Expression of ethylene response factors (ERFs) From Betula platyphylla and the confer salt and drought tolerance analysis in a yeast

Ethylene response factors (ERFs) are plant-specific transcription factors that function as multiple regulators in various stress-responsive pathways. In the current study, to investigate the transcription patterns of ERFs in response to salt and drought treatments, four ERF genes were cloned and identified from Japanese white birch (Betula platyphylla). The real-time quantitative polymerase chain reaction (qPCR) results showed that these four BpERF genes all responded to NaCl and PEG stress. Most BpERF genes were significantly induced in roots and leaves, but not in stems, such as BpERF 1,4 under NaCl treatment, and exhibited tissue-specific expression profiles in response to different abiotic stress. Further, we cloned the four BpERF genes into pYES2 vector, transformed and expressed these genes in yeast Saccharomyces cerevisiae to investigate their tolerance to salt and drought stress. Compared with the control (yeast transformed with empty pYES2), yeast cells expressing BpERF genes showed improved tolerance to salt and drought stress, indicating that these BpERFs could confer salt and drought tolerance to transgenic yeast cells. These results suggested that these BpERF genes play important roles in abiotic stress tolerance in B. platyphylla.