ABSTRACT
Papaya ringspot virus (PRSV) severely affects the global papaya industry. Transgenic papaya has been proven to have effective resistance to PRSV isolates from Hawaii, Thailand, Taiwan, and other countries. However, those transgenic cultivars failed to show resistance to Hainan Island isolates. Some 76 PRSV samples, representative of all traditional papaya planting areas across five cities (Wen Chang, n = 13; Cheng Mai, n = 14; Chang Jiang, n = 11; Le Dong, n = 25; and San Ya, n = 13) within Hainan Province, were investigated. Results revealed three genetic diversity groups (Hainan I, II, and III) that correlated with geographical distribution. Frequent mutations among PRSV isolates from Hainan were also observed. The high genetic divergence in PRSV isolates from Hainan is likely to be the cause of the failure of genetically modified papaya that targets sequence-specific virus.
Subject(s)
Carica/virology , Genetic Variation , Plant Diseases/virology , Potyvirus/genetics , China , PhylogenyABSTRACT
A specific technique capable of producing high-quality RNA for rapid amplification of cDNA ends (RACE) was established for challenging tissues: leaves of the rubber tree. Total RNA was extracted by cetyltrimethylammonium bromide (CTAB)-LiCl combined with TRIzol reagent. The isolated RNA was highly intact. With RNA as template, full-length cDNA was obtained (NCBI, AY461413) by RACE.
Subject(s)
Hevea/chemistry , Plant Leaves/chemistry , RNA, Plant/isolation & purification , Cetrimonium , Cetrimonium Compounds/chemistry , DNA, Complementary/genetics , Databases, Genetic , Electrophoresis, Agar Gel , Guanidines/chemistry , Hevea/genetics , Lithium Chloride/chemistry , Nucleic Acid Amplification Techniques , Phenols/chemistry , Plant Leaves/genetics , RNA, Plant/geneticsABSTRACT
Three new compounds, 2-methyl-2,5,6-bornantriol (1), 4,4'-(3-hydroxypropane-1,1-diyl)diphenol (2), and 7-(4-methoxybenzyl)-4,5,6,7-tetrahydro-1,3-oxazepine-5,6-diol (3), were isolated from the fermentation broth of the soil actinomycete Streptomyces albospinus 15-4-2. Their structures were completely elucidated using the combination of 1D, 2D NMR techniques (COSY, HMQC, HMBC, and ROESY), and HR-ESI-MS analysis. None of the compounds 1-3 showed any inhibitory effect on Fusarium oxysporum f.sp. cubense race 4.