Molecular cloning and expression profile of an abiotic stress and hormone responsive MYB transcription factor gene from Panax ginseng

The v-myb avian myeloblastosis viral oncogene homolog （MYB） family constitutes one of the most abundant groups of transcription factors and plays vital roles in developmental processes and defense responses in plants. A ginseng （Panax ginseng C.A. Meyer） MYB gene was cloned and de- signated as PgMYB1. The cDNA of PgMYB1 is 762 base pairs long and encodes the R2R3-type pro- tein consisting 238 amino acids. Subcellular localization showed that PgMYBI-mGFP5 fusion protein was specifically localized in the nucleus. To understand the functional roles of PgMYBI, we investi- gated the expression patterns of PgMYB1 in different tissues and under various conditions. Quanti- tative real-time polymerase chain reaction and western blot analysis showed that PgMYB1 was expressed at higher level in roots, leaves, and lateral roots than in stems and seeds. The expression of PgMYB1 was up-regulated by abscisic acid, salicylic acid, NaCI, and cold （chilling）, and down- regulated by methyl jasmonate. These results suggest that PgMYB 1 might be involved in responding to environmental stresses and hormones.