Chemical and Biological Technologies in Agriculture最新文献

Background

Climate change-associated environmental pollution has intensified heavy metal contamination, particularly cadmium (Cd), posing a serious threat to agricultural productivity and food safety. The present study investigated the potential role of arbuscular mycorrhizal fungi (AMF) in mitigating Cd-induced toxicity in squash plants cultivated under Cd-stressed soil conditions (100 µM Cd). For this purpose, four treatments were performed, i.e., Group I- Control; Group II- Cd (100 µM); Group III- AMF; Group IV- AMF + Cd (100 µM).

Results

Exposure to Cd markedly suppressed squash growth and physiological performance, as evidenced by reductions in root biomass (fresh: 18.18% and dry: 20.92%), shoot height (11.32%), root length (12.32%), chlorophyll contents (19.05%) and Carotenoids (19.32%) accompanied by excessive Cd accumulation in both roots and shoots. Cd stress also induced severe oxidative damage through increased hydrogen peroxide (H₂O₂) production. In contrast, AMF inoculation substantially alleviated Cd toxicity by significantly improving morphological and physiological traits relative to Cd-stressed plants. AMF treatment enhanced chlorophyll content (11.40%) and Carotenoids (16.76%), reduced H₂O₂ accumulation, and stimulated osmoprotective and antioxidative defense systems. Specifically, AMF significantly increased proline and protein contents, along with the activities of peroxidase, ascorbate peroxidase, polyphenol oxidase, and catalase. Furthermore, AMF restricted Cd uptake and reduced its translocation from roots to shoots, indicating improved metal sequestration and limited Cd mobility within plant tissues. Enhanced accumulation of secondary metabolites, particularly total phenolics and flavonoids, was also observed in AMF-inoculated plants under Cd stress.

Conclusions

Overall, AMF effectively mitigated Cd-induced phytotoxicity in squash plants through modulation of antioxidant defense mechanisms, osmolyte accumulation, secondary metabolite biosynthesis, and limitation of Cd translocation. These findings highlight the promising potential of AMF as an eco-friendly and sustainable strategy for improving plant tolerance and productivity under heavy metal-contaminated conditions.

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Background

Soil salinity is a major environmental constraint limiting crop productivity worldwide. Arbuscular mycorrhizal fungi (AMF) and titanium dioxide nanoparticles (TiO₂ NPs) have emerged as promising tools for enhancing plant tolerance to abiotic stress. However, their combined effects on salt-stressed cowpea have not been previously investigated. Therefore, a pot experiment was conducted using a completely randomized design with five replicates to evaluate the individual and combined effects of AMF consortium (Gigaspora nigra, Glomus monosporum, G. clarum, and Acaulospora laevis) and TiO₂ NPs (100 ppm) on cowpea plants grown under 0, 100, and 200 mM NaCl.

Results

Salinity significantly reduced plant growth and chlorophyll content while increasing lipid peroxidation. At 200 mM NaCl, shoot biomass and chlorophyll content index decreased by 61.13 and 39.57%, respectively, whereas lipid peroxidation increased by 153.03% compared with the control, after 45 days from sowing. However, AMF consortium or TiO₂ NPs application alleviated these adverse effects by enhancing biomass production, photosynthetic performance, and the accumulation of proteins and carbohydrates. Further, their combined (AMF + TiO₂ NPs) treatment was the most effective that markedly enhanced antioxidant enzyme activities, acid and alkaline phosphatases and improved root colonization parameters, indicating enhanced physiological and biochemical adaptation to salinity stress.

Conclusion

The combined application of AMF consortium and TiO₂ NPs effectively mitigated salinity-induced damage in cowpea and produced greater benefits than either treatment alone. Thus the interaction between biological and nanotechnological approaches enhanced growth, antioxidant defense, and metabolic adaptation, highlighting a sustainable strategy for improving crop productivity under saline conditions.

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Purpose

The rhizosphere microbiome, as the “second genome” of plants, plays a crucial role in nutrient acquisition, stress resistance, and soil health maintenance. Polyploidization is a key breeding strategy for watermelon: triploids are valued for seedlessness and high stress resistance, while tetraploids serve as important parental materials for triploid hybridization. However, how ploidy level (diploid, triploid, tetraploid) shapes the micro-ecological environment and microbial community assembly remains unclear. This study aims to investigate the associations between ploidy level and rhizosphere microbiota composition in watermelon.

Methods

High-throughput sequencing (Illumina MiSeq PE300 for bacteria, PE250 for fungi) targeting the bacterial 16S rRNA gene and fungal ITS region was used to analyze rhizosphere microbial communities of diploid (HLL40-3), triploid (Guixi No.5), and tetraploid (MT410n-1) watermelons. α diversity, β diversity, taxonomic composition and functional prediction were performed to compare differences among groups.

Results

The Shannon index and richness indices (Ace and Chao1) of bacteria in the triploid were significantly higher than those in the diploid and tetraploid. Regarding fungi, only the richness in the triploid was significantly higher than that in the diploid and tetraploid. There was no significant difference in the fungal Shannon index between the triploid and diploid, and both were significantly higher than that of the tetraploid. β diversity analysis confirmed distinct separation of microbial communities across ploidy levels (p < 0.05). Taxonomically, diploid rhizospheres were enriched in Proteobacteria, Melanconiella, and Hypomyces; triploids were enriched in Bacteroidota, Microvirga, Mortierellomycota, Cercophora, and Neocosmospora; tetraploids were specifically enriched in Patescibacteria, Gaiella, Trichoderma, and Papiliotrema. Functional prediction showed diploids were dominated by plant/wood saprotrophs; triploids harbored diverse functional guilds (animal pathogens, endophytes, soil saprotrophs, etc.); tetraploids had the highest relative abundance of undefined saprotrophs.

Conclusions

Triploid watermelons establish a more diverse microbial community via selective recruitment, which might contribute to their superior agronomic characteristics.

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Background

Drought constitutes a significant limiting factor globally, impacting plant growth and development while constraining productivity, with its influence intensifying under global climate change. China’s primary potato-producing regions predominantly lie within arid and semi-arid zones, where frequent drought presents a core constraint on the potato industry. To clarify the differential mechanisms underlying drought responses, this study compared the physiological traits and transcriptomic profiles of drought-tolerant (‘LS10’) and a water-sensitive (‘Atlantic’) potato cultivars under drought stress.

Results

Physiological analysis identified marked cultivar-specific differences in malondialdehyde (MDA) and proline (Pro) contents, superoxide dismutase (SOD) and peroxidase (POD) activities, and relative leaf chlorophyll content (RLCC) under water deficit. Under drought, ‘LS10’ exhibited compensatory SOD and POD activation at 30 days, delayed membrane damage progression, sustained Pro accumulation, and maintained stable RLCC, whereas ‘Atlantic’ showed earlier MDA elevation, persistently weak antioxidant responses, and continuously declining RLCC. Transcriptome sequencing of ‘LS10’ leaves identified 3,077, 781, and 1158 differentially expressed genes (DEGs) at 15, 30, and 45 days of drought stress, respectively, which were primarily enriched in photosynthesis-related and metabolic pathways. RT-qPCR of DEGs in both cultivars further showed that six light-harvesting chlorophyll a/b-binding proteins (LHCP) genes were strongly induced in ‘LS10’ but remained near baseline in ‘Atlantic’, revealing their potential as key candidate genes for drought tolerance.

Conclusions

The two cultivars displayed essential differences in drought protection efficiency. ‘LS10’ mitigated oxidative damage via enhanced antioxidant enzyme activity and osmoprotectant accumulation while preserving photosynthetic stability, whereas ‘Atlantic’ failed to mount effective antioxidant defenses and suffered progressive photosynthetic decline. These findings provide a theoretical basis for understanding cultivar-specific drought tolerance mechanisms and offer candidate genetic targets for improving potato drought resistance.

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Petroselinic acid (PeA), a rare monounsaturated fatty acid (C18:1Δ⁶), has garnered scientific interest due to its unique cis-Δ⁶ double bond configuration and limited botanical distribution. Predominantly found in the Apiaceae family (e.g., parsley, coriander, dill), PeA exhibits distinct physicochemical traits such as enhanced oxidative stability, polymorphic control favoring β′ crystals, and amphiphilic interfacial behavior. These properties render it valuable in food, cosmetic, pharmaceutical, and oleochemical industries. This review comprehensively explores PeA’s biosynthesis, emphasizing acyl-ACP pathways and metabolic engineering strategies to enhance accumulation in plants and microbes. Various extraction methods, including green alternatives such as ultrasound-assisted and supercritical CO₂ extraction, are evaluated for efficiency and sustainability. PeA undergoes selective chemical transformations (e.g., epoxidation, ozonolysis) and enzymatic modifications, facilitating its application in surfactants, polymers, and bio-based lubricants. Functionally, PeA supports structured emulsions, improves product stability, and promotes health benefits, including anti-inflammatory, antimicrobial, and metabolic regulatory effects. Challenges in biosynthetic yield, industrial scalability, and bioavailability are also discussed. Ultimately, PeA emerges as a promising bioactive lipid, with future potential dependent on integrated efforts in green chemistry, biotechnology, and health research.

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Background

The rapid deterioration of ready-to-eat pomegranate arils during cold storage remains a major challenge limiting their commercial distribution and consumer acceptance. This study evaluated the effectiveness of psyllium (PSY) and kojic acid (KA), applied individually or in combination (PSY + KA), as natural coating agents for preserving quality, extending storage life, and suppressing microbial growth in minimally processed pomegranate arils during cold storage.

Results

Pomegranate arils coated with PSY + KA and stored at 4 ± 1 °C and 90–95% relative humidity for 12 days exhibited superior preservation compared with untreated and individually treated samples. The combined coating showed favorable barrier properties, creating a modified internal atmosphere that supported quality retention. PSY + KA-treated arils maintained significantly higher antioxidant capacity, reflected by enhanced DPPH and ABTS radical scavenging activities, together with increased activities of antioxidant enzymes (ascorbate peroxidase, superoxide dismutase, catalase, and peroxidase) and key phenylpropanoid pathway enzymes (phenylalanine ammonia-lyase, cinnamyl alcohol dehydrogenase, cinnamate-4-hydroxylase, 4-coumarate-CoA ligase, cinnamoyl-CoA reductase, and caffeic acid O-methyltransferase). These biochemical responses were associated with enhanced phenolic metabolism, reduced oxidative stress, delayed senescence, and improved preservation of color, nutritional quality, and sensory attributes. Moreover, PSY + KA reduced microbial proliferation by more than 30% compared with the control, demonstrating an antimicrobial effect.

Conclusions

The combined PSY + KA coating effectively enhanced the postharvest quality and storage stability of minimally processed pomegranate arils by improving barrier properties, stimulating antioxidant and phenylpropanoid metabolism, mitigating oxidative stress, delaying senescence, and suppressing microbial growth. These findings highlight PSY + KA as a promising natural coating strategy for extending the shelf life and maintaining the marketability of ready-to-eat pomegranate arils.

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