Sequence‐specific hypomethylation of the tobacco genome induced with dihydroxypropyladenine, ethionine and 5‐azacytidine

FEBS Letters

Holý, A.²  Koukalová, B.¹  Kovav̌ík, A.¹  Bezdĕk, M.¹ 

[1] Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic;Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 150 00 Prague, Czech Republic

关键词: DNA methylation inhibitor;    CG and CNG DNA sequence;    Nicotiana tabacum;   

DOI  :  10.1016/0014-5793(94)01048-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Higher plant DNA is methylated at CG and CNG targets. In this study we have investigated the tobacco methylation system in tissue culture using the methylation inhibitors 5-azacytidine (5-azaC), dihydroxypropyladenine (DHPA) and ethionine (Ethi), and methylation-sensitive restriction endonucleases HpaII, MspI, HhaI, EcoRII, ScrFI, and Fnu4HI. Surprisingly, CAG/CTG sequences, contrary to CG doublets and CCG/CGG triplets, appeared to be refractory to the inhibitory effect of 5-azaC. Thus 5-azaC cannot be considered a general inhibitor of DNA methylation in tobacco cells. On the other hand, DHPA, the inhibitor of S-adenosylhomocysteine (SAH) hydrolase, and Ethi caused hypomethylation of both CAG/CTG and CCG/CGG triplets but not of the CG doublets. The sensitivity of triplet-specific methylation to the inhibition of SAH hydrolase suggests the possibility that plant-specific DNA methylation at CNG targets might be modulated by alterations of the SAH/S-Adenosyhnethionine ratio in plant cells.

【 授权许可】

Unknown