BIOLISTIC TRANSFER OF HOP VIROID DISEASE SYNDROME FROM SLOVENIAN CULTIVAR ‘CELEIA’ TO CZECH HOP ‘OSVALD’S 72’: PATHOGENESIS SYMPTOMS AND IDENTIFICATION OF DOMINANT SEQUENCE UPON TRANSFER OF HPSVD COMPONENT

A viroid disease syndrome that was recently described on Slovenian cultivar ‘Celeia’ was investigated.
The disease was transferred using biolistic approach to Czech hop under isolated experimental conditions.
A complex of strong symptoms appeared on cultivar ‘Osvald’s 72’ that was quite comparable to cultivar ‘Celeia’; low plant fitness strong stunting, leaf malformation, small (tiny) leaves and frequently visible leaf mosaic, which was not associated with virus infection. Hop stunt viroid (HpSVd) was analyzed in detail in the inoculated Czech hop that survived initial infection.
It was confirmed that a population of viroid was detectable in the leaves with a clearly dominant HpSVd-cucumber pale fruit viroid-like (HpSVd-cuc) sequence.
Besides HpSVd, also traces of truncated Citrus viroid (CVd IV) were detected in surviving biolistically infected hop samples.
In some samples, HpSVd was detectable by Northern blots, but not by RT PCR, suggesting some viroid sequence change(s) upon adaptation in hop.
An expression of several pathogenesis-associated marker genes were investigated.
It was found that experimentally induced viroid syndrome in ‘Osvald’s 72’ led to gene deregulation and especially to strong depression of HlbHLH2 transcription factor participating in metabolome regulation in hop.

III International Humulus Symposium

J. Matousek, S. Radisek, J. Jakse, G.S. Duraisamy, K. Uhlírová, L. Orctová, P. Svoboda, J. Patzak, J. Rausche

viroid symptoms, biolistic, Pospiviroids, transcription factor, Humulus lupulus L., gene deregulation, Real Time quantitative RT-PCR

https://doi.org/10.17660/ActaHortic.2013.1010.14