and temporal (α) and spatial (ß) diffusion heterogeneity indexes sourced from the CTRW. The mono-exponential DWI-derived apparent diffusion coefficient (ADC), transient elastography-derived liver stiffness measurement (LSM), aspartate aminotransferase-to-platelet ratio index (APRI), and fibrosis-4 (FIB-4) index were calculated. We assessed and compared the correlations of these parameters with fibrosis stages and their efficacy in staging liver fibrosis. RESULTS: Significant correlations with fibrosis stages were found for APRI (r = 0.336), FIB-4 (r = 0.351), LSM (r = 0.523), D (r = -0.458), and ADC (r = -0.473). Significant differences were observed between APRI, LSM, D, and ADC of different fibrosis stages. The diagnostic performance of an index that combined D, α, ß, ADC, and LSM was superior to that of ADC or LSM alone for fibrosis stage F ≥ 2 and better than the index that combined D, α, ß for fibrosis stage F ≥ 4. CONCLUSIONS: Accurate liver fibrosis staging was achieved with a model that combined CTRW-derived parameters (D, α, and ß), ADC, and LSM. The model could serve as a reliable tool for noninvasive fibrosis evaluation.

Rice Defense Responses Orchestrated by Oral Bacteria of the Rice Striped Stem Borer, Chilo suppressalis.

Plant defenses in response to chewing insects are generally regulated by jasmonic acid (JA) signaling pathway, whereas salicylic acid (SA) signaling is mainly involved in plant defense against biotrophic pathogens and piercing-sucking insects. Previous studies showed that both JA- and SA-related defenses in rice plants were triggered by the infestation of the rice striped stem borer (SSB, Chilo suppressalis), a destructive pest causing severe damage to rice production. Herbivore-associated microbes play an important role in modulating plant-insect interaction, and thus we speculate that the SSB symbiotic microbes acting as a hidden player may cause this anomalous result. The antibiotics (AB) treatment significantly depressed the performance of field-collected SSB larvae on rice plants, and reduced the quantities of bacteria around the wounds of rice stems compared to non-AB treatment. In response to mechanical wounding and oral secretions (OS) collected from non-AB treated larvae, rice plants exhibited lower levels of JA-regulated defenses, but higher levels of SA-regulated defenses compared to the treatment of OS from AB-treated larvae determined by using a combination of biochemical and molecular methods. Among seven culturable bacteria isolated from the OS of SSB larvae, Enterobacter and Acinetobacter contributed to the suppression of JA signaling-related defenses in rice plants, and axenic larvae reinoculated with these two strains displayed better performance on rice plants. Our findings demonstrate that SSB larvae exploit oral secreted bacteria to interfere with plant anti-herbivore defense and avoid fully activating the JA-regulated antiherbivore defenses of rice plants.

Impact of Wedge Parameters on Ultrasonic Lamb Wave Liquid-Level Sensor.

The ultrasonic Lamb wave detection principle can realize the noncontact measurement of liquid level in closed containers. When designing an ultrasonic Lamb wave sensor, it is vital to thoroughly study and select the optimal wedge size at the front of the sensor. In this paper, firstly, we select the best working mode of Lamb waves according to their propagation dispersion curve in aluminum alloy, and we obtain the best angle of wedge through experiments. Secondly, we study the impact of the size of the wedge block on the results, and we obtain the selection method of wedge block parameters. The evaluations show that, when the frequency-thickness product is 3 MHz·mm, the Lamb waves work in the A1 mode, and the experimental effect is the best. At this time, the incident angle of the ultrasonic wave is 27.39°. The wedge thickness should be designed to avoid the near-field area of the ultrasonic field, and we should choose the length as odd multiples of 1/4 wavelength. The rules obtained from the experiment can effectively select the best working mode for ultrasonic Lamb waves, while also providing a basis for the design of the wedge block size in a Lamb wave sensor.

Random phase shifting shadow moiré using a one-dimensional minimizer.

The introduction of a random phase-shifting technique into a shadow moiré system, where an equal and known (or unknown) phase step is used to demodulate the phase of interest, is beneficial for the improvement of measurement accuracy. However, in spite of recent advances in optical metrology phase-shifting techniques, simultaneously estimating unequal and unknown phase shifts from three random phase-shifting fringe patterns remains a significant challenge. This paper presents a one-dimensional minimizer-based technique to address this ill-posed problem of phase demodulation from random phase-shifting patterns. In this method, two new sets of connected fringe patterns, without background illumination, are constructed through normalizing the secondary fringe patterns. Then, a generalized phase-shifting algorithm is developed by utilizing the character of the modulation factor's standard deviation distribution. Both numerical simulations and optical experiments are performed to demonstrate the high accuracy and robustness of the proposed method.

Production of an aberrant splice variant of CCL5 is not caused by genetic mutation in the mammary glands of mastitis­infected Holstein cows.

Genetic mutations, including single nucleotide polymorphisms (SNPs), result in aberrant alternatively splicing of gene and involves in susceptibility of inflammatory diseases, including bovine mastitis. C­C motif chemokine ligand 5 (CCL5) is an immune­associated gene, but its alternative splicing (AS) mechanism of gene expression has not yet been understood. The present study identified the splice variant of CCL5 and the compared differential expression of various transcripts between healthy and mastitic mammary gland tissue from cows. A novel transcript lacking exon 2 with a deletion of 112 bp (referred to as CCL5­AS) was identified in the mammary gland. The expression of CCL5­AS was lower compared with CCL5­reference in the healthy and mastitic mammary tissues. A total of two novel SNPs (g.1647 C>T and g.1804 G>A) were identified in exon 2 of CCL5. Using the splicing mini­gene reporter assay in bovine mammary epithelial cells (MAC­T) and 293T cells, it was confirmed that the production of CCL5­AS was not caused by the two SNPs. The present findings suggested that alternative splicing is one of the mechanisms of CCL5 expression regulation and is involved in mastitis infection, but that genetic mutation was not responsible for the generation of the abnormal transcript of CCL5 in cows.