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In this study, the changes in myofibrillar protein oxidation, taste substance and taste characteristics of dried Penaeus vannamei were investigated under accelerated storage conditions, and a correlation analysis was carried out between myofibrillar protein oxidation and taste characteristics. As a result, the color of dried Penaeus vannamei gradually changed to dark brown, the content of total sulfhydryl group decreased, and the carbonyl group content and surface hydrophobicity increased, which indicated increased degree of oxidation of myofibril protein. The content of inosine monphosphate and umami free amino acids in dried shrimp showed a trend of first increasing and then decreasing, while the contents of sweet free amino acids and total free amino acids decreased gradually. The electronic tongue was used to characterize the taste change of dried Penaeus vannamei, and it was found that the umami and sweetness intensity of dried Penaeus vannamei decreased, the bitterness intensity increased, but the saltiness intensity did not obvious change. The richness first increased and then decreased. The correlation analysis between protein oxidation and taste indexes showed that the degree of protein oxidation of dried Penaeus vannamei was positively correlated with the bitterness intensity, and negatively correlated with the umami, sweetness, saltiness intensity and richness. These results showed that there was no significant difference in the taste of dried white shrimp during short-term storage, but with the extension of storage time, the appearance and color deteriorated, the oxidation of myofibrillar protein increased, and the taste quality decreased. The findings from this study provide a theoretical and data basis for regulating the storage quality of white shrimp.

The lower reaches of the Minjiang River are located in an area of land-sea-air interaction. It is not only a sensitive area concerning environmental evolution, but also a hotspot for archaeological research on the southeast coast of China. Exploring the scope of ancient human activities and the evolution of land-use patterns is of great significance for understanding the development of human-land relations. By generating various cost surfaces of sites through GIS cost distance analysis and combining with the site catchment theory and method, we comprehensively analyzed the human activity range and land-use pattern in every cultural period from the Neolithic to the Bronze Age in the lower reaches of the Minjiang River and reconstructed the potential population in each period of the region. The results show that: (1) the area of site catchment, available and actually developed land increased from the Keqiutou to Huangtulun culture period in the lower reaches of the Minjiang River. Chronologically, the area of the site catchment continues to grow from 212 km2 to 4,858 km2, the accessible land area increased from 261 km2 to 7,599 km2, and the land area that was actually used by ancient humans continuously increased from 173 km2 to 3,914 km2. (2) With the development process of culture, the land-use intensity of prehistoric humans in the region first increased and then decreased by 81.58%, 92.95%, 87.99%, 79.33% and 80.57%, respectively, and the degree of land development was reduced, which may be related to the development and progress of productive forces. The frequency of ancient human exchanges can be represented by the ratio of the number of sites in the overlapping site catchment to the total number of sites in the same period (87.50%, 60.00%, 66.67%, 92.54%, and 97.81%, respectively). (3) The reconstruction results showed that the potential population in the area continued to expand, with substantial population growth in the lower Tanshishan-Tanshishan and Huangguashan-Huangtulun transitional periods. It was inferred that there was a relationship between population pressure and culture succession.

Mung bean seed was soaked and germinated in CaCl2 electrolyzed water (CEW) in order to investigate the effect and mechanism of CEW on preserving the quality of mung bean sprouts. The results showed that after 5 days of storage, the mass loss percentage of mung bean sprouts treated with electrolyzed CaCl2 solution at a concentration of 25 mmol/L decreased, and the hardness and brittleness increased by approximately 1.28 times higher than compared with the control group treated with tap water. The bactericidal effect of CEW was obvious, reducing the microbial load on the surface of mung bean sprouts by nearly one lg (CFU/g). Low-field nuclear magnetic resonance (NMR) spectroscopy showed that the state of water in mung bean sprouts changed, and the bound water content increased. The relative conductivity, malondialdehyde (MDA) content and hydrogen peroxide content decreased by 16.5%, 27.5%, and 36.8%, respectively, the integrity of the cell membrane was maintained, and the accumulation of reactive oxygen species (ROS) was reduced, thus reducing the degree of membrane lipid peroxidation. In addition, the browning of mung bean sprouts during storage was inhibited by CEW treatment, and the mechanism could be related to the decrease in the content of total phenols as browning substrates and the decrease in the activities of polyphenol oxidase (PPO), peroxidase (POd) and phenylalanine ammonialyase (PAL). Therefore, CEW treatment can delay the quality deterioration of mung bean sprouts during storage to a certain extent.

Viral diseases are a leading cause of worldwide yield losses in crop production. Breeding of resistance genes (R gene) into elite crop cultivars has been the standard and most cost-effective practice. However, R gene-mediated resistance is limited by the available R genes within genetic resources and in many cases, by strain specificity. Therefore, it is important to generate new and broad-spectrum antiviral strategies. The CRISPR-Cas9 (clustered regularly interspaced palindromic repeat, CRISPR-associated) editing system has been employed to confer resistance to human viruses and several plant single-stranded DNA geminiviruses, pointing out the possible application of the CRISPR-Cas9 system for virus control. Here, we demonstrate that strong viral resistance to cauliflower mosaic virus (CaMV), a pararetrovirus with a double-stranded DNA genome, can be achieved through Cas9-mediated multiplex targeting of the viral coat protein sequence. We further show that small interfering RNAs (siRNA) are produced and mostly map to the 3 end of single-guide RNAs (sgRNA), although very low levels of siRNAs map to the spacer region as well. However, these siRNAs are not responsible for the inhibited CaMV infection because there is no resistance if Cas9 is not present. We have also observed edited viruses in systematically infected leaves in some transgenic plants, with short deletions or insertions consistent with Cas9-induced DNA breaks at the sgRNA target sites in coat protein coding sequence. These edited coat proteins, in most cases, led to earlier translation stop and thus, nonfunctional coat proteins. We also recovered wild-type CP sequence in these infected transgenic plants, suggesting these edited viral genomes were packaged by wild-type coat proteins. Our data demonstrate that the CRISPR-Cas9 system can be used for virus control against plant pararetroviruses with further modifications.

Background: Electrolyzed water, a green chemistry invention, is a novel disinfectant that has been widely used in the food field. Previous studies have found that slightly acidic electrolyzed water not only has a bactericidal effect but also promotes the accumulation of active substances in many types of sprouts. We developed a new type of electrolyzed water, CaCl2–HCl electrolyzed water (CHEW), which can effectively enhance the formation of glucosinolates and isothiocyanates in broccoli sprouts. The molecular mechanism by which CaCl2–HCl electrolyzed water promotes glucosinolate metabolism in broccoli sprouts during growth was investigated in this study. Results: On the 4th day, the total glucosinolate content in broccoli sprouts reached 195.50 μmol/g DW under CHEW treatment. On the 8th day, compared to treatment with tap water, the contents of three isothiocyanates (sulforaphane, erucin, and 4-isothiocyanato-1-butene) in broccoli sprouts under CHEW treatment were significantly increased by 45.93, 34.04 and 185.15%, respectively. The results of calcium distribution and qRT‒PCR assessments indicated that CHEW treatment activated calcium signalling in broccoli sprouts and promoted the relative expression of glucosinolate biosynthesis-related genes through calcium sensors [calmodulin (CaM), calmodulin-like protein (CML), and calcium-dependent protein kinase (CDPK)] and the calcium-binding nuclear protein IQD1. Conclusion: Our research provides new insights into the molecular mechanism of glucosinolate metabolism and a theoretical basis for cultivating high-quality broccoli sprouts. [ABSTRACT FROM AUTHOR]

Pseudomonas syringae causes plant diseases, and the main virulence mechanism is a type III secretion system (T3SS) that translocates dozens of effector proteins into plant cells. Here we report the existence of a subgroup of P. syringae isolates that do not cause disease on any plant species tested. This group is monophyletic and most likely evolved from a pathogenic P. syringae ancestor through loss of the T3SS. In the nonpathogenic isolate P. syringae 508 the genomic region that in pathogenic P. syringae strains contains the hrp-hrc cluster coding for the T3SS and flanking effector genes is absent. P. syringae 508 was also surveyed for the presence of effector orthologues from the closely related pathogenic strain P. syringae pv. syringae B728a, but none were detected. The absence of the hrp-hrc cluster and effector orthologues was confirmed for other nonpathogenic isolates. Using the AvrRpt2 effector as reporter revealed the inability of P. syringae 508 to translocate effectors into plant cells. Adding a plasmid-encoded T3SS and the P. syringae pv. syringae 61 effector gene hopA1 increased in planta growth almost 10-fold. This suggests that P. syringae 508 supplemented with a T3SS could be used to determine functions of individual effectors in the context of a plant infection, avoiding the confounding elect of other effectors with similar functions present in effector mutants of pathogenic isolates.

Aims/Introduction: Tubulointerstitial fibrosis is a hallmark of diabetic nephropathy and is associated with an epithelial‐to‐mesenchymal transition (EMT) program and aberrant glycolysis. Dimeric pyruvate kinase (PK) M2 (PKM2) acts as a key protein kinase in aberrant glycolysis by promoting the accumulation of hypoxia‐inducible factor (HIF)‐1α, while tetrameric PKM2 functions as a pyruvate kinase in oxidative phosphorylation. The aim of the research is to study the effect of PKM2 tetramer activation on preventing kidney fibrosis via suppression of aberrant glycolysis and the EMT program. Materials and methods: In vivo: Streptozotocin (STZ) was utilized to induce diabetes in 8‐week‐old CD‐1 mice; 4 weeks after diabetes induction, proteinuria‐induced kidney fibrosis was developed by intraperitoneal injection of bovine serum albumin (BSA: 0.3 g/30 g BW) for 14 days; The PKM2 activator TEPP‐46 was also administered orally simultaneously. In vitro: HK2 cells were co‐treated with high‐glucose media or/and TGF‐β1 and TEPP46 for 48 h, cellular protein was extracted for evaluation. Results: Diabetic mice developed kidney fibrosis associated with aberrant glycolysis and EMT; BSA injection accelerated kidney fibrosis in both the control and diabetic mice; TEPP‐46 rescued the kidney fibrosis. In HK2 cells, TEPP‐46 suppressed the EMT program induced by TGF‐β1 and/or high‐glucose incubation. TEPP‐46‐induced PKM2 tetramer formation and PK activity resulted in suppression of HIF‐1α and lactate accumulation. Specific siRNA‐mediated knockdown of HIF‐1α expression diminished high glucose‐induced mesenchymal protein levels. Conclusion: PKM2 activation could restore the tubular phenotype via suppression of the EMT program and aberrant glycolysis, providing an alternative target to mitigate fibrosis in diabetic kidneys. [ABSTRACT FROM AUTHOR]

Aims/Introduction: To establish novel therapies to combat diabetic kidney disease, a human disease‐relevant animal model is essential. However, a type 2 diabetic mouse model presenting progressive kidney fibrosis has not yet been established. Kidneys of streptozotocin‐induced diabetic CD‐1 mice showed severe fibrosis compared with other backgrounds of mice associated with the suppression of antifibrotic peptide N‐acetyl‐seryl‐aspartyl‐lysyl‐proline. The BKS background (BKSdb/db) is often utilized for diabetic kidney disease research; the kidney fibrosis in the BKSdb/db phenotype is minimal. Materials and Methods: We generated CD‐1db/db mice by backcrossing the db gene into the CD‐1 background, and analyzed phenotypic differences compared with BKSdb/db and CD‐1db/m mice. Results: Male CD‐1db/db mice appeared to have elevated blood glucose levels compared with those of BKSdb/db mice. Fasting insulin levels declined in CD‐1db/db mice. Plasma cystatin C levels tended to be elevated in CD‐1db/db mice from 16 to 24 weeks‐of‐age. Male CD‐1db/db mice showed significantly progressive kidney and heart fibrosis from 16 to 24 weeks‐of‐age when compared with that of age‐matched BKSdb/db mice. The gene expression profile showed fibrogenic program‐associated genes in male CD‐1db/db mice. Male CD‐1db/db mice displayed significantly lower urine antifibrotic peptide N‐acetyl‐seryl‐aspartyl‐lysyl‐proline when compared to that of BKSdb/db at 24 weeks‐of‐age. The gene expression of prolyl oligopeptidase, the enzyme essential for antifibrotic peptide N‐acetyl‐seryl‐aspartyl‐lysyl‐proline production from thymosin β4, was significantly lower in the CD‐1 mice. Thymosin β4 levels were also lower in CD‐1 mice. Conclusions: These results suggest that CD‐1db/db mice are a novel type 2 diabetic mouse model with progressive kidney and heart fibrosis. [ABSTRACT FROM AUTHOR]