摘要
A circular DNA molecule, designated as DNAp, was identified in tobacco plants infected with Tobacco leaf curl virus (TLCV) isolates Y5 and Y8 by PCR using primers based on the conserved region of the two reported DNAp sequences of whitefly-transmitted geminiviruses (WTGs). The complete nucleotide sequences of DNAβ of Y5 and Y8 (TLCV DNAβ) were determined. Y5 DNAβ comprises 1333 nucleotides encoding 8 predicted ORFs with 4 ORFs in virion-sense DNA and 4 ORFs in complementary-sense DNA; Y8 DNAP consists of 1338 nucleotides encoding 7 predicted ORFs with 4 ORFs in virion-sense DNA and 3 ORFs in complementary-sense DNA. TLCV DNAβhas little sequence homology to DNA-A of TLCV, except that it shares conserved TAATATTAC loop sequence with TLCV DNA-A. Sequence comparison showed that Y5 DNAβ shared 85% sequence homology with Y8 DNAβ, and both Y5 DNAβ and Y8 DNAβ had relatively low sequence identity (51%-65%) with the reported DNAβ molecules associated with Agera-tum yellow vein virus and Cotton leaf
A circular DNA molecule, designated as DNAβ, was identified in tobacco plants infected with Tobacco leaf curl virus (TLCV) isolates Y5 and Y8 by PCR using primers based on the conserved region of the two reported DNAβ sequences of whitefly-transmitted geminiviruses (WTGs). The complete nucleotide sequences of DNAβ of Y5 and Y8 (TLCV DNAβ) were determined. Y5 DNAβ comprises 1333 nucleotides encoding 8 predicted ORFs with 4 ORFs in virion-sense DNA and 4 ORFs in complementary-sense DNA; Y8 DNAβ consists of 1338 nucleotides encoding 7 predicted ORFs with 4 ORFs in virion-sense DNA and 3 ORFs in complementary-sense DNA. TLCV DNAβ has little sequence homology to DNA-A of TLCV., except that it shares conserved TAATATTAC loop sequence with TLCV DNA-A. Sequence comparison showed that Y5 DNAβ shared 85% sequence homology with Y8 DNAβ, and both Y5 DNAβ and Y8 DNAβ had relatively low sequence identity (51%–65%) with the reported DNAβ molecules associated with Ageratum yellow vein virus and Cotton leaf curl virus. The immunotrapping PCR and whitefly transmission tests showed that DNAβ molecule could be encapsidated in virus particle and transmitted by Bemisia tabaci. This is the first report of DNAβ associated with WTGs in China.
基金
This work was partially supported by the National Outstanding Youth Foundation (Grant No.30125032)
the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE
also by the National Natural Science F
