Soluble Protein Content Research Articles

Potassium humate supplementation improves photosynthesis and agronomic and yield traits of foxtail millet

Foxtail millet is a highly nutritious crop, which is widely cultivated in arid and semi-arid areas worldwide. Humic acid (HA), as a common plant growth regulator, is used as an organic fertilizer and feed additive in agricultural production. However, the impact of potassium humate KH on the photosynthetic rate and yield of foxtail millet has not yet been studied. We explored the effects of KH application on the morphology, photosynthetic ability, carbon and nitrogen metabolism, and yield of foxtail millet. A field experiment was performed using six concentrations of KH (0, 20, 40, 80, 160, and 320 kg ha−1) supplied foliarly at the booting stage in Zhangza 10 cultivar (a widely grown high-yield variety). The results showed that KH treatment increased growth, chlorophyll content (SPAD), photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs). In addition, soluble protein content, sugar content, and nitrate reductase activity increased in KH-treated plants. With increased KH concentration, the effects became more evident and the peak values of each factor were achieved at 80 kg ha−1. Photosynthetic rate showed significant correlation with SPAD, Tr, Gs, and soluble protein content, but was negatively correlated with intercellular CO2 concentration. Compared to that of the control, the yield of foxtail millet under the T2, T3, T4, and T5 (40, 80, 160, and 320 kg ha−1 of KH) treatments significantly increased by 6.0%, 12.7%, 10.5%, and 8.6%, respectively. Yield exhibited a significant positive correlation with Tr, Pn, and Gs. Overall, KH enhances photosynthetic rate and yield of foxtail millet, therefore it may be conducive to stable millet production. These findings may provide a theoretical basis for the green and efficient production of millet fields.

Comparative antioxidant potential, proximal biochemical composition, and pigment content of 11 brown seaweeds from the West of Ireland

The biorefinery and valorisation of sustainable bioresources such as seaweeds have increased in response to global circular economy initiatives. Several seaweed species are exploited worldwide in the biofertilizer, nutrition, bioenergy, cosmetics, or pharmaceutical sectors. Brown seaweeds are widespread, easily accessible, and abundant in northwest Europe regions, with some species being commercially harvested and processed.Here, both commercially exploited, and less studied brown seaweeds (n = 11) were collected from Irelands Atlantic coast and analysed for soluble carbohydrates, lipids, proteins, fatty acid, and pigment profiles as well as antioxidant potential. Soluble carbohydrates (62.7 µg glucose eq mg−1 DW) were highest in Saccharina latissima while lipids (148.2 mg L g−1 DW), fucoxanthin (1.35 mg g−1) and β-carotene (4.10 mg g−1) were greater in Dictyota dichotoma. The highest antioxidant activity (456.3 µmol Trolox eq mg−1 DW with TEAC assay) and soluble protein content (562.5 µg BSA eq mg−1 DW) were in Halidrys siliquosa extracts.Data matrix multivariate ordination indicated that some less studied brown seaweeds have further valorisation potential owing to their biochemical composition and bioactivity. The development of species-specific tailored cultivation strategies as part of integrated multi-trophic aquaculture systems has potential to contribute to environmental sustainability while introducing new natural bioactive products to markets.

Different Parts of a Dendrocalamus brandisii (Munro) Kurz Shoot, Rather Than the Shoot’s Height, Are More Indicative of Its Nutrient Properties

Bamboo shoots are considered as a healthy food and are popular in Asian cooking. The distribution of nutrients and their dynamics during the growth of bamboo shoots play a crucial role in guiding the harvesting and processing of bamboo shoots. In this study, Dendrocalamus brandisii (Munro) Kurz, an important bamboo species for harvesting fine edible shoots in southern China and Southeast Asia, was used to measure several indicators related to the edibility and nutritional value of fresh shoots across five height grades (H1: 20~30 cm; H2: 31~40 cm; H3: 41~50 cm; H4: 51~60 cm; and H5: 61~70 cm). The results indicated that, although the nutrient and mineral elements showed an increasing (crude fiber content, CFC), decreasing (total soluble sugars content, TSSC; ash content, AC; Fe; Zn), or fluctuating (soluble protein content, SPC; P; K; Ca) pattern with the growth of bamboo shoots, both the CFC and TSSC showed the highest values in the lower part at five growth heights, indicating that carbohydrates were mainly enriched in the bases of bamboo shoots. The SPC, AC, and other mineral elements were higher in the upper part, especially in H1–H3. Combined with the relatively high activity of metabolic enzymes (sucrose-phosphate synthase, SPS; neutral invertase, NI) in the upper part of bamboo shoots (although not statistically significant), it can be inferred that the shoot tip may be the main tissue for early nutrient synthesis and metabolism. Compared with the shoot height, different parts of a D. brandisii bamboo shoot are more indicative of its nutrient properties. Although all heights of bamboo shoots showed an abundance of nutrients and mineral elements, bamboo shoots with a height of less than 40 cm had a higher TSSC, AC, Fe, and Zn, and a lower CFC, thus having a better balance between nutrients and edibility.

Uncovering quality changes of surimi-sol based products subjected to freeze–thaw process: The potential role of oxidative modification on salt-dissolved myofibrillar protein aggregation and gelling properties

Frozen surimi quality generally correlates with oxidation, but impacts of protein oxidation on salt-dissolved myofibrillar protein (MP) sol in surimi remain unclear. Hence, physicochemical and gelling properties of MP sol with different oxidation degrees were investigated subjected to freeze–thaw cycles. Results showed that mild oxidation (≤1 mmol/L) improved unfrozen MP gel quality with lowest cooking loss (3.29 %) and highest hardness (829.76 N). Whereas, oxidized sol suffering freeze-thawing degenerated severely, showing reduction of 23.85 % of salt soluble protein contents with H2O2 concentrations of 10 mmol/L. Shearing before heating influenced gelling properties of freeze-thawed sol, depending on oxidation levels. Oxidized gel with shearing displayed disorganized network structures, whereas gel without shearing displayed relatively complete appearances without holes under high oxidation condition (10 mmol/L). Overall, freeze–thaw process aggravated denaturation extents of MP sol subjected to oxidation, further causing high water loss and yellow color of heat-induced gel, especially to gel with shearing.

Purification, characterisation and visualisation of soybean protein hydrolysis by aspergillopepsin I from mangrove Aspergillus tubingensis

In order to obtain marine-derived enzymes suitable for protein hydrolysis in acid brewing system, seven species of fungi were obtained from mangrove soil. One of the strains, Aspergillus tubingensis, was determined to have a high acid protease production capacity. Its fermentation broth was purified and the obtained protease was identified as aspergillopepsin I (ATAP) with a molecular weight of 41205 Da. Homology modelling shows that ATAP contains three active sites, each containing to a Zn atom and amino acid residues. The enzyme had the highest relative activity at pH 3.5 and 35–40 °C, and exhibited pH and thermal stability at pH 3.0–3.5 and 20–50 °C. ATAP showed certain salt tolerance. K+ and Zn2+ promoted the enzyme activity, while Mg2+, Cu2+, Co2+, and Fe2+ slightly inhibited the enzyme activity. The results of inhibitors suggest that ATAP belongs to the class of aspartic proteases containing metal atoms. Furthermore, the results of enzymatic hydrolysis of defatted soybean powder showed that the contents of soluble protein, amino nitrogen, free amino acids and the proportion of small molecular peptides (<3 kDa) in the hydrolysate increased significantly. In addition, molecular docking of ATAP and aspergillopepsin I from Aspergillus oryzae 3.042 with soybean globulins (7S and 11S), respectively, showed better hydrolysis of soybean globulins by the former, especially for 7S globulin. Visual analysis indicated the interaction forces between enzymes and soybean globulins were dominated by hydrogen bond and hydrophobic interaction. In conclusion, ATAP may be a candidate as an enzyme preparation for the hydrolysis of soybean proteins.

Use of turbidimetry for determination of heat treatment intensity applied at pasteurization of milk

Express methods for estimating the intensity of heat treatment of milk are necessary in industry and in research work. For this reason, there are many ways to measure this parameter, which are based on different physical principles, including turbidimetric methods. The Harland &amp; Ashworth turbidimetric method has been developed for a long time, however, due to its high reliability and ease of implementation, it is still used in practice. However, this method has a drawback: it takes a long time to perform the analysis. In this regard, the aim of the work is to develop an express method for evaluating the thermal class of milk based on the principle of measuring the concentration of soluble whey proteins. The result is achieved through the use of a turbidimetric measurement method with optimized sample preparation parameters and parameters for measuring the optical density of a suspension of protein aggregates. The method is implemented as follows. The milk sample is mixed with 0.1 N acetate buffer (pH 4.6) in a ratio that allows to obtain a concentration of soluble milk whey proteins from 0.05% to 0.1%. Recommended dilution coefficients: 1:3 for samples of ultra-pasteurized milk and pasteurized milk with high heat treatment intensity; 1:7 for samples of pasteurized milk with low heat treatment intensity and 1:14 for raw milk samples. The solution is filtered on a membrane filter with a pore size of 0.45 microns. The resulting filtrate is mixed with 24% trichloroacetic acid (TCA) in a 1:1 ratio to coagulate soluble whey proteins and form protein aggregates. After holding for 5–10 minutes, the optical density of the suspension of protein aggregates is measured at a wavelength of 650 nm. The content of water-soluble whey proteins in the sample can be calculated according to the calibration curve. The developed method allows to obtain the measurement result in less time than the Harland &amp; Ashworth turbidimetric method.

Meat analogue preparation from cricket and rice powder mixtures with controlled textural and nutritional quality by freeze alignment technique

The rising demand for sustainable protein sources has encouraged interest in alternative food products like meat analogues. This study explores formulating meat analogues using cricket powder (CP) and rice flours, comparing them with soy protein-based analogues. CP exhibited a higher soluble protein content (5.9%) than soy protein powder (4.7%), enhancing textural properties by forming fiber-like structures, increasing firmness and adhesion, and reducing chewiness. Despite having a lower water holding capacity (WHC) than soy analogues, all samples outperformed chicken breast WHC. Under freezing conditions, CP and rice flour combinations formed multilayered structures in protein gels. The optimal formulations were CP and sticky rice flour (ratio 6:1) with respect to their texture properties, fiber structure, and nutritional value. This study highlights the potential of cricket powder and rice flour combinations as viable meat analogue ingredients, addressing the need for sustainable protein sources in the food industry.

Dynamics of industrial hemp vegetative growth and metabolite accumulation in response to light intensity

Industrial hemp (Cannabis sativa L.) is a high-yielding cash crop with strong stress resistance, and its fibrous and metabolic profile holds significant development potential. In this study, we measured various agronomic traits, amino acids, saccharides, and their derivatives under four different light intensities (30 μmol·m−2·s−1, 80 μmol·m−2·s−1, 130 μmol·m−2·s−1, 180 μmol·m−2·s−1). Results showed that plant height decreased with increasing light intensity and reached a minimum at 180 μmol·m−2·s−1, which was 27 % less than the control treatment. Further, stem diameter increased by 52 %, leaf fresh weight by 130 %, stem fresh weight by 116 %, and root fresh weight by 264 % were at their maximum at 130 μmol·m−2·s−1. Plant dry weight of leaf (113 %), stem (214 %), and root (427 %) were also found to be maximum at 130 μmol·m−2·s−1. Metabolic results revealed that the free amino acid content was 10 %, 61 %, and 60 % higher under 30 μmol·m−2·s−1 compared to 80, 130, and 180 μmol·m−2·s−1. Additionally, soluble protein contents were 42 %, 81 %, and 77 % higher under 30 μmol·m−2·s−1 compared to 80, 130, and 180 μmol·m−2·s−1. In contrast, the soluble sugar contents were 42 %, 61 %, and 75 % higher than in the other three treatments. In conclusion, industrial hemp morphological characteristics and metabolite profiles exhibit distinct responses to different light intensities. To achieve desired outcomes, it is imperative to carefully choose an optimized light intensity specifically tailored to align with the defined objectives. These findings provide a foundation for a deeper understanding of the characteristics of industrial hemp, optimizing cultivation techniques, and investigating the impact of light intensity on industrial hemp vegetative period growth, amino acids, and saccharides.

Effects of combined drying techniques and cellulase hydrolysis on the nutritional value and sensory properties of shiitake mushrooms (Lentinus edodes)

Dried shiitake mushrooms offer rich nutritional value and unique sensory properties, prompting further investigation. The effects of different drying techniques (hot air drying (HAD), infrared hot air drying (IRHAD), pulsed vacuum drying (PVD), vacuum freeze drying (VFD), and natural drying (ND)) combined with enzymatic hydrolysis on the release of flavor compounds and nutrients from shiitake mushrooms were explored. The combination of HAD with cellulase hydrolysis yielded notably high levels of umami amino acids (5.4723 ± 0.1501 mg/g) and 5′-nucleotides (4.0536 ± 0.0062 mg/g), and superior volatile flavors. Combined with cellulase hydrolysis, IRHAD achieved the highest level of total sugars (6.57 ± 0.34 mg/mL), VFD resulted in the greatest soluble protein content (153.21 ± 0.23 μg/mL), PVD yielded the highest total phenolics content (93.20 ± 0.41 μg GAE/mL), and ND produced the maximum reducing sugar content (5.79 ± 0.13 mg/mL). This study addresses crucial gap in the post-drying processing of shiitake mushrooms, offering valuable insights for further product development of shiitake mushrooms.

Cryoprotectant-Mediated Cold Stress Mitigation in Litchi Flower Development: Transcriptomic and Metabolomic Perspectives.

Temperature is vital in plant growth and agricultural fruit production. Litchi chinensis Sonn, commonly known as litchi, is appreciated for its delicious fruit and fragrant blossoms and is susceptible to stress when exposed to low temperatures. This study investigates the effect of two cryoprotectants that counteract cold stress during litchi flowering, identifies the genes that generate the cold resistance induced by the treatments, and hypothesizes the roles of these genes in cold resistance. Whole plants were treated with Bihu and Liangli cryoprotectant solutions to protect inflorescences below 10 °C. The soluble protein, sugar, fructose, sucrose, glucose, and proline contents were measured during inflorescence. Sucrose synthetase, sucrose phosphate synthetase, antioxidant enzymes (SOD, POD, CAT), and MDA were also monitored throughout the flowering stage. Differentially expressed genes (DEGs), gene ontology, and associated KEGG pathways in the transcriptomics study were investigated. There were 1243 DEGs expressed after Bihu treatment and 1340 in the control samples. Signal transduction pathways were associated with 39 genes in the control group and 43 genes in the Bihu treatment group. The discovery of these genes may contribute to further research on cold resistance mechanisms in litchi. The Bihu treatment was related to 422 low-temperature-sensitive differentially accumulated metabolites (DAMs), as opposed to 408 DAMs in the control, mostly associated with lipid metabolism, organic oxidants, and alcohols. Among them, the most significant differentially accumulated metabolites were involved in pathways such as β-alanine metabolism, polycyclic aromatic hydrocarbon biosynthesis, linoleic acid metabolism, and histidine metabolism. These results showed that Bihu treatment could potentially promote these favorable traits and increase fruit productivity compared to the Liangli and control treatments. More genomic research into cold stress is needed to support the findings of this study.

Genetic evidence for functions of Chloroplast CA in Pyropia yezoensis: decreased CCM but increased starch accumulation

In response to the changing intertidal environment, intertidal macroalgae have evolved complicated Ci utilization mechanisms. However, our knowledge regarding the CO2 concentrating mechanism (CCM) of macroalgae is limited. Carbonic anhydrase (CA), a key component of CCM, plays essential roles in many physiological reactions in various organisms. While many genes encode CA in the Pyropia yezoensis genome, the exact function of specific CA in P. yezoensis remains elusive. To explore the particular function of chloroplast CA in intertidal macroalgae, we produced chloroplast-localized βCA1 knockdown mutants of P. yezoensis through RNA interference, and Pyβca1i mutants (hereinafter referred to as ca1i) showed a notable decrease in leaf area and overall biomass, as well as decreased soluble protein and unsaturated fatty acid content under different DIC conditions. However, ca1i mutants showed relatively higher starch content compared to the wild-type. The activity of enzymes involved in the Calvin cycle, photorespiration, Pentose-phosphate pathway, and floridean starch synthesis of P. yezoensis indicated an effective starch accumulation pathway after the interference of βCA1. All results suggest that the decreased activity of PyβCA1 impaired the CCM and development of thalli of P. yezoensis, but stimulated starch accumulation in the cytoplasm through feedback to the photorespiration pathway and pentose phosphate pathway to replenish intermediates for the Calvin cycle. This study is the first to explore the specific function of chloroplast CA in intertidal macroalgae using genomic technology. The results provide valuable insights into the adaption mechanisms of intertidal macroalgae to their environment.

Phosphate-solubilizing bacteria improve the antioxidant enzyme activity of Potamogeton crispus L. and enhance the remediation effect on Cd-contaminated sediment

Phosphorus-solubilizing bacteria (PSB) assisted phytoremediation of cadmium (Cd) pollution is an effective method, but the mechanism of PSB-enhanced in-situ remediation of Cd contaminated sediment by submerged plants is still rare. In this study, PSB (Leclercia adecarboxylata L1–5) was inoculated in the rhizosphere of Potamogeton crispus L. (P. crispus) to explore the effect of PSB on phytoremediation. The results showed that the inoculation of PSB effectively improved the Cd extraction by P. crispus under different Cd pollution and the Cd content in the aboveground and underground parts of P. crispus all increased. The μ-XRF images showed that most of the Cd was enriched in the roots of P. crispus. PSB especially showed positive effects on root development and chlorophyll synthesis. The root length of P. crispus increased by 51.7 %, 80.5 % and 74.2 % under different Cd pollution, and the Ca/Cb increased by 38.9 %, 15.2 % and 8.6 %, respectively. Furthermore, PSB enhanced the tolerance of P. crispus to Cd. The contents of soluble protein, MDA and H2O2 in 5 mg·kg−1 and 7 mg·kg−1 Cd content groups were decreased and the activities of antioxidant enzymes were increased after adding PSB. The results showed that the application of PSB was beneficial to the in-situ remediation of submerged plants.

Effect of different monochromatic lights on nutritional, antioxidant properties and spore microstructure of dried mushroom (Suillus granulatus)

SummaryMonochromatic light has been shown to improve the flavour quality of dried mushrooms, but its effect on the nutritional, bioactive, antioxidant, rehydration and textural properties has not been studied. In this study, the effects of monochromatic light on these qualities of the dried Suillus granulatus were investigated and the porous characteristics and spore morphology were observed. The results showed that contents of soluble sugars, soluble proteins, flavonoid, phenolics, DPPH and rehydration under blue light were higher on the sixth day, it was 1.85 times, 1.58 times, 1.27 times and 1.20 times of the lowest content, respectively. While ABTS and FRAP were higher on the ninth day. The values are 33.5% and 0.749 mmol/LFeSO4, respectively. The texture of rehydrated mushrooms was higher under red light and lower under blue light. Clear pore structure and severely deformed spores can be observed under blue light, revealing the reason why mushrooms have better qualities under light. Correlation analysis results showed that nutrients, active components, antioxidant activity and rehydration showed a strong positive correlation. Totally, blue light is a promising processing technology to improve the quality of dried mushrooms.

Effect of low microwave temperature on the physical and chemical properties of waste activated sludge

In this study, the effect of microwave (MW) irradiation at a target temperature of 80 °C with a heating rate of two °C/min and a holding time of five minutes on the physicochemical properties of activated sludge was studied. The results showed that subjecting biosludge to MW pretreatment resulted in a reduction in particle size to 14.5, 44.6, and 72.8 for d10, d50, and d90, respectively and an increase in the specific surface area of the biosludge to 235.9 m&lt;sup&gt;2&lt;/sup&gt;/kg. Pretreatment resulted in an increase in soluble oxygen demand, sugar, and protein concentrations to 2,380.0 mg/L, 66.5 mg/L, and 1.81 g/L, respectively. A slight increase in the release of inorganic compounds, especially NH&lt;sub&gt;4&lt;/sub&gt;-N and PO&lt;sub&gt;4&lt;/sub&gt;-P, was observed in the disintegrated biosludge. While there was an increase in release of K and Zn, a decrease in concentrations of Na, Ca, Mg, and Al in the liquid was observed after MW irradiation. It was determined that the dewatering property deteriorated after biosludge disintegration, as it increased from raw sludge to disintegrated sludge by 21-fold.

Improving chilling tolerance of peanut seedlings by enhancing antioxidant-modulated ROS scavenging ability, alleviating photosynthetic inhibition, and mobilizing nutrient absorption.

Peanut production is threatened by climate change. Damage to seedlings from low temperatures in early spring can limit yield. Plant adaptations to chilling stress remain unclear in peanut seedlings. It is essential to understand how peanut acquires chilling tolerance. We evaluated effects of chilling stress on growth and recovery of peanut seedlings. We compared and analysed biological characteristics, antioxidants, photosynthesis, biochemical and physiological responses, and nutrient absorption at varying levels of chilling. Compared with chilling-sensitive FH18, the reduced impact of chilling stress on chilling-tolerant NH5 was associated with reduced ROS accumulation, higher ascorbate peroxidase activity and soluble sugar content, lower soluble protein content, and smaller reductions in nutrient content during stress. After removal of chilling stress, FH18 had significant accumulation of O2 •- and H2O2, which decreased photosynthesis, nutrient absorption, and transport. ROS-scavenging reduced damage from chilling stress, allowed remobilization of nutrients, improved chilling tolerance, and restored plant functioning after chilling stress removal. These findings provide a reference for targeted research on peanut seedling tolerance to chilling and lay the foundation for bioinformatics-based research on peanut chilling tolerance mechanisms.

Effects of Different Combinations of Red and Blue Light on the Edible Organ Morphology and Quality of Buckwheat (Fagopyrum esculentum Moench) Microgreens

Buckwheat microgreens are rich in nutrients and have a unique flavor that is favored by consumers. The light environment is closely related to the growth and development of the plant. In order to study the effects of treatments with different combinations of red and blue light on the edible organ morphology and nutritional quality of buckwheat microgreens, five experimental treatments were designed, with energy ratios of red light to blue light of 5:1 (R5B1), 3:1 (R3B1), 1:1 (R1B1), 1:3 (R1B3) and 1:5 (R1B5), respectively, and a white light treatment used as the control (CK). The results showed that different combination treatments of red and blue light had obvious effects on the growth of buckwheat microgreens. The hypocotyl length and main root length of buckwheat microgreens treated with a high proportion of red light (R5B1) were obviously higher than those of other treatment designs. However, contents of soluble protein, chlorophyll, rutin and total flavonoids in buckwheat microgreens showed an increasing trend with an increase in the proportion of blue light. Considering the fresh weight, dry weight and quality indexes of the edible organ, the combination of red light and blue light with a ratio of 1:1 was most suitable for buckwheat microgreen production. The results could provide a reference for the production of buckwheat microgreens.

Effect of Low Temperature on Content of Primary Metabolites in Two Wheat Genotypes Differing in Cold Tolerance.

The study of cold-tolerance mechanisms of wheat as a leading cereal crop is very relevant to science. Primary metabolites play an important role in the formation of increased cold tolerance. The aim of this research is to define changes in the content of primary metabolites (soluble proteins and sugars), growth, and photosynthetic apparatus of freezing-tolerant and cold-sustainable wheat (Triticum aestivum L.) genotypes under optimal conditions and after prolonged (7 days) exposure to low temperature (4 °C). In order to gain a deeper comprehension of the mechanisms behind wheat genotypes' adaptation to cold, we determined the expression levels of photosynthetic genes (RbcS, RbcL) and genes encoding cold-regulated proteins (Wcor726, CBF14). The results indicated different cold-adaptation strategies of freezing-tolerant and cold-sustainable wheat genotypes, with soluble proteins and sugars playing a significant role in this process. In plants of freezing-tolerant genotypes, the strategy of adaptation to low temperature was aimed at increasing the content of soluble proteins and modification of carbohydrate metabolism. The accumulation of sugars was not observed in wheat of cold-sustainable genotypes during chilling, but a high content of soluble proteins was maintained both under optimal conditions and after cold exposure. The adaptation strategies of wheat genotypes differing in cold tolerance were related to the expression of photosynthetic genes and genes encoding cold-regulated proteins. The data improve our knowledge of physiological and biochemical mechanisms of wheat cold adaptation.

Comparative metabolomic analyses reveal metabolites associated with seed deterioration in Chinese cabbage

Seed deterioration during storage results in a decline in vigor, which has a negative impact on agricultural production. However, the mechanisms responsible for ageing are still poorly understood. The aim of present study was to investigate the physiological, biochemical, and metabonomic changes in naturally aged Chinese cabbage (Brassica pekinensis L.) seeds, and identify potential markers of seed deterioration. In this study, Chinese cabbage seeds with different moisture contents (1 % and 4 %) were stored under ambient conditions for 13 years. We employed a biochemical and metabolomics approach to investigate the impact of seed deterioration on naturally aged Chinese cabbage seeds and to identify the types and variations of differentially accumulated metabolites. Our findings demonstrate that the initial storage moisture content has a significant impact on the loss of seed vigor. The seed lot with an initial moisture content of 1 % exhibited higher viability and vigor after natural storage. High-vigor seeds showed higher catalase (CAT) activity, lower H2O2 and malondialdehyde (MDA) content, and reduced electrolyte leakage. No significant difference was observed between the two seed lots in terms of superoxide dismutase (SOD) activity, peroxidase (POD) activity, and soluble protein content. Metabolite analysis revealed 1,117 differential metabolites between the two seed lots. The differential metabolites were associated with various aspects of seed ageing, including changes in glycerophospholipids, phytohormones, antibiotics, reduction of antioxidant substances and raffinose, degradation of triglycerides, accumulation of toxic compounds, and DNA damage. Longicamphenylone was the prominent metabolite in response to seed deterioration. Pathway enrichment analysis revealed that flavonoid biosynthesis, which is involved in scavenging reactive oxygen species(ROS), was the most significant metabolic pathway associated with seed deterioration. Our findings also present the initial evidence linking endogenous antibiotics with seed aging.

The trade-off between root growth redundancy and premature senescence under different straw returning modes affects boll formation and seedcotton yield

The indeterminate growth habit of cotton (Gossypium hirsutum L.) makes a coordinated rootshoot relationship critical for increasing yield, which requires comprehensive consideration of root growth redundancy and premature senescence. Although recent evidence suggests that straw management affects root growth and thus seedcotton yield, there is limited documentation on the dynamics of root physiological activity and the rootshoot relationship of cotton under different straw returning modes. The present study compared four treatments: straw removal (CK), straw mulching (SM), straw incorporation (SI), and strawderived biochar incorporation (SBI) in an 8year field experiment. The growth dynamics of roots, shoots and reproductive organs, root physiological activity and seedcotton yield were investigated. The results showed that longterm straw application significantly enhanced seedcotton yield, but the effect varied significantly with straw returning modes. The seedcotton yield increased by 30.5%, 17.8% and 1.8% under SBI, SI and SM respectively in the 8th year of straw management, compared to CK. SBI and SI significantly enhanced the biomass of cotton roots and shoots while had higher growth rate of shoots relative to roots from peak squaring stage to peak bollsetting stage. This reduced root growth redundancy and increased the boll loading and boll capacity of root system. Besides, SBI increased the root activity, soluble protein content and antioxidant enzyme activities, and reduced the root malondialdehyde content from peak bollsetting stage to boll opening stage. These resulted in the greatest increase in boll number (53.862.1%) and boll biomass (39.480.4%) at the boll opening stage under SBI compared to CK. Overall, strawderived biochar improved the boll retention capacity of cotton roots by balancing the growth redundancy and premature senescence of the root system, and was a more suitable straw returning strategy to promote boll formation and increase cotton yield.

Effects of Cadmium Stress on Seed Germination and Physiology and Biochemistry during Early Seedling Growth of Masson Pine (Pinus massoniana Lamb.)

Abstract This study evaluated the effects of cadmium (Cd) on seed germination and the physiological and biochemical characteristics of Pinus massoniana, which was used as the experimental material; culture dishes and germination boxes were used as testing devices. Seed germination and seedling growth in the presence of various Cd concentrations (0.4, 0.8, 1.2, 2, and 0 mg/L) were explored. The germination indexes of Pinus massoniana seeds used were germination percentage (GP), germination energy (GE), germination index (GI), vigor index (VI). and embryo length. The indexes of early growth of seedlings used were soluble sugar and soluble protein content, antioxidant enzyme activity, Cd content, and Cd enrichment. We found that Pinus massoniana presented reduced GP, GE, GI, VI, and embryo length with increasing Cd concentrations, and the VI and embryo length significantly decreased (P &amp;lt; .05). The physiological and biochemical indexes of Pinus massoniana seedlings were promoted at low Cd concentrations and inhibited at high Cd concentrations; each index peaked under 0.4 mg/L Cd. The Cd content in seedlings and the degree of enrichment decreased and then increased with increasing Cd concentration. Grey correlation analysis results showed that the effects of Cd stress were the strongest on embryo length in seeds (correlation degree: 0.769). Study Implications The effect of heavy metal pollution on seed germination and growth is closely related to phytoremediation of heavy metal soil. Pinus massoniana is the most widely distributed pine species in China. It is an economically important industrial timber with important ecological value. This study found that under the stress of different cadmium concentrations, heavy metal Cd stress inhibited the germination of Pinus massoniana seeds, and moderate Cd concentration promoted the physiological and biochemical of Pinus massoniana seedlings. Pinus massoniana seedlings have the ability to enrich heavy metal Cd.