Scientia Horticulturae最新文献

Phytoremediation is commonly used to remediate copper (Cu) pollution in water bodies. Epipremnum aureum is often used as a restoration plant because of its rapid reproduction, high population density and high landscape value. However, neither its ability to remediate Cu-polluted water nor its mechanism of resistance to Cu stress has been fully clarified. Therefore, the present study revealed the Cu removal ability and resistance mechanism of E. aureum through physiology and metabolomics. And based on the results of this study, the response surface was applied to the application of plant growth regulator (PGR) to propose a precise restoration program. We first examined the growth physiological indices and repair of Cu in E. aureum under different Cu stress levels and found that the resistance mechanism of E. aureum to Cu was significantly initiated at 400 mg·L^-1. And as the level of Cu stress increased, the Cu content in the plant also increased, and the underground part was the main accumulating part. The translocation factor of E. aureum was <1, and the bioconcentration factor was greater than 1 at all different Cu concentrations. Subsequently, metabolomics studies on E. aureum concluded that arginine and proline metabolism, indole alkaloid synthesis and brassinosteroid biosynthesis are the major pathways involved in the mechanism of Cu stress resistance in E. aureum. Based on these results, we proposed that salicylic acid, sodium nitroprusside and 2,4-epibrassinolide could be selected as PGRs, and further optimized the administration of PGRs using response surfaces. The optimized scheme allowed E. aureum to reach a maximum Cu removal of 84.39 % under 400 mg·L^-1 Cu stress, which was 35.61 % higher than the non-fortified treatment. This study provides supporting materials and application options for the Cu repair capacity and resistance mechanisms of E. aureum.

Automating the detection of fruits and vegetables using computer vision is essential for modernizing agriculture, improving efficiency, ensuring food quality, and contributing to sustainable and technologically advanced farming practices. This paper presents an end-to-end pipeline for detecting and localizing fruits and vegetables in real-world scenarios. To achieve this, a dataset named FRUVEG67 was curated that includes images of 67 classes of fruits and vegetables captured in unconstrained scenarios, with only a few manually annotated samples per class. A semi-supervised data annotation algorithm (SSDA) was developed that generates bounding boxes for objects to label the remaining nonannotated images. For detection, Fruit and Vegetable Detection Network (FVDNet) was proposed, an ensemble version of YOLOv8n featuring three distinct grid configurations. In addition, an averaging approach for the prediction of the bounding box and a voting mechanism for the prediction of the classes was implemented. Finally Jensen–Shannon Divergence (JSD) in conjunction with focal loss was integrated as the overall loss function for better detection of smaller objects. Experimental results highlight the superiority of FVDNet compared to recent versions of YOLO, showcasing remarkable improvements in detection and localization performance. An impressive mean average precision (mAP) score of 0.82 across all classes was achieved. Furthermore, the efficacy of FVDNet on open-category refrigerator images were evaluated, where it demonstrates promising results.

The selenium application to plants resulted in increased resistance to biotic and abiotic stress as well as in improvement of nutritional quality of edible parts. The current study was aimed to compare the effects of different selenium forms (selenite, selenate, selenocystine, and selenomethionine) on primary and secondary metabolism in sage (Salvia officinalis L.). In Se-treated plants, the enhancement of growth traits, photosynthetic activity, carbohydrate and protein content were recorded, especially under selenocystine treatment, and of selenium concentration in sage leaves, particularly upon selenate application. Selenate and selenocystine had a greater stimulating effect on both ascorbic acid and phenolic compounds compared to selenite and selenomethionine. Through high performance liquid chromatography (HPLC), it arose that the organic forms of selenium showed a higher stimulating effect on the content of caffeic acid and apigenin derivatives, while the inorganic forms had a greater impact on the content of rosmarinic and ferulic acids. Compared to organic forms, selenite and selenate exerted a stronger phenylalanine ammonia-lyase stimulation (2.3–2.8 times vs. 1.2–1.7 times). In sage treated with selenium, the content of ascorbic acid and phenolic compounds positively correlated with the antioxidant activity. The organic forms of selenium stimulated plant growth and the accumulation of secondary metabolites through the intensification of primary metabolism (photosynthesis, amino acid and carbohydrate metabolism). The inorganic forms of selenium elicited the activation of phenylalanine ammonia-lyase, intensifying carbon flux from primary to secondary metabolism.

Perennial ryegrass (Lolium perenne L.), one of the main turfgrass species widely planted, is often subjected to drought and salt stresses due to its perennial nature and worldwide distribution. However, the molecular mechanisms and key genes involved in the adaptation of perennial ryegrass to these environmental stresses are largely unknown. Ycf3-interacting protein 1 (Y3IP1), an auxiliary factor of photosystem I (PSI), has recently been shown to enhance stress tolerance. However, the detailed mechanisms through which Y3IP1 enhances stress resistance remain poorly understood. In this study, we discovered that LpY3IP1 in perennial ryegrass positively regulates the drought and salt tolerance by protecting the photosynthetic apparatus under adverse conditions. Seedlings overexpressing LpY3IP1 exhibited improved photosynthetic performance and survival rates under drought and salt stresses, whereas RNAi lines were more vulnerable. Under drought and salt stresses, overexpression lines maintained higher levels of PSI core subunits, while the RNAi mutants showed a reduction in these subunits. LpY3IP1 promoted cyclic electron flow (CEF) at PSI and inhibited the accumulation of ROS under stress. Chloroplasts in RNAi lines were more disorganized and degraded, exhibiting shrunken structures, low staining vesicles, protrusions, and more unstacked and swollen thylakoids under drought or salt treatment. Nevertheless, these changes were less pronounced in the overexpression lines. Therefore, our results reveal that LpY3IP1 enhances the drought and salt tolerance of perennial ryegrass by promoting CEF and mitigating oxidative damage to chloroplasts under stressful conditions.

As an effective ethylene action inhibitor, 1-methylcyclopropene (1-MCP) could delay ripening and senescence processes of the climacteric fruits. However, our knowledge on the effects of pre-storage 1-MCP treatment on the expression patterns of aromatic volatiles and their biosynthesis-related genes during pear fruit ripening is still rudimentary. In this study, ‘Housui’ fruit at commercial mature stage were respectively treated with 0.5 mL L⁻¹ 2-chloroethyl phosphonic acid (ethrel) and 1.5 μL L⁻¹ 1-MCP prior to metabolome and transcriptome assays to reveal the regulatory mechanism of 1-MCP on volatile components. 1-MCP treatment significantly suppressed respiration rate and ethylene evolution, and thus the ripening of pear fruit. Moreover, 1-MCP up-regulated the expression levels of most DEGs in association with the reduced abundances of most DEVOCs; on the other hand, a opposite phenomenon was observed for the ethrel-treated fruit. For linolenic acid-derived volatile components, when compared with H₂O (CK) and ethrel treatments, 1-MCP fumigation promoted the expression of PbrLOXs and PbrADHs, leading to the elevated accumulation of 3-hexenal and 3-hexenol. Taken together, our results implicated that 1-MCP and ethrel demonstrated opposite role in aroma compound synthesis during ripening process of ‘Housui’ fruit; in addition, 1-MCP could maintain the quality of postharvest fruit via the enhancement of linolenic acid metabolism. This study provided theoretical basis and technical support for storage and preservation of pears.

Melissa officinalis (lemon balm) is a susceptible plant to various pathogens such as Fusarium species, which significantly affect the plant's yield. The mycorrhizal symbiosis can increase the plant's resistance to many fungal pathogens. Therefore, this study was conducted to elucidate the effect of pre-inoculation of lemon balm with the arbuscular mycorrhizal (AM) fungus Glomus mosseae on the disease severity caused by Fusarium culmorum. The obtained results indicated that mycorrhizal colonization significantly reduced disease index of F. culmorum in lemon balm leaves and roots by 46 % compared to non-mycorrhizal plants. Also, it has been observed that AM symbiosis results in compensation of pathogen-induced losses in the length of shoots (58 %) and roots (53 %), dry weight of shoot (49 %) and root (51 %) and, total chlorophyll content (46 %). Furthermore, stronger pathogen-induced defense responses were found in lemon balm pre-inoculated with AM compared to non-mycorrhizal plants. The activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POX), and polyphenol oxidase (PPO), as well as the contents of non-enzymatic antioxidants (carotenoid, ascorbate, and phenolic compounds) in mycorrhizal plants infected with pathogen was higher than in non-mycorrhizal ones. Stronger antioxidant reactions led to a reduction in the pathogen-induced hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) accumulation in mycorrhizal plants. Symbiosis increased phenylalanine ammonia lyase (PAL) and lipoxygenase (LOX) activities which resulted in the accumulation of salicylic acid (SA) and jasmonic acid (JA). In conclusion, obtained results suggest G. mosseae colonization of lemon balm increases resistance against F. culmorum infection through recovering photosynthesis rate, strengthening antioxidants machinery, and triggering SA and JA signals.

The application of micronutrients to deficient agricultural soils using environmentally friendly chelates is essential for sustainable agriculture. This paper explores the ability to increase the Zinc (Zn) level in the edible part of lettuce (Lactuca sativa L.) crop by applying non-traditional Zn sources. For this purpose, Zn-citric (Zn-CIT) and Zn-glycine (Zn-GLY) complexes were applied to an acidic agricultural soil (dose of 8 mg Zn kg^-1 soil). The effects were compared with a treatment of ZnSO₄, the source traditionally used to supply this micronutrient. The influence of Zn-CIT, Zn-GLY and ZnSO₄ treatments on different plant and soil parameters after lettuce cultivation was studied. The experimental results showed that the application of Zn-CIT and Zn-GLY to the selected acid soil produced a biofortification efficiency in the edible part of the crop, with increases in Zn concentration of 119% and 148% for Zn-CIT and Zn-GLY in young leaves or 337% and 479% for Zn-CIT and Zn-GLY in mature leaves, with respect to the control. Otherwise, the mobility patterns of Zn within the plant and from the soil to the plant depended on the treatment applied. The glycine treatment showed a stimulating effect on the crop, specifically on yield, morphometric parameters and Zn translocation between mature and young leaves (increases of 21%, 9% and 33% in yield, stem diameter and Zn translocation respectively, with respect to the control). However, the positive effect of the Zn-GLY treatment was not due to a synergistic effect of Zn²⁺ and glycine application. The use of Zn-glycine in this acid soil is highly recommended as an environmentally friendly zinc source to achieve adequate biofortification in lettuce plants, allowing subsequent cultivation without additional Zn supplementation.

In this study, the regulation of regreening in the flavedos of citrus fruit was investigated in vitro. The results showed blue light was much more effective than red light for inducing regreening in citrus fruit. In the blue light treatment, the up-regulation of chlorophyll biosynthetic genes and the down-regulation of chlorophyll degradation genes led to the re-accumulation of chlorophyll in the flavedos of mature fruit. In addition, we found that blue light was a necessary factor for GA-induced regreening in citrus fruit. Under blue light, GA treatment accelerated the re-accumulation of chlorophyll in the flavedos. In contrast to GA, ABA treatment did not induce regreening under blue light, and the flavedos kept in orange color. Compared with the blue light treatment alone, the contents of chlorophyll a, chlorophyll b, and total chlorophyll were decreased by the combination of ABA and blue light treatments. The results presented in this study suggested that blue light and GA are positive regulators for inducing regreening, while ABA is a negative regulator of regreening in the flavedo of mature citrus fruit.

Mexican lime (Citrus aurantifolia Swingle), a widely grown commercial citrus cultivar, serves as a common rootstock for various citrus species. However, its susceptibility to cold temperatures poses a significant challenge to successful cultivation and productivity. This study was conducted to assess the combined effect of melatonin (ML) (500 μM), mannitol (Ma) (50 mM), and acetic acid (AA) (15 mM) on the chlorophyll fluorescence parameters and biochemical traits of Mexican lime plants exposed to low temperatures (0 and -6 °C). The results showed that both the ML+MA+AA and ML+AA treatments significantly enhanced the PIABS and PItotal parameters at 0 and -6 °C temperatures. Furthermore, the ML+AA treatment resulted in the highest level of chlorophyll a+b content (2.5 mg/gFW) in comparison to the control group and the other treatment. Notably, the ML+AA treatment effectively mitigated cold stress in Mexican lime plants by increasing total phenols, flavonoids, and carbohydrates, while reducing electrolyte leakage and malondialdehyde levels. In addition, the ML+AA treatment significantly decreased leaf abscission (82.3 %) at -6 °C in contrast to the control group, which experienced a 100 % rate of leaf abscission. Both ML+MA+AA and ML+AA treatments exhibited the highest antioxidant capacity (53.8 %). Moreover, the ML+MA+AA treatment significantly enhanced the activity of the SOD enzyme in contrast to the control. The PCA results indicated that both ML+MA+AA and ML+AA treatments clustered together and were distant from the control at both 0 and -6 °C, suggesting their effectiveness in mitigating cold stress. In conclusion, the ML+AA is recommended as an effective treatment to alleviate low-temperature damage in Mexican lime plants.

Anthocyanin is a natural plant pigment whose biosynthesis is intricately linked to light regulation. Here, pericarps of red mango cultivars named 'Xinshiji (XSJ)' and 'Hongmang No.6 (HM6)' directly exposed to sunlight were red while they were green under shade conditions, whereas the pericarps of green mango cultivar known as 'Guiqi (GQ)' maintained green within both light and shade conditions. However, the mechanisms underlying these color changes under different light conditions remain largely unexplored. Therefore, we analyzed the contents, components, and biosynthesis of anthocyanins in the above mango pericarps through metabolome and transcriptome analyses. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis releaved a total of 35 anthocyanin compounds were detected in the mango pericarps. Transcriptome analysis uncovered 44 differentially expressed genes among the comparison of 'XSJ', 'HM6', and 'GQ' samples. Twelve and eight candidate genes were identified in the anthocyanin biosynthesis and chlorophyll breakdown pathways, respectively. A co-expression network of the key anthocyanin biosynthetic genes revealed that twelve transcription factors may govern anthocyanin biosynthesis and chlorophyll breakdown processes under light. These candidate genes were further verified by real-time quantitative PCR (RT-qPCR) for providing a regulatory model for the formation of red-and green-pericarps in mangoes under light and shade conditions. These results deepen our understanding of light-induced anthocyanin biosynthesis in fruits.