Serological and Molecular Studies of a Novel Virus Isolate Causing Yellow Mosaic of Patchouli [Pogostemon cablin (Blanco) Benth]

Abstract

Here we have identified and characterized a devastating virus capable of inducing yellow mosaic on the leaves of Patchouli [Pogostemon cablin (Blanco) Benth]. The diagnostic tools used were host range, transmission studies, cytopathology, electron microscopy, serology and partial coat protein (CP) gene sequencing. Evidence from biological, serological and sequence data suggested that the causal virus belonged to genus Potyvirus, family Potyviridae. The isolate, designated as Patchouli Yellow Mosaic Virus (PaYMV), was transmitted through grafting, sap and the insect Myzus persicae (Sulz.). Flexuous rod shaped particles with a mean length of 800 nm were consistently observed in leaf-dip preparations from natural as well as alternate hosts, and in purified preparation. Cytoplasmic cylindrical inclusions, pinwheels and laminar aggregates were observed in ultra-thin sections of infected patchouli leaves. The purified capsid protein has a relative mass of 43 kDa. Polyclonal antibodies were raised in rabbits against the coat protein separated on SDS – PAGE; which were used in ELISA and western blotting. Using specific antibodies in ELISA, PaYMV was frequently detected at patchouli plantations at Lucknow and Bengaluru. Potyvirus-specific degenerate primer pair (U335 and D335) had consistently amplified partial CP gene from crude preparations of infected tissues by reverse transcription polymerase chain reaction (RT-PCR). Comparison of the PCR product sequence (290 bp) with the corresponding regions of established potyviruses showed 78–82% and 91–95% sequence similarity at the nucleotide and amino acid levels, respectively. The results clearly established that the virus under study has close homology with watermelon mosaic virus (WMV) in the coat protein region and therefore could share a common ancestor family. Further studies are required to authenticate the identity of PaYMV as a distinct virus or as an isolate of WMV.

Progressive Regulation of Sesquiterpene Biosynthesis in Arabidopsis and Patchouli (Pogostemon cablin) by the miR156-Targeted SPL Transcription Factors

“…For example, the major sesquiterpene of Arabidopsis floral volatiles, (E)-b-caryophyllene, is active in directly inhibiting bacterial growth on the sigma (Huang et al, 2012). Although to date there have been no comprehensive investigations on the role of patchoulol in plant biotic or abiotic defense, it could serve as an antimicrobial reagent and insect deterrent (Wu et al, 2006;Zaim et al, 2013). In any case, the involvement of miR156-SPLs in regulating the developmental biosynthesis of terpenoid confers much to the successful reproduction of the plant population (Wu et al, 2006;Huang et al, 2012;Zaim et al, 2013).…”

Pengamatan OPT Penting Tanaman Nilam

“…Minyak nilam adalah salah satu sumber devisa negara di mana Indonesia adalah pengekspor terbesar minyak nilam di dunia. Indonesia menyumbang lebih dari 80% dari perkiraan produksi tahunan dunia dan sampai tahun 1996 merupakan penghasil dan pengekspor utama minyak nilam (Zaim et al, 2013). Propinsi Sumatera Utara merupakan salah satu daerah penghasil nilam terbesar di Indonesia.…”

IDENTIFIKASI MOLEKULER CUCUMBER MOSAIC VIRUS (CMV) ASAL TANAMAN NILAM (Pogostemon cablin) / Molecular Identification of Cucumber Mosaic Virus Infecting Patchouli (Pogostemon cablin)

“…CMV pada tanaman nilam baru ditemukan di Indonesia. Di luar negeri, virus yang menginfeksi tanaman nilam adalah dari genus Potyvirus (Natsuaki et al 1994;Singh et al 2009;Zaim et al 2013), Fabavirus (Natsuaki et al 1994) dan Potexvirus (Filho et al 2002). Hasil penelitian ini merupakan laporan pertama karakterisasi molekuler CMV asal nilam, baik di Indonesia maupun di luar negeri.…”