BACKGROUND: Invertases (INVs) are key enzymes in sugar metabolism, cleaving sucrose into glucose and fructose and playing an important role in plant development and the stress response, however, the INV gene family in passion fruit has not been systematically reported.
RESULTS: In this study, a total of 16 PeINV genes were identified from the passion fruit genome and named according to their subcellular location and chromosome position. These include six cell wall invertase (CWINV) genes, two vacuolar invertase (VINV) genes, and eight neutral/alkaline invertase (N/AINV) genes. The gene structures, phylogenetic tree, and cis-acting elements of PeINV gene family were predicted using bioinformatics methods. Results showed that the upstream promoter region of the PeINV genes contained various response elements; particularly, PeVINV2, PeN/AINV3, PeN/AINV5, PeN/AINV6, PeN/AINV7, and PeN/AINV8 had more response elements. Additionally, the expression profiles of PeINV genes under different abiotic stresses (drought, salt, cold temperature, and high temperature) indicated that PeCWINV5, PeCWINV6, PeVINV1, PeVINV2, PeN/AINV2, PeN/AINV3, PeN/AINV6, and PeN/AINV7 responded significantly to these abiotic stresses, which was consistent with cis-acting element prediction results. Sucrose, glucose, and fructose are main soluble components in passion fruit pulp. The contents of total soluble sugar, hexoses, and sweetness index increased significantly at early stages during fruit ripening. Transcriptome data showed that with an increase in fruit development and maturity, the expression levels of PeCWINV2, PeCWINV5, and PeN/AINV3 exhibited an up-regulated trend, especially for PeCWINV5 which showed highest abundance, this correlated with the accumulation of soluble sugar and sweetness index. Transient overexpression results demonstrated that the contents of fructose, glucose and sucrose increased in the pulp of PeCWINV5 overexpressing fruit. It is speculated that this cell wall invertase gene, PeCWINV5, may play an important role in sucrose unloading and hexose accumulation.
CONCLUSIONS: In this study, we systematically identified INV genes in passion fruit for the first time and further investigated their physicochemical properties, evolution, and expression patterns. Furthermore, we screened out a key candidate gene involved in hexose accumulation. This study lays a foundation for further study on INV genes and will be beneficial on the genetic improvement of passion fruit breeding.

Mitoviruses are cryptic capsidless viruses belonging to the family Mitoviridae that replicate and are maintained in the mitochondria of fungi. Complete mitovirus-like sequences were recently assembled from plant transcriptome data and plant leaf tissue samples. Passion fruit (Passiflora spp.) is an economically important crop for numerous tropical and subtropical countries worldwide, and many virus-induced diseases impact its production. From a large-scale genomic study targeting viruses infecting Passiflora spp. in Brazil, we detected a de novo-assembled contig with similarity to other plant-associated mitoviruses. The contig is ∼2.6 kb long, with a single open reading frame (ORF) encoding an RNA-dependent RNA polymerase (RdRP). This contig has been named \"passion fruit mitovirus-like 1\" (PfMv1). An alignment of the predicted amino acid sequence of the RdRP of PfMv1 and those of other plant-associated mitoviruses revealed the presence of the six conserved motifs of mitovirus RdRPs. PfMv1 has 79% coverage and 50.14% identity to Humulus lupulus mitovirus 1. Phylogenetic analysis showed that PfMV1 clustered with other plant-associated mitoviruses in the genus Duamitovirus. Using RT-PCR, we detected a PfMv1-derived fragment, but no corresponding DNA was identified, thus excluding the possibility that this is an endogenized viral-like sequence. This is the first evidence of a replicating mitovirus associated with Passiflora edulis, and it should be classified as a member of a new species, for which we propose the name \"Duamitovirus passiflorae\".

East Asian Passiflora virus (EAPV) causes passionfruit woodiness disease, a major threat limiting passionfruit production in eastern Asia, including Taiwan and Vietnam. In this study, an infectious cDNA clone of a Taiwanese severe isolate EAPV-TW was tagged with a green fluorescent protein (GFP) reporter to monitor the virus in plants. Nicotiana benthamiana and yellow passionfruit plants inoculated with the construct showed typical symptoms of EAPV-TW. Based on our previous studies on pathogenicity determinants of potyviral HC-Pros, a deletion of six amino acids (d6) alone and its association with a point mutation (F8I, simplified as I8) were conducted in the N-terminal region of the HC-Pro gene of EAPV-TW to generate mutants of EAPV-d6 and EAPV-d6I8, respectively. The mutant EAPV-d6I8 caused infection without conspicuous symptoms in N. benthamiana and yellow passionfruit plants, while EAPV-d6 still induced slight leaf mottling. EAPV-d6I8 was stable after six passages under greenhouse conditions and displayed a zigzag pattern of virus accumulation, typical of a beneficial protective virus. The cross-protection effectiveness of EAPV-d6I8 was evaluated in both N. benthamiana and yellow passionfruit plants under greenhouse conditions. EAPV-d6I8 conferred complete cross-protection (100%) against the wild-type EAPV-TW-GFP in both N. benthamiana and yellow passionfruit plants, as verified by no severe symptoms, no fluorescent signals, and PCR-negative status for GFP. Furthermore, EAPV-d6I8 also provided complete protection against Vietnam\'s severe strain EAPV-GL1 in yellow passionfruit plants. Our results indicate that the attenuated mutant EAPV-d6I8 has great potential to control EAPV in Taiwan and Vietnam via cross-protection.

The Yellow passion fruit belongs to the Passifloraceae family with great economic, nutritional and social importance in Colombia. It presents a great phenotypic and genotypic diversity, which has not yet been explored or used in genetic improvement programs. The objective of this study was to evaluate the genetic diversity of 84 cultivars of Passiflora edulis f. flavicarpa from nine farms in the municipality of Miraflores, Boyacá, using eight microsatellite markers (SSR). On the basis of this information, estimates of genetic diversity parameters, molecular variance analysis (AMOVA), genetic distances, and cluster of cultivars were obtained. Low levels of genetic differentiation between cultivars were observed in the Bayesian analysis using Structure software, as well as the absence of correlation between genetic and geographic distances. The observed heterozygosity (0.50) was greater than the expected heterozygosity (0.43), suggesting a significant number of heterozygous individuals. The number of alleles per locus varied from 2 to 4, with a mean 2.88. In general, SSR were classified as informative (0.36). The average value of the Shannon Index was 0.71, which shows moderate variability in this cultivar. AMOVA showed higher diversity within cultivars (98%). The gene flow (Nm=28.4) was moderate, this can be explained by the flow of pollen between the different cultivars, the reproduction system of the species, self-incompatibility and the introduction of genotypes from other sites by farmers. The genetic diversity identified in this study is sufficient to initiate breeding programs aimed at identifying cultivars with higher yields.

BACKGROUND: Passiflora coriacea Juss., a medicinal plant in the family Passifloraceae, is widely used to treat anxiety and depression in Mexican folk medicine. However, its chemical profile and biological activity have not been characterized.
OBJECTIVE: The aim of the study was to determine the antidepressant activity, anxiolytic effect, and chemical profile of Passiflora coriacea.
METHODS: An organic fraction (PcEA) from a hydroalcoholic extract of the aerial parts of P. coriacea was obtained, followed by a chemical analysis and separation, yielding six fractions (PcEA, T1, T2, T1.1, T2.1, and T2.2). Male ICR mice were used to determine the antidepressant activity of selected treatments (PcEA, T1, T2, and T1.1) based on a forced swim test (FST). The anxiolytic-like effects of various treatments (PcEA, T1, T2, T2.1, and T2.2) were determined using the elevated plus maze (EPM) test.
RESULTS: The organic fraction of P. coriacea decreased anxiety-like behaviors in mice and increased the time of mobility in the FST. After chemical separation, two compounds were isolated from the species with antidepressant activity and anxiolytic-like effects, T1.1 (tricin 7-O-glucoside) and T2.2 (harmane), respectively.
CONCLUSIONS: Compounds isolated from P. coriacea exerted anxiolytic and antidepressant effects in mice based on the EPM and FST. The flavonoid tricin-7-O-glucoside and the alkaloid harmane contributed to these biological activities.

In this chapter, we report advances in tissue culture applied to Passiflora. We present reproducible protocols for somatic embryogenesis, endosperm-derived triploid production, and genetic transformation for such species knowledge generated by our research team and collaborators in the last 20 years. Our research group has pioneered the work on passion fruit somatic embryogenesis, and we directed efforts to characterize several aspects of this morphogenic pathway. Furthermore, we expanded the possibilities of understanding the molecular mechanism related to developmental phase transitions of Passiflora edulis Sims. and P. cincinnata Mast., and a transformation protocol is presented for the overexpression of microRNA156.

The HD-ZIP (homeodomain-leucine zipper) genes hold significant importance in transcriptional regulation, especially in plant development and responses to abiotic stresses. However, a comprehensive study targeting HD-ZIP family members in passion fruit has been absent. In our current research, 34 HD-ZIP family members (PeHBs) were identified by bioinformatics analysis. Transcriptome analysis revealed that PeHBs exhibited distinct expression patterns when subjected to the four different abiotic stresses, and significant differential expression of PeHBs was also found among the three developmental stages of the fruit and between the purple and yellow genotype passion fruit leaves. An integrated metabolome and transcriptome analysis further revealed that the HD-ZIP III class gene PeHB31 (homologous to ATHB8), was co-upexpressed with lignans in yellow fruit P. edulis (commonly used as a resistance rootstock) when compared to purple fruit P. edulis. The transformation of Arabidopsis and yeast with the PeHB31 gene showed an enhancement in their capacity to withstand drought conditions. Notably, the transgenic Arabidopsis plants exhibited an increase in lignin content within the vascular tissues of their stems. This research lays the groundwork for future studies on the control mechanisms of lignin biosynthesis by HD-ZIP genes (especially HD-ZIP classes III and I) involved in drought tolerance.

BACKGROUND: The calmodulin (CaM) and calmodulin-like (CML) proteins play regulatory roles in plant growth and development, responses to biotic and abiotic stresses, and other biological processes. As a popular fruit and ornamental crop, it is important to explore the regulatory mechanism of flower and fruit development of passion fruit.
RESULTS: In this study, 32 PeCaM/PeCML genes were identified from passion fruit genome and were divided into 9 groups based on phylogenetic analysis. The structural analysis, including conserved motifs, gene structure and homologous modeling, illustrates that the PeCaM/PeCML in the same subgroup have relative conserved structural features. Collinearity analysis suggested that the expansion of the CaM/CML gene family likely took place mainly by segmental duplication, and the whole genome replication events were closely related with the rapid expansion of the gene group. PeCaM/PeCMLs were potentially required for different floral tissues development. Significantly, PeCML26 had extremely high expression levels during ovule and fruit development compared with other PeCML genes, suggesting that PeCML26 had potential functions involved in the development of passion fruit flowers and fruits. The co-presence of various cis-elements associated with growth and development, hormone responsiveness, and stress responsiveness in the promoter regions of these PeCaM/PeCMLs might contribute to their diverse regulatory roles. Furthermore, PeCaM/PeCMLs were also induced by various abiotic stresses. This work provides a comprehensive understanding of the CaM/CML gene family and valuable clues for future studies on the function and evolution of CaM/CML genes in passion fruit.
CONCLUSIONS: A total of 32 PeCaM/PeCML genes were divided into 9 groups. The PeCaM/PeCML genes showed differential expression patterns in floral tissues at different development stages. It is worth noting that PeCML26, which is highly homologous to AtCaM2, not only interacts with multiple BBR-BPC TFs, but also has high expression levels during ovule and fruit development, suggesting that PeCML26 had potential functions involved in the development of passion fruit flowers and fruits. This research lays the foundation for future investigations and validation of the potential function of PeCaM/PeCML genes in the growth and development of passion fruit.

The genus Anastrepha contains some of the most important fruit pests in the Americas. It comprises more than 300 species, of which 129 occur in Brazil. The genus is divided into 26 species groups, including the pseudoparallela group with 31 species, whose known host plants are primarily fruits of the genus Passiflora (Passifloraceae). Fourteen species are recorded in Brazil. Here, a new species of Anastrepha reared from fruits of Passiflora actinia Hook. and Passiflora elegans Mast. from southern Brazil is described and illustrated. In addition, a synopsis of the Brazilian species of the pseudoparallela group is provided.

Passion fruits are highly perishable during postharvest storage and transportation, prompting the exploration of natural preservatives. This study investigates the synergistic effects of Aloe vera (ALV) and tea polyphenols (TP) coatings on quality retention, ripening modulation, and associated regulatory mechanisms in stored \"golden\" passion fruit (Passiflora spp.) at 10 °C. The application of a composite coating comprising 40 % ALV and 0.1 g/L TP led to notable improvements in fruit preservation over a 28-day storage period. At the day of 28, quantitatively, the ALV + TP treatment reduced weight loss by 41.60 %, shrinkage index by 28.13 %, and decay index by 50 %, significantly outperforming the control and individual treatments; the treated fruits exhibited enhanced firmness, reduced ethylene production, and the respiration peak was delayed about 6 days. Metabolomic analysis revealed pronounced alterations in key metabolic pathways, notably phenylpropanoid and flavonoid biosynthesis. Specifically, significant increases in metabolites such as phenolic acids (Feruloylmalic acid and Acropyrone) and flavonoids (Okanin-4\'-O-glucoside, Apigenin-8-C-Arabinoside, Quercetin-3-O- (2\'-O-galloyl) galactoside, and Catechin callate) were observed. Concurrently, transcript levels of key biosynthetic genes including cinnamate 4-hydroxylase (PeC4H), 4-coumarate-coenzyme a ligase (PeC4L), hydroxycinnamoyl transferase (PeHCT) and flavonol synthase (PeFLS) were significantly up-regulated by ALV + TP coating, indicating a robust activation of these pathways. The findings underscore the effectiveness of the ALV + TP composite coating as an environmentally friendly strategy for enhancing postharvest quality by promoting the accumulation of beneficial phenolic acids and flavonoids in passion fruits.