Cloning And Functional Analysis Of ERF Transcription Factor Genes In Oryza Sativa L. And Malus Robusta R.

Plants are constantly challenged by various biotic and abiotic stresses such as drought, high salinity, low temperature and disease in their natural environment, which cause adverse effects on the growth of plants and serious reductions in the quantity and quality of agriculturally important crops. Accordingly, the researches of protection mechanisms of the tolerance of plants to environmental stress are more and more systematic. The plants that surviving under stress conditions are in need of their ability to receive signals and responses in an opportune way. In Arabidopsis, a number of transcription factor families have been found involving in plant stress responses, and each contain a different type of DNA-binding domain, including AP2/EREBP, MYB, WRKY, and bZIP and so on. A variety of genes induced by stresses play an important role in the plant stress response, and these induced genes take place chiefly at the transcriptional level. The transcription factors OsAP210 from Oryza Sativa and MrPF1 from Malus robusta R in this article belong to AP2/EREBP transcription factors.In this study, we isolated a putative ERF transcription factor OsAP210 that interacted specifically with ERE-2cis from Oryza sativa L by yeast one-hybrid method. The full-length cDNA of OsAP210 has a 1014bp open reading frame (ORF). It has a conserved DNA binding domain present in a large family of EREBP/AP2 and contains a basic region in its C-terminal that might function as a nuclear localization signal and two acidic regions on either side of the AP2 domain. The results of RT-PCR analysis for Oryza sativa IR36 exposed to various treatments indicated that the mRNA of gene OsAP210 was not induced by various hormone and biotic stress. We show here overexpression of OsAP210 resulted in a dramatic increase in tolerance to salt stress, drought stress and oxidation stress in transgenic Arabidopsis.A novel gene MrPF1 in Malus robusta R. was cloned by rapid amplification of cDNA ends (RACE). The gene consisted of 1164bp encoding a protein of 388 amino acids. MrPF1 has the most similarity in amino acid sequence with the pepper transcription factor CaPF1, tomato JERF1 tobacco NtDRF1. Conserved domains include the ERF/AP2 domain, putative nuclear localization signal, and a conserved N-terminal motif of unknown function (MCGGAIISD) that only found in ERF genes. The results of Real Time Quantitative PCR analysis for Malus robusta R. exposed to various treatments demonstrated that the mRNA of gene OsAP210 was induced by low-temperature stress, ABA (100μM) and PEG (100μM) .