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Background: Balancing nutrient application is crucial for plant growth. However, excessive fertilizer use, especially imbalanced applications of macronutrients such as phosphate (P), can hinder plant uptake of micronutrients. Balanced P and zinc (Zn) are vital for apple yield and quality, and apple trees are highly sensitive to deficiencies in these nutrients. Therefore, this study was conducted in May 2022, employed a sand culture experiment to investigate the effects of varying P and Zn levels on the growth phenotype, photosynthetic capacity, antioxidant enzyme activity, sugar composition, endogenous hormone levels, and nutrient absorption and utilization of M9-T337 seedlings. Three levels of P (low, medium, high) and three levels of Zn (low, medium, high) were combined to create a total of nine distinct treatment. Results: The results indicate that combined P and Zn fertilization at various levels exerts either synergistic or antagonistic effects on the growth, nutrient absorption, and utilization of M9-T337 seedlings. Compared to low and medium levels of P, a combination of high P (4 mmol·L−1) and an adequate amount of Zn significantly enhanced plant growth, root system development, and the microstructure of leaves. Notably, seedlings treated with high P and low Zn (HPLZn) reached a height 1.54 times that of the medium P and medium Zn (MPMZn, control). Physiological indicators under HP conditions revealed significant increases in antioxidant enzyme activity, leaf water retention, photosynthetic pigment concentration, osmotic adjustment substances, and the contents of glucose, sucrose, fructose, endogenous hormones, as well as P and Zn accumulation in the leaves, compared to the control. However, an increase in Zn application led to a declining trend in these parameters. Specifically, the HPLZn treatment exhibited substantial increases in Net photosynthetic rate (Pn), Total chlorophyll (Chl a + b), glucose, fructose, sucrose, and Auxin(IAA), with increments of 7.12%, 27.32%, 11.40%, 23.20%, 16.67%, and 55.11%, respectively, compared to the control. Conclusion: Based on the comprehensive ranking from principal component analysis, the combination of HP (4 mmol·L−1) and LZn (0.5 µmol·L−1) was found to be the most effective in enhancing the antioxidant capacity, sugar accumulation, osmotic regulation ability, photosynthetic capacity, endogenous hormone levels, as well as P and Zn nutrient absorption and utilization in M9-T337 seedlings. [ABSTRACT FROM AUTHOR]

Caffeic acid O-methyltransferase (COMT), as a multifunctional enzyme involved in various physiological and biochemical processes in lignin metabolism, plays an important role in a plant's response to stress. In this study, we isolated COMT family members from the walnut genome by bioinformatics and analyzed their physicochemical properties and their expression under drought stress to provide gene resources for drought resistance in walnut. The results showed that 33 COMT genes were identified from walnuts and distributed on different chromosomes. The molecular weight of proteins varies greatly. According to the phylogenetic tree, the family can be divided into seven subgroups, which are relatively conservative in evolution and closely related to Arabidopsis thaliana. Promoter analysis showed that the promoter of the walnut COMT gene contains rich cis-elements of plant hormone response and stress response, and the real-time fluorescence scale name can be significantly induced by drought stress. Compared with wild-type Arabidopsis, overexpression JrCOMT19 significantly increased the enzyme activity (SOD, POD, and CAT) and proline content. Meanwhile, overexpression of JrCOMT19 significantly increased the lignin content and expression of related genes. Therefore, JrCOMT plays an important role in responding to drought in walnuts, and overexpression JrCOMT19 can improve the resistance to drought stress by increasing lignin content, antioxidant enzyme activity, and osmotic substance content. [ABSTRACT FROM AUTHOR]

The PYL protein family are crucial sensors of the core signals of abscisic acid (ABA) and significantly influence the plant's response to ABA-mediated abiotic stresses as well as its growth and development. However, research on the role of the MhPYL4 gene in iron (Fe) deficiency in apple trees is limited. Studies have shown that the MhPYL4 gene, when exposed to Fe-deficiency stress, exhibits more rapid transcriptional upregulation than other genes' quickly elevated transcription. However, the precise mechanism by which it alleviates this stress remains unclear. The MhPYL4 gene (ID:103432868), isolated from Malus halliana, was analyzed to elucidate its function. Arabidopsis plants engineered to overexpress the MhPYL4 gene exhibited increased leaf chlorosis and slower growth in response to Fe stress compared to the unmodified controls. The transgenic plants also exhibited elevated levels of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities, as well as ferric chelate reductase (FCR) activities. Levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2−) were increased. In addition, these transgenic plants had lower concentrations of proline (Pro) and Fe2+, which indicated that their stress tolerance was reduced. Similarly, the overexpression of MhPYL4 in apple calli resulted in inhibited growth and increased susceptibility under Fe stress conditions. Physiological evaluations indicated that the overexpression of MhPYL4 in Arabidopsis reduced its Fe stress tolerance by inhibiting chlorophyll synthesis. In apple calli, it altered pH levels, antioxidant enzyme activity, and Fe-reducing capabilities under the same stress conditions. In summary, the elevated expression of the MhPYL4 gene reduced the tolerance of both Arabidopsis and apple calli to Fe stress, suggesting that MhPYL4 acts as a negative regulator in response to Fe deficiency. [ABSTRACT FROM AUTHOR]

Saline–alkali stress is a significant abiotic stress that restricts plant growth globally. Basic region leucine zipper (bZIP) transcription factor proteins are widely involved in plants in response to abiotic stress such as saline–alkali stress. Based on transcriptome and quantitative real-time PCR (qRT-PCR), we found that the MhbZIP23 gene could respond to saline–alkali stress. Despite this discovery, the underlying mechanism by which the MhbZIP23 transcription factor responds to saline–alkaline stress remains unexplored. To address this gap in knowledge, we successfully cloned the MhbZIP23 (MD05G1121500) gene from Malus halliana for heterologous expression in Arabidopsis thaliana, facilitating the investigation of its functional role in stress response. Compared to the wild type (WT), Arabidopsis plants demonstrated enhanced growth and a lower degree of wilting when subjected to saline–alkali stress. Furthermore, several physiological indices of the plants altered under such stress conditions. The transgenic Arabidopsis plants (OE-5, 6, and 8), which grew normally, exhibited a higher chlorophyll content and had greater root length in comparison to the control check (CK). MhbZIP23 effectively regulated the levels of the osmoregulatory substance proline (Pro), enhanced the activities of antioxidant enzymes such as peroxidase (POD) and superoxide dismutase (SOD), and reduced the levels of malondialdehyde (MDA) and relative conductivity (REC). These actions improved the ability of plant cells in transgenic Arabidopsis to counteract ROS, as evidenced by the decreased accumulation of O2− and hydrogen peroxide (H2O2). In summary, the MhbZIP23 gene demonstrated effectiveness in alleviating saline–alkali stress in M. halliana, presenting itself as an outstanding resistance gene for apples to combat saline–alkali stress. [ABSTRACT FROM AUTHOR]

Plants have, throughout evolution, developed a hydrophobic cuticle to protect them from various stresses in the terrestrial environment. The cuticle layer is mainly composed of cutin and cuticular wax, a mixture of very‐long‐chain fatty acids and their derivatives. With the progress of transcriptome sequencing and other research methods, the key enzymes, transporters and regulatory factors in wax synthesis and metabolism have been gradually identified, especially the study on the regulation of wax metabolism by transcription factors and others in response to plant stress has become a hot topic. Drought is a major abiotic stress that limits plant growth and crop productivity. Plant epidermal wax prevents non‐stomatal water loss and improves water use efficiency to adapt to arid environments. In this study, the ways of wax synthesis, transport, metabolism and regulation at different levels are reviewed. At the same time, the regulation of wax by different transcription factors and plant hormones in response to drought is elaborated, and key research questions and important directions for future solutions are proposed to enhance the potential application of epidermal wax in agriculture and the environment. [ABSTRACT FROM AUTHOR]

Undergraduate bilingual teaching is an important practice to realize the internationalization of education and the future. It is a powerful starting point for education reform in the new era and a necessary way to cultivate international undergraduate talents. Although there are some difficulties and problems in undergraduate bilingual teaching in China, there are many ways to explore. Based on the analysis of the teaching practice of the course “Internet and New Media” in colleges and universities, this paper discusses the key points and difficulties of the bilingual course of media in colleges and universities from the aspects of teaching orientation, teacher allocation, students’ English literacy and bilingual teaching material construction. Through the discussion in this paper, we try to continuously improve the teaching mode of the bilingual course “Internet and New Media”, improve the teaching quality, and cultivate excellent undergraduate talents with media literacy and international vision.

Increasing the use of organic fertilizers is an effective measure to improve, increase soil fertility and maintain crop yields. The aim of this study was to investigate the influence of different types of organic fertilizers on the early yield of grapes and soil parameters, as well as the relationship between soil parameters and grape yield under fertilization conditions. The 'Shine Muscat' grape was used as the material, with early maturing cultivation in the solar greenhouse. From the time of grape planting, three-year continuous fertilization management was carried out using five types of base fertilizers: chemical fertilizer (CK), fermented corn stalk residue (A1), mature sheep manure (A2) and two types of commercial organic fertilizers (B1 and B2). In the third year, berry and soil samples were collected to determine grape yield and evaluate soil physicochemical properties, nutrient status and changes in enzyme activity, studying the relationship between grape yield and soil indicators. The results show that compared to CK, the grape yields with B1 and B2 increased by 19.04% and 16.26%, respectively, while A1 and A2 decreased by 24.09% and 18.97%. Organic fertilizer application reduced soil bulk density, increased soil porosity, enhanced soil organic matter content and effectively buffered soil pH levels. Two types of commercial fertilizers (B1 and B2) improved soil total nitrogen, total phosphorus, total potassium, available nitrogen and available phosphorus content to varying degrees. All organic fertilizer treatments effectively increased soil enzyme activity, except for soil sucrase activity. Through correlation and regression analyses, it was found that in this study, the levels of available nitrogen, available potassium and soil saccharase activity were most closely related to early grape yield. Their influence on grape yield was in the order of available nitrogen > soil saccharase activity > available potassium. Therefore, with a combined organic and inorganic basal fertilization system, the fertilizer nutrients are more comprehensive and help to increase the productivity of grapes at the beginning of the fruiting period. Nitrogen and phosphorus are very important in the maintaining of grape yields and improving sucrose activity in the soil through the application of organic fertilizers cannot be ignored when increasing yields. [ABSTRACT FROM AUTHOR]

The effects of NaCl-induced salinity on biomass allocation, anatomical characteristics of leaves, ion accumulation, salt repellency, and salt secretion ability were investigated in two apple rootstock cultivars (Malus halliana '9-1-6' and Malus baccata), which revealed the physiological adaptive mechanisms of M. halliana '9-1-6' in response to salt stress factors. This experiment was conducted in a greenhouse using a nutrient solution pot. Salt stress was simulated by treating the plants with a 100 mM NaCl solution, while 1/2 Hoagland nutrient solution was used as a control (CK) instead of the NaCl solution. The results showed that the two rootstocks responded to salt environments by increasing the proportion of root biomass allocation. According to the stress susceptibility index, '9-1-6' exhibits a lower salt sensitivity index and a higher salt tolerance index. The thickness of the leaf, upper and lower epidermis, palisade tissue, and mesophyll tissue compactness (CTR) of the two rootstocks were significantly decreased, while the thickness of sponge tissue and mesophyll tissue looseness (SR) were significantly increased, and the range of '9-1-6' was smaller than that of M. baccata. With an extension of stress time, the accumulation of Na+ increased significantly, and the accumulation of K+ decreased gradually. The stem and leaves of '9-1-6' showed a lower accumulation of Na+ and a higher accumulation of K+, and the roots displayed a higher ability to reject Na+, as well as young and old leaves showed a stronger ability to secrete Na+. In conclusion, within a certain salt concentration range, the '9-1-6' root part can maintain lower salt sensitivity and a higher root-to-shoot ratio by increasing the proportion of root biomass allocation; the aerial part responds to salt stress through thicker leaves and a complete double-layer fence structure; the roots and stem bases can effectively reduce the transportation of Na+ to the aerial parts, as well as effectively secrete Na+ from the aerial parts through young and old leaves, thereby maintaining a higher K+/Na+ ratio in the aerial parts, showing a strong salt tolerance. [ABSTRACT FROM AUTHOR]

The Bayer red mud generated from the alumina industry is a hazardous solid waste. In our team, a green calcification–carbonation process is proposed for its disposal. Red mud is treated with lime to convert the silicon phase in solution into hydrogarnet, which is then decomposed by CO2 to recover alumina. In order to simplify the process flow, the direct carbonation process is employed, in which the NaOH-containing solution resulting from calcification is sent directly to carbonation without prior liquid–solid separation. The discrete and direct carbonation processes gave 34.9% and 35.5% alumina recoveries, respectively, with Na2O contents in the final red muds of 0.15%wt and 0.21%wt, respectively. The optimum NaOH concentration in the whole calcification–carbonation process liquor was 40 g/l. Under this alkali condition, alumina recovery reached 40.5% and the Na2O content in the processed red mud was reduced to

Fruit trees are perennial crops that grow in one place for their whole lives, which leads to the deterioration of the soil as well as a decline in fruit quality and yield. Microbial diversity and community structure are important soil factors affecting stress resistance and the quality of fruit trees. Additionally, biogas fertilizer also plays an important role in improving fruit quality. Whether biogas fertilizer can improve continuous cropping barriers by affecting microbial diversity and community structure remains to be further investigated. Therefore, 7-year-old Fuji apples were used as material, and biogas fertilizer was applied continuously for three years. The results show that the contents of soil organic matter (SOM), available nitrogen (AN), available phosphorus (AP), and soil porosity (SP) increased by 0.712, 0.217, 1.089, and 0.401 after applying biogas fertilizer, respectively. The concentrations of vitamin C, titratable acid, and soluble solids also significantly increased. We also found that the relative abundance of dominant soil flora significantly increased, such as Sphingomonas (g_Sphingomonas), Chlamydomonas (g_Chlamydomonas), and Stachybotry (g_Stachybotry), while the relative abundance of inferior flora significantly decreased, such as Cryptococcus (g_Cryptococcus) and Alternaria (g_Alternaria). In summary, biogas fertilizer can improve the physicochemical properties of the soil as well as the structure and diversity of the microbial communities in rainfed orchards, resulting in higher fruit quality. [ABSTRACT FROM AUTHOR]