Responses of Passiflora spp. to cowpea aphid-borne mosaic virus reveal infection in asymptomatic plants and new species with probable immunity.

Passion fruit woodiness disease (PWD), caused by cowpea aphid-borne mosaic virus (CABMV), produces socioeconomic problems in Brazil. The objectives of this study were to i) evaluate the temporal progression of PWD, ii) identify Passiflora genotypes with resistance to CABMV, and iii) detect virus infection in asymptomatic plants by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in cases where standard RT-PCR detection failed. The experiment was conducted in a greenhouse using 128 genotypes belonging to 12 species and three hybrids (inter- and intraspecific) of Passiflora, evaluated at five time points after inoculation. Progression rates and disease severity were lower in P. cincinnata, P. gibertii, P. miersii, and P. mucronata than in P. edulis, P. alata, Passiflora sp., and hybrids. Of the genotypes tested, 20.31% were resistant, especially the accessions of P. suberosa, P. malacophylla, P. setacea, P. pohlii, and P. bahiensis, which remained asymptomatic throughout the experiment. The absence of symptoms does not imply immunity of plants to the virus, since RT-qPCR analysis confirmed infection by the virus in asymptomatic plants of P. cincinnata, P. gibertii, P. miersii, P. mucronata, P. setacea, P. malacophylla, and P. suberosa. Even after four inoculations, the virus was not detected by RT-qPCR in the upper leaves in plants of the species P. pohlii and P. bahiensis, indicating that these species are probably immune to CABMV.

Aqueous leaf extract of Passiflora alata Curtis promotes antioxidant and anti-inflammatory effects and consequently preservation of NOD mice beta cells (non-obese diabetic).

Passiflora alata Curtis (P. alata) leaves have anti-inflammatory properties; the present study aimed to investigate the anti-diabetogenic properties of P. alata aqueous leaf extract. HPLC analysis identified the phenolic compounds catechin, epicatechin and rutin. The aqueous extract was administered for 30weeks to non-obese diabetic (NOD) mice presenting a decrease of 28.6% in diabetes incidence and the number of inflammatory cells in pancreatic islets, when compared with the control group (water). The P. alata group presented an antioxidant effect and decreased lipid peroxidation in the serum of NOD mice. Increased numbers of insulin-positive cells were also observed in the pancreatic islets of the treated group. The diabetic group exhibited higher levels in the glucose tolerance test and glycemic index, in comparison to the P. alata-treated group and non-diabetic control BALB/c mice. In addition, the P. alata extract reduced the percentage and the proliferation index of NOD mice lymphocytes submitted to in vitro dose/response mitogenic stimulation assays. These results suggest that the aqueous extract of P. alata has anti-inflammatory properties, contributing to the protection of beta cells in pancreatic islets in NOD mice, and presents potential for use a supporting approach to treat type 1 diabetes.

Antioxidant and anti-diabetic potential of Passiflora alata Curtis aqueous leaves extract in type 1 diabetes mellitus (NOD-mice).

Leaves of Passiflora alata Curtis were characterized for their antioxidant capacity. Antioxidant analyses of DPPH, FRAP, ABTS, ORAC and phenolic compounds were made in three different extracts: aqueous, methanol/acetone and ethanol. Aqueous extract was found to be the best solvent for recovery of phenolic compounds and antioxidant activity, when compared with methanol/acetone and ethanol. To study the anti-inflammatory properties of this extract in experimental type 1 diabetes, NOD mice were divided into two groups: the P. alata group, treated with aqueous extract of P. alata Curtis, and a non-treated control group, followed by diabetes expression analysis. The consumption of aqueous extract and water ad libitum lasted 28 weeks. The treated-group presented a decrease in diabetes incidence, a low quantity of infiltrative cells in pancreatic islets and increased glutathione in the kidney and liver (p<0.05), when compared with the diabetic and non-diabetic control-groups. In conclusion, our results suggest that the consumption of aqueous extract of P. alata may be considered a good source of natural antioxidants and compounds found in its composition can act as anti-inflammatory agents, helping in the control of diabetes.

Molecular investigations of pathogenesis-related Bet v 1 homologues in Passiflora (Passifloraceae).

The major birch pollen allergen, Bet v 1, responsible for allergic reactions in many areas of the world, is homologous to a large number of pathogenesis-related proteins (PRs), identified as PR10. As part of a long-range investigation of these types of proteins and of evolution in Passiflora, DNA sequences from eight Bet v 1 homologue isoforms were obtained from five species of this genus in Brazil, and their sequences compared among themselves and with 30 others from 8 different species, classified in different taxonomic units. The objective was a first characterization of these PRs in wild passionflowers, and their use for evolutionary and applied investigations. High interspecific, but low intraspecific variability was observed, as expected from multigenic families subjected to concerted evolution. The relationships obtained both within Passiflora and between it and seven other genera probably best reflect functional similarities than evolutionary history.