Search Results (49)

Nitrogen is the nutrient most required by plants and plays a central role in agricultural productivity due to its involvement in essential nutrients. This study evaluated the effects of different nitrogen sources on the physiological and morphological development of yellow passion fruit (Passiflora edulis Sims) seedlings. The experiment followed a randomized block design with six treatments (water, urea, ammonium sulfate, potassium nitrate, calcium nitrate, and magnesium nitrate), six replicates per treatment, and two plants per plot. An equal amount of nitrogen was supplied to all treatments, while the urea treatment excluded the additional macronutrients present in the other fertilizers (S, K, Ca, and Mg), allowing us to assess whether the benefits were exclusively attributable to the nitrogen source. The results indicated that ammonium sulfate and calcium nitrate promoted better root system development, while ammonium sulfate also improved shoot growth and physiological characteristics. Multivariate analysis revealed that CP1 explained most of the variability between treatments, highlighting the contribution of these sources compared to the control. Overall, fertilization with ammonium sulfate produced the best results, indicating that it is a more efficient nitrogen source for seedling development. Full article

Heat stress caused a stagnation in the growth and development of Passiflora edulis Sims. To investigate the effects of high-temperature stress, this study subjected P. edulis to 40 °C treatment for different durations; the changes in chlorophyll content, chlorophyll fluorescence parameters, photosynthetic parameters, transcriptome profiles, and photosynthesis-related genes of P. edulis under high-temperature stress were analyzed. The results showed that after 5 h of heat stress, the chlorophyll content of the leaves decreased by 31%, variable fluorescence/maximum fluorescence (Fv/Fm) decreased by 26.91%, photochemical performance index (PI_abs) by 99.28%, comprehensive performance index (PI_total) by 94.20%, light energy absorbed per unit area (ABS/CSm) by 13.56%, light energy captured per unit area (TRo/CSm) by 17.90% and quantum yield of electron transfer per unit area (ETo/CSm) by 92.61%. The net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) decreased by 47%, 41% and 38%, respectively, while intercellular CO₂ concentration (Ci) increased by 1.34 times. Transcriptome sequencing results of P. edulis under heat stress identified 2336 differentially expressed genes (DEGs), which were significantly enriched in pathways including chloroplast function and plant hormone signal transduction. GO enrichment analysis demonstrated that DEGs were significantly enriched in terms related to catalytic activity and chloroplast components. Concurrently, KEGG pathway analysis revealed that carbon fixation in photosynthetic organisms was among the key pathways showing significant enrichment of these DEGs. The expression levels of photosynthesis-related genes, including PePSAE, PeMADs, PebHLH, PeFAR1, PePSBS, PePnsB4, PebZIP and PeC2H2, exhibited a significant increase after 3 h of high-temperature stress and rapidly declined following 5 h. These findings lay a foundation for further research on the high-temperature stress response mechanism and photosynthetic regulation of heat tolerance in P. edulis. Full article

Practices that mitigate the deleterious effects of water deficit are of great importance for agricultural production in the semi-arid region of Northeastern Brazil. The objective of this study was to evaluate the effect of foliar application of salicylic acid on mitigating water deficit in the morphophysiology and yield components of sour passion fruit during different phenological stages. Treatments were arranged in a randomized block design in a 6 × 2 factorial scheme, consisting of six irrigation strategies under water deficit, based on reference evapotranspiration (ETr) [irrigation with 100% ETr throughout the entire cultivation cycle—IS1; irrigation with 50% ETr during the vegetative stage—IS2; flowering—IS3; fruiting—IS4; vegetative/flowering—IS5; and vegetative/fruiting—IS6], combined with or without salicylic acid (SA) application (0 and 1 mM). The application of 1.0 mM salicylic acid alleviated the effects of water deficit during the flowering stage, improving gas exchange, photochemical efficiency, relative water content, growth, and yield of sour passion fruit. In addition, it contributed to reducing electrolyte leakage in the leaf blade. Therefore, foliar application of salicylic acid represents a promising strategy to maintain the integrity of the photosynthetic apparatus and the productive performance of sour passion fruit under water deficit conditions. Full article

Glycine betaine (GB) is a compatible solute that enhances plant tolerance to abiotic stresses, yet its role in fruit crops remains insufficiently explored. This study assessed whether GB improves drought tolerance in Passiflora edulis Sims f. flavicarpa, a crop sensitive to irregular rainfall. A 3 × 2 × 2 factorial design was employed, combining three drought levels (control, mild, and severe), two propagation methods (seedlings and cuttings), and two GB treatments (0 and 100 mM), with 60 plants and five replicates. Plants were grown under controlled conditions, and irrigation was adjusted to maintain target field capacities. Chlorophyll content was monitored daily, and agronomic and physiological traits were measured after 45 days. GB application influenced leaf water dynamics and stress responses. Cuttings generally showed clearer improvements in drought tolerance when treated with GB, while seedlings exhibited more variable outcomes. These differences appear linked to the propagation method and developmental stage as cuttings were at a more advanced phase, whereas seedlings remained vegetative. Overall, the results demonstrate that exogenous GB can enhance drought tolerance in passion fruit, although its effectiveness is propagation-dependent and context-specific, highlighting the need to tailor its application to cultivation practices. Full article

Passion fruit (Passiflora edulis Sims), belonging to the Passifloraceae family, is an economically important plant in tropical and subtropical regions. The advances in functional genomics research of passion fruit have been significantly hindered by its recalcitrance to regeneration and stable transformation. This study establishes the first efficient Agrobacterium rhizogenes-mediated hairy root transformation system for passion fruit. Utilizing the eGFP marker gene, transformation efficiencies of 11.3% were initially achieved with strains K599, MSU440, and C58C1, with K599 proving most effective. Key transformation parameters were systematically optimized to achieve the following: OD₆₀₀ = 0.6, infection duration 30 min, acetosyringone concentration 100 μM, and a dark co-cultivation period of 2 days. The system’s utility was further enhanced by incorporating the red visual marker RUBY, enabling direct, instrument-free identification of transgenic roots via betaxanthin accumulation. Finally, this system was applied for functional analysis using PeMYB123, which may be involved in proanthocyanidin accumulation. Overexpression of PeMYB123 produced a higher content of proanthocyanidin in hairy roots. Additionally, the PeANR gene involved in the proanthocyanidin pathway was strongly activated in the transgenic hairy roots. This rapid and efficient visually simplified hairy root transformation system provides a powerful tool for functional gene studies in passion fruit. Full article

This study evaluated the effects of reduced glutathione (GSH) application on the production and quality of sour passion fruit irrigated with brackish water in the semi-arid region of Paraíba, Brazil. The experiment was conducted in drainage lysimeters under greenhouse conditions at the Center of Technology and Natural Resources of the Federal University of Campina Grande (UFCG). Treatments combined five levels of electrical conductivity of brackish irrigation water (Bw: 0.4, 1.2, 2.0, 2.8, and 3.6 dS m⁻¹) and four GSH concentrations (0, 40, 80, and 120 mg L⁻¹), arranged in a randomized block design with three replicates. Salinity levels above 0.4 dS m⁻¹ negatively affected fruit production and post-harvest quality of ‘BRS GA1’ sour passion fruit. Foliar application of 120 mg L⁻¹ GSH increased fruit yield, while 74 mg L⁻¹ GSH mitigated salt stress effects on production and pulp chemical quality. The ‘BRS GA1’ cultivar was highly sensitive to salinity, showing a 26.9% yield reduction per unit increase in Bw electrical conductivity above 0.4 dS m⁻¹. The results suggest that GSH can alleviate salt stress damage, improving crop productivity and fruit quality under semi-arid conditions. Full article

Passion fruit is an underutilised fruit in Northeastern India, known for its unique flavour and health benefits. This study analysed 15 genotypes (P1 to P15) to explore their morphological and biochemical traits related to fruit quality and yield. P. quadrangularis L. (P15) exhibited maximum flower length, fruit size, weight, juice content, shelf-life, and yield. P. edulis f. flavicarpa (P3, P5, and P2) had the highest seed count per fruit and antioxidant activity, along with greater chlorophyll and anthocyanin levels. Passiflora edulis Sims (P8 and P11) showed superior total soluble solids, carotenoids, and vitamin C. The study found that fruit shelf life positively correlated with seed weight, while the number of fruits per vine negatively correlated with seed traits and peel weight. Additionally, certain traits, such as total carotenoids, had strong positive correlations with reducing sugar and flavonoids. Principal component analysis revealed distinct trait relationships, particularly for genotypes P7 and P10. SDS-PAGE protein profiling indicated a significant distance between P3 and P14, emphasising genetic diversity. In conclusion, this research highlights the diverse morphological and biochemical characteristics of passion fruit genotypes, paving the way for the region’s improved fruit quality, yield, and breeding strategies. Full article

Heat stress severely inhibited the flower bud growth and development of passion fruit (Passiflora edulis Sims) in summer, resulting in severe production damage. Protein phosphorylation plays a key role in plant protein regulatory networks in response to abiotic stress, while the mechanism of phosphorylation regulation response to heat stress in passion fruit is still unknown. In this study, 97.62% of passion fruit floral buds withered and fell off after 2 h of heat stress, compared to 3.33% after 0.5 h. A total of 10,614 phosphorylation sites across 2906 proteins were identified by phosphoproteomic analysis. Among them, 1343 differentially regulated phosphoproteins (DRPPs) were mainly located in the nucleus, cytoplasm, and chloroplast. The DRPPs whose phosphorylation sites were induced by heat stress were mainly involved in the ‘ABC transporters’, ‘Plant hormone signal transduction’, and ‘MAPK signaling’ pathways. In addition, the accumulations of ABA and H₂O₂ were induced under heat stress for 0.5 h. Through protein interaction prediction and qRT-PCR analyses, we identified a key protein PePP2C1, in which the levels of gene expression, protein expression, and phosphorylation were induced by heat stress. The transient assays showed that the overexpression of PePP2C1 inhibited the accumulation of H₂O₂. Our results suggested the potential role of phosphoproteins under heat stress in the floral buds of passion fruit. The findings in this study contribute to a better understanding of the molecular mechanism of phosphoproteins in response to heat stress. Full article

A disease detection network based on a sparse parallel attention mechanism is proposed and experimentally validated in the passion fruit (Passiflora edulis [Sims]) disease detection task. Passiflora edulis, as a tropical and subtropical fruit tree, is loved worldwide for its unique flavor and rich nutritional value. The experimental results demonstrate that the proposed model performs excellently across various metrics, achieving a precision of 0.93, a recall of 0.88, an accuracy of 0.91, an mAP@50 (average precision at the IoU threshold of 0.50) of 0.90, an mAP@50–95 (average precision at IoU thresholds from 0.50 to 0.95) of 0.60, and an F1-score of 0.90, significantly outperforming traditional object detection models such as Faster R-CNN, SSD, and YOLO. The experiments show that the sparse parallel attention mechanism offers significant advantages in disease detection with multi-scale and complex backgrounds. This study proposes a lightweight deep learning model incorporating a sparse parallel attention mechanism (SPAM) for passion fruit disease detection. Built upon a Convolutional Neural Network (CNN) backbone, the model integrates a dynamically selective attention mechanism to enhance detection performance in cases with complex backgrounds and multi-scale objects. Experimental results demonstrate that the model has superior precision, recall, and mean average precision (mAP) compared with state-of-the-art detection models while maintaining computational efficiency. Full article

Plant biostimulants (PBs) have been considered the new wave for ecological intensification and sustainability, but are they sustainable? They increase nutrient use efficiency and reduce the impact of abiotic stress in plants. However, commercially available PBs based on humic substances are obtained using non-renewable sources of organic matter. At the same time, the microbial inoculants include a discussion of the properties of microorganisms and formulation design, as well as standards of purity and process control. Farmers depend on biological inputs like others to generate additional income for agribusiness. We produced a composite PB using humic substances isolated from vermicompost with KOH 5% and microbial consortia of plant growth-promoting bacteria (H. seropedicae, G. diazotrophicus, Bacillus spp.) grown in a simple medium with molasses and fishmeal as sources of C and N, respectively, in a homemade reactor at 37 °C for 36 h. The on-farm PB was applied directly in a passion fruit trial, and plant health and yield were monitored. The plants treated with the PB showed decreased visual symptoms of pests and diseases concurrent to higher activities of the enzymes used to monitor the induction of the plant resistance system (1,3-β glucanase, peroxidase, and phenylalanine ammonia-lyase). Plants treated with the PB yielded more than 50% more passion fruit than the control in soil with natural low fertility, fertilized with vermicompost. It is possible to produce PBs directly on the farm, leveraging locally available resources and simple technologies to sustainably enhance plant health and productivity. Full article

The Apetala2/Ethylene Responsive Factor (AP2/ERF) family represents a critical group of transcription factors in plants, recognized for their roles in growth, development, fruit ripening, and postharvest processes. This study aimed to identify and characterize the AP2/ERF gene family in passion fruit (Passiflora edulis Sims) and investigate their potential roles in flavor enhancement. A total of 91 PeAP2/ERF genes were identified and classified into five subfamilies. Chromosome localization and collinearity analysis demonstrated their distribution across all nine chromosomes of passion fruit, with tandem duplication events identified as a key driver of family expansion. Exon–intron configurations and motif compositions were highly conserved among PeAP2/ERF genes. Promoter cis-acting element analysis indicated potential regulation by environmental signals, including abiotic and biotic stresses, as well as hormonal cues. Postharvest storage induced the expression of 59 PeAP2/ERF genes over time. Notably, PeAP2-10 was found to enhance the expression of PeSTP6, a gene associated with sugar transport, suggesting its potential influence on the flavor profile of passion fruit. These findings provide valuable insights into the functional roles of PeAP2/ERF genes in passion fruit, highlighting their significance in postharvest management and flavor quality enhancement strategies. Full article

Passiflora edulis Sims peel (Chinese name Baixiangguo, BXG) is a by-product with a high nutritional and economic value of Passiflora edulis Sims. In this study, corn was partly replaced with BXG to make feed for finishing pigs and the effects on the carcass traits, meat quality, muscle amino acid profile, and gene expression of finishing pigs were evaluated. A total of 20 healthy finishing pigs (Duroc × Landrace × Large) were randomly divided into two groups. The control group (CON) was fed the basal diet, and the experimental group (BXG) was fed a basal diet with BXG instead of 10% corn for a period of 43 d. Compared to the CON group, the carcass weight, intramuscular fat content, and marbling score were significantly increased, while the drip loss, b^* value, and shear force of the BXG group were significantly reduced (p < 0.05). Gene expression analysis showed that the mRNA expression of lipid synthesis and oxidative-type fiber related genes was significantly increased in the BXG group (p < 0.05). Proteomic research revealed that the metabolic pathways of the BXG and CON groups differed significantly. A total of 36 differentially expressed proteins were identified, mainly related to energy metabolism, fatty acid degradation, and endocrine regulation pathways. However, the contents of glutamine, glutamate, proline, and other amino acids in the BXG group were significantly reduced (p < 0.05). Overall, this study has a positive effect on improving meat quality, but the specific mechanism needs to be further explored, which offers practical guidance for the application of BXG in producing higher-quality pork and further promotes its commercial application. Full article

Background: The passion fruit (Passiflora edulis Sims) is a diploid plant (2n = 2x = 18) and is a perennial scrambling vine in Southern China. However, the occurrence and spread of stem rot in passion fruit severely impact its yield and quality. Methods: In this study, we re-sequenced a BC₁F₁ population consisting of 158 individuals using whole-genome resequencing. We constructed a high-density genetic linkage map and identified the quantitative trait locus (QTL), and analyzed candidate genes associated with stem rot resistance in passion fruit. Results: Based on the passion fruit reference genome (MER), a high-density genetic linkage map was constructed with 1,180,406 single nucleotide polymorphisms (SNPs). The map contains nine linkage groups, covering a total genetic distance of 1559.03 cM, with an average genetic distance of 311.81 cM. The average genetic distance between 4206 bins was 0.404 cM, and the average gap length was 10.565 cM. The collinearity correlation coefficient between the genetic map and the passion fruit genome was 0.9994. Fusarium solani was used to infect the BC₁F₁ population, and the resistance to stem rot showed a continuous distribution. A QTL, qPSR5, was mapped to the 113,377,860 bp–114,811,870 bp genomic region on chromosome 5. We performed RNA sequencing (RNA-seq) and real-time quantitative polymerase chain reaction (RT-qPCR) to analyze the expression levels of predicted genes in the candidate region and identified ZX.05G0020740 and ZX.05G0020810 as ideal candidate genes for stem rot resistance in passion fruit. Conclusions: The findings in this study not only lay the foundation for cloning the qPSR5 responsible for stem rot resistance but also provide genetic resources for the genetic improvement of passion fruit. Full article

Passion fruit (Passiflora edulis Sims) is a Passifloraceae plant with high economic value. Crown rot caused by Rhizoctonia solani is a major fungal disease, which can seriously reduce the yield and quality of passion fruit. Receptor-like proteins (RLPs), which act as pathogen recognition receptors, are widely involved in plant immune responses and developmental processes. However, the role of RLP family members of passion fruit in resistance to crown rot remains unclear. In this study, evolutionary dynamics analysis and comprehensive genomic characterization of the RLP genes family were performed on passion fruit. A total of 141 PeRLPs in the genome of the ‘Zixiang’ cultivar and 79 PesRLPs in the genome of the ‘Tainong’ cultivar were identified, respectively. Evolutionary analysis showed that proximal and dispersed duplication events were the primary drivers of RLP family expansion. RNA-seq data and RT-qPCR analysis showed that PeRLPs were constitutively expressed in different tissues and induced by low temperature, JA, MeJA, and SA treatments. The PeRLP8 gene was identified as the hub gene by RNA-seq analysis of passion fruit seedlings infected by Rhizoctonia solani. The expression levels of PeRLP8 of the resistant variety Passiflora maliformis (LG) were significantly higher than those of the sensitive variety Passiflora edulis f. flavicarpa (HG). Transient overexpression of PeRLP8 tobacco and passion fruit leaves enhanced the resistance to Rhizoctonia solani, resulting in reduced lesion areas by 52.06% and 54.17%, respectively. In addition, it can increase reactive oxygen species levels and upregulated expression of genes related to active oxygen biosynthesis and JA metabolism in passion fruit leaves. Our research provides new insights into the molecular mechanism and breeding strategy of passion fruit resistance to crown rot. Full article

Salt stress results in physiological changes that inhibit plant growth and development. Ca-complex sources are used as a potential salt stress attenuator. This study was carried out with the aim of verifying the effects of Ca-complex sources in reducing the effects of saline water stress on the physiological aspects of sour passion fruit seedlings. The experiment was carried out in a randomized block design with a 2 × 2 × 3 factorial scheme, consisting of two cultivars of sour passion fruit (BRS GA1 and BRS SC1), two levels of water salinity (electrical conductivity of 0.5 and 4.0 dS m⁻¹) and three sources of Ca-complex (without, organic acids and amino acids). The traits measured at 60 days after sowing were gas exchange, chlorophyll indices, chlorophyll fluorescence, electrolyte leakage, and relative water content in the leaf limb. Under moderate water salinity, the application of Ca-complex in amino acids promoted increases of 49.84% and 43.71%, respectively, in the efficiency of water use and carboxylation. The application of complex sources increased the stability of cell membranes, reducing electrolyte leakage, providing higher relative water content in seedlings irrigated with moderately saline water. From the results, we conclude that Ca-complex sources have potential as modulators of moderately saline water stress in sour passion fruit seedlings. Full article