Abstract:This study aimed to explore the effects of supplementary feeding on milk yield, blood biochemical indexes, milk components, and fecal microflora diversity of Yili horses under grazing condition.18 grazing Yili mare horses with physiological condition consistent were randomly assigned to three groups with six mare horses each. The control group normal grazing, whereas the test group I and II were provided with supplemented with 1 kg/d of concentrate and 1 kg/d of concentrate + 0.4 kg/d coated fatty acids, respectively. After 3 days of pre-feeding, begin the experiment.Horse milk was collected every 7 days, and 10% of the milk yield of each horse was mixed in 100 mL milk sample bottles and stored in -20℃ refrigerator.Which blood samples were collected from the jugular vein before morning feeding (0 h) and at 1,2,3,4,6,9 and 12 h after morning feeding on day 40, and the plasma were centrifuged at 4000 rpm for 15 min and conservation at-20℃. Excrement was collected within 8 h on days 45 and 46 of the test, mixed with 5g of fresh fecal samples in a 5 mL frozen storage tubes and stored in liquid nitrogen. Compared with the control group, the lactation volume of Yili horses in test groups I and II was significantly higher throughout the trial period (P <0.05), and the late test group II was significantly higher than test group I (P <0.05). The yield of milk fat, lactose, and milk protein in test group II was significantly higher than that in test group I and control group (P <0.05); the urea nitrogen content in test group I was significantly lower than the control group (P <0.01). The lauric acid, tetradecanoic acid, cis-11,14,17-eicosotrienic acid, total saturated fatty acid, and total saturated fatty acid/total unsaturated fatty acid in test group II were significantly higher than those in the control group and test group I (P <0.05); The plasma glucose concentration of mares in test group II was significantly higher than that of control group and test group I at 1, 2 and 9 h after feeding (P <0.05), and significantly higher at 4 h after feeding (P <0.05); At 3 h and 6 h after feeding, test group II mares had significantly higher plasma free fatty acids and triglycerides concentrations than the control and test group I (P <0.05), at 4 h after feeding, the plasma triglyceride concentrations were significantly higher than the control and test I groups (P <0.05). Plasma low density lipoprotein and very low density lipoprotein concentrations were significantly higher in mares at 3 h and 9 h after feeding than in control and group I (P <0.05). The total number of OTUs was 3483, and the number of OTUs was 4984,5487, and 5158 in the control and test I and II, respectively. At the phylum level, the total abundance of Bacteroidetes and Firmicutes was more than 75%, and the test group Verrucomicrobia was significantly higher than the control group (P <0.05), and the test group II was significantly higher than the test group I (P <0.05). The Treponema_saccharophilum was significant difference in the feces of the control group (P <0.05); WCHB 1_41, kiritimatiellae, and Verrucomicrobia were significant difference of the test group II (P <0.05) and the fecal flora was mainly related to lipid synthesis, metabolism, and energy metabolism (P <0.05). Supplemental feeding can improve lactation volume of grazing Yili horses, improve the absorption and utilization of fatty acids, and improve the composition and diversity of horse milk and fecal flora to a certain extent.

Aluminum (Al) and manganese (Mn) toxicity are the top two constraints to crop production in acid soil. Crops have evolved common and specific mechanisms to tolerate the two stresses. In the present study, the responses (toxicity and tolerance) of wheat near-isogenic lines (ET8 and ES8) and their parents (Carazinho and Egret) to Al and Mn were compared by determining physiolog-ical parameters and transcriptome profiling of roots. The results showed that: (1) Carazinho and ET8 exhibited dual tolerance to Al and Mn as compared with Egret and ES8, indicated by higher relative root elongation and SPAD; (2) After entering into roots, Al was mainly distributed in the root and fixed in the cell wall, while Mn was mainly distributed in the cell sap and then trans-ported to leaves. Both Al and Mn stresses decreased the contents of Ca, Mg, and Zn; Mn stress al-so inhibited the accumulation of Fe, while Al showed an opposite effect; (3) Transcriptomic analy-sis identified 5581 differentially expressed genes (DEGs) under Al stress and 4165 DEGs under Mn stress. Among these, 2774 DEGs were regulated by both Al and Mn stresses, while 2280 and 1957 DEGs were exclusively regulated by Al and Mn stress, respectively. GO and KEGG analyses indi-cated that cell wall metabolism responds exclusively to Al, while nicotianamine synthesis exclu-sively responds to Mn. Pathways such as signaling, phenylpropanoid metabolism, and metal ion transport showed commonality and specificity to Al and Mn. TFs, such as MYB, WRKY, and AP2 families, were also regulated by Al and Mn, and WGCNA identified PODP7, VATB2, and ABCC3 as the hub genes for Al tolerance and NAS for Mn tolerance. The identified genes and pathways can be used as targets for pyramiding genes and breeding multi-tolerant varieties.

Aluminum (Al) toxicity and low phosphorus availability (LP) are the top two co-existing edaphic constraints limiting agriculture productivity in acid soils. Plants have evolved versatile mechanisms to cope with the two stresses alone or simultaneously. However, the specific and common molecular mechanisms, especially those on flavonoids and carbohydrate metabolism, are still unclear. Laboratory studies were conducted on two wheat genotypes, Fielder (Al-tolerant and P-efficient) and Ardito (Al-sensitive and P-inefficient), exposed to 50 μM Al and 2 μM Pi (LP) in hydroponic solutions. After 4 days of stress, wheat roots were analyzed via transcriptomic and targeted metabolomic techniques. A total of 2296 differentially expressed genes (DEGs, 1535 up and 761 down) under Al and 3029 DEGs (1591 up and 1438 down) under LP were identified in Fielder. Similarly, 4404 DEGs (3191 up and 1213 down) under Al and 1430 DEGs (1176 up and 254 down) under LP were identified in Ardito. The GO annotation analysis results that 4079 DEGs annotated to the metabolic processes term. These DEGs were significantly enriched in the phenylpropanoid, flavonoid, flavone and flavonol biosynthesis, and carbohydrate metabolism pathways by performing the KEGG enrichment analysis. The targeted metabolome analysis detected 19 flavonoids and 15 carbohydrate components in Fielder and Ardito under Al and LP. More responsive genes and metabolites were involved in flavonoid metabolism under LP than Al in the Fielder, while an opposite trend in the Ardito. In the carbohydrate metabolism pathway, the genes and metabolites were higher in Fielder than in Ardito. The combined transcriptome and metabolome analysis revealed that the flavonoid and carbohydrate genes and metabolites differed between Fielder and Ardito under Al and LP, which may be an important reason for Fielder’s high Al and LP resistance. The results of this study lay a foundation for pyramiding genes and breeding multi-resistance varieties.