Passiflora edulis, commonly known as passion fruit, is a vine species of passionflower native to South America. In Colombia, yellow passion fruit (P. edulis f. flavicarpa) is the most important species in terms of net production and local consumption. Recently two brevipalpus transmitted cileviruses, (i) passion fruit green spot virus (PfGSV) and (ii) hibiscus strain of citrus leprosis virus C2 (CiLV-C2H) were detected in passion fruit in Brazil and Hawaii, respectively (Ramos-González et al., 2020, Olmedo-Velarde et al., 2022). CiLV-C2H infects both citrus and hibiscus in Colombia (Roy et al., 2015, 2018) but there was no report of PfGSV elsewhere apart from Brazil and Paraguay (Costa-Rodrigues et al., 2022). Apart from emerging begomovirus diseases, five major viruses are known to infect passion fruit in Colombia: soybean mosaic virus (SMV), cowpea aphid-borne mosaic virus, passion fruit yellow mosaic virus, cucumber mosaic virus, and a tentative Gulupa bacilliform badnavirus A (Cardona et al., 2022). Current findings of CiLV-C2H in passion fruit and PfGSV in hibiscus motivated us to investigate the possibilities of cilevirus infection in passion fruit in Colombia. During surveys, along with healthy yellow passion fruit leaves, five symptomatic plant samples from Meta and three from Casanare were collected before sent to the Molecular Plant Pathology Laboratory at Beltsville, MD under APHIS permit. Passion fruit samples from Meta showed leaf mottling, rugose mosaic, and leaf distortion, whereas leaf variegation, chlorotic spots, yellowing, green spots in senescent leaves and green vein banding were observed in the Casanare samples (Supp. Fig. 1). Total RNA was extracted using RNeasy Plant Mini Kit (Qiagen, USA). To know the potential cilevirus infection in these samples, three PfGSV specific (Ramos-González et al. 2020) and a CiLV-C2 generic primer pairs (Olmedo-Velarde et al. 2021) were used in the RT-PCR assays. All five passion fruit samples from Meta failed to produce either CiLV-C2 or CiLV-C2H or PfGSV amplicon whereas all three Casanare samples successfully amplified 321, 244 and 299 nts of PfGSV-RNA1 and -RNA2 amplicons using C13F/C13R, C6F/C6R and C8F/C8R primers, respectively. Bi-directional amplicon sequencing followed by BlastN analysis revealed ≥99% nt identity with the PfGSV-RNA1 (MK804173) and -RNA2 (MK804174) genome sequences. An optimized ribo-depleted library preparation protocol was utilized to prepare two cDNA libraries using the RNA extracts of a PfGSV suspected positive (Casanare) and a negative (Meta) samples (Chellappan et al., 2022). HTS libraries of Casanare and Meta samples resulted in 22.7 to 29.5 million raw reads, respectively. After adapter trimming and filtering, clean reads were mapped to the Arabidopsis thaliana reference genome and unmapped reads were de novo assembled (Chellappan et al., 2022). BlastN analysis from the assembled contigs identified 1-3 contigs corresponding to PfGSV-RNA1 and -RNA2, respectively, from Casanare sample whereas 3 contigs of SMV were identified in Meta passion fruit sample. No other virus sequence was obtained from either of the libraries. Assembled contigs covered 99.33% of the RNA1 and 94.42% of the RNA2 genome, with read depths of 64,474 and 119,549, respectively. Meta sample contigs (OP564897) covered >99% of the SMV genome, which shared >99% nt identity with the Colombian SMV isolates (KY249378, MW655827). Both RNA-1 (OP564895) and -2 (OP564896) segments of the Casanare isolate shared 99% nt identity with PfGSV isolate (MK804173-74). Our discovery identified PfGSV in Colombia, for the first-time outside Brazil and Paraguay. The findings of PfGSV in yellow passion fruit increases the potential threat and possibility of PfGSV movement via Brevipalpus sp. from passion fruit to other hosts.
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May 21, 2024
Neemias Da Silva Santos + 5
Open Access