Ethephon Research Articles

Integration of Transcriptomics and WGCNA to Characterize Trichoderma harzianum-Induced Systemic Resistance in Astragalus mongholicus for Defense against Fusarium solani.

Beneficial fungi of the genus Trichoderma are among the most widespread biocontrol agents that induce a plant's defense response against pathogens. Fusarium solani is one of the main pathogens that can negatively affect Astragalus mongholicus production and quality. To investigate the impact of Trichoderma harzianum on Astragalus mongholicus defense responses to Fusarium solani, A. mongholicus roots under T. harzianum + F. solani (T + F) treatment and F. solani (F) treatment were sampled and subjected to transcriptomic analysis. A differential expression analysis revealed that 6361 differentially expressed genes (DEGs) responded to T. harzianum induction. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the 6361 DEGs revealed that the genes significantly clustered into resistance-related pathways, such as the plant-pathogen interaction pathway, phenylpropanoid biosynthesis pathway, flavonoid biosynthesis pathway, isoflavonoid biosynthesis pathway, mitogen-activated protein kinase (MAPK) signaling pathway, and plant hormone signal transduction pathway. Pathway analysis revealed that the PR1, formononetin biosynthesis, biochanin A biosynthesis, and CHIB, ROS production, and HSP90 may be upregulated by T. harzianum and play important roles in disease resistance. Our study further revealed that the H2O2 content was significantly increased by T. harzianum induction. Formononetin and biochanin A had the potential to suppress F. solani. Weighted gene coexpression network analysis (WGCNA) revealed one module, including 58 DEGs associated with T. harzianum induction. One core hub gene, RPS25, was found to be upregulated by T. harzianum, SA (salicylic acid) and ETH (ethephon). Overall, our data indicate that T. harzianum can induce induced systemic resistance (ISR) and systemic acquired resistance (SAR) in A. mongholicus. The results of this study lay a foundation for a further understanding of the molecular mechanism by which T. harzianum induces resistance in A. mongholicus.

Effects of chemical regulation on the growth, yield and fiber quality of cotton varieties with different plant architectures

Chemical regulation has beneficial effects on the growth, yield, and fiber quality of cotton with different plant architectures. This study aimed to investigate the combined effects of chemical regulators such as mepiquat chloride (1,1-dimethyl-piperidiniuchloride, DPC), chlormequat chloride (CCC), thidiazuron (TDZ), and ethephon (ETH) during the growth period of cotton. Different combinations of chemical regulators were applied to examine the growth, development, yield, and quality of cotton. The results showed that the application of different chemical regulators had varying effects on the yields of the two cotton varieties with distinct plant architecture. Specifically, K1C1 (before and after topping with 1:1 25% DPC, 50% TDZ, and 40% ETH) and K2C2 (before topping with 25% DPC and after topping with 50% CCC, 50% TDZ, and 40% ETH) were sprayed on ‘Wankemian-1’ and ‘Wanmian-191’, thereby increasing the cotton yield. The K2C2 treatment increased the upper half mean length and fiber strength of the two varieties but decreased the fiber length uniformity index. The fiber strength, fiber length uniformity index, and spinning consistency index of ‘Wankemian-1’ were higher than those of ‘Wanmian-191’. Based on comprehensive yield, quality, and economic benefits, K1C1 and K2C2 were determined to be the most effective chemical regulators of ‘Wankemian-1’ and ‘Wanmian-191’, respectively.

Varying concentrations of ethephon induce antioxidant defences and cell wall degradation to regulate storage quality of fresh-cut lotus root

This study examined the impact of varying concentrations of ethephon (ET) immersion on the storage quality of fresh-cut lotus root. Compared to the 0.1%, the 0.8% and 1.6% ET groups inhibited phenolic oxidation and showed stronger antioxidant and reactive oxygen species balancing capacity during early storage, which led to better browning inhibition. During the early storage period, varying concentrations of ET treatments were inversely associated with microbial growth, and Pseudomonas as the major microorganism was significantly inhibited. During the post-storage period, the ET group exacerbated cell wall metabolism, contributed to the softening of lotus root slices. Additionally, ET stimulated enhanced respiration and reduced total soluble solids content as ET concentration increased. The heightened expression of NnERF in the late storage stage suggested a potential link to the regulation of root quality deterioration. Both browning inhibition and quality deterioration promotion exhibited gradient shifts in accordance with ET concentration. Combined with DNA affinity purification sequencing technology to identify the presence of motifs that bind specifically to ERF1B in lotus root, and screening for the possible target genes NnPL18 and NnACO that may be regulated by NnERF1B-like (104610030), it further suggests that NnERF1B-like (104610030) may mediate the process of lotus root flake softening and ethylene biosynthesis.

Aluminium-based metal-organic frameworks for the colorimetric ethephon detection in fruit by paper microsensor

Ethephon (ETH) is a plant growth regulator extensively utilized in agriculture, but its overuse is associated with several health issues. However, detecting ETH sensitively and easily in the field is challenging due to the complexity and time-consuming operation of current approaches. In this study, we synthesized aluminum-based metal-organic frameworks (CAU-1) as fluorescent probes for the detection of ETH in fruit. ETH exposure enhanced and shifted the light green fluorescence of CAU-1 to blue through high absorption of phosphate by electrostatic attraction. We observed a linear correlation between fluorescent intensity and ETH concentration ranging from 2 mg/L to 400 mg/L, with the lowest detection limit at 1 mg/L. This fluorescent analysis exhibited good selectivity towards ETH. To facilitate easy identification of samples in the field, we designed a fluorescent paper-based platform with a logic gate operation, allowing visual distinction of samples containing ETH. We applied this platform to monitor ETH in various fruits, including apples, pears, and tomatoes, through fluorescent spectrum, and visual detection. The platform offered simplicity, speed, ease of use and sensitivity, providing a promising future for ETH detection in agriculture.

Elucidating the molecular mechanisms in phytohormones-induced alleviation of postharvest physiological deterioration in cassava tuberous roots

Cassava is a staple food crop in tropical regions, serving as a significant source of carbohydrates. However, rapid postharvest physiological deterioration (PPD) significantly limits the shelf life and utilization of cassava. Despite its importance, the overlapping molecular mechanisms underlying phytohormones-induced PPD alleviation in cassava tuberous roots remain unknown. In this study, the phytohormones ethephon (ET), gibberellic acid (GA), and methyl jasmonate (MeJA) were applied to cassava tuberous roots after harvest. These treatments led to significantly reduced H2O2 accumulation and alleviation of PPD. Transcriptomic analysis revealed shared functions, including transcriptional regulation and oxidoreductase activity, among differentially expressed genes (DEGs) affected by ET, GA, or MeJA. A total of 305 genes encoding antioxidant enzymes were systematically identified, with 151 responsive to phytohormone treatments across ten families. Notably, the expression of 10 Glutathione S-transferase (GST) genes was induced by all three phytohormone treatments, while their expression was suppressed in the absence of phytohormones during PPD. By using co-expression network analysis, DNA-binding motif analysis, and experimental validation using yeast one-hybrid and dual-luciferase assays, a regulatory network involving MeMYB102 and MeZAT11 transcription factors (TFs) that directly promote the expression of MeGST42, MeGST43, MeGST44, and MeGST46 was established. Overall, this study enhances the understanding of the overlapping molecular mechanisms underlying phytohormones-induced alleviation of PPD in cassava, thereby providing genetic resources for developing PPD-resistant cassava.

Impacts of 1-methylcyclopropene (1-MCP) and ethephon treatments on expression of aquaporin (AQP) genes during apple fruit ripening

The main aim of the present study was to determine the effects of ethephon (ET) and 1-methylcyclopropene (1-MCP) treatments on expression of aquaporin (AQP) genes during apple fruit ripening. The harvested apples were treated with 1-MCP (1 μL L−1) and ET (0.2 mmol L−1), respectively, and then ripened at room temperature (20 ± 1 °C). Our results suggested that 1-MCP application reduced weight loss, total soluble solids (TSS) content, respiration rate and ethylene production, maintained flesh firmness, and slowed down the increase in content of soluble sugar and the decrease in content of titratable acidity (TA) and dry matter concentration (DMC) in flesh and peel during ripening compared with the control, while ET treatment had the opposite effects. Quantitative real-time PCR (qPCR) analysis indicated that MdAQPs expression was differentially regulated by both treatments in flesh and peel during ripening. Expression of MdSIP1;2 and MdNIP5;3 in flesh and MdPIP1;3 and MdPIP2;7 in peel was generally up-regulated by both treatments, while MdTIP4;2 expression in peel was down-regulated by both treatments during ripening. Expression of MdNIP1;1, MdNIP2;1 and MdTIP1;1 in flesh and MdTIP2;2, MdTIP3;1 and MdNIP5;1 in peel was differentially down-regulated by ET treatment while differentially up-regulated by 1-MCP application during ripening. Transcript levels of MdTIP2;2, MdPIP1;2, MdPIP2;4, MdPIP2;3 and MdNIP5;2 in flesh and MdNIP2;1, MdSIP2;2, MdSIP1;2 and MdNIP1;1 in peel were differentially up-regulated by ET application while differentially reduced by 1-MCP application during ripening. After transient over-expression of MdERF2, MdAQPs exhibited varying expression profiles in both tissues during ripening. The results indicated that MdAQPs expression was modulated by ethylene signal in ripening apple fruit.

A Nanofilm-Based Fluorescent Sensor toward Highly Efficient Detection of Ethephon.

Ethephon (ETH) is widely used to promote fruit ripening and improve fruit quality. However, improper use is harmful to human health and to the environmental safety. Therefore, development of the techniques for on-site and at real-time monitoring of ETH is of importance for its safe use. In this work, we developed a nanofilm-based fluorescence film sensor (FFS) and realized highly efficient detection of ETH in vapor phase, where the detection limit (DL) is <0.2 ppb, the response time is less than 10 s, and the interference is almost free. The unusual sensing performance of the sensor was ascribed to the specific binding of the nanofilm to ETH and to its great porosity, which enables efficient adlayer mass transfer, a requirement for high signal-to-noise ratio. Moreover, visualization-based qualitative sensing is also realized. The nanofilm, a key component of the sensor, was prepared at the humid air/DMSO interface. The building blocks used were a specially designed fluorescent o-carborane derivative (CB-2CHO) and a cross-linker BTN possessing three acylhydrazine groups. The nanofilm as prepared is flexible, uniform, thickness tunable, and photochemically super stable. We believe our effort not only addresses the challenging issue of on-site and at real-time detection of ETH but also provides another route for developing new FFSs via sensing film innovation.

Effects of ethephon on heartwood formation and related physiological indices of Dalbergia odorifera T. Chen

IntroductionDalbergia odorifera T. Chen, known as fragrant rosewood, is a rare and endangered tree species. Studies have shown that plant growth regulators can effectively promote heartwood formation. This study aimed to investigate the effects of ethephon (ETH) on heartwood formation and the influence of ethephon and hydrogen peroxide (H2O2) on the physiological characteristics in D. odorifera.MethodsD. odorifera branches underwent treatment with 2.5% plant growth regulators, including ETH, jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), H2O2, and inhibitors such as ascorbic acid (AsA) to inhibit H2O2 synthesis, and (S) -trans 2-amino-4 - (2-aminoethoxy) -3-butene (AVG) to inhibit ethylene synthesis. After a 14-day period, we conducted an analysis to evaluate the impact of these plant growth regulators on elongation distance, vessel occlusion percentage, and trans-nerol content. Additionally, the effects of ETH and H2O2 on endogenous plant hormones, H2O2 content, soluble protein content, and enzyme activity were investigated within 0-48 h of treatment.ResultsAfter treatment with ETH for 14 days, the extension distance of the heartwood material was 15 cm, while the trans-nerolol content was 15 times that of the ABA group. ETH and H2O2 promoted endogenous ethylene synthesis; Ethylene content peaked at 6 and 18 h. The peak ethylene content in the ETH group was 68.07%, 12.89%, and 20.87% higher than the initial value of the H2O2 group and ddH2O group, respectively, and 29.64% higher than that in the AVG group. The soluble protein content and activity of related enzymes were significantly increased following ETH treatment.DiscussionETH exhibited the most impact on heartwood formation while not hindering tree growth. This treatment effectively triggered the production of endogenous ethylene in plants and enhanced the activity of essential enzymes involved in heartwood formation. These findings serve as a valuable reference for future investigations into heartwood formation.

A Multienzyme Reaction-Mediated Electrochemical Biosensor for Sensitive Detection of Organophosphorus Pesticides.

Ethephon (ETH), a commonly employed growth regulator, poses potential health risks due to its residue in fruits and vegetables, leading to both acute and subchronic toxicity. However, the detection accuracy of ETH is compromised by the color effects of the samples during the detection process. In this work, a multienzyme reaction-mediated electrochemical biosensor (MRMEC) was developed for the sensitive, rapid, and color-interference-resistant determination of ETH. Nanozymes Fe3O4@Au-Pt and graphene nanocomplexes (GN-Au NPs) were prepared as catalysts and signal amplifiers for MRMEC. Acetylcholinesterase (AChE), acetylcholine (ACh), and choline oxidase (CHOx) form a cascade enzyme reaction to produce H2O2 in an electrolytic cell. Fe3O4@Au-Pt has excellent peroxidase-like activity and can catalyze the oxidation of 3,3',5,5'-tetramethvlbenzidine (TMB) in the presence of H2O2, resulting in a decrease in the characteristic peak current of TMB. Based on the inhibitory effect of ETH on AChE, the differential pulse voltammetry (DPV) current signal of TMB was used to detect ETH, offering the limit of detection (LOD) of 2.01 nmol L-1. The MRMEC method effectively analyzed ETH levels in mangoes, showing satisfactory precision (coefficient of variations, 2.88-15.97%) and recovery rate (92.18-110.72%). This biosensor holds promise for detecting various organophosphorus pesticides in food samples.

Overexpression of cucumber CYP82D47 enhances resistance to powdery mildew and Fusarium oxysporum f. sp. cucumerinum.

Cytochrome P450s are a large family of protein-encoding genes in plant genomes, many of which have not yet been comprehensively characterized. Here, a novel P450 gene, CYP82D47, was isolated and functionally characterized from cucumber (Cucumis sativus L.). Quantitative real-time reverse-transcription polymerase chain reaction analysis revealed that CYP82D47 expression was triggered by salicylic acid (SA) and ethephon (ETH). Expression analysis revealed a correlation between CYP82D47 transcript levels and plant defense responses against powdery mildew (PM) and Fusarium oxysporum f. sp. cucumerinum (Foc). Although no significant differences were observed in disease resistance between CYP82D47-RNAi and wild-type cucumber, overexpression (OE) of CYP82D47 enhanced PM and Foc resistance in cucumber. Furthermore, the expression levels of SA-related genes (PR1, PR2, PR4, and PR5) increased in CYP82D47-overexpressing plants 7days post fungal inoculation. The levels of ETH-related genes (EIN3 and EBF2) were similarly upregulated. The observed enhanced resistance was associated with the upregulation of SA/ETH-signaling-dependent defense genes. These findings indicate the crucial role of CYP82D47 in pathogen defense in cucumber. CYP82D47-overexpressing cucumber plants exhibited heightened susceptibility to both diseases. The study results offer important insights that could aid in the development of disease-resistant cucumber cultivars and elucidate the molecular mechanisms associated with the functions of CYP82D47.

Comprehensive transcriptome analysis of AP2/ERFs in Osmanthus fragrans reveals the role of OfERF017-mediated organic acid metabolism pathway in flower senescence.

Osmanthus fragrans is an ethylene-sensitive flower, and flower senescence was mediated by ethylene-responsive transcription factors (OfERFs). A total of 227 OfERFs were identified from O. fragrans, which were classified into five subfamilies: AP2 (35), DREB (57), ERF (125), RAV (6), and Soloist (4). Gene composition and structural analysis indicate that members of different subfamilies have different gene structures and conserved domains. Their gene promoter contains various functional responsive elements, including auxin, jasmonic acid, and other responsive elements. Among them, 124 OfAP2/ERF genes have expressed at any stage of flowering, and 10 of them may play roles in flowering or senescence. By comparative transcriptome analysis, OfAP2/ERFs affected by ethephon (ETH) and 5'-azacytidine (Aza) treatment were divided into three categories, which have various target gene sets. Importantly, these target gene sets participate in similar or different biological processes and metabolic pathways, suggesting that ethylene and DNA hypomethylation have crosstalk and a unique mechanism in regulating the flower senescence of O. fragrans. Co-expression analysis revealed that several key OfAP2/ERFs played a central role in organic acid metabolism and biosynthesis of branched-chain amino acids (BcAAs), among which OfERF017 was selected for further functional analysis. Overexpression of OfERF017 leads to significant enrichment of genes in organic acid metabolism pathways, which leads to a decrease in organic acid levels and promoting the flower senescence of O. fragrans. Together, these results give insights into the characteristics and functional analysis of OfAP2/ERF genes in O. fragrans.

Functional validation of Lobularia maritima thioredoxin-h2 protein for its ability to combat bacterial and fungal infections

Thioredoxins (Trxs) belong to a family of multifunctional redox proteins that is critical for maintaining and regulating the cellular redox environment during plant cell growth. Also, they are important for the development of plant's response to biotic and abiotic stress; however, the specific biological functions of h-type thioredoxins (Trxhs) in plants have not been fully elucidated. Herein, we investigated the role of LmTrxh2, a specific member of the Trxh family, in response to various biotic stress simulants, including mechanical wounding, exposure to jasmonic acid (JA), picolinic acid (PA), salicylic acid (SA), ethephon (ETP), and hydrogen peroxide (H2O2). We observed that LmTrxh2 transcripts were significantly upregulated upon exposure to these stress simulants. The characterization of enzymatic activity revealed that the recombinant LmTrxh2 protein functions as a disulfide reductase. While the role of Trx proteins in redox regulation is well known, their involvement in antimicrobial activity is still unexplored. Therefore, we assessed the antimicrobial effect of LmTrxh2 towards various microorganisms and observed a concentration-dependent inhibition of microbial growth. The minimum inhibitory and minimum bactericidal concentrations and the diameters of the inhibition zones were 40–1250 μg/mL, 40–1250 μg/mL, and 12.5–32.5 mm, respectively. In addition, we used previously developed LmTrxh2-transgenic tobacco lines and found that they showed enhanced resistance to fungal infections triggered by Fusarium graminearum and Aspergillus niger. This resistance was associated with an upregulation of known defense-related genes. Overall, our findings suggest that LmTrxh2 is responsive to multiple biotic stress simulants and plays a critical role in the basal resistance of plants to pathogen infections. These results highlight the potential of LmTrxh2 in the development of strategies to protect crops from various stress factors and emphasize its importance in the adaptation of plants to different stress conditions.

Light and Ethephon Overcoming Seed Dormancy in Friar's Crown (Melocactus zehntneri, Cactaceae), a Brazilian Cactus.

Seed germination in Melocactus and other cactus species is hampered by dormancy. However, most studies failed to achieve high seed-germination rates, suggesting a complex mechanism of dormancy in Cactaceae. Thus, the objective of this study was to evaluate whether factors such as light and phytoregulators overcome the dormancy in the seeds of the friar's crown cactus (Melocactus zehntneri). Two consecutive experimental sets were designed: one with seed germination under filter paper conditions and different wavelengths and Photosynthetically Photon Flux Densities (PPFDs); and one in vitro experiment using a culture medium to evaluate the influence of different phytoregulators, such as gibberellic acid (GA3), benzylaminopurine (BAP) and ethephon (ET), both in the germination of seeds of M. zehntneri. Seeds of M. zehntneri are positive photoblastic. Red light and gradual increases in PPFD resulted in the highest germination rates (60.8-61.7%) and germination speed index (4.4-4.5). In vitro seeding in culture media increased the germination percentage to 76% in control without phytoregulators. Ethephon showed a major effect in releasing the germination of dormant seeds of M. zehntneri, totaling 98% of seeds germinated under in vitro conditions, while GA3 and BAP showed minor or no effect on germination. The present study resulted in an efficient in vitro technique for germination and a better understanding of cacti seed dormancy.

Real-time intelligent detection of ethephon based on a high-throughput ratiometric fluorescent probe

Ethephon (ETH) is a common pesticide, and its overuse has resulted in a variety of health problems for humans. However, the existing ETH detection methods are tedious and time-consuming, and real-time ETH identification remains a significant difficulty. To mitigate this concern, a dual-emission ratiometric fluorescent probe Ru@ZrMOF was rationally synthesized for the detection of ETH. In the presence of ETH, the emission peak at 435 nm gradually increased, while the peak at 600 nm remained constant, accompanied by the fluorescence color change from red, pink, blue-violet to blue. The fluorescence intensity ratio (F435/F600) demonstrated two linear relations with the ETH concentration ranges at 3 − 50 μM and 50 − 500 μM, with a lowest detection limit at 1 μM. This was attributed to the formation of Zr−O−P bonds which attenuated the ligand-metal charge transfer (LMCT) process, resulting in the recovery of blue fluorescence of the ligand 2-Aminoterephthalic acid (2-APDC). To validate the practical application of the developed platform, a YOLO v5x-based WeChat applet "96 Speckles" was developed, and a 96-well plate and smartphone-embedded 3D-printed portable toolbox was designed for the real-time intelligent detection of ETH. This smart platform allows for real-time and efficient ETH analysis in various real samples including apples, pears and tomatoes.

Identification and characterization of the Bicupin domain family and functional analysis of GhBCD11 in response to verticillium wilt in cotton

Bicupin domain protein (BCD) family, an important component of Cupin domain superfamily, plays important roles in oxalic acid (OA) degradation and stress responses in high plants. However, no studies have been reported on the Cupin domain family in cotton up till now. In our study, a total 110 proteins including Cupin domain were identified from the upland cotton (Gossypium hirsutum). Among them, 17 proteins contained Bicupin domain. Subsequently, we found that V. dahliae produces OA leading to cotton leaf wilting. RT-qPCR analysis of GhBCDs revealed that OA and V. dahliae Vd080 significantly enhanced the expression of GhBCD11. The Virus-induced gene silencing and overexpression analysis showed that GhBCD11 positively regulates plant resistance to V. dahliae. Subcellular localization showed GhBCD11 located on the plasma membrane. The analysis of expression pattern showed that GhBCD11 can be induced via hormone-mediated signal pathway including salicylic acid (SA), ethephon (ET), methyl jasmonate (JA) and abscisic acid (ABA). In addition, we identified an interaction between 60 S ribosomal protein GhRPL12–3 and GhBCD11 by yeast double hybridization. Overall, this is the first study, where we identified Cupin domain family in cotton, clarified the role of GhBCD11 in cotton for resistance to V. dahliae and found an interaction between GhRPL12–3 and GhBCD11.

Growth of Paulownia ssp. Interspecific Hybrid ‘Oxytree’ Micropropagated Nursery Plants under the Influence of Plant-Growth Regulators

The aim of the study was to examine the effects of application of plant-growth regulators (PGR) on the growth of paulownia plants and evaluate their usefulness in paulownia nurseries. The experiment was carried out on the paulownia interspecific hybrid (Paulownia elongata × Paulownia fortunei) ‘Oxytree’. Micropropagated plants grown in pots were sprayed with PGR solutions. Gibberellins (GA3, GA4+GA7), 6-benzyladenine (BA), triclopyr (TPA), ethephon (ETH), daminozide (DA), prohexadione-Ca (PH), and trinexapac-ethyl (TE) were used. They were included in commercial products (Florgib 245 mg dm−3, Gibb plus 11 SL 5 cm3 dm−3, Globaryll 100 SL 1.5 cm3 dm−3, Topper 10 ST 200 mg dm−3, Agrostym 480 SL 2 cm3 dm−3, B-Nine 85 SG 2 g dm−3, Regalis plus 10 WG 2.5 g dm−3, Moddus 250 EC 1 cm3 dm−3, respectively). None of the studied preparations modified positive correlations between the longitudinal vs. transverse growth of stems and growth of leaves. Not only GA3, GA4+GA7, but also BA (cytokinin) and unexpectedly TE (retardant) stimulated stem elongation and thickening. Furthermore, the effect of TE lasted longer than influence of GAx and BA. Leaves of TE-treated plants were distinguished by a higher chlorophyll a/b ratio, and a lower relative chlorophyll content and efficiency of photosystem II (Fv/Fm, Fv/F0). TPA strongly deformed the stems and leaves of liners. Other regulators (ETH, DA, PH) retarded the diameter growth of stems and leaf expansion. Some results obtained by GAx, BA, and especially by TE treatment, might be beneficial for paulownia grown as ornamental and/or timber tree.

Ethylene modulates root growth and mineral nutrients levels in trifoliate orange through the auxin-signaling pathway

Roots are fundamental to plant growth, with their development being profoundly influenced by water, mineral nutrients, and notably, plant hormones. Citrus, a leading horticultural crop cultivated globally, holds immense economic value. This study tried to investigate the roles and mechanisms effect of foliar spray 1.0 μmol/L ethephon (ETH) of ethylene and 5.0 μmol/L AgNO3 (an ethylene inhibitor) its inhibitor with auxin on root growth and mineral nutrients content levels in trifoliate orange under sand culture conditions for 45 days. Our findings indicate that ethephon treatment significantly boosted the number of lateral roots, root fresh weight, and enhanced the mineral nutrient content (N, P, K, B, Ca, Mg, Fe, Mn, and Zn, with the exception of Cu) in both root and shoot tissues. In contrast, the inhibitors notably reduced the length of lateral roots and decreased the content of P, and Fe in both root and shoot, whilst elevating Zn contents. Furthermore, ETH incited the up-regulation of auxin biosynthesis and transportation genes, leading to an increased endogenous auxin content in the lateral root-hair region. whereas, the inhibitors produced an opposite effect. We thus conclude that ethylene modulates auxin transportation and biosynthesis. This activity stimulates the auxin signaling pathway locally-specifically, in the root hair zone in the lateral root, which in turn, regulates root growth and mineral nutrient content.

Exogenous plant growth regulator and foliar fertilizers for phytoextraction of cadmium with Boehmeria nivea [L.] Gaudich from contaminated field soil

As a enrichment plant, ramie can be used for the phytoremediation of cadmium (Cd)-contaminated soil. However, it is worth exploring the role of plant growth regulators and foliar fertilizers in the process of plant growth and development and Cd adsorption. By measuring the agronomic traits, Cd content of aboveground and underground ramie, calculating the Cd transfer coefficient (TF) and Cd bioconcentration factors (BCF), and the correlation between various indicators. This study examined the effects of plant growth regulators and foliar fertilizers on ramie’s capacity for Cd accumulation and transportation. Plant growth regulators and foliar fertilizers increased the Cd content of the aboveground ramie, reduced the Cd content of the underground ramie, and increased the TF. Among them, GA-1 increased the Cd content of the aboveground ramie to 3 times more than that of the control and reduced the Cd content of the underground ramie by 54.76%. Salicylic acid (SA) increased the Cd content of the aboveground ramie to three times more than that of the control. The combination of GA and foliar fertilizer reduced the Cd content of the aboveground and underground ramie and the TF and BCF of the underground ramie. After the hormones were sprayed, the TF of ramie had a significant positive correlation with the Cd content of the aboveground ramie; the BCF of the aboveground ramie had a significant positive correlation with the Cd content and TF of the aboveground ramie. The results indicate that Brassinolide (BR), gibberellin (GA), ethephon (ETH), polyamines (PAs), and salicylic acid (SA) have different effects on the enrichment and transport of Cd in ramie. This study provided an effective method to improve the capacity for ramie to adsorb heavy metals during cultivation.

Physicochemical properties in NOR tomato line MA 131-6-3 after treated with ethephon and calcium carbide induced ripening

Abstract. Khairi A, Murti RH, Irwan SNR, Putra ETS. 2023. Physicochemical properties in NOR tomato line MA 131-6-3 after treated with ethephon and calcium carbide induced ripening. Biodiversitas 24: 3029-3037. Tomato fruit Postharvest Losses (PHL) from rotting, Physiological Weight Loss (PWL), inadequate nutrition, and other factors can lower fruit quality. Tomato is included as climacteric fruit which shows a significant increase in respiration and ethylene. The use of tomato with an extended shelf life due to genetic engineering, such as a Non-Ripening (NOR) tomato, can lower PHL. This experiment was carried out to evaluate physicochemical characteristics of NOR tomato fruit (lineMA 131-6-3 as result of selection F6)during postharvest after being treated by Ethephon (ET) (375, 750, 1,125, and 1,500 ppm), calcium carbide (CaC2) (5, 10, 15, and 20 gkg?1), and control. The experimental design was arranged in Randomized Completely Block Design with three replications.The ambient temperature was 28.30±1.75°C and relative humidity of 60.69±2.33%. The results showed the fruit ripening and physicochemical altered with CaC2 treatment, then followed by yellow but did not alter to the red color for all treatments. The value of reduction sugar, respiration, ethylene, PWL, and pH increased, meanwhile the fruit firmness decreased caused by CaC2. Furthermore, ET could increase rotting during storage.

Influence of Plant Growth Retardants and Nitrogen Doses on the Content of Plant Secondary Metabolites in Wheat, the Presence of Pests, and Soil Quality Parameters

Wheat is the cereal most susceptible to lodging, particularly during the flowering period and at the early ripening stage. The use of plant growth retardants (PGRs) is especially recommended when intensive nitrogen (N) fertilisation is applied, which increases the susceptibility of plants to lodging. This paper presents the results of tests into the effects of PGRs (PGR0—control; PGR1—chlormequat chloride (CCC) + trinexapac-ethyl (TE); PGR2—chlormequat chloride (CCC) + ethephon (ET)), and N dose—N0, N20, N40, and N60 [0, 20, 40, and 60 kg N ha−1] on the content of selected plant secondary metabolites (PSM) in the Indian dwarf wheat (Triticum sphaerococcum Percival) of the Trispa cultivar, and on the abundance of insect pests. In the developmental stage of wheat (BBCH 39), insects were collected with an entomological net. The study also investigated the effect of experimental factors on the physicobiochemical properties of the soil (pH in KC, granulometric composition, total organic carbon TOC, total nitrogen TN, fractional composition of humus, and the activity of enzymes). An increase in the plant secondary metabolite (PSM) and FRAP (ferring reducing ability of plasma) contents following the application of PGRs and N fertilisation already from as low a rate as 20 kg ha−1 was demonstrated. A significant positive correlation was noted between the abundance of Oulema spp. and the contents of total polyphenols, chlorogenic acid, and FRAP. No such relationship was noted for Aphididae or Thysanoptera. TOC content was higher on the plots on which N fertilisation was applied at the highest rate and after the application of PGRs. The factor determining the TN content was N fertilisation. Soil samples of the PGR0 N0 treatment were characterised by the greatest proportion of carbon in the humic and fulvic acid fractions and by the smallest proportion of carbon in the humin fraction. N fertilisation increased the proportion of carbon in the humin fraction on the plots on which no PGRs were applied. The study demonstrated an increase in the activity of oxidoreductive enzymes following the application of higher N rates. The application of PGRs resulted in no inhibition of enzymes in the soil compared to the control (PGRs0).