A survey of begomoviruses infecting leguminous weeds (family Fabaceae) was carried out in four states of northeastern Brazil. A total of 26 full-length begomovirus components (19 DNA-A and seven DNA-B, with three pairs of cognate A and B components) were amplified using rolling-circle amplification, then cloned and sequenced. Sequence analysis indicated the presence of six species, four of them novel. In phylogenetic analysis five of the viruses clustered with other Brazilian begomoviruses, but one of them (Euphorbia yellow mosaic virus, EuYMV) clustered with viruses from other countries in Central and South America. Evidence of recombination was found among isolates of Macroptilium yellow spot virus (MaYSV). The MaYSV population had a high degree of genetic variability. Macroptilium lathyroides was revealed as a common host for several of these viruses, and could act as a mixing vessel from which recombinant viruses could emerge. The results indicate that leguminous weeds are reservoirs of several begomoviruses in Brazil, and could play a significant role in begomovirus epidemics, both as inoculum sources and as sources of emerging novel viruses.

Leaf samples of yellow passionfruit (Passiflora edulis f. flavicarpa) displaying fruit woodiness symptoms were collected in seven Brazilian states and the Federal District. Viral infection was confirmed by host range and ELISA, and fourteen viral isolates were obtained. All isolates were capable of infecting several leguminous host species, although differences in symptom severity were noticeable. Woodiness symptoms were reproduced in yellow passionfruit, and mosaic symptoms were induced in common bean. All isolates infected cowpea, reported as a non-host of passion fruit woodiness virus (PWV). Indirect ELISA demonstrated that all isolates were serologically related to each other and also to cowpea aphid-borne mosaic virus (CABMV). The complete sequence of the capsid protein was determined for all isolates. Comparison of these sequences with those of other potyviruses indicated the highest identity with CABMV isolates (85 to 94%). Identity with PWV isolates ranged from 54 to 70%. Phylogenetic analysis grouped all of the Brazilian isolates in a monophyletic cluster with the CABMV isolates, clearly distinct from the PWV isolates. Furthermore, this analysis demonstrated that a group of previously characterized isolates from Brazil that had been designated as PWV should be reclassified as CABMV. Together, these results provide unequivocal evidence that, in Brazil, passionfruit woodiness disease is primarily caused by CABMV. The presence of PWV in Brazil has yet to be confirmed.

Severely stunted cowpea plants have been found in similar to those observed on field plants. When inoculated Georgia fields in each of the last 4 yr, 1974 to 1977. Leaves of singly, each virus caused a relatively mild disease; leaves had the stunted plants were small, mottled, blistered, and a mild mottle, and plants displayed moderate stunting during malformed. The causal agent was sap-transmitted to the early infection period and almost no stunting at cowpeas. Several other hosts were susceptible and back senescence. In a greenhouse study, CMV reduced yield of inoculation from Cucumis sativus and Cassia obtusifolia to California Blackeye seed by 14.2% and BICMV by 2.5%. cowpeas established the presence of two viruses: cucumber Yield on doubly infected plants, however, was reduced mosaic virus (CMV) from C. sativus and a potyvirus, later 86.4%. Furthermore, the double infection reduced leaf identified as blackeye cowpea mosaic virus (BICMV), from weight, stem weight, and root weight by 94.3, 89.3, and C. obtusifolia. When seedlings of California Blackeye 87.3%, respectively. Seed and aphid transmission studies cowpeas were inoculated simultaneously with CMV and showed that the viruses can be transmitted from doubly-BICMV, a strong synergistic reaction occurred; the primary infected plants to cause single or double infections in and first two trifoliolate leaves became necrotic within 5-10 cowpeas. The name cowpea stunt is proposed for the disease days and usually abscised. Subsequent leaves were severely caused by the synergistic interaction of CMV and BICMV. diseased but free of the necrosis; the symptoms then appeared

Thaumatin-like proteins (TLPs) are a highly complex protein family associated with host defense and developmental processes in plants, animals, and fungi. They are highly diverse in angiosperms, for which they are classified as the PR-5 (Pathogenesis-Related-5) protein family. In plants, TLPs have a variety of properties associated with their structural diversity. They are mostly associated with responses to biotic stresses, in addition to some predicted activities under drought and osmotic stresses. The present review covers aspects related to the structure, evolution, gene expression, and biotechnological potential of TLPs. The efficiency of the discovery of new TLPs is below its potential, considering the availability of omics data. Furthermore, we present an exemplary bioinformatics annotation procedure that was applied to cowpea (Vigna unguiculata) transcriptome, including libraries of two tissues (root and leaf), and two stress types (biotic/abiotic) generated using different sequencing approaches. Even without using genomic sequences, the pipeline uncovered 56 TLP candidates in both tissues and stresses. Interestingly, abiotic stress (root dehydration) was associated with a high number of modulated TLP isoforms. The nomenclature used so far for TLPs was also evaluated, considering TLP structure and possible functions identified to date. It is clear that plant TLPs are promising candidates for breeding purposes and for plant transformation aiming a better performance under biotic and abiotic stresses. The development of new therapeutic drugs against human fungal pathogens also deserves attention. Despite that, applications derived from TLP molecules are still below their potential, as it is evident in our review.

RESUMOAs viroses constituem o principal grupo de doenças do mamoeiro (Carica papaya), ocasionando grandes perdas na produção, podendo chegar à destruição total das plantações afetadas. Embora mais de dez vírus tenham sido constatados infetando naturalmente o mamoeiro, em todo o mundo, no Brasil, até o presente, foram assinaladas apenas as ocorrências do vírus da mancha anelar do mamoeiro (Papaya ringspot virus, PRSV), do vírus do amarelo letal do mamoeiro (Papaya lethal yellowing virus, PLYV) e do vírus da meleira que se encontra em fase de caracterização. A mancha anelar causada pelo PRSV é, inquestionavelmente, o mais importante problema sanitário do mamoeiro. O controle do PRSV mostra-se imprescindível, apesar de bastante difícil, em razão da sua forma de disseminação rápida e eficiente por diversas espécies de afídeos e ausência de resistência genética em C. papaya. Na tentativa de controlar o PRSV, várias medidas já foram testadas, não existindo, até o momento, nenhuma estratégia eficiente e duradoura para seu controle no Brasil. O desenvolvimento de plantas transgênicas de mamoeiro expressando o gene da capa protéica (cp) do PRSV, imunes ao mesmo, abriu nova possibilidade para solução do problema.Palavras-chave adicionais: mancha anelar, amarelo letal, meleira, Papaya lethal yellowing virus, Papaya ringspot virus, plantas transgênicas. ABSTRACT Etiology and control strategies of papaya virus diseases in Brazil