Malonaldehyde Content Research Articles

Resistance index and browning mechanism of apple peel under high temperature stress

Apples are one of the most important economic crops worldwide. Because of global warming and an aggravation of environmental, abnormally high temperatures occur frequently in fruit-growing season and seriously affect normal fruit growth and reduce fruit quality and yield. We took five-year-old ‘Ruixue’ (Qinfu 1 × Pink Lady; CNA20151469.1) fruits as test materials, and the ambient temperature during fruit development was monitored. The results showed that during the fruit-growing season, especially during the rapid growth stage (July to August), the maximum daily temperature exceeded 30 °C and lasted for more than 40 days. To determine the effects of high temperature stress on the apple fruit resistance, we treated expanding, veraison, and maturity-period fruits at different temperatures. It was found that the fruits of the expanding period showed strong resistance to high temperature stress, whereas during veraison and maturity, fruit resistance to high temperature stress decreased, and the fruit peel browning phenotype appeared. Meanwhile, the content of malonaldehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2.-) in the peel gradually increased with increasing temperature. The content of total phenols, flavanol, and flavonoids in the peel decreased substantially at 45 °C. Moreover, it was found that polyphenol oxidase gene (MdPPO1) was most sensitive to high temperature stress in apple. Furthermore, transient and stable MdPPO1 overexpression significantly promoted peel browning. The transgenic materials were more sensitive to high temperatures, and browning was more severe compared to non-genetically modified organism (WT). Stable MdPPO1 knockout calli obtained via clustered regularly interspersed short palindromic repeats (CRISPR/Cas9) gene knockout technology reduced the browning phenotype, and the resultant fruits were not sensitive to the effects of high temperature stress. Thus, MdPPO1 expression may be a key factor of high temperature–related changes observed in the browning phenotype that provides a scientific theoretical basis for the selection of high temperature–resistant varieties and apple cultivation and management in the future.

The halophilic bacteria Gracilibacillus dipsosauri GDHT17 alleviates salt stress on perennial ryegrass seedlings.

Adverse abiotic environmental conditions including excess salt in the soil, constantly challenge plants and disrupt the function of plants, even inflict damage on plants. Salt stress is one of the major limiting factors for agricultural productivity and severe restrictions on plant growth. One of the critical ways to improve plant salt tolerance is halotolerant bacteria application. However, few such halotolerant bacteria were known and should be explored furtherly. Halophilic bacterium strain was isolated from saline soil with serial dilution and identified with classical bacteriological tests and 16S rRNA analysis. Perennial ryegrass (Lolium perenne L) was used in this study to evaluate the potential effect of the bacteria. A halophilic bacterium strain GDHT17, was isolated from saline soil, which grows in the salinities media with 1.0%, 5.0%, and 10.0% (w/v) NaCl, and identified as Gracilibacillus dipsosauri. Inoculating GDHT17 can significantly promote ryegrass's seedling height and stem diameter and increase the root length, diameter, and surface area at different salt concentrations, indicating the significant salt stress alleviating effect of GDHT17 on the growth of ryegrass. The alleviating effect on roots growth showed more effective, especially on the root length, which increased significantly by 26.39%, 42.59%, and 98.73% at salt stress of 100 mM, 200 mM, and 300 mM NaCl when the seedlings were inoculated with GDHT17. Inoculating GDHT17 also increases perennial ryegrass biomass, water content, chlorophyll and carotenoid content under salt stress. The contents of proline and malonaldehyde in the seedlings inoculated with GDHT17 increased by 83.50% and 6.87%, when treated with 300 mM NaCl; however, the contents of MDA and Pro did not show an apparent effect under salt stress of 100 mM or 200 mM NaCl. GDHT17-inoculating maintained the Na+/K+ ratio in the salt-stressed ryegrass. The Na+/K+ ratio decreased by 26.52%, 6.89%, and 29.92% in the GDHT17-inoculated seedling roots treated with 100 mM, 200 mM, and 300 mM NaCl, respectively. The GDHT17-inoculating increased the POD and SOD activity of ryegrass seedlings by 25.83% and 250.79%, respectively, at a salt stress of 300 mM NaCl, indicating the properties of GDHT17, improving the activity of antioxidant enzymes of ryegrass at the salt-stress condition. Our results suggest that G. dipsosauri GDHT17 may alleviate salt stress on ryegrass in multiple ways; hence it can be processed into microbial inoculants to increase salt tolerance of ryegrass, as well as other plants in saline soil.

Feasibility evaluation of fermented peanut meal to replace soybean meal in the diet of common carp (Cyprinus carpio): Growth performance, serum biochemistry, intestinal health and microflora composition

The effectiveness of soybean meal (SBM) substitution with fermented peanut meal (FPM) were appraised in common carp juveniles. A diet containing 30 % SBM was perceived as the control diet, then 25 %, 50 %, 75 % and 100 % of SBM was replaced by the FPM (FPM0, FPM25, FPM50, FPM75, FPM100 groups). Each group was fed to three replicate groups of common carp (4.83 ± 0.02 g) for 56 days. Results exhibited that FPM50 group attained the significantly higher mass gain rate and specific growth rate than those of the other groups except for FPM25, higher protein efficiency ratio and lower feed conversion rate than those of the FPM75 and FPM100 groups. The FPM50 group significantly increased the contents of serum total protein and albumin and decreased the content of serum urea nitrogen. The activity of hindgut protease was significantly enhanced in the FPM50 group. Significantly higher and lower intestinal villi height was, respectively, observed in the FPM50 and FPM100 group. The FPM50 group significantly enhanced the gene expression and activities of antioxidant enzymes in the intestine, reversely decreased the content of malonaldehyde. Significant increments in the occludin, myosin light chain kinase and claudin3 gene expressions in the FPM50 group improved the increase of intestinal permeability induced by pro-inflammatory factor related genes interleukin 1β, interleukin 6 and tumor necrosis factor α. Staphylococcus and Enterococcus in the intestine abundances were effectively suppressed in the FPM50 group, and Lactococcus became the dominant intestinal bacteria genera. The optimum substitution level was estimated to be 50.93 % and 49.89 % using broken-line regression analyses based on MGR and FCR. Overall, the soybean meal in common carp feed could be substituted up to 50 % by FBM without negative influence on growth, feed utilization and intestinal health.

Can sulforaphane alter growth performance, innate immunity and antioxidant capability of common carp (Cyprinus carpio Huanghe var)?

Sulforaphane (SFN) is a plant extract with demonstrated immunity, anti-inflammatory and antioxidant properties. However, its research on aquatic animals is still lacking. Herein, this study aimed to investigate the effects of SFN on growth performance, innate immunity and antioxidant capability of common carp (Cyprinus carpio Huanghe var). Fish (76.17 ± 0.23 g) were fed diets supplemented with five levels (0, 5 mg kg−1, 10 mg kg−1,15 mg kg−1 and 20 mg kg−1) of SFN for 8 weeks. The results indicated that fish fed 10 mg kg−1 SFN showed higher weight gain rate (P < 0.05) than the control group and the group of 15 mg kg−1 SFN. Feed conversion ratio was significantly lower (P < 0.05) in fish fed 10 mg kg−1 SFN than the group of 15 mg kg−1 SFN. Plasma complement component 4 and interleukin-10 (IL-10) contents, acid phosphatase activity, and liver superoxide dismutase, glutathione peroxidase and catalase activities, glutathione content, and interleukin-1β, IL-10, tumor necrosis factor-α (TNF-α) and toll-like receptor 2 mRNA expressions all increased (P < 0.05) in response to dietary SFN levels from 0 to 10 mg kg−1, then decreased with further increasing SFN levels. Plasma TNF-α content increased (P < 0.05) in response to dietary SFN levels from 0 to 15 mg kg−1, then decreased with further increasing SFN levels. Plasma lysozyme and myeloperoxidase activities both increased (P < 0.05) in response to dietary SFN levels from 0 to 5 mg kg−1, then decreased with further increasing SFN levels. Liver malonaldehyde content was significantly lower (P < 0.05) in fish fed 10 mg kg−1 SFN than other groups except for the 5 mg kg−1 SFN. Overall, these findings suggested that dietary SFN could promote growth, enhance immunity and antioxidant capacity, and the best benefit was obtained in fish fed 10 mg kg−1. These results encouraged further research of SFN as feed additive in aquaculture and provided basic data for the future application of SFN in aquatic animals.

Melatonin Mitigated Salinity Stress on Alfalfa by Improving Antioxidant Defense and Osmoregulation

Melatonin (MT) is a growth regulator and antioxidant that can resist peroxidation damage on plants caused by environmental stresses. In this study, the alleviation effects of melatonin on alfalfa under salt stress were investigated in terms of photosynthesis, antioxidant enzymes, and osmoregulation. The alfalfa seedlings were cultured in 200 mM NaCl Hoagland solution. Five levels of MT (0, 0.1, 0.2, 0.3, and 0.4 mM) were applied as a foliar spray. Generally, the foliar spray of MT increased root length, root surface area, height, leaf length and width, aerial and root biomass, SPAD readings, the content of proline and soluble protein, and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Malonaldehyde (MDA) content was decreased by MT foliar spray. The beneficial effects of MT on alfalfa under salt stress were dosage-dependent, and excessive MT levels inhibited alfalfa growth. The alleviating effects of MT on salt stress were more pronounced at 0.3 mM MT. This study suggested that exogenous MT foliar spray at appropriate levels can ameliorate the adverse effects of salt stress on alfalfa seedlings.

Enhanced phytoremediation efficiency of PHE-contaminated soil by rape (Brassica napus L.) assisted with PHE-degradable PGPR through modulating rhizobacterial communities

Polycyclic aromatic hydrocarbons (PAHs) accumulate excessively in soil environment recently, posing a significant threat to soil ecology and human health. The application of plant growth promoting rhizobacteria (PGPR) with PAHs degradable capacity in assissting with phytoremedeation of PAHs contaminated soil has not been reported yet. The purpose of this study was to verify the feasibility of a novel PGPR-assisted phytoremediation strategy for the remediation of PAHs contaminated soil. A phenanthrene (PHE) degradable strain Serratia sp. DLN5 with great plant growth-promoting (PGP) traits was selected by two steps of bacterial culture and plant verification. Through a 40-d pot experiment, the effects of DLN5 application on rape (Brassica napus L.) physiology and phytoremediation efficiency were determined. The results showed that DLN5 inoculation significantly promoted the growth of rape cultivated in PHE contaminated soil (200 mg kg−1 PHE), mainly reflecting by the increase of root length (22.2%), net photosynthetic rate (334.9%) and the decrease of malonaldehyde (MDA) content (79.0% in roots). The inoculation of PGPR could also modulate the activity of enzymes that related to nutrient cycling and pollutant degradation in soil. Besides, the analysis of high-throughput sequencing of rhizosphere soil samples revealed that DLN5 upregulated the abundance of some bacteria, which could contribute to the enhancement of PHE degradation process (e.g., Flavobacterium, Methylophilaceae and Burkholderiaceae). Through the regulation of plant growth and rhizosphere bacterial community by strain DLN5, the phytoremediation efficiency of PHE contaminated soils by rape inoculated with PGPR was elevated from 71.5% to 82.5%. In general, this study proposed an innovative PGPR-assisted phytoremediation strategy, while the mechanisms in this remediation process were also be proposed, which might not affect the economic value of industrial crop, providing a theoretical basis for the practical application of PAHs contaminated soil.

Genome-wide identification and analysis of glyceraldehyde-3-phosphate dehydrogenase family reveals the role of GmGAPDH14 to improve salt tolerance in soybean (Glycine max L.).

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential key enzyme in the glycolytic pathway and plays an important role in stress responses. Although GAPDH family genes have been found in different plant species, the determination of their gene family analysis and their functional roles in soybean are still unknown. In this study, gene sequence and expression data were obtained using online tools, and systematic evolution, expression profile analysis, and qRT-PCR analysis were conducted. Here a total of 16 GmGAPDH genes were identified on nine chromosomes, which were classified into three clusters. Additionally, all GmGAPDH genes harbor two highly conserved domains, including Gp_dh_N (PF00044) and Gp_dh_C (PF02800). The qRTPCR analysis also showed that most GmGAPDH genes significantly responded to multiple abiotic stresses, including NaHCO3, polyethylene glycol, cold, and salt. Among them, GmGAPDH14 was extraordinarily induced by salt stress. The GmGAPDH14 gene was cloned and overexpressed through soybean hair roots. The overexpressed transgenic soybean plants of the GmGAPDH14 gene have also shown better growth than that of control plants. Moreover, the overexpressed transgenic plants of GmGAPDH14 gene had higher activities of superoxide dismutase but lower malonaldehyde (MDA) content than those of control plants under salt stress. Meanwhile, a total of four haplotypes were found for the GmGAPDH14 gene, and haplotypes 2, 3, and 4 were beneficial for the tolerance of soybean to salt stress. These results suggest that the GmGAPDH14 gene might be involved in the process of soybean tolerance to salt stress. The results of this study will be valuable in understanding the role of GAPDH genes in the abiotic stress response of soybean.

Lycium barbarum polysaccharides improve lipid metabolism disorders of spotted sea bass Lateolabrax maculatus induced by high lipid diet

This experiment explored the effects of Lycium barbarum polysaccharides (LBP) on lipid metabolism of spotted sea bass Lateolabrax maculatus. Blank and experimental control diets with 100 and 150 g/kg lipid were designed, respectively, and three dosages of LBP (0.75, 1.00, 1.25 g/kg) were supplemented in the experimental control diet. A total 375 of spotted sea bass (19.33 ± 0.15) g were divided into 5 groups, and were given experimental diets for 56 days, respectively. Results showed fish were induced to lipid metabolism disorders with dietary 150 g/kg lipid intake, which manifested in reduced feeding, oxidative stress, elevated serum lipid, and more severe hepatic damage. Dietary LBP improved the lipid metabolism disorders of fish, as indicated by significant enhancements in weight gain, digestion, superoxide dismutase activity, and decreases in malonaldehyde content, and activity of alanine aminotransferase and aspartate aminotransferase. Accordingly, an improvement in the hepatic morphological and expression of lipid metabolism related genes, including FAS, PPAR-α, CPT1 and ATGL, was observed. Nevertheless, no significant variation in serum triglyceride and total cholesterol was observed. Overall, dietary LBP can improve the growth, digestion, antioxidant capacity, and liver health of spotted sea bass, thereby improving the lipid metabolism disorders induced by 150 g/kg dietary lipid intake.

Saxagliptin promotes random skin flap survival

BackgroundFlap necrosis is a common issue encountered in clinical flap transplantation surgery. Here, we assessed the effects of saxagliptin, a dipeptidyl peptidase-4 inhibitor, on flap survival and explored the underlying mechanisms. MethodsA dorsal McFarlane flap model was established in 36 rats, which were randomly divided into a high-dose saxagliptin (HS) group (saxagliptin, 30 mg/kg/day, n = 12), low-dose saxagliptin (LS) group (saxagliptin, 10 mg/kg/day, n = 12), and control group (n = 12). On day 7, flap survival was examined by eye in six rats from each group, along with determination of blood perfusion by laser Doppler flowmetry and angiogenesis by angiography. The remaining rats were sacrificed for harvesting of flap tissue. The status of the flap tissue was examined histopathologically by staining with hematoxylin and eosin (H&E). Oxidative stress was evaluated by determination of superoxide dismutase (SOD) activity and malonaldehyde (MDA) content. Gasdermin D (GSDMD), vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), NOD-like receptor pyrin domain containing 3 (NLRP3), interleukin (IL)-6, IL-18, Toll-like receptor 4 (TLR4), IL-1β, caspase-1, and nuclear factor-κB (NF-κB) expression were detected by immunohistochemical analysis. ResultsThe experimental group exhibited a larger area of flap survival, with more blood perfusion and neovascularization and better histopathological status than the control group. The degree of oxidative stress and the levels of NF-κB, TLR4, proinflammatory cytokines, and pyroptosis-associated protein were decreased in the experimental group, while the VEGF level was increased in a saxagliptin dose-dependent manner. ConclusionSaxagliptin promotes random skin flap survival.

Effects of mulberry leaf extract on the intestinal health of spotted sea bass (Lateolabrax maculatus)

Mulberry leaf extract (ELM) has the functions of promoting growth, antioxidant, improving intestinal microbial composition, thus providing a potential solution the occurrence of fish intestinal diseases. Therefore, this experiment was conducted to explore the effects of ELM on intestinal health of spotted sea bassLateolabrax maculatus. A total of 360 spotted sea bass (9.00 ± 0.02 g) were selected and randomly divided into 6 groups. Fish in each group were given feed with varying ELM concentration (0, 3, 6, 9, 12, 15 g/kg) for 52 days, respectively. Results show, dietary intake of 9 g/kg ELM increased the weight gain, specific growth ratio and feed intake of the spotted sea bass (P&amp;lt;0.05). Meanwhile, dietary intake of 9 g/kg ELM increased the activity of enteric trypsin, amylase and lipase (P&amp;lt;0.05). The enteric catalase activity was improved in fish fed with 3 g/kg ELM (P&amp;lt;0.05), while a limited effect of ELM on the activity of enteric superoxide dismutase, glutathione, and content of malonaldehyde was observed (P&amp;gt;0.05). ELM improved the morphology of fish intestine, as manifested in significant improvement in the length of intestinal villi, thereby increasing the surface area of the intestinal tract (P&amp;lt;0.05). Compared with the control group, dietary intake of ELM significantly increased the intestinal microbial ACE, Chao1, and Shannon indexes of fish (P&amp;lt;0.05), indicated that the intestinal microbial composition and the abundance of the dominant flora of fish were improved. The above results suggested that the dietary supplementation of about 9 g/kg ELM can improve the growth performance, enteric antioxidant capacity, and intestinal morphology and microbial composition, therefore improving the intestinal health of spotted sea bass. The research results provide a theoretical basis for the application of ELM in improving the enteric health of spotted sea bass, and providing a potential solution the occurrence of fish intestinal diseases.

Staged and repeated drought-induced regulation of phenylpropanoid synthesis confers tolerance to a water deficit environment in Camellia sinensis

This year, more than four months of extreme drought caused a nearly 30% yield reduction in Chinese tea (Camellia sinensis, Theaceae) plantations. The related dicot plants potato (Solanum tuberosum, Solanaceae) and apple (Malus pumila, Rosaceae) deploy species specific, specialized metabolites as core stress defenses. In contrast, the specialized chemical defenses in tea plants are largely unknown. The high levels of polyphenols and theanine in tea plants are potential drought-resistant substances. Stress-related overreduction is known to cause a passive accumulation of plant metabolites to dissipate excess energy. To investigate specialized metabolic drought responses, we integrated tea plant physiological, transcriptomic, and metabolite analyses with different stress modes of staged and repeated drought. Under staged drought, tea leaves were subjected to more severe oxidative stress and photosynthetic system disruption after long-term drought. However, differentially expressed genes in response to the Calvin cycle and energy metabolism were significantly increased compared with short-term drought. Tea plants that experienced three rounds of drought exhibited more robust antioxidant defense and photosynthetic efficiency and lower energy requirements than those in their first drought. Metabolomic analyses identified carbohydrates, amino acids, and phenylpropanoid compounds that accumulated significantly in tea plants after drought. Consistent with altered transcriptomics, tea plants in the two drought modes were significantly enriched in 'phenylpropanoid biosynthesis', and several phenolic acid compounds exhibited significant accumulation. Exogenous irrigation of tea plants before drought with phenylpropanoid derivatives (tea polyphenols) extracted from tea leaves significantly reduced the malonaldehyde content in the roots. In summary, the passive transfer of metabolites and upregulation of biosynthesis rates combined to regulate metabolite levels in tea plants under drought, ultimately reducing the levels of toxic oxygen radicals.

Quality attributes of large yellow croaker (Larimichthys crocea) during refrigerated storage as affected by theaflavins.

Large yellow croaker (Larimichthys crocea) is an economical marine fish in China. Theaflavins have antibacterial and antioxidant properties. However, there is a lack of its application in the large yellow croakers during refrigerated storage. This study investigated the effect of theaflavins on the quality large yellow croaker (Larimichthys crocea) during 12 days of storage at 4°C. The results showed that theaflavins treatment was able to inhibit microbial growth and reduce the production of total volatile basic nitrogen (TVB-N). Meanwhile, theaflavins were beneficial in reducing the unfolding of myofibrillar proteins, decreasing the degree of protein aggregation, and improving the stability of protein structure. Therefore, the degree of protein oxidation was lower in the theaflavin-treated group compared with untreated group. In addition, theaflavins treatment effectively inhibited the increase in acid value (AV), peroxide value (PV), and malonaldehyde (MDA) content due to the ability of scavenging free radical. The effect of theaflavin was positively correlated with the increase in concentration under refrigeration conditions. Therefore, this study suggests that theaflavins handling is an auspicious and valid method to extend the preservation of refrigerated large yellow croaker. Overall, adding theaflavins to large yellow croaker can be an effective method of quality preservation during refrigerated storage. This article is protected by copyright. All rights reserved.

More Effective Protection Supports Male Better Than Female Siblings over Water Deficit in Artificially Bred Poplar Hybrids

Sexually dimorphic response to stress has been observed in assorted natural dioecious plants. Up to now, few studies have focused on the difference of stress responses between artificially bred siblings. To determine the sexual dimorphism between artificially bred sibling poplar trees, we conducted a study comparing the response to water deficit between male and female Populus × euramericana siblings. This pair of hybrids was analyzed in terms of growth, photosynthesis, membrane injury and repair systems, as well as gene regulation patterns. The female and male siblings presented distinct responses to water deficit, with greater inhibition in females’ growth and photosynthesis. The results also displayed that in females, relative electrolyte leakage and malonaldehyde content were higher than those in males under water deficit conditions. On the other hand, water deficit caused a greater increase in both SOD activity and POD activity in males than those in females. Consistent with these physiological differences, the expression of several stress-related genes, including SOD, GST, bHLH35, and PsbX1, was regulated differently between female and male hybrids by water deficit stress. Higher expression of SOD in moderate-water-deficit-treated females and higher GST, bHLH35 expression in both moderate- and severe-water-deficit-treated females suggest that the female sib is more sensitive, whilst higher expression of SOD in severe-water-deficit-treated males and higher PsbX1 expression in water-deficit-treated males testify that males protect cells better. To achieve an integrated view, all these variables were analyzed through the use of a principal component analysis and a total discrepancy between the sexes in their response to water deficit was demonstrated. The results indicate that, compared with male poplar sibs, females are more sensitive, but deploy a weaker protective apparatus to deal with water deficit.

The Functional Characterization of DzCYP72A12-4 Related to Diosgenin Biosynthesis and Drought Adaptability in Dioscorea zingiberensis.

Dioscorea zingiberensis is a perennial herb famous for the production of diosgenin, which is a valuable initial material for the industrial synthesis of steroid drugs. Sterol C26-hydroxylases, such as TfCYP72A616 and PpCYP72A613, play an important role in the diosgenin biosynthesis pathway. In the present study, a novel gene, DzCYP72A12-4, was identified as C26-hydroxylase and was found to be involved in diosgenin biosynthesis, for the first time in D. zingiberensis, using comprehensive methods. Then, the diosgenin heterogenous biosynthesis pathway starting from cholesterol was created in stable transgenic tobacco (Nicotiana tabacum L.) harboring DzCYP90B71(QPZ88854), DzCYP90G6(QPZ88855) and DzCYP72A12-4. Meanwhile, diosgenin was detected in the transgenic tobacco using an ultra-performance liquid chromatography system (Vanquish UPLC 689, Thermo Fisher Scientific, Bremen, Germany) tandem MS (Q Exactive Hybrid Quadrupole-Orbitrap Mass Spectrometer, Thermo Fisher Scientific, Bremen, Germany). Further RT-qPCR analysis showed that DzCYP72A12-4 was highly expressed in both rhizomes and leaves and was upregulated under 15% polyethylene glycol (PEG) treatment, indicating that DzCYP72A12-4 may be related to drought resistance. In addition, the germination rate of the diosgenin-producing tobacco seeds was higher than that of the negative controls under 15% PEG pressure. In addition, the concentration of malonaldehyde (MDA) was lower in the diosgenin-producing tobacco seedlings than those of the control, indicating higher drought adaptability. The results of this study provide valuable information for further research on diosgenin biosynthesis in D. zingiberensis and its functions related to drought adaptability.

2-Oxoglutarate contributes to the effect of foliar nitrogen on enhancing drought tolerance during flowering and grain yield of soybean

Drought severely affects the growth and yield of soybean plants especially during the flowering period. To investigate the effect of 2-oxoglutarate (2OG) in combination with foliar nitrogen (N) at flowering stage on drought resistance and seed yield of soybean under drought stress. This experiment was conducted in 2021 and 2022 on drought-resistant variety (Hefeng 50) and drought-sensitive variety (Hefeng 43) soybean plants treated with foliar N (DS + N) and 2-oxoglutarate (DS + 2OG) at flowering stage under drought stress. The results showed that drought stress at flowering stage significantly increased leaf malonaldehyde (MDA) content and reduced soybean yield per plant. However, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were significantly increased by foliar N treatment, and 2-oxoglutarate synergistically with foliar N treatment (DS + N + 2OG) was more beneficial to plant photosynthesis. 2-oxoglutarate significantly enhanced plant N content, glutamine synthetase (GS) and glutamate synthase (GOGAT) activity. Furthermore, 2-oxoglutarate increased the accumulation of proline and soluble sugars under drought stress. Under drought stress, soybean seed yield was increased by DS + N + 2OG treatment by 16.48–17.10% and 14.96–18.84% in 2021 and 2022, respectively. Thus, the combination of foliar N and 2-oxoglutarate better mitigated the adverse effects of drought stress and could better compensate for the yield loss of soybean under drought stress.

TabZIP60 is involved in the regulation of ABA synthesis-mediated salt tolerance through interacting with TaCDPK30 in wheat (Triticum aestivum L.).

TabZIP60 is found to interact with TaCDPK30 and act as a positive regulator of ABA synthesis-mediated salt tolerance in wheat. Wheat basic leucine zipper (bZIP) transcription factor (TabZIP60) was previously found to act as a positive regulator of salt resistance. However, its molecular mechanism in response to salt stress in wheat is still unclear. In this study, TabZIP60 was found to interact with wheat calcium-dependent protein kinase (TaCDPK30), which belonged to group III of CDPK family, and was induced by salt, polyethylene glycol, and abscisic acid (ABA) treatments. This mutation of serine 110 in TabZIP60 resulted in no interaction with TaCDPK30. Moreover, TaCDPK30 was involved in interactions with wheat protein phosphatase 2C clade A (TaPP2CA116/TaPP2CA121). TabZIP60-overexpressing wheat plants showed increased salt tolerance, as exhibited by better growth status, higher soluble sugar, and lower malonaldehyde contents of transgenic plants than wild-type wheat cv. Kenong 199 under salt stress. Moreover, transgenic lines showed high ABA content by upregulating ABA synthesis-related gene expression levels. TabZIP60 protein could bind and interact with the promoter of the wheat nine-cis epoxycarotenoid dioxygenase (TaNCED2) gene. Furthermore, TabZIP60 upregulated several stress response gene expression levels, which could also increase the plant's ability to resist salt stress. Thus, these results suggest that TabZIP60 could function as a regulator of ABA synthesis-mediated salt tolerance through interacting with TaCDPK30 in wheat.

Effects of Spraying KH2PO4 on Flag Leaf Physiological Characteristics and Grain Yield and Quality under Heat Stress during the Filling Period in Winter Wheat.

As one of the most important wheat-producing areas in China, wheat is prone to heat stress during the grain filling period in the Huang-Huai-Hai Plain (3HP), which lowers yields and degrades the grain quality of wheat. To assess the effects of spraying potassium dihydrogen phosphate (KH2PO4) on the physiological traits in flag leaves and grain yield (GY) and quality under heat stress during the filling period, we conducted a two-year field experiment in the winter wheat growing seasons of 2020-2022. In this study, spraying water combined with heat stress (HT), 0.3% KH2PO4 (KDP), and 0.3% KH2PO4 combined with heat stress (PHT) were designed, and spraying water alone was used as a control (CK). The dates for the spraying were the third and eleventh day after anthesis, and a plastic film shed was used to impose heat stress on the wheat plants during the grain filling period. The results showed that spraying KH2PO4 significantly improved the chlorophyll content and net photosynthesis rate (Pn) in flag leaves compared with the non-sprayed treatments. Compared with CK, the Pn in HT decreased by 8.97% after heat stress, while Pn in PHT decreased by 7.44% compared to that of KDP. The activities of superoxide dismutase, catalase, and peroxidase in flag leaves were significantly reduced when the wheat was subjected to heat stress, while malonaldehyde content increased, and the enzyme activities were significantly enhanced when KH2PO4 was sprayed. Heat stress significantly decreased the contribution rate of dry matter accumulation (DM) after anthesis of wheat to grain (CRAA), whereas spraying KH2PO4 significantly increased the CRAA and harvest index. At maturity, the DM in CK was significantly higher than that in HT, KDP was significantly higher than PHT, and KDP had the highest DM. Compared with CK, the GY in KDP significantly increased by 9.85% over the two years, while the GY in HT decreased by 11.44% compared with that of CK, and the GY in PHT decreased by 6.31% compared to that of KDP. Spraying KH2PO4 after anthesis primarily helped GY by maintaining a high thousand grain weight to lessen the negative effects of heat stress on wheat. Moreover, heat stress significantly reduced protein concentration, wet gluten content, dough development time, and hardness index in grains of mature, while spraying KH2PO4 maintained a sufficient grain quality under the conditions of achieving higher yields. Overall, spraying KH2PO4 after anthesis could enhance the heat stress resistance of wheat and maintain the photosynthetic capacity of flag leaves, ensuring the dry matter production and reducing the negative effects on grain yield and quality in the 3HP.

Impairment of the photorespiratory pathway on tomato leaves during the infection process of Septoria lycopersici

Septoria leaf spot, caused by Septoria lycopersici, is a destructive disease on tomato that reduces fruit quality and yield. Plants infected by pathogens display profound changes in photosynthesis, photorespiration, and respiration that affect defense responses. This study investigated the impacts caused by S. lycopersici infection on the photorespiration of tomato plants. Infected leaves showed a remarkable reduction in photosynthesis and in the pool of photosynthetic pigments. The respiration and photorespiration-to-gross photosynthesis ratio increased in the infected leaves. Reduction in photosynthesis on infected leaves was mainly associated with biochemical limitations. Infection by S. lycopersici resulted in increased concentrations of malonaldehyde, superoxide anion, and hydrogen peroxide indicating great oxidative damage. Genes involved in the photorespiratory pathway (GOX1, GOX2, SHMT2, SMHT3, and GLYK), nitrogen metabolism (Fd-GOGAT), and stress acclimatization (mMDH1, mMDH2, and CAT) were up-regulated during the infection process of S. lycopersici. A better comprehension of the physiological changes in tomato leaves infected by S. lycopersici at the photorespiration level may contribute to breeding cultivars with increased resistance to cope with Septoria leaf spot.

Integration of Metabolome and Transcriptome Profiling Reveals the Effect of Modified Atmosphere Packaging (MAP) on the Browning of Fresh-Cut Lanzhou Lily (Lilium davidii var. unicolor) Bulbs during Storage.

The fresh-cut bulbs of the Lanzhou lily (Lilium davidii var. unicolor) experience browning problems during storage. To solve the problem of browning in the preservation of Lanzhou lily bulbs, we first investigated the optimal storage temperature and gas ratio of modified atmosphere packaging (MAP) of Lanzhou lily bulbs. Then, we tested the browning index (BD), activity of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and peroxidase (POD), the content of malonaldehyde (MDA) and other physiological activity indicators related to browning. The results showed that the storage conditions of 10% O2 + 5% CO2 + 85% N2 and 4 °C were the best. To further explore the anti-browning mechanism of MAP in fresh-cut Lanzhou lily bulbs, the integration of metabolome and transcriptome analyses showed that MAP mainly retarded the unsaturated fatty acid/saturated fatty acid ratio in the cell membrane, inhibited the lipid peroxidation of the membrane and thus maintained the integrity of the cell membrane of Lanzhou lily bulbs. In addition, MAP inhibited the oxidation of phenolic substances and provided an anti-tanning effect. This study provided a preservation scheme to solve the problem of the browning of freshly cut Lanzhou lily bulbs, and discussed the mechanism of MAP in preventing browning during the storage of the bulbs.

Phenylethanoid glycosides from traditional Mongolian medicine Cymbaria daurica alleviate alloxan-induced INS-1 cells oxidative stress and apoptosis

Cymbaria daurica L. is a well-known traditional Mongolian medicine, which has been used to treat diabetes-related conditions characterized by persistent thirst and hunger, copious urination, and weight loss. We aimed to investigate the protective effects of C. daurica extracts and phenylethanoid glycosides including verbascoside and isoacteoside on INS-1 cells. We discovered phenylethanoid glycosides from n-butanol extract with large content through extraction and separation. We continue to study the protective effects of phenylethanoid glycosides including verbascoside and isoacteoside on INS-1 cells. INS-1 cells were treated with C. daurica, cell viability assay, RNA-seq technology, superoxide dismutase activity and malonaldehyde content, quantitative real time-PCR and Western blot analysis were used to study the protective effects of C. daurica. Cell viability assay resulted that n-butanol extract and verbascoside, isoacteoside showed protective effects of C. daurica. According to the RNA-seq technology to identify the differentially expressed genes in INS-1 cells, the pathway of gene enrich the protective effect of C. daurica on oxidative stress. SOD activity and the content of MDA indicated that C. daurica could enhance the antioxidant capacity of INS-1 cells. Further investigation indicated C. daurica alleviate oxidative stress by inhibiting INS-1 cell apoptosis. C. daurica may play an anti-diabetic role by inhibiting islet cell apoptosis.