On Abiotic Stress Response-related PoMYB96 in Paeonia ostii

Objective PoMYB96 related to the response to abiotic stresses of Paeonia ostii was cloned to analyze the roles it played in regulating growth of the plant.

Method The R2R3-MYB transcription factor PoMYB96 that regulates the response of tree peony (P. ostii Fengdan) to high or low temperature, drought, and salinity stresses, which can severely hinder the normal growth of the plant, was cloned using RT-PCR. Sequence and encoded protein of the gene were analyzed. An evolutionary tree was constructed between PoMYB96 and MYB family members from Arabidopsis thaliana. Expressions of the gene in the leaves under high and low temperatures, draught, flooding, and high salinity were determined by qRT-PCR.

Result The full-length cDNA sequence of PoMYB96 was 984bp encoding 327 amino acids. The protein contained two conserved SANT domains and shared the highest homology with AtMYB96 of A. thaliana. Its promoter region harbored anaerobic-, salicylic acid-, and light-responsive elements, as well as hormone-responsive elements for ABA, gibberellin, and jasmonic acid. The gene was expressed in the roots, stems, leaves, flowers, stamens, and pistils, with the highest level observed in the leaves. Its relative expression was significantly upregulated under low or high temperature, drought, waterlogging, and salt stress.

Conclusion PoMYB96 participated in the response of tree peony to abiotic stresses and could be a candidate marker for molecular breeding selection.