|HAN, SANG-HYUK - Chungnam National University|
|PARK, JONG-SEO - Chungnam National University|
|HAN, JAE-YEONG - Chungnam National University|
|GONG, JUN-SU - Chungnam National University|
|PARK, CHAN-HWAN - Chungnam National University|
|KIM, JUNG-KYU - Chungnam National University|
|SEO, EUN-YOUNG - Chungnam National University|
|LIM, HYOUN-SUB - Chungnam National University|
Submitted to: Virus Genes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2017
Publication Date: 2/1/2017
Citation: Han, S., Park, J., Han, J., Gong, J., Park, C., Kim, J., Seo, E., Domier, L.L., Hammond, J., Lim, H. 2017. New Korean isolates of Pepper mild mottle virus (PMMoV) differ in symptom severity, seed yield in pepper, and subcellular localization of the 126 kDa protein. Virus Genes. 53:434-445.
Interpretive Summary: Plant virus infections impose significant constraints on crop productivity. Seed-transmitted viruses pose great threats because they can spread readily into new regions and lead to subsequent increased crop losses. Pepper mild mottle virus (PMMoV) causes major losses of productivity in peppers in Korea and the United States, but seed treatments are generally ineffective to control the disease. Two new Korean isolates of PMMoV were selected from a Korea-wide survey of pepper crops, and studies were conducted to examine molecular and biological differences between them. The isolates caused different symptoms in a test host plant. One isolate resulted in both reduced seed production in pepper and reduced seedling growth rate. These biological differences and associated molecular differences will be useful to identify differences in seed transmissibility, in gaining further understanding and possible methods of reducing seed transmission in peppers, and in screening for resistance to PMMoV in the pepper crop.
Technical Abstract: Two isolates of Pepper mild mottle virus (PMMoV) were selected from a nationwide survey of pepper fields in South Korea in 2014 and 2015, in which Cucumber mosaic virus was also detected; the two PMMoV isolates, Sangcheong 47 (S-47, KX399390) and Jeongsong 76 (J-76, KX399389), share ~99% nucleotide and amino acid identity and are closely related to Japanese and Chinese isolates at the nucleotide level. Amino acid sequence comparisons revealed 99.73%, 99.81%, 98.44%, and 100% identity in the ORF1, ORF2, MP, and CP respectively between S-47 and J-76. In addition, we generated infectious clones of S-47 and J-76, and T7 promoter driven transcripts of each inoculated to Nicotiana benthamiana produced very severe symptoms, whereas only mild symptoms developed in Capsicum annuum. The two isolates differed in effects on seed production in C. annuum, which might be the result of the nearly 13-fold higher accumulation of viral RNA of J-76 than S-47. Gene silencing suppressor function of 126 kDa and cytoskeleton connected plasmodesmata localization of movement protein of S-47 and J-76 showed no difference between isolates, whereas 126 kDa of J-76 clearly formed intracellular aggregates not observed with S-47 126 kDa protein. Differences between these isolates in 126 kDa/183 kDa related functions including replication level and subcellular localization suggest that variation in replication efficiency or differential interactions with host proteins may affect seed production and symptom development in C. annuum.