Photosynthesis occurs mainly in chloroplasts, whose development is regulated by proteins encoded by nuclear genes.  Among them, pentapeptide repeat (PPR) proteins participate in organelle RNA editing.  Although there are more than 450 members of the PPR protein family in rice, only a few affect RNA editing in rice chloroplasts.  Gene editing technology has created new rice germplasm and mutants, which could be used for rice breeding and gene function study.  This study evaluated the functions of OsPPR9 in chloroplast RNA editing in rice.  The osppr9 mutants were obtained by CRISPR/Cas9, which showed yellowing leaves and a lethal phenotype, with suppressed expression of genes associated with chloroplast development and accumulation of photosynthetic-related proteins.  In addition, loss of OsPPR9 protein function reduces the editing efficiency of rps8-C182, rpoC2-C4106, rps14-C80, and ndhB-C611 RNA editing sites, which affects chloroplast growth and development in rice.  Our data showed that OsPPR9 is highly expressed in rice leaves and encodes a DYW-PPR protein localized in chloroplasts.  Besides, the OsPPR9 protein was shown to interact with OsMORF2 and OsMORF9.  Together, our findings provide insights into the role of the PPR protein in regulating chloroplast development in rice. 

Insufficient available phosphorus in soil has become an important limiting factor for the improvement of yield and quality in soybean.  The mining of QTLs and candidate genes controlling soybean phosphorus utilization related traits is a necessary strategy to solve this problem.  In this study, 11 phosphorus utilization related traits of a natural population of 281 typical soybean germplasms and a recombinant inbred line (RIL) population of 270 lines were evaluated under different phosphorus conditions at two critical stages: the four-leaf stage as the seedling critical stage was designated as the T₁ stage, and the six-leaf stage as the flowering critical stage was designated as the T₂ stage.  In total, 200 single nucleotide polymorphism (SNP) loci associated with phosphorus utilization related traits were identified in the natural population, including 91 detected at the T₁ stage, and 109 detected at the T₂ stage.  Among these SNP loci, one SNP cluster (s715611375, ss715611377, ss715611379 and ss715611380) on Gm12 was shown to be significantly associated with plant height under the low phosphorus condition at the T₁ stage, and the elite haplotype showed significantly greater plant height than the others.  Meanwhile, one pleiotropic SNP cluster (ss715606501, ss715606506 and ss715606543) on Gm10 was found to be significantly associated with the ratio of root/shoot, root and total dry weights under the low phosphorus condition at the T₂ stage, and the elite haplotype also presented significantly higher values for related characteristics under the phosphorus starvation condition.  Furthermore, four co-associated SNP loci (ss715597964, ss715607012, ss715622173 and ss715602331) were identified under the low phosphorus condition at both the T₁ and T₂ stages, and 12 QTLs were found to be consistent with these genetic loci in the RIL population.  More importantly, 14 candidate genes, including MYB transcription factor, purple acid phosphatase, sugar transporter and HSP20-like chaperones superfamily genes, etc., showed differential expression levels after low phosphorus treatment, and three of them were further verified by qRT-PCR.  Thus, these genetic loci and candidate genes could be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of soybean phosphorus utilization.

Whole genome duplication (WGD) and tandem duplication (TD) are important modes of gene amplification and functional innovation, and they are common in plant genome evolution.  We analyzed the genomes of three Solanaceae species (Solanum lycopersicum, Capsicum annuum, and Petunia inflata), which share a common distant ancestor with Vitis vinifera, Theobroma cacao, and Coffea canephora but have undergone an extra whole genome triplication (WGT) event.  The analysis was used to investigate the phenomenon of tandem gene evolution with (S. lycopersicum) or without WGT (V. vinifera).  Among the tandem gene arrays in these genomes, we found that V. vinifera, which has not experienced the WGT event, retained relatively more and larger tandem duplicated gene (TDG) clusters than the Solanaceae species that experienced the WGT event.  Larger TDG clusters tend to be derived from older TD events, so this indicates that continuous TDGs (absolute dosage) accumulated during long-term evolution.  In addition, WGD and TD show a significant bias in the functional categories of the genes retained.  WGD tends to retain dose-sensitive genes related to biological processes, including DNA-binding and transcription factor activity, while TD tends to retain genes involved in stress resistance.  WGD and TD also provide more possibilities for gene functional innovation through gene fusion and fission.  The TDG cluster containing the tomato fusarium wilt resistance gene I3 contains 15 genes, and one of these genes, Solyc07g055560, has undergone a fusion event after the duplication events.  These data provide evidence that helps explain the new functionalization of TDGs in adapting to environmental changes.  

    The increase of atmospheric carbon dioxide (CO₂) concentration adversely affect several quality traits of rice grains, but the biochemical mechanism remains unclear. The objectives of this study were to determine how changes in the source-sink relationship affected rice quality. Source-sink manipulation was achieved by free-air CO₂ enrichment from tillering to maturity and partial removal of spikelet at anthesis using a japonica rice cultivar Wuyunjing 23. Enrichment with CO₂ decreased the head rice percentage and protein concentration of milled rice, but increased the grain chalkiness. In contrast, spikelet removal resulted in a dramatic increase in the head rice percentage and protein concentration, and much less grain chalkiness. Neither CO₂ enrichment nor spikelet removal affected the starch content, but the distribution of starch granule size showed distinct treatment effects. On average, spikelet removal decreased the percentage of starch granules of diameter >10 and 5–10 μm by 23.6 and 5.6%, respectively, and increased those with a diameter of 2–5 and <2 μm by 4.6 and 3.3%, respectively. In contrast, CO₂ elevation showed an opposite response: increasing the proportion of large starch granules (>5 μm) and decreasing that of <5 μm. The starch pasting properties were affected by spikelet removal much more than by CO₂ elevation. These results indicated that the protein concentration and starch granule size played a role in chalkiness formation under these experimental conditions.

Strategies for insect population control are currently targeting chemical communication at the molecular level. The diamondback moth Plutella xylostella represents one of the most serious pests in agriculture, however detailed information on the proteins mediating olfaction in this species is still poor. This species is endowed with a repertoire of a large number of olfactory receptors and odorant binding proteins (OBPs). As a contribution to map the specificities of these chemical sensors in the moth and eventually unravel the complexity of chemodetection, we have measured the affinities of three selected OBPs to a series of potential odorants. Three proteins are highly divergent in their amino acid sequences and show markedly different expression profiles. In fact, PxylOBP3 is exclusively expressed in the antennae of both sexes, PxylOBP9 is male specific and present only in antennae and reproductive organs, while PxylOBP19, an unusual OBP with nine cysteines, is ubiquitously present in all the organs examined. Such expression pattern suggests that the last two proteins may be involved in non-chemosensory functions. Despite such differences, the three OBPs exhibit similar binding spectra, together with high selectivity. Among the 26 natural compounds tested, only two proved to be good ligands, retinol and coniferyl aldehyde. This second compound is particularly interesting being part of the chemical pathway leading to regeneration of lignin, one of the defense strategies of the plant against insect attack, and might find applications as a repellent for P. xylostella and other pests.

This study was carried out to determine the effect of replacement of forage fiber sources from alfalfa and Leymus chinensis with nonforage fiber sources (NFFS) from dried distillers grains with solubles and corn germ meal on calves growth, rumen development and blood parameters. 48 female and 12 male calves ((110.55±15.36) kg of body weight and 12 wk of age) were assigned randomly to four dietary treatments (15 calves/treatment) in a completely randomized design. Experimental diets were: 0% NFFS (control), 9% NFFS (group 1), 18% NFFS (group 2), 27% NFFS (group 3), and contained equivalent neutral detergent fiber and total digestible nutrients, respectively. The dry matter intake was similar among diets, averaging 3.33 kg d-1, and no differences were detected for body weight, withers height, body length and heart girth. In addition, the development of rumen, reticulum, omasum and abomasum also were similar among diets. Dry matter, crude protein, and neutral detergent fiber digestibilities increased with the increasing levels of NFFS in the experimental diets, but had no significant effect. Blood urea nitrogen, total protein and glubulin were not affected by the dietary treatment, but group 3 resulted in the highest (P<0.05) concentrations of glucose and the lowest (P<0.05) concentrations of triglycerides and albumin. In conclusion, dried distillers grains with solubles (DDGS) and corn germ meal (CGM) were available and alternative fiber sources for Holstein calf diets.

The purpose of the study was to investigate the pharmacokinetics of cefquinome in plasma and milk samples of lactating Chinese Holstein following a single intramammary administration into one quarter at the dose of 75 mg. Residue depletion of cefquinome in milk administrated at one quarter following three consecutive infusions at the same dose were also carried out. Cefquinome concentrations in plasma and milk were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. A non-compartmental analysis was used to obtain the pharmacokinetic parameters of cefquinome. Following the single treatment, cefquinome wasn’t detected in any of the plasma samples. The concentration of cefquinome in milk reached peaked values (Cmax) of (599.00±322.00) μg mL-1 at 2 h after administration (Tmax), elimination half-life (t1/2λz) was (4.63±0.26) h, area under the concentration-time curve (AUC0-∞) was (4 890.19±1 906.98) μg mL-1 h, and mean residence time (MRT) was (6.03±2.27) h. In residue depletion study, cefquinome concentrations in 5 out of 6 milk samples at 72 h were lower than the maximum residue limit fixed by the European regulatory agency (20 μg kg-1 for cefquinome) and cefquinome still could be detected in milk of treated quarters at 120 h post-treatment. The maximum concentration (Cmax) of cefquinome in milk from treated quarters was (486.50±262.92) μg mL-1 and arrived at 6 h after administration (Tmax), elimination half-life (t1/2λz) was (6.30±0.76) h, area under the concentration-time curve (AUC0-∞) was (44747.79±11434.43) μg mL-1 h, and mean residence time (MRT) was (10.09±1.40) h. This study showed that cefquinome has the feature of poor penetration into blood and was eliminated quickly from milk in lactating cows after intramammary administration.

Hybrid indica rice (Oryza sativa L.) cultivars play an important role in rice production system due to its heterosis, resistance to environmental stress, large panicle, and high yield potential. However, no attention has been given to its root growth dynamic responses to rising atmospheric CO2 concentration ([CO2]) in conjunction with nitrogen (N) availability. Free air CO2 enrichment (FACE) and N have significant effects on rice root growth. In this experiment, a hybrid cultivar Shanyou 63 (Oryza sativa L.) was used to study the effects of FACE and N levels on roots growth of rice. The results showed a significant increase in both adventitious root volume (ARV) and adventitious root dry weight (ARD) under the FACE treatment. The application of nitrogen also increased ARV and ARD, but the increase was smaller than that under FACE treatment. On the basis of the FACE experiment, numerical models for rice adventitious root volume and dry weight were built with the time as the driving factor. The models illustrated the dynamic development of rice adventitious root volume and dry weight after transplanting, regulated either by the influence factor of atmospheric [CO2] or by N application. The models were successfully used to predict ARV and ARD under FACE treatment in a different year with the predicted data being closely related to the actual experimental data. The model had guiding significance to growth regulation of rice root under the condition of atmospheric [CO2] rising in the future.

The water uptake dynamics in maize, wheat, and barley under salt stress were investigated with a xylem pressure probe. The average xylem pressure responses to salt stress in the three plants were 36, 93, and 89% of the osmotic stresses for maize, wheat, and barley, respectively, which are significantly smaller than the magnitude of the osmotic stresses being applied. In order to explain the thermodynamic discrepancies among the water potential changes in the root xylem of the three plants, a novel approach, tentatively named the “symplastic flow dilution model” was proposed in this paper. The model was presented in an attempt to give answers to the problem of how the roots under salt stress could absorb water when the water potential of the xylem sap is considerably higher than that of the solution in the root ambient. According to the model, the salt solution in the microenvironment of the endodermis of a root was diluted to some extent by the efflux from cells so the central stele of the root is not exposed to the same solution bathing the root with the same salt concentration. In contrast, we also presented another approach, the “reflection coefficient progression approach”, which was less likely to be true because it requires a considerable amount of solute to be transported into the root xylem when the salt stress is severe.

In this paper, toxicity and safety of high-dose irradiated chicken-breast meat were evaluated. For assays of acute toxicity, genetic toxicity, and sub-chronic toxicity, ames test, mice bone marrow erythrocyte micronucleus, and mice sperm abnormality were performed. The results showed that, in the acute oral toxicity tests, median lethal dose (more than 10 000 mg kg-1) in male and female ICR mice showed no toxicological signs. For subacute 30-d oral toxicology of irradiated chicken-breast meat with dose of 10, 15 and 25 kGy in both male and female SD rats, no noticeable toxicological effects were observed. It is concluded that chicken-breast meat with high-dose irradiation has no acute toxicity and no genotoxicity, nor harmful effects on the animal body at the tested dosage range. Therefore, high-dose irradiated chicken-breast meat is safe for pet consumption.

Mycotoxins are the most widely present pollutants in both dietary provisions and livestock feed, and they pose a series of hazards for humans and animals. Deoxynivalenol (DON) is a prevalent mycotoxin that is primarily produced by Fusarium spp. and commonly found in various cereal products. Feeding swine diets contaminated with trichothecene DON can lead to major adverse effects, including reduced feed intake, diminished weight gains, and compromised immune function. Among all animal species tested, swine were the most sensitive to DON. Here we explored the disruption of gut health by DON, considering aspects such as intestinal histomorphology, epithelial barrier functions, the intestinal immune system, microflora, and short-chain fatty acid production in the intestines. Numerous additives have been documented for their potential in the detoxification of DON. These additives can alleviate the toxic effects of DON on pigs by modulating the Nrf2-Keap1, mitogen-activated protein kinases (MAPKs) and Nuclear factor kappa-B (NF-κB) signaling pathways. Additionally, there are additives capable of mitigating the toxicity of DON through adsorption or biotransformation. This update has novel potential for advancing our comprehension of the mechanisms linked to DON intestinal toxicity and facilitating the formulation of innovative strategies to mitigate the impact of DON.