R2R3型MYB转录因子HbMYB88结构和功能分析

Structural and Functional Analysis of R2R3 MYB Transcription Factor HbMYB88

R2R3-MYB转录因子参与植物生长发育、激素信号传导和逆境响应等生物过程。为了揭示橡胶树MYB家族成员结构与功能,从橡胶树热研73397(RY73397)叶片中克隆HbMYB88的cDNA全长。该基因长为1848 bp,含1440 bp的ORF,编码479个氨基酸。HbMYB88蛋白序列包含2个SANT保守结构域,存在HTH三级结构,与拟南芥AtMYB88、AtMYB124具有高度相似性。AtMYB88、AtMYB124与干旱等逆境相关且未划分亚族。qRT-PCR分析发现HbMYB88在橡胶树茎和花中表达量高,在根、叶片、树皮和胶乳中表达量极低。热研73397组培苗叶片喷施过氧化氢(H 2O 2)和脱落酸(ABA)等处理后,HbMYB88表达量受诱导显著上调表达。表明HbMYB88与橡胶树抗旱等逆境反应有关,为深入研究其结构和功能打下基础。

The R2R3-MYB transcription factors are involved in biological processes,such as plant growth and development,hormone signaling transduction,and stress response,etc.To explore the structure and functions of the MYB family members in the rubber tree,we cloned the full-length cDNA of HbMYB88 from the leave of rubber tree Reyan 73397(RY73397).It is 1848 bp in length,containing a 1440 bp ORF which encodes 479 amino acid residues.The deduced amino acid sequence of HbMYB88 contains two SANT conserved domains,has HTH tertiary structure,share highly similarity to Arabidopsis AtMYB88,AtMYB124.AtMYB88 and AtMYB124,not divided into subfamilies,are related to drought stress response,etc.By qRT-PCR analysis,HbMYB88 was mainly expressed in the stem and flower of rubber tree,whilst its expressions in root,leaf,bark and latex were extremely low.The expression level of HbMYB88 in tissue culture seedling leave was significantly upregulated under the treatment of hydrogen peroxide(H 2O 2),and abscisic acid(ABA).These indicated that HbMYB88 has a relationship with stress response such as drought in rubber trees,which providing a foundation for further study of its structure and function.