Horticulturae

Research

17 pages, 5030 KiB

Open AccessArticle

Beneficial Roles of 1-MCP on Regulation of Photosynthetic Electron Transport and Energy Dissipation in Chrysanthemum Under Heat Stress

by Runtian Miao, Xiaoman Liu, Yilin Zhao, Yanli Zhao, Han Dong, Gan Huang and Yonghua Li

Horticulturae 2025, 11(1), 68; https://doi.org/10.3390/horticulturae11010068 - 10 Jan 2025

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Abstract

1-Methyl cyclopropene (1-MCP) is known as an ethylene antagonist, yet its mechanisms in regulating photosynthetic electron transport and energy dissipation in chrysanthemum under heat stress are not well understood. Here, the chlorophyll a fluorescence and modulated 820 nm reflection transients were analyzed in [...] Read more.

1-Methyl cyclopropene (1-MCP) is known as an ethylene antagonist, yet its mechanisms in regulating photosynthetic electron transport and energy dissipation in chrysanthemum under heat stress are not well understood. Here, the chlorophyll a fluorescence and modulated 820 nm reflection transients were analyzed in heat-tolerant and heat-sensitive chrysanthemum plants. This study demonstrates that 1-MCP pre-treatment helps maintain the net photosynthetic rate (P_n) and the reaction center activity of photosystems I and II (PSI and PSII) during heat stress. Specifically, 1-MCP treatment significantly increases the fraction of active oxygen-evolving complex (OEC) centers and reduces relative variable fluorescence intensity at the J step (V_J) as well as the efficiency of electron transfer at the PSI acceptor side (δ_Ro). These effects mitigate damage to the photosynthetic electron transport chain. Additionally, 1-MCP-treated plants exhibit decreased quantum yield of energy dissipation (φ_Do) and reduced energy flux per reaction center (DI_o/RC). Overall, 1-MCP enhances light utilization efficiency and excitation energy dissipation in the PSII antennae, alleviating heat stress-induced damage to PSI and PSII structures and functions. This study not only advances our understanding of 1-MCP’s regulatory role in photosynthetic processes under heat stress but also provides a basis for using exogenous substances to improve chrysanthemum heat resistance. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress, 2nd Edition)

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13 pages, 2279 KiB

Open AccessEditor’s ChoiceArticle

Foliar Application of Nettle and Japanese Knotweed Extracts on Vitis vinifera: Consequences for Plant Physiology, Biochemical Parameters, and Yield

by Eliana Monteiro, Sofia Correia, Miguel Baltazar, Sandra Pereira, Helena Ferreira, Radek Bragança, Isabel Cortez, Isaura Castro and Berta Gonçalves

Horticulturae 2024, 10(12), 1275; https://doi.org/10.3390/horticulturae10121275 - 30 Nov 2024

Cited by 1 | Viewed by 796

Abstract

Climate change is expected to affect grapevine physiology, berry quality, and yield in the Douro Demarcated Region (DDR). In this study, nettle (NE) and Japanese knotweed (JKE) extracts were tested to verify their biostimulant effect on the physiological and biochemical parameters of grapevine [...] Read more.

Climate change is expected to affect grapevine physiology, berry quality, and yield in the Douro Demarcated Region (DDR). In this study, nettle (NE) and Japanese knotweed (JKE) extracts were tested to verify their biostimulant effect on the physiological and biochemical parameters of grapevine leaves and in vine yields. In fact, some parameters were improved after foliar application of the plant extracts, namely the photosynthetic activity and consequently, the levels of photosynthetic pigments (Clb), starch, and total soluble sugars. We also observed a reduction in lipid peroxidation, which could play a crucial role in protecting cell membranes from oxidative damage induced by the climatic conditions prevalent in this region. Therefore, we confirmed that the foliar application of plant extracts, along with the enhancement of secondary metabolites and the upregulation of plant defense genes, as previously reported, resulted in the enhancement of grapevine physiology, while also increasing the yield at harvest. In the future, these plant extracts could serve as a vital tool for winegrowers in mitigating the effects of expected changes in climatic conditions. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress, 2nd Edition)

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12 pages, 1534 KiB

Open AccessArticle

Effect of the Root Endophytic Fungus Piriformospora indica on Strawberry Growth, Fruit Quality and Physiological Traits Under Elevated Electrical Conductivity

by Mohamed Ewis Abdelaziz, Muein Qaryouti, Saif Al-Sahly, Mohamed Osman, Omer Babiker, Abrar Felemban, Saif Alharbi and Abdullah Alrajhi

Horticulturae 2024, 10(11), 1174; https://doi.org/10.3390/horticulturae10111174 - 6 Nov 2024

Cited by 1 | Viewed by 1085

Abstract

Strawberries are sensitive to abiotic stresses such as salinity, high levels of electrical conductivity, and nutrient imbalances. The mutualistic endophytic fungus Piriformospora indica has significant potential to be used in improving crop production under adverse conditions, with a large host range. However, greenhouse [...] Read more.

Strawberries are sensitive to abiotic stresses such as salinity, high levels of electrical conductivity, and nutrient imbalances. The mutualistic endophytic fungus Piriformospora indica has significant potential to be used in improving crop production under adverse conditions, with a large host range. However, greenhouse production requires novel tactics to improve the efficiency of saline water irrigation in areas with limited freshwater resources. This study was conducted at the National Research and Development Center for Sustainable Agriculture (Estidamah), KSA, to investigate the impact of P. indica colonization on the growth, photosynthesis traits, productivity, and fruit quality of Fragraria × ananassa Duch cv. Festival strawberry grown in pots and irrigated with two electrical conductivity (EC) nutrient solutions of 1.5 and 3.0 dS/m. The results showed that higher-EC-nutrient solution clearly reduced growth and early yield and improved vitamin C, TSS, and anthocyanin of strawberry in comparison to low-EC-nutrient solution. On the other hand, P. indica colonization significantly increased plant height, shoot fresh weight, root length, and early yield of plants grown under high-EC-nutrient solution with no impact on fruit quality. Obviously, the symbiosis between strawberry roots and P. indica enhanced chlorophyll content, photosynthetic rate, stomatal conductance, and transpiration rate, as well as antioxidant activity such as proline, malondialdehyde, catalase, superoxide dismutase, and peroxidase under higher-EC-nutrient solution. Our study indicated that P. indica might be used as a sustainable tool for strawberry production in arid and semiarid zones, to mitigate the negative impacts of higher-EC-nutrient solution. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress, 2nd Edition)

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17 pages, 2927 KiB

Open AccessArticle

Synergistic Effects of Salicylic Acid and Bacillus butanolivorans KJ40 for Enhancing Napa Cabbage (Brassica napa subsp. pekinensis) Resilience to Water-Deficit Stress

by Sang Tae Kim and Mee Kyung Sang

Horticulturae 2024, 10(6), 618; https://doi.org/10.3390/horticulturae10060618 - 10 Jun 2024

Viewed by 1764

Abstract

Climate change exacerbates drought, globally impacting crop production and necessitating the adoption of sustainable strategies. This study investigates the potential synergistic effects of salicylic acid (SA) and Bacillus butanolivorans KJ40 (KJ40) on napa cabbage (Brassica rapa subsp. pekinensis) under water-deficit stress conditions by [...] Read more.

Climate change exacerbates drought, globally impacting crop production and necessitating the adoption of sustainable strategies. This study investigates the potential synergistic effects of salicylic acid (SA) and Bacillus butanolivorans KJ40 (KJ40) on napa cabbage (Brassica rapa subsp. pekinensis) under water-deficit stress conditions by watering withheld for five days. Results demonstrate that the combined application of KJ40 and SA, particularly at concentrations of 0.5 mM and 1 mM, significantly enhances plant growth and mitigates the negative impacts of water deficit. Moreover, the combination treatment with SA (0.5 mM) and KJ40 (1 × 10⁸ cells/mL) reduces lipid oxidation and enhances antioxidant enzyme activity, indicating improved plant stress tolerance. Analysis of soil microbial profiles reveals alterations in metabolic activity and substrate utilization patterns, suggesting potential changes in rhizosphere dynamics. Additionally, this study examines the impact of SA on KJ40 population dynamics in soil, revealing concentration-dependent effects on bacterial survival. Overall, the combination of KJ40 and SA was effective in mitigating water-deficit stress in napa cabbage. These findings highlight the combination as a novel synergistic strategy to enhance plant resilience to water-deficit stress, offering insights into plant–microbe interactions and soil ecosystem dynamics. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress, 2nd Edition)

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13 pages, 1866 KiB

Open AccessEditor’s ChoiceCommunication

N-Acetylglutamic Acid Enhances Tolerance to Oxidative and Heat Stress in Humulus lupulus

by Takeshi Hirakawa and Kazuaki Ohara

Horticulturae 2024, 10(5), 484; https://doi.org/10.3390/horticulturae10050484 - 8 May 2024

Cited by 1 | Viewed by 1523

Abstract

Humulus lupulus (hop) is a necessary material in beer brewing because its female inflorescences (called hop cones) give a floral aroma, bitterness and foam stability to beer. Various aspects of growth conditions in the cultivation area, especially temperature, strongly affect the yield and [...] Read more.

Humulus lupulus (hop) is a necessary material in beer brewing because its female inflorescences (called hop cones) give a floral aroma, bitterness and foam stability to beer. Various aspects of growth conditions in the cultivation area, especially temperature, strongly affect the yield and quality of hop cones. Recent estimates suggest that climate change accompanied by global warming is negatively impacting hop production, with high temperatures reducing the expression of genes that regulate beneficial secondary metabolites in hops. This underscores the need for techniques to enhance hop tolerance to high temperatures. This study explores the potential of N-acectylglutamic acid (NAG), a non-proteinogenic amino acid, to confer hops with tolerance against oxidative and heat stress by suppressing ROS accumulation. Exogenous NAG treatment activated the expression of HlZAT10/12 and HlHSFA2, which are putative homologues considered master regulators in response to oxidative and heat stress in Arabidopsis thaliana (Arabidopsis). Additionally, histone acetylation, a histone modification associated with transcriptional activation, was increased at these stress-responsive genes in the NAG-treated hops. These findings reveal NAG as a potential chemical compound to mitigate hop production reduction caused by high temperatures and suggest the conservation of epigenetic modification-mediated regulation of gene expression in response to environmental stresses in hops. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress, 2nd Edition)

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16 pages, 4114 KiB

Open AccessFeature PaperArticle

Wood Distillate Mitigates Ozone-Induced Visible and Photosynthetic Plant Damage: Evidence from Ozone-Sensitive Tobacco (Nicotiana tabacum L.) BelW3

by Andrea Vannini and Alessandro Petraglia

Horticulturae 2024, 10(5), 480; https://doi.org/10.3390/horticulturae10050480 - 7 May 2024

Cited by 1 | Viewed by 1427 | Correction

Abstract

The use of wood distillate (WD) is emerging as a valuable strategy for protecting horticultural crops from the oxidizing effects of ozone (O₃). To fully understand its effectiveness, extensive testing on different plant species is needed. As a viable interim measure, [...] Read more.

The use of wood distillate (WD) is emerging as a valuable strategy for protecting horticultural crops from the oxidizing effects of ozone (O₃). To fully understand its effectiveness, extensive testing on different plant species is needed. As a viable interim measure, an assessment of WD efficacy in model plants can be made until species-specific results become available. The aim of this study is to evaluate the ability of WD to protect the ozone-sensitive tobacco plant (Nicotiana tabacum L.) BelW3 from the oxidizing effects of O₃, using the ozone-resistant tobacco plant BelB as a benchmark. The protective effect was evaluated during treatment applications and three weeks after these were completed. Ten BelW3 and five BelB plants were grown just outside Parma from June to October 2023, a period when average maximum O₃ concentrations were approximately 61 ppb. Starting from July, five BelW3 plants were sprayed weekly with WD at 0.2% for two months. Morphometric and photosynthetic measurements were then taken after six and 11 weeks from the beginning of treatments and three weeks after the end to assess protection persistence (if any). BelW3 showed a significant effect of O₃ compared to BelB plants for both morphometric and photosynthetic measurements, exhibiting increased necrotic areas on the leaf blade, reduced number of viable leaves, reduced average plant height, together with reduced chlorophyll content and impaired photosynthetic system functionality. BelW3 plants also showed a significant decrease in the efficiency of parameters related to PSII and PSI when compared to BelB. Wood distillate application, however, successfully mitigated O₃ effects on BelW3, as revealed by morphometric and photosynthetic values, which were in line with those observed in BelB. Notably, WD protective effect persisted 3 weeks after treatment cessation, highlighting the short-term protective capacity of the distillate against the oxidative action of O₃. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress, 2nd Edition)

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Review

Jump to: Research, Other

35 pages, 5560 KiB

Open AccessReview

Elicitors and Biostimulants to Mitigate Water Stress in Vegetables

by Diana Victoria Melo-Sabogal and Luis Miguel Contreras-Medina

Horticulturae 2024, 10(8), 837; https://doi.org/10.3390/horticulturae10080837 - 7 Aug 2024

Cited by 5 | Viewed by 2281

Abstract

The acceleration of the climate crisis and increased demand for water have caused water stress in many agricultural lands worldwide. This issue is of utmost importance as water stress represents one of the most crucial challenges for the agricultural sector and food security, [...] Read more.

The acceleration of the climate crisis and increased demand for water have caused water stress in many agricultural lands worldwide. This issue is of utmost importance as water stress represents one of the most crucial challenges for the agricultural sector and food security, affecting the growth and yield of crops. Developing agricultural strategies to mitigate the adverse effects of water stress and improve crop stress tolerance and crop yield is therefore crucial. This review aimed to analyze the effect of agricultural practices such as elicitation and biostimulation on mitigating the effects of water stress in vegetables. This manuscript provides relevant and recent information about the studied effects on various vegetable species and their responses under water deficit and agricultural and non-agricultural strategies to mitigate water stress, highlighting the use of elicitors and biostimulants. Inclusion criteria were scientific reports and book chapters published from 2000 to 2024, including keywords as follows: water stress + vegetables, water deficit + effects, drought stress management, agricultural strategies for water stress management, eustressors + water stress, elicitors and biostimulants + water stress mitigation. According to the reported literature, it was found that the physiological, biochemical, and molecular responses of vegetables to water stress depended on factors such as the severity and duration of the water deficit, the plant species, and the phenological state of the plants. Traditional agronomic strategies such as tillage, mulching, and intercropping for crop drought management were evaluated. Recently, alternative strategies for mitigating the effects of water stress have gained significant interest, such as the exogenous application of phytohormones and osmoprotectants, nutrient management, and the use of UV-B light, radiation, and acoustic waves, among others, whose eustressive effects (as biostimulants and elicitors) have been demonstrated. Among these eustressors, those of physical origin show great potential for mitigating water stress. To improve the individual potential of eustressors for water stress mitigation, we proposed the combination of practices such as tillage, mulching, application of hormones and osmoprotectants, and physical elicitors and biostimulants such as gamma rays, He-Ne laser, and UV-B. Further exploration is required to establish doses, application conditions, and effects on water stress mitigation and vegetable yield, underscoring the importance and ongoing nature of this research. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress, 2nd Edition)

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