Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) are two active substances that play important roles in plants. As second messengers or key signaling molecules, they participate in and regulate various physiological and biochemical reactions in plants, and have great utilization value and application prospects. This paper systematically reviewed the roles of cyclic adenosine monophosphate and cyclic guanosine monophosphate in seed germination, plant growth and development, responding to biological and abiotic stresses. It can provide references for their further research and utilization.

In order to investigate the function of the maize BTB-TAZ protein ZmBT2b in maize resistance to pathogenic fungal infection, the ZmBT2b gene was systematically analyzed using bioinformatics techniques in this study. It was determined that ZmBT2b has both BTB and TAZ structural domains. It showed obvious tissue specific expression and different expression patterns under biotic and abiotic stresses. By constructing ZmBT2b gene overexpressing Arabidopsis thaliana plants ZmBT2b-OE, the function of this gene in the process of plant disease resistance was investigated. ZmBT2b-OE plants showed significantly enhanced resistance to Botrytis cinerea and Pst. DC3000, suggesting its function in the process of plant disease resistance. In order to clarify the function of ZmBT2b gene in the process of maize resistance to Fusarium graminearum infestation, maize mutants Zmbt2b-1 and Zmbt2b-2 of this gene were obtained whose disease resistance of were tested. It was found that the F. graminearum resistance was significantly higher in mutants Zmbt2b-1 and Zmbt2b-2 than that of the wild type. The expression of ZmLOXs in JA synthesis pathway and ZmPRs as disease course-related genes were significantly down-regulated during F. graminearum infestation, indicating that ZmBT2b has a positive regulatory function in maize resistance toF. graminearum infestation. The results laid the foundation for elucidating the function of maize BTB-TAZ protein and its regulatory mechanism in the process of maize disease resistance, and provided genetic resources for maize disease resistance breeding.

In order to systematically analyze the synergistic lodging resistance of maize stems and roots, six maize cultivars with different lodging resistance were selected as the research materials with a planting density of 60 000, 75 000, and 90 000 plants/hm². The stalk pull lodging force (PLF) and angle (PLA) as the lodging resistance evaluation indicators were correlatively analyzed with the morphological characteristics and material accumulation per unit length of the basal third internode and root traits. Simultaneously, a path analysis of basal internode and root traits was conducted. The results showed that the length, diameter, fresh and dry weight per unit length, content of each component per unit length of internode, root plate spread, brace root diameter, total root number, root diameter, and root dry weight were significantly correlated with the evaluation indicators of lodging resistance, among which the diameter (PLF: r=0.561**, PLA: r =0.521**), fresh weight per unit length (PLF: r=0.520**) and dry weight per unit length (PLA: r=0.562**) of internode displayed the greatest correlation. Root traits such as root dry weight and brace root diameter were positively correlated with the diameter and mass accumulation per unit length of basal internode, which synergistically influence lodging resistance of plants. When the planting density increased, the diameter and material accumulation per unit length of internode, structural root depth, brace root diameter, total root number, root diameter and root dry weight significantly decreased, resulting in a significant decrease in the stalk pull lodging force and angle and in lodging rate. The diameter (1.76, 1.72, 1.71 and 1.70 cm), fresh weight per unit length (2.9, 2.7, 2.4 and 2.5 g/cm), dry weight per unit length (0.45, 0.40, 0.35 and 0.45 g/cm) of internode and other traits of internode and root related to lodging resistance were higher of ‘Lishou1’, ‘Chuangyu 107’, ‘MC278’ and ‘Jingnongke 728’, which was consistent with their larger PLF (18.1, 17.1, 14.7 and 13.0 N) and PLA (63.3°, 56.7°, 50.3° and 49.6°). After densification, the variation amplitude of PLF, PLA and traits related to lodging resistance of internode and root were smaller. Therefore, the lodging resistance and density tolerance of these four cultivars were stronger. This study provided a certain theoretical basis for ensuring the high and stable yield of maize and improving the mechanization level.

In this study, we analyzed the differentially expressed genes (DEGs) and metabolites (DAMs) between different varieties at different growth stages to investigate the mechanism of anthocyanin synthesis in emerald green and pink quinoa (Chenopodium quinoa Willd.) leaves. 11 DEGs were closely related to anthocyanin biosynthesis including 4CL, C3'H, HCT, CHS, CHI, ANR, CYP75B1, UGT79B1, FG3, FG2 and CYP73A. 4 DEGs were MYC2, BHLH14, HY5 and TGA transcription factors. The DEGs enriched in seven GO Terms (GO:0009812 (Flavonoid metabolic process), GO:0010468 (Regulation of gene expression), GO:0051553 (Flavone biosynthetic process), GO:0009813 (Flavonoid biosynthetic process), GO:0009411 (Response to UV), GO:0043169 (Cation binding) and GO:0016703 (Oxidoreductase activity)) that are closely related to anthocyanin biosynthesis. KEGG enrichment analysis showed that there were 6 metabolic pathways significantly related to anthocyanin biosynthesis including Phenylalanine metabolism (ko00360), Phenylpropanoid biosynthesis (ko00940), Flavonoid biosynthesis (ko00941), Plant hormone signal transduction (ko04075), Flavone and flavonol biosynthesis (ko00944), and Circadian rhythm-plant (ko04712). Metabolomics analysis confirmed that Cyanidin 3-O-(3'',6''-O-dimalonyl glucoside) and Naringenin were the key DAMs formed by pink leaves. Transcriptomics-metabolomics joint analysis indicated that flavonoid biosynthesis pathway (ko00941) and anthocyanin biosynthesis pathway (ko00942) were the enrichment pathway of anthocyanin biosynthesis. 10 DEGs were verified by qRT-PCR, and the results showed that the verification results were consistent with the results of transcriptome.

It is of significant importance that UAV remote sensing technology was adopted to identify farmland anomalies to ensure agricultural production. Most current farmland anomaly detection methods require labeling a large number of normal and abnormal samples. However, the abnormal samples in the farm area are too small to be collected adequately. In particular, the diversity and unpredictability of farmland anomalies require advanced detection methods. To address these issues, this paper proposed an improved PatchSVDD (Patch-level Support Vector Data Description) model for detecting abnormal areas in the farm, which only utilized the labeling information of normal areas in the farm without labeling the abnormal ones. First, the improved method introduced a margin-based loss function between non-adjacent image patches to improve the discriminability of the boundary between normal and abnormal samples and enhance the robustness of the detector. Second, an external memory module was adopted to store the compressed regular sample features to effectively reduce the time and space consumption in the testing phase while ensuring detection accuracy. Third, a farmland anomaly detection dataset was constructed containing a total of five anomaly types, i.e., weed clusters, missing planting, obstacles, double planting and standing water. The proposed method achieved 96.9 % and 94.6 % in the average detection AUC (Area Under Curve) value and average localization AUC value, respectively, which demonstrated improvements of about 1.2 % and 1.6 % compared with the original PatchSVDD, suggesting the effectiveness of the method.

To study the effects of soil application of biogas slurry formula fertilizer on the quality of pear fruits and soil nutrients, ‘Huangguan’ and ‘Yali’ were used as test materials, and different amounts of biogas slurry combined with chemical fertilizers were set up. By applying biogas slurry formula fertilizer to the soil, fruit quality related indicators such as yield, single fruit weight, soluble total sugar content, as well as soil nutrient related indicators such as soil nutrient elements and organic matter were measured. The results showed that compared with conventional fertilization in orchards, T5 treatment significantly increased the single fruit weight, yield, soluble solid content, and total soluble sugar content of ‘Huangguan’ by 16.96%, 28.25%, 11.87%, and 17.46%, respectively, compared with conventional fertilization in orchards. T5 treatment significantly reduced the titratable acid content of ‘Huangguan’ by 18.18%; T5 treatment significantly increased the single fruit weight, yield, soluble solid content, and total soluble sugar content of ‘Yali’ by 12.12%, 20.69%, 20.40%, and 15.84%, respectively. Biogas slurry formula fertilizer demonstrated varying degrees of improvement in total nitrogen, total phosphorus, and total potassium. T5 treatment showed the most significant effect, increasing the above indicators by 19.47%-26.46%, 20.45%-23.81%, and 25.00%-28.89% in the 0-20 cm soil layer, respectively; In the soil layer of 20-50 cm, they increased by 18.08%-26.67%, 20.56%-27.24%, and 9.46%-13.89%, respectively. T5 treatment significantly increased soil alkaline nitrogen, available phosphorus, available potassium, and organic matter. In the 0-20 cm soil layer, they increased by 14.57%-24.77%, 22.85%-34.06%, 17.87%-27.20%, and 23.95%-36.20%, respectively; In the soil layer of 20-50 cm, they increased by 22.52%-26.50%,15.16%-26.20%,12.60%-33.01%, and 13.95%-16.04%, respectively. In summary, T5 treatment was more conducive to improving the quality of pear fruit and soil nutrients content through soil application of biogas slurry formula fertilizer.

It is one of the important means to explore the application of antigens to construct engineered bacteria expressing antigen proteins using the lactic acid bacteria expression system. In this study, the signal peptide linked cell wall anchor protein domain sequence (Usp45-3LysM) was fused with GFP protein or the receptor-binding domain (RBD) sequence of S1 protein of Omicron variants respectively using overlap extension PCR technology. The expression vectors pNZ8149-GFP, pNZ8149-2RBD and pNZ8149-3RBD were constructed and transformed into Lactococcus lactis NZ3900, generating the engineered strains for surface displaying GFP, 2RBD, or 3RBD. The results showed that the optimal concentration and time of expression of GFP induced by nisin were 20 ng/mL and 20 h, respectively. The results of western blot and indirect immunofluorescence showed that the three target proteins were successfully expressed and displayed on the cell wall of the engineered bacteria, suggesting that the engineered L. lactisthe strain surface displaying SARS-CoV-2 antigen protein had been successfully constructed. This study laid the foundation for the development of a novel oral vaccine based on lactic acid bacteria against the SARS-CoV-2 or other animal viruses and their related products.

This paper explored the temporal and spatial variation law of soil water and nitrogen to provide a theoretical basis for controlling groundwater pollution in Xiong'an new area, which is of great significance to the construction of "blue-green Xiong'an". We selected cultivated land, forest land and vegetable land in Xiong'an New area as the research object whose soil indexes such as soil moisture content, nitrate nitrogen, ammonium nitrogen and bulk density were measured. Then we analyzed the temporal and spatial variation laws and influencing factors of soil moisture content, nitrate nitrogen and ammonium nitrogen of different agricultural lands. The results showed that the soil moisture content first increased and then decreased with the depth of the soil layer and finally tend to be stable in the vertical direction of the soil layer. The content of nitrate nitrogen in cultivated land and vegetable soil increased first and then decreased with the increase of soil depth. The content of ammonium nitrogen in cultivated land, forest land and vegetable soil decreased gradually with the increase of soil depth. In terms of time, the water content of cultivated land fluctuated greatly, and the change of forest land was less affected by seasons. The water content of vegetable field changed steadily with time, and decreased significantly after October. The content of nitrate nitrogen in forest land and vegetable soil first increased and then decreased with time, while the content of cultivated land fluctuated sinusoidally with time. The content of ammonium nitrogen in vegetable soil decreased gradually with time, and the content of ammonium nitrogen in forest soil changed little and the content was the smallest. The soil moisture content of the three agricultural lands was negatively correlated with soil bulk density and significantly positively correlated with precipitation and irrigation (P < 0.05). The soil bulk density of cultivated land was significantly correlated with the depth of soil layer (P < 0.01). Nitrate nitrogen and ammonium nitrogen in cultivated land and vegetable soil were significantly negatively correlated with soil depth, precipitation and irrigation. There was a significant positive correlation between soil nitrate nitrogen and ammonium nitrogen in the three agricultural lands. The distribution of water and nitrogen content in cultivated land and vegetable land has a greater impact on groundwater pollution. Therefore, reasonable irrigation and application of nitrogen fertilizer to improve soil properties will help to protect the groundwater environment in Xiong’an New Area.

Aiming at the problems of manual cutting of the handle of the crown pears after picking that requires the high labor intensity for bag removal, a handle-breaking and bag-removing integrated machine was designed, and its handle-breaking device was optimized. Matlab software was used to calculate the bag removal movement of the bag removal robot Trajectory. In order to optimize the structural parameters of the device, a three-factor Box-Behnken test was designed. The design-Expert software was used to analyze the variance of the test results, and a regression model of significant parameters was established to obtain the optimal structure of the crown pear broken handle and bag removal device Parameters. The cutting gap was 0.89 mm. the "V"-shaped positioning opening angle of the positioning plate was 36.5°, and the feed per tooth was 7.8 r/min. With this combination, the broken handle rate was 90.15%, and the average width of the paper bag tear was 50.63 mm. The research results can provide a theoretical basis for the design and improvement of the device for removing the broken handle of the crown pear.

It is important for the green and sustainable development of agriculture to improve the nutrient use efficiency of farmland ecosystem and reduce soil N₂O emission. In this study, the effects of plant extracts such as procyanidins and tannic acid were investigated on plant biomass, N₂O emission and nitrogen use efficiency in pot experiments of rape grown in northern China calcareous soil. A total of five treatments were designed including UR (UR), UR+low procyanidins (PC1), UR+high procyanidins (PC2), UR+low tannic acid (TA1) and UR+high tannic acid (TA2). The results showed that procyanidins and tannic acid treatments increased the rape yield by 7.9%-17.9% and nitrogen content by 10.3%-23.2% compared to the UR. Procyanidins and tannic acid treatments significantly inhibited the content of inorganic nitrogen such as NO₂^- and NO₃^- in the soil. Procyanidins and tannic acid treatments significantly reduced N₂O emission during the growth period of rape. The reduction of N₂O affected by the procyanidins was 28.1%-33%, and was 32.9%-41.5% by the tannic acid treatments. The nitrogen use efficiency of rape was increased by 5.0%-9.7%. In summary, the application of procyanidins and tannic acid in calcareous soil not only significantly reduced N₂O emissions, but also helped to improve the yield and nitrogen use efficiency of rape. This study provided a novel idea for the simultaneously realization of the green recycling of plant extracts such as procyanidins and tannic acid together with the N₂O emission reduction in calcareous farmland soil in northern China.

In this study, ‘Zheng dan 958’ was selected as the study object due to its high level of resistance to Cd and phenanthrene. An indoor pot experiment was performed to determine the impact of the interaction between soil-borne Cd (0, 2.5, and 5 mg/kg) and Phe (0, 1 and 50 mg/kg) on the uptake and transport of soil Cd and phenanthrene in maize. The results showed that the growth of ‘Zheng dan 958’was positively stimulated by single Phe stress treatments. The plant height and biomass were not affected much by the single pollution of Cd. However, the coexistence of cadmium and phenanthrene hindered the plant height in variable degrees. Also the plant height of maize seedlings was greatly raised by 8.22% compared to the single cadmium pollution. The plant height was significantly reduced by 13.65% compared to that under the single Phe pollution. While the effect on biomass was not significant. The presence of low and high concentrations of Phe inhibited the absorption and accumulation of Cd in root of maize seedlings. Compared different treatments of Phe with the single of, Low concentration Phe treatment decreased the Cd content in root by 29.40% and 32.70% compared to that of the low and high concentration of Cd pollution suggesting antagonistic effects of low concentration Phe on Cd pollution. The presence of high concentration Phe promoted the absorption and accumulation of Cd in the stem and leaf of maize seedlings. The Cd content in stem and leaf significantly increased by 22.22% under the high concentration Phe and Cd treatment compared with that under the single pollution of low concentration of Cd. The synergy between the two was significant. The presence of Cd promoted the accumulation of Phe in the roots, stems and leaves of maize seedlings. Compared treatments of Cd with the single pollution treatment with low concentration of Phe, The presence of low concentration Cd significantly increased of the Phe content in root by 61.84%. The presence of high concentration Cd significantly increased the Phe content in the stems and leaves of maize seedlings by 187.53%, which showed significant synergy between the two. In addition, the presence of Phe promoted the transport of Cd from root to stem and leaf in ‘Zheng dan 958’. The presence of Cd also promoted the transport of Phe. Therefore, maize ‘zheng dan 958’ is not available for cultivating and edible on the contaminated soils with Cd and Phe. But it is better to be a soil remediation crop for compound contamination.

In order to realize the nondestructive picking of citrus, a soft end effector was designed in this paper. A mechanical model of soft finger bending deformation was established based on Yeoh constitutive model. The center combination design test was carried out by finite element simulation. The optimal combination parameters were as follows: the height of the airbag was 7mm; the thickness of the limiting layer was 3.5mm and the thickness of the air chamber was 3mm. The mechanical model was modified by fitting ANSYS finite element simulation results with MATLAB. The mechanical model and finite element simulation were verified by bending test of soft finger. Through ANSYS finite element simulation, the inflatable pressure of soft finger was 0.035 ~ 0.07 mpa, and the soft manipulator not only met the stiffness requirements but also did not damage citrus. The experiment platform was set up, and the maximum squeeze pressure was 18.13 N under the maximum atmospheric pressure. The experiment proved that the success rate of nondestructive clamping of citrus by the soft end-effencer was 96.67%, and the average time of picking a citrus was 3.54 s.

In order to evaluate the water use efficiency of different varieties of apple rootstocks under drought stress and explore the physiological mechanisms causing the differences, this experiment used one-year-old malus hupehensis as the base stock and selected three varieties of apple rootstocks (‘13#30’ ‘M9’ and ‘10-1’) as scions for budding. This experiment adopted the potted water control method for 60 days with two water treatments including normal water supply and moderate drought stress, and the treatment time is 60 days. We measured the instantaneous water use efficiency (WUE_i) and long-term water use efficiency (WUE_L) of the three varieties of apple rootstocks under drought stress, as well as related morphological and physiological indicators, and conducted correlation analysis on the above indicators. The results showed that after long-term moderate drought stress, significantly increased, the WUEi of the leaves of rootstock ‘M9’ while the WUEi of the leaves of rootstock ‘13#30’ decreased significantly. And the leaf WUE_i rootstock ‘10-1’ showed no significant variation. Meanwhile, at the end of drought treatment, the WUE_L ranking of the three varieties of apple rootstocks was as follows: M9 > 13#30 > 10-1. Furthermore, WUE_i showed a significant positive correlation with carotenoid content and soluble protein content (P≤0.05); WUE_L showed a significant positive correlation with root to shoot ratio, CAT activity and proline content. And WUE_Lsignificantly negatively correlated with P_n, and extremely significantly negatively correlated with T_r (P≤0.01). This study has important guiding significance for the breeding and promotion of high WUE apple rootstock varieties, and provides a theoretical basis for evaluating the WUE of apple rootstocks.

In this study, probiotics were isolated from the feces of healthy calves and its probiotic properties were analyzed. The probiotics were identified by morphological observation and 16S rDNA sequencing followed by analysis of their antibacterial activity and antibacterial substances. The growth curve and acid production curve were established to explore their adhesion ability and tolerance. The safety was evaluated by drug sensitivity test and hemolysis test. The results showed that four probiotics were identified as Lactobacillus agilis, Pediococcus pentosaceus, Lactobacillus salivarius and Lactobacillus johnsonii that displayed antibacterial activities against Escherichia coli O111:K58(B4), Staphylococcus aureus and E. coli K99. The antibacterial substances of strain 12 and 30 were organic acids and hydrogen peroxide. Bacteriocins were found in strain 26 in addition to organic acids and hydrogen peroxide. Strain 14 produced organic acids and bacteriocin. They showed good growth characteristics, acid production ability, strong cell adhesion ability, strong tolerance to bile salt solution and artificial gastroenteric fluid, strong sensitivity to antibiotics, and no hemolytic. The four probiotics strains isolated in this study met the need of searching for antifungal substances, and provided a theoretical basis for the prevention and treatment of bacterial diarrhea in calves.

In order to screen the resistant varieties of creeping bentgrass, the physiological indexes of 7 varieties of creeping bentgrass infected by Rhizoctonia solani were determined and their disease resistance was compared by principal component analysis. The results showed that after being invaded by pathogens, the content of chlorophyll, soluble protein (SP), and hydrogen peroxide (H₂O₂) in plant leaves decreased; the content of malondialdehyde (MDA), soluble sugar (SS), free proline (Pro), superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and glutathione reductase (APX) increased. the score D value was calculated following conversion of these 10 physiological indicators into 4 principal component factors, The highest score D went to factor was ‘Guangmang’. The disease resistance level of 7 varieties of creeping bentgrass was ranked as Guangmang > A-1 > 007 > A4 > Sun Rise > Xuanyan > Jiamei by principal component analysis. The results laid the foundation for the subsequent research on the resistance mechanism of creeping bentgrass and the breeding of new resistant varieties.