Morphological and molecular response mechanisms of the root system of different Hemarthria compressa species to submergence stress.

Introduction: The severity of flood disasters is increasing due to climate change, resulting in a significant reduction in the yield and quality of forage crops worldwide. This poses a serious threat to the development of agriculture and livestock. Hemarthria compressa is an important high-quality forage grass in southern China. In recent years, frequent flooding has caused varying degrees of impacts on H. compressa and their ecological environment. Methods: In this study, we evaluated differences in flooding tolerance between the root systems of the experimental materials GY (Guang Yi, flood-tolerant) and N1291 (N201801291, flood-sensitive). We measured their morphological indexes after 7 d, 14 d, and 21 d of submergence stress and sequenced their transcriptomes at 8 h and 24 h, with 0 h as the control. Results: During submergence stress, the number of adventitious roots and root length of both GY and N1291 tended to increase, but the overall growth of GY was significantly higher than that of N1291. RNA-seq analysis revealed that 6046 and 7493 DEGs were identified in GY-8h and GY-24h, respectively, and 9198 and 4236 DEGs in N1291-8h and N1291-24h, respectively, compared with the control. The GO and KEGG enrichment analysis results indicated the GO terms mainly enriched among the DEGs were oxidation-reduction process, obsolete peroxidase reaction, and other antioxidant-related terms. The KEGG pathways that were most significantly enriched were phenylpropanoid biosynthesis, plant hormone signal transduction etc. The genes of transcription factor families, such as C2H2, bHLH and bZIP, were highly expressed in the H. compressa after submergence, which might be closely related to the submergence adaptive response mechanisms of H. compressa. Discussion: This study provides basic data for analyzing the molecular and morphological mechanisms of H. compressa in response to submergence stress, and also provides theoretical support for the subsequent improvement of submergence tolerance traits of H. compressa.

Unraveling the Mechanism of StWRKY6 in Potato (Solanum tuberosum)'s Cadmium Tolerance for Ensuring Food Safety.

The WRKY transcription factor plays a crucial role in plant stress adaptation. Our research has found that WRKY6 in Solanum tuberosum (potatoes) is closely related to cadmium (Cd) tolerance. Therefore, investigating the mechanism of StWRKY6 in plant resistance to Cd toxicity is of great scientific importance for food safety. This research further analyzed the gene structure and functional regions of the nuclear transcription factor WRKY6 in potatoes, discovering that StWRKY6 contains W box, GB/box, ABRE, and other elements that can act as a nuclear transcription regulatory factor to execute multiple functional regulations. The results of the heterologous expression of StWRKY6 in Arabidopsis under Cd stress showed that the overexpression line (StWRKY6-OE) had significantly higher SAPD values and content of reactive oxygen species scavenging enzymes than the wild type, indicating that StWRKY6 plays a crucial role in protecting the photosynthetic system and promoting carbohydrate synthesis. Transcriptome analysis also revealed that the Cd-induced expression of StWRKY6 up-regulated many potential gene targets, including APR2, DFRA, ABCG1, VSP2, ERF013, SAUR64/67, and BBX20, which are involved in Cd chelation (APR2, DFRA), plant defense (VSP2, PDF1.4), toxic substance efflux (ABCG1), light morphology development (BBX20), and auxin signal (SAUR64/67). These genes coordinate the regulation of Cd tolerance in the StWRKY6 overexpression line. In summary, this study identified a potential gene set of the co-expression module of StWRKY6, providing useful evidence for the remediation of Cd-contaminated soil and the genetic breeding of low Cd-accumulating crops, thereby ensuring food safety.

Feeding Laying Ducks Eucommia ulmoides oliv. Leaves Increases the n-3 Fatty Acids Content and Decreases the n-6: n-3 PUFA Ratio in Egg Yolk without Affecting Laying Performance or Egg Quality.

The objective was to determine the effects of supplementing duck diets with Eucommia ulmoides oliv. leaf powder (EUL). Laying ducks (n = 480) were randomly allocated into 4 experimental treatments and fed diets containing 0, 1, 2, or 4% EUL. Dietary inclusion of EUL had no effect (p > 0.05) on laying performance or egg quality, but linearly increased (p < 0.05) total plasma protein, globulin, and HDL-C concentrations with concurrent reductions (p < 0.05) in plasma concentrations of cholesterol and LDL-C. Eggs laid by ducks receiving EUL had yolks with linearly higher phenolic concentrations (p < 0.05) but lower cholesterol concentrations (p < 0.05). EUL supplementation in duck diets significantly reduced n-6: n-3 PUFA ratio by enriching n-3 fatty acids in yolks (p < 0.05) with no changes in n-6 PUFA (p >0.05).

Effects of Nano-Cu2O on the Productivity in the Cu-Stripped Chinese Merino Sheep.

This research is to study the effects of nano-Cu2O on blood parameters, growth performance, and wool yield in the Cu-stripped ranches, and provide reference for further study on prevention and treatment in Cu-deficient Chinese Merino sheep. We selected twenty Chinese Merino sheep from Cu-deficient and normal ranch, respectively. The results have shown that the Cu content in the soils, forages, blood, and wool from Cu-deficient ranches was significantly lower than those from normal ranches (P < 0.01). There were no significant differences in the contents of other elements. Treatment experiments of nano-Cu2O were carried out for 50 days. We found that the Cu content in the blood was increased continuously in the sheep after adding nano-Cu2O, and reached the highest level at 40 days. The levels of Hb, RBC, PCV, MCV, and MCH in the nano-Cu2O-fed animals were remarkably higher than those in the control animals (P < 0.01). The daily gain and wool yield in the nano-Cu2O-fed animals were also significantly higher than those in the control sheep (P < 0.01). Therefore, adding nano-Cu2O not only remarkably increases the Cu content in the blood, but also greatly improves the daily gain and wool yield in Cu-deficient animals.

Effect of Foliage Dressing in Nano-Potassium Molybdate on Daily Gain and Antioxidant Function in Grazing the Chinese Merino Sheep.

The study was implemented for exploring influences of nano-K2MoO4 on the daily gain and antioxidant function of Chinese merino sheep in the native pasture, Xinjiang Uygur Autonomous Region, Northwest of China. Eighty of the sheep, weight of (45.56 ± 2.35) kg, were randomly distributed to the tested areas for 90 days, 20 sheep/group. The findings showed that the contents of Mo and N in the forage of applying nano-K2MoO4 were extremely higher than those in the control pastures (P <0.01). The daily gain in the fertilized groups were remarkably lower than that in the control group (P <0.01). The harvest of forage in the fertilized pastures were significantly higher than those in control (P <0.01). The contents of Mo in blood and liver in grazing the Chinese merino sheep were extremely higher than those from the control group (P <0.01). The contents of Cu in blood and liver in grazing the Chinese merino sheep were extremely lower than those in the unfertilized pastures (P <0.01). The levels of hemoglobin (Hb), blood platelet (PLT), and erythrocyte count (RBC) in animals from the fertilized pastures were extremely lower than those in the control pastures (P < 0.01). The activities of SOD, GSH-Px, and CAT in serum were significantly lower than those in group C. The serum MDA levels were significantly higher than those in the control group (P < 0.01). In conclusion, the application of nano-K2MoO4 in pastures can greatly improve the yield of forage, but strikingly decreased the daily gain and antioxidant function in grazing the Chinese merino sheep.

Effect of Nano-potassium Molybdate on the Copper Metabolism in Grazing the Pishan Red Sheep.

The aims of this study were to investigate the impact of different levels of nano-potassium molybdate (nano-K2MoO4) fertilization on the copper (Cu) metabolism in grazing the Pishan red sheep in the natural pasture. The fertilization and grazing experiments were conducted on the Pishan farm in Southern Xinjiang, China. The natural pastures of 16 hm2 were randomly divided into four groups (4 hm2/group), consisting of group C (no fertilized), group I, group II, and group III. The fertilizing amount of Mo from nano-K2MoO4 was 0, 7, 8, and 9 kg/hm2 for group C, group I, group II, and group III, respectively. The 40 Pishan red sheep were randomly distributed to the tested pastures for 90 days, and the 10 sheep/group. The results showed that the contents of Mo and N in forage from the fertilized pastures were extremely increased (P < 0.01). The yield and dry matter digestibility of forage in fertilized pastures were significantly higher than those in no fertilized pasture (P < 0.01). The values of crude protein (CP) and crude fat (EE) in forage from fertilized pastures were significantly increased (P < 0.01). The Mo contents in the blood and liver in the Pishan red sheep from fertilized pastures were greatly increased (P < 0.01). The Cu contents in the blood and liver in the Pishan red sheep from the fertilized pastures were greatly decreased (P < 0.01). The activities of serum superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in group I, group II, and group III were extremely lower than those in group C (P < 0.01), and the contents of serum malondialdehyde (MDA) in group I, group II, and group III were greatly higher than those from group C (P < 0.01). In summary, the application of nano-K2MoO4 improved the nutritive values and the yield of forage, but overuse will remarkably reduce the Cu contents of blood and greatly interfere with the Cu metabolism, leading to the Cu deficiency and low antioxidant capacity in grazing the ruminants.