Physiological Stages Research Articles

Dynamic surface adapts to multiple service stages by orchestrating responsive polymers and functional peptides

Control over the implant surface functions is highly desirable to enhance tissue healing outcomes but has remained unexplored to adapt to the different service stages. In the present study, we develop a smart titanium surface by orchestrating thermoresponsive polymer and antimicrobial peptide to enable dynamic adaptation to the implantation stage, normal physiological stage and bacterial infection stage. The optimized surface inhibited bacterial adhesion and biofilm formation during surgical implantation, while promoted osteogenesis in the physiological stage. The further temperature increase driven by bacterial infection induced polymer chain collapse to expose antimicrobial peptides by rupturing bacterial membranes, as well as protect the adhered cells from the hostile environment of infection and abnormal temperature. The engineered surface could inhibit infection and promote tissue healing in rabbit subcutaneous and bone defect infection models. This strategy enables the possibility to create a versatile surface platform to balance bacteria/cell-biomaterial interactions at different service stages of implants that has not been achieved before.

PHYSIOLOGICAL RESPONSES OF FEMALE BEEF CATTLE AGAINST PEATLAND MICROCLIMATE STRESS IN CENTRAL KALIMANTAN

This study aimed to evaluate the physiological response of female beef cattle to peatland microclimate stress in Central Kalimantan. This study used direct observation on small holder beef cattle farm. Microclimate data on 41 units cattle barns and physiological parameters of female cattle were collected in the morning, at noon and in the afternoon. The physiological parameter measurements involved 215 female beef cattle, consisting of 119 Bali and 96 crossbred cattle with different physiological stages including pregnant cows, lactating cows, dry cows, heifers and calves. The microclimate condition within cattle barns on peatland of Central Kalimantan is not the comfort zone for beef cattle. It is characterized by high air temperature and relative humidity, and low wind speed, which result in high temperature humidity index (THI). The barn with gable roof type and asbestos materials gave the lowest THI. This Microclimate caused heat stress to beef cattle reared on the peatlands, indicated by the high rectal temperature, heart rate, respiratory rate, and heat tolerance coefficient, although it was still categorized as mild to moderate stress. Bali cattle showed better physiological responses to microclimate stress than crossbred cattle. Pregnant crossbred cows were the most susceptible to peatland microclimate stress.

Temporal Changes in Clinical Characteristics and Outcomes of Adults With Congenital Heart Disease

The purpose of this study was to assess differences in the clinical characteristics (defined by congenital heart disease [CHD] anatomic and physiologic classification scheme) of adults with CHD across different eras, and how these differences influence outcomes (heart failure hospitalization and all-cause mortality). Patients were divided into depending on year of baseline encounter: cohort #1 (1991-2000, n=1,984 [27%]), cohort #2 (2001-2010, n=2,448 [34%]), and cohort #3 (2011-2020, n=2,847 [39%]). Patients were classified into 3 anatomic groups (simple, moderate, and complex CHD) and 4 physiologic stages (stage A-D). There was a temporal increase in the proportion of patients in physiologic stage C (17% vs 21% vs 24%, P < .001), and stage D (7% vs 8% vs 10%, P=.09), with a corresponding decrease in physiologic stage A (39% vs 35% vs 28%, P < .001). No temporal change in anatomic groups. There was a temporal decrease in the incidence of all-cause mortality (12.7 vs 10.6 vs 9.5 per 1,000 patient-years, P < .001). However, there was a temporal increase in the incidence of heart failure hospitalization (6.8 vs 8.4 vs 11.2 per 1,000 patient-years, P < .001). CHD physiologic stage (but not anatomic groups) was associated with heart failure hospitalization and all-cause mortality. There is a need for better strategies to identify and treat heart failure, and to modify the risk factors associated with heart failure and all-cause mortality.

Efficacy of a feed additive consisting of Bacillus velezensisNITE BP-01844 (BA-KING®) for chickens for fattening, chickens reared for laying, turkeys for fattening, turkeys reared for breeding and all avian species for fattening, or rearing to slaughter or point of lay including non-food producing species (Toa Biopharma Co., Ltd.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of BA-KING® Bacillus velezensis as a zootechnical feed additive to be used as a gut flora stabiliser for chickens for fattening, chickens reared for laying, turkeys for fattening, turkeys reared for breeding and all avian species for fattening or rearing to slaughter or point of lay including non-food producing species. The product under assessment is based on viable spores of a strain identified as B.velezensis, which is considered suitable for the qualified presumption of safety (QPS) approach to safety assessment. In a previous opinion, the FEEDAP Panel concluded that BA-KING® was safe for the target species, consumers of products derived from animals fed the additive and the environment. Additionally, the additive was not irritant to skin but potentially irritant to eyes and respiratory sensitiser. The Panel could not conclude on the efficacy of the additive for the target species at the proposed conditions of use. In the current application, two additional efficacy trials in chickens for fattening were provided. The results showed an improvement in the performance parameters of chickens when supplemented with BA-KING® at 2.0 × 108 CFU/kg complete feed relative to a control group. Considering the previously submitted studies and the newly submitted studies in chickens for fattening, the Panel concluded that BA-KING®, supplemented at 2.0 × 108 CFU/kg complete feed, has the potential to be efficacious in all avian species for fattening or reared for laying/breeding and non-food-producing avian species at the same physiological stage.

Characteristics of food environments that influence food acquisition and diets of women in low-and middle-income countries: a scoping review protocol.

This scoping review aims to identify and map characteristics of food environments that influence food-acquisition practices and dietary intake of women of reproductive age in low- and middle-income countries. Due to the disproportionate burden of malnutrition on women of reproductive age in low- and middle-income countries, accelerated progress in improving women's nutrition is required to achieve Sustainable Development Goal 2 "Zero hunger" by 2030. Food environments are increasingly recognized as the key interface between consumers and food systems; however, little is known about the characteristics that influence women's food acquisition and diets in low- and middle-income countries, especially during physiological stages of heightened nutritional requirement, such as pre-conception, pregnancy, and breastfeeding. This review will consider quantitative, qualitative, mixed method, or review studies that report on the influence of food environment characteristics on food-acquisition practices and dietary intakes of women aged 15 to 49 years in any low- and middle-income country, as defined by the World Bank in 2021. Studies published in English, Spanish, Portuguese, or French from January 2010 onwards will be included. Twenty-one databases across EBSCO, Web of Science Core Collection, and PubMed will be searched. Screening, selection, and data extraction will be performed in duplicate by 2 members of the team, with any discrepancies resolved by group discussion. The patterns of food-acquisition and dietary intake in relation to food environment characteristics will be charted, mapped, and summarized in tabular and graphical formats. Findings will inform the refinement of effective food environment conceptual frameworks for this nutritionally vulnerable group.

ADAMTS Proteases: Importance in Animal Reproduction.

Many reproductive physiological processes, such as folliculogenesis, ovulation, implantation, and fertilization, require the synthesis, remodeling, and degradation of the extracellular matrix (ECM). The ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin Motifs) family genes code for key metalloproteinases in the remodeling process of different ECM. Several genes of this family encode for proteins with important functions in reproductive processes; in particular, ADAMTS1, 4, 5 and 9 are genes that are differentially expressed in cell types and the physiological stages of reproductive tissues. ADAMTS enzymes degrade proteoglycans in the ECM of the follicles so that the oocytes can be released and regulate follicle development during folliculogenesis, favoring the action of essential growth factors, such as FGF-2, FGF-7 and GDF-9. The transcriptional regulation of ADAMTS1 and 9 in preovulatory follicles occurs because of the gonadotropin surge in preovulatory follicles, via the progesterone/progesterone receptor complex. In addition, in the case of ADAMTS1, pathways involving protein kinase A (PKA), extracellular signal regulated protein kinase (ERK1/2) and the epidermal growth factor receptor (EGFR) might contribute to ECM regulation. Different Omic studies indicate the importance of genes of the ADAMTS family from a reproductive aspect. ADAMTS genes could serve as biomarkers for genetic improvement and contribute to enhance fertility and animal reproduction; however, more research related to these genes, the synthesis of proteins encoded by these genes, and regulation in farm animals is needed.

Expression of Locally Produced Adipokines and Their Receptors during Different Physiological and Reproductive Stages in the Bovine Corpus Luteum.

This study aimed to determine the gene expression of different local novel adipokines, such as vaspin, adiponectin, visfatin, and resistin, and their known receptors, namely, heat shock 70 protein 5, adiponectin receptor 1, and adiponectin receptor 2, in the bovine corpus luteum (CL) during different phases of the estrous cycle (on days 1-2, 3-4, 5-7, 8-12, 13-18, >18) and pregnancy (at months 1-2, 3-4, 5-7, >7). The mRNA expression was measured by reverse transcription polymerase chain reaction (RT-qPCR). The mRNA expression levels were normalized to the geometric mean of all three constantly expressed reference genes (cyclophilin A, ubiquitin, ubiquitin C). Our findings suggest that adipokines are expressed and present in all investigated groups, and are specifically up- or downregulated during the estrus cycle and during pregnancy. Vaspin and adiponectin levels were upregulated in the middle and late cycle stages. Resistin was abundant during the CL regression stage and in the first months of pregnancy. The specific expression of adipokine receptors indicates their involvement in the local mechanisms that regulate CL function. Further investigations are required to elucidate the regulative mechanisms underlying the different local effects of adipokines on the ovarian physiology of cows.

Oversized liposomes boost macrophage-targeted RNA delivery to regulate macrophage polarity

Oversized liposomes boost macrophage-targeted RNA delivery to regulate macrophage polarity

Balancing selection and candidate loci for survival and growth during larval development in the Mediterranean mussel, Mytilus galloprovincialis.

Many marine bivalves have complex life histories with distinct developmental processes and genetic mechanisms. Larval development for most bivalves is often a prolonged and crucial physiological stage, where they suffer mass mortality due to early-acting genetic load. In this study, we describe genetic changes taking place within a single generation of families of the Mediterranean mussel Mytilus galloprovincialis over 23 days of larval development. Using replicated cultures and a pooled sequencing approach, we demonstrate that temporal balancing selection at the majority of loci preserve genetic variation in the early developmental stages of M. galloprovincialis. Balancing selection may be the mechanism which maintains standing genetic variation within the mussel genome and may improve the chances of survival and shield larvae from high levels of genetic load. Additionally, we used changes in allele frequencies to identify potential size-associated SNPs and viability-associated SNPs and found that patterns of genetic changes in directionally selected SNPs cannot be simply explained by traditional theories of genetic purging or directional selection without consideration of balancing selection. Finally, we observed a negative correlation between larval growth rates and survival, implying a potential trade-off relationship between the 2 commercially relevant phenotypes.

Nitrogen uptake and remobilization from pre- and post-anthesis stages contribute towards grain yield and grain protein concentration in wheat grown in limited nitrogen conditions

BackgroundIn wheat, nitrogen (N) remobilization from vegetative tissues to developing grains largely depends on genetic and environmental factors. The evaluation of genetic potential of crops under limited resource inputs such as limited N supply would provide an opportunity to identify N-efficient lines with improved N utilisation efficiency and yield potential. We assessed the genetic variation in wheat recombinant inbred lines (RILs) for uptake, partitioning, and remobilization of N towards grain, its association with grain protein concentration (GPC) and grain yield.MethodsWe used the nested association mapping (NAM) population (195 lines) derived by crossing Paragon (P) with CIMMYT core germplasm (P × Cim), Baj (P × Baj), Watkins (P × Wat), and Wyalkatchem (P × Wya). These lines were evaluated in the field for two seasons under limited N supply. The plant sampling was done at anthesis and physiological maturity stages. Various physiological traits were recorded and total N uptake and other N related indices were calculated. The grain protein deviation (GPD) was calculated from the regression of grain yield on GPC. These lines were grouped into different clusters by hierarchical cluster analysis based on grain yield and N-remobilization efficiency (NRE).ResultsThe genetic variation in accumulation of biomass at both pre- and post-anthesis stages were correlated with grain-yield. The NRE significantly correlated with aboveground N uptake at anthesis (AGNa) and grain yield but negatively associated with AGN at post-anthesis (AGNpa) suggesting higher N uptake till anthesis favours high N remobilization during grain filling. Hierarchical cluster analysis of these RILs based on NRE and yield resulted in four clusters, efficient (31), moderately efficient (59), moderately inefficient (58), and inefficient (47). In the N-efficient lines, AGNa contributed to 77% of total N accumulated in grains, while it was 63% in N-inefficient lines. Several N-efficient lines also exhibited positive grain protein deviation (GPD), combining high grain yield and GPC. Among crosses, the P × Cim were superior and N-efficient, while P × Wya responded poorly to low N input.ConclusionsWe propose that traits favouring pre- or post-anthesis biomass accumulation and pre-anthesis N uptake may be targeted for breeding to improve grain-yield under limited N. The lines with positive GPD, a first report of genotype-dependent GPD associated with both AGNpa and AGNa in wheat, may be used as varieties or genetic resources to improve grain yield with high GPC for sustainable development under limited N conditions.

Identification of differentially expressed genes and signaling pathways in Gaoyou duck ovary at different physiological stages.

Gaoyou duck is famous in China and abroad for its good production of double-yolk eggs. However, there has been no systematic research on the egg-laying characteristics of the Gaoyou duck, which limits the development and utilization of breed resource. To identify the essential genes related to ovarian development, the transcriptome profiles of the ovaries of Gaoyou ducks at different physiological stages were analyzed. The transcriptome profiles of the ovaries of Gaoyou ducks at 150 d (before laying), 240 d (egg laying) and 500 d (nesting) were constructed, and the differentially expressed genes (DEGs) underwent GO (gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses. The 6 randomly selected DEGs were verified by real-time fluorescent quantitative PCR that their relative expression was consistent with the transcriptional expression profile. Furthermore, KEGG analysis found that 8 candidate signaling pathways were essential for ovarian development, including the MAPK signaling pathway, Progesterone-mediated oocyte maturation, Cell adhesion molecules (CAMs), NOD-like receptor signaling pathway, ECM-receptor interaction, Focal adhesion, TGF-beta signaling path-way and Phagosome. Finally, 5 key DEGs were identified to participate in ovarian development, including TGIF1, TGFBR2, RAF1, PTK2 and FGF10. Our findings reveal the mechanisms under-lying the molecular regulation of related genes in Gaoyou duck ovarian development.

Role and functions of micro and macro-minerals in swine nutrition: a short review.

Livestock production depends on the utilization of nutrients, and when this is accomplished, there is accelerated momentum toward growth with a low cost-to-feed ratio. Public concern over the consumption of pork with antibiotic residues in animals fed antibiotic growth promoters (AGP) has paved the way for using other natural additives to antibiotics, such as herbs and their products, probiotics, prebiotics, etc. Numerous feed additives are trending to achieve this goal, and a classic example is vitamins and minerals. Vitamins and minerals represent a relatively small percentage of the diet, but they are critical to animal health, well-being, and performance; both play a well-defined role in metabolism, and their requirements can vary depending on the physiological stage of the animals. At the same time, the absence of these vitamins and minerals in animal feed can impair the growth and development of muscles and bones. Most commercial feeds contain vitamins and trace minerals that meet nutrient requirements recommended by National Research Council and animal feeding standards. However, the potential variability and bioavailability of vitamins and trace elements in animal feeds remain controversial because daily feed intake varies, and vitamins are degraded by transportation, storage, and processing. Accordingly, the requirement for vitamins and minerals may need to be adjusted to reflect increased production levels, yet the information presented on this topic is still limited. Therefore, this review focuses on the role and function of different sources of minerals, the mode of action, the general need for micro and macro minerals in non-ruminant diets, and how they improve animal performance.

Embryonic injection of Lactobacillus plantarum PA01 alters the microbial diversity in the gastrointestinal tract of the broilers before and after hatching

The total number of intestinal microbiotas is low, and the intestinal tract develops rapidly and imperfectly at the embryonic stage. Embryonic period as a particular physiological stage is an important time window to explore how to regulate organismal health by probiotics. Therefore, this experiment was conducted to investigate the effect of embryonic injection of Lactobacillus plantarum PA01 at embryonic d 14 (E14) on the microbiome of the contents of the gizzard, cecum at embryonic d 20 (E20) and cecum at d 1 posthatch (D1) by 16S rRNA sequencing. Results showed that PA01 had no significant effect on broiler body weight and yolk sac weight at E20 and D1 (P > 0.05). PA-01 altered the Shannon index and β diversity of the gizzard at E20 (P < 0.05), increased the abundance of Firmicutes (P < 0.05), and decreased the relative abundance of Proteobacteria, Bacteroidota, and Actinobacteriota (P < 0.05). At the genus level of the microbiota, PA01 significantly increased the relative abundance of Lactiplantibacillus (P < 0.05). At 20 embryos, PA01 altered the α and β diversity indices (P < 0.05) and decreased the relative abundance of Salmonella (P < 0.05) of the cecal microbiota. The biomarkers of PA01 group were Lactobacillales, Blautia, Lachnospiraceae, and Asinibacterium. Embryonic injection of PA01 altered the E20 intestinal microbes. PA01 altered the β-diversity index of the 1-day-old cecum (P < 0.05), and there was no significant effect on microbial composition at the phylum and genus level (P > 0.05). LefSe analysis revealed that the biomarkers of the PA01 group were Lactobacillaceae, Lactiplantibacillus, Moraxellaceae, and Acinetobacter. Biomarkers in the Con group were Devosia, Bacillus, Nordella, Mesorhizobium, and Pseudolabrys. PA01 increased acetic acid in the gastrointestinal tract at E20 along with acetic and butyric acid in cecum of 1-day-old. In conclusion, embryo-injected L. plantarum PA01 altered the structure and metabolites of the microbial flora before and after hatching, in particular promoting the colonization of Lactobacillus.

Canonical correlation analysis applied to regulated deficit irrigation in ‘Tommy Atkins’ mango trees

The objective was to identify the effect of regulated deficit irrigation on physiological, yield and root descriptors of ‘Tommy Atkins’ mango tree grown in a semi-arid region of Brazil. The work was carried out during two production cycles on an 11-year-old mango orchard. The design was randomized blocks with five treatments and six replications. Irrigation treatments were based on the trees’ development stage: T1, irrigation supplying 100% of the crop evapotranspiration (ETc) in three production stages: fruit set stage (SI), fruit expansion stage (SII), and physiological maturation stage of the fruits (SIII); T2, 50% ETc in SI and 100% ETc in SII and SIII; T3, 100% ETc in SI and SIII and 50% ETc in SII; T4, 100% ETc in SI and SII, and 50% ETc in SIII; and T5, without irrigation in all three stages. Physiological data were measured once per stage. After harvesting the second cycle, roots were collected, following a completely randomized design, with five treatments and three replications, to determine the total root length density. Total or partial water deficit in ‘Tommy Atkins’ mango trees was identified by decreasing transpiration (E) and photosynthesis (A) and increasing leaf temperature (Tleaf). The total root length density is similar in all irrigation strategies up to 1 m horizontal distance and 0.10 m depth. Water deficit applied in the physiological maturation stage improves yield and water use efficiency.

Effects of organic and inorganic selenium on selenium bioavailability, growth performance, antioxidant status and meat quality of a local beef cattle in China.

Selenium (Se) is an essential nutrient with multiple health benefits to humans and animals. Cattle generally require dietary Se supplementation to meet their daily requirements. The two main forms of dietary Se in cattle are organic Se and inorganic Se. Data comparing the health and productivity effects of organic Se and inorganic Se on cattle are still insufficient, and it is necessary to conduct more research to evaluate the bioavailability, nutritional value, deposition, and body functions of Se sources in different breeds and physiological stages of cattle raised in areas with different Se levels. The objectives of this study were to determine the effects of organic and inorganic sources of Se on plasma biochemical indices, Se bioavailability, deposition in body tissues and organs, growth performance, antioxidant capacity and meat quality of beef cattle raised in Se-deficient areas. Fifteen Chinese Xiangzhong Black beef cattle with an average weight of 254.5 ± 8.85 kg were assigned to three dietary groups. The three groups were fed the same basal ration and supplemented with either an inorganic [sodium selenite (SS)] or organic [selenomethionine (SM) or Se-enriched yeast (SY)] source of Se (0.1 mg/kg dry matter) for 60 days. At the end of the experiment, three cattle from each group were randomly selected and slaughtered, and samples were collected from tissues and organs for analysis. The results revealed that growth performance, slaughter performance, Se content of tissues and organs, meat quality characteristics including chemical composition, pH45min, pH24h, drip loss, and cooking losses did not differ (p > 0.05) due to supplementation of the different organic and inorganic sources of Se. SM and SY were more effective in increasing (p < 0.05) immunoglobulin M (IgM) concentrations in the blood and reducing (p < 0.05) malondialdehyde (MDA) content in the longissimus dorsi than SS. In conclusion, organic Se is more effective than inorganic Se in improving the immune and antioxidant capacity of Chinese Xiangzhong Black beef cattle.

Chikungunya Virus Infection and Gonotrophic Cycle Shape Aedes aegypti Oviposition Behavior and Preferences.

Targeting gravid females through chemical lures is a promising strategy in vector control; however, it requires the understanding of the factors susceptible to alter female oviposition behavior. Here, we evaluated the effect of infection with chikungunya virus (CHIKV) and the number of gonotrophic cycles (GCs) on oviposition activity in A. aegypti. Dual choice oviposition assays were performed, where dodecanoic acid, pentadecanoic acid, n-heneicosane and a Sargasssum fluitans (Børgesen) Børgesen extract were tested in uninfected females and females infected with CHIKV, at the 1st and 2nd GC. Infected females displayed a lower percentage of oviposition and a higher number of eggs laid at the 1st GC. Then, the combined effects of GC and CHIKV were observed on oviposition preferences, with a chemical-dependent effect. For instance, the deterrent effect of n-heneicosane and pentadecanoic acid increased at the 2nd GC in infected females. These results allow for a deeper understanding of the mechanisms involved in oviposition site selection and highlight the need for taking into account physiological stage changes to increase the control programs' efficacy.

COVID-19 in Cyanotic Congenital Heart Disease.

Congenital heart disease (CHD) is the most prevalent congenital defect in newborn infants. Due to the various types of heart abnormalities, CHD can have a wide range of symptoms. Cardiac lesions comprise a range of different types and accordingly varying severities. It is highly helpful to classify CHD into cyanotic and acyanotic heart diseases. In this review, we are investigating the course of Coronavirus disease 2019 (COVID-19) in cyanotic CHD patients. The infection may directly or indirectly affect the heart by affecting the respiratory system and other organs. The effect on the heart that is pressure- or volume-overloaded in the context of CHD is theoretically more severe. Patients with CHD are at a higher risk of mortality from COVID-19 infection or suffering worse complications. While the anatomic complexity of CHD does not seem to predict the severity of infection, patients with worse physiological stages are more susceptible such as cyanosis and pulmonary hypertension. Patients with CHD exhibit continuous hypoxemia and have lower oxygen saturations because of a right-to-left shunt. Such individuals run the danger of rapidly deteriorating in the event of respiratory tract infections with inadequate oxygenation. Additionally, these patients have a higher risk of paradoxical embolism. Hence, critical care should be given to cyanotic heart disease patients with COVID-19 in comparison to acyanotic patients and this is through proper management, close observation, and adequate medical therapy.

Alternative hormone-free reproduction management of a dairy sheep flock disrupts the farm's annual feeding system calendar and its associated strategies

Hormone-free (HF) reproduction in dairy sheep is a way to meet current societal demands, but it requires being prepared for collateral impacts on related system components. The efficiency of HF practices (e.g., using the male effect for estrus induction and synchronization) is uncertain compared with hormonal treatment (HT). For example, these practices can lead to higher variability in the flock physiological stage patterns throughout the year, which has direct consequences for feeding regimens. The objective of this work was to simulate the impacts of HF reproduction management, including artificial insemination (AI), on the temporal distribution of productive performance and nutritional requirements of a conventional dairy sheep flock. Using the REPROsheep2.0 model, 6 scenarios were compared over one typical production season for the same flock (n = 597 Lacaune ewes) intensively reared in the Roquefort region of France. These scenarios depicted reproduction with HT and AI in mid-May (Early); HT and AI in July (Summer Late); HT and AI in November (Autumn Late); and their HF versions (HF-Early; HF-Summer Late, and HF-Autumn Late, respectively). In all HF scenarios, a reduction in the number of ewes lambing and consequently in the annual milk production of the farm was observed (-1 to -7%). This affected annual performance with a subsequent decrease of total annual nutritional requirements (-2 to -6%). The HF scenarios resulted in a staggering of lambing events with a 7- to 14-d shift in the appearance of milk production peaks and related nutritional requirements compared with the HT scenarios. Transitioning from conventional to HF reproduction management, while preserving AI, would increase farm workload, lengthen milking period operations, and necessitate a readjustment of feeding management strategies with regard to available feed resources. Depending on the production season, the observed delay in the distribution of nutritional requirements could be either an attractive or an unfavorable outcome for farmers. The delay may be concordant, for example, with the recently observed impacts of climate change on seasonal forage availability in Mediterranean regions (less spring herbage production and warmer temperatures) that are affecting farmers' decision-making about the most efficient use of forage and feed resources.

Systematic characterization of Ustilago maydis sirtuins shows Sir2 as a modulator of pathogenic gene expression.

Phytopathogenic fungi must adapt to the different environmental conditions found during infection and avoid the immune response of the plant. For these adaptations, fungi must tightly control gene expression, allowing sequential changes in transcriptional programs. In addition to transcription factors, chromatin modification is used by eukaryotic cells as a different layer of transcriptional control. Specifically, the acetylation of histones is one of the chromatin modifications with a strong impact on gene expression. Hyperacetylated regions usually correlate with high transcription and hypoacetylated areas with low transcription. Thus, histone deacetylases (HDACs) commonly act as repressors of transcription. One member of the family of HDACs is represented by sirtuins, which are deacetylases dependent on NAD+, and, thus, their activity is considered to be related to the physiological stage of the cells. This property makes sirtuins good regulators during environmental changes. However, only a few examples exist, and with differences in the extent of the implication of the role of sirtuins during fungal phytopathogenesis. In this work, we have performed a systematic study of sirtuins in the maize pathogen Ustilago maydis, finding Sir2 to be involved in the dimorphic switch from yeast cell to filament and pathogenic development. Specifically, the deletion of sir2 promotes filamentation, whereas its overexpression highly reduces tumor formation in the plant. Moreover, transcriptomic analysis revealed that Sir2 represses genes that are expressed during biotrophism development. Interestingly, our results suggest that this repressive effect is not through histone deacetylation, indicating a different target of Sir2 in this fungus.

Effects of plant age on antioxidant activity and endogenous hormones in Alpine Elymus sibiricus of the Tibetan Plateau.

Elymus sibiricus L. is a perennial forage species that has potential to serve as a forage source in livestock grazing systems. However, E. sibiricus has been shown to have a rapid and substantial reduction of aboveground biomass and seed yield after 3 or 4 years and an accelerated aging process. To determine possible aging mechanisms, we planted E. sibiricus seeds in triplicate blocks in 2012, 2015, and 2016, respectively, and harvested samples of leaves and roots at the jointing and heading stages in 2018 and 2019 to determine oxidative indices and endogenous hormones. The fresh aboveground biomass of 4- and 5-year old plants declined by 34.2% and 52.4% respectively compared with 3-year old plants, and the seed yield declined by 12.7% and 34.1%, respectively. The water content in leaves was 51.7%, 43.3%, and 35.6%, and net photosynthesis was 7.73, 6.35, and 2.08 µmol/m2·s in 3-, 4-, and 5-year old plants, respectively. The superoxide anion radical generation rate in leaves and roots did not show any aging pattern. There was a non-significant increase in malondialdehyde concentration with plant age, particularly in leaves and roots at the heading stage in 2019. The superoxide dismutase activity showed a declining trend with age of plant roots at the jointing stage in both 2018 and 2019. The peroxidase activity declined with plant age in both leaves and roots, for example, and the catalase activity in roots 4- and 7-year old plants declined by 13.8% and 0.85%, respectively, compared to 3-year old plants at the heading stage in 2018. Therefore, the reduced capacity of the antioxidant system may lead to oxidative stress during plant aging process. Overall, the concentrations of plant hormones, auxin (IAA), gibberellin (GA), zeatin (ZT), and abscisic acid (ABA) were significantly lower in roots than in leaves. The IAA concentration in leaves and roots exhibited different patterns with plant age. The ZT concentrations in leaves of 3-year old plants was 2.39- and 2.62-fold of those in 4- and 7-year old plants, respectively at the jointing stage, and in roots, the concentration declined with plant age. The changes in the GA concentration with plant age varied between the physiological stages and between years. The ABA concentrations appeared to increase with plant age, particularly in leaves. In conclusion, the aging process of E. sibiricus was apparently associated with an increase in oxidative stress, a decrease of ZT and an increase of ABA, particularly in roots. These findings highlight the effects of plant age on the antioxidant and endogenous hormone activity of E. sibiricus. However, these plant age-related trends showed variations between plant physiological stages and between harvest years that needs to be researched in the future to develop strategies to manage this forage species.