The Primary Exploration Of ANAC084in The Resistance Of Arabidopsis To Stress

The NAC members belong to one of the largest gene families of plant transcription factors, and are involved in various physiological aspects, especially in plant defense responses during biotic and abiotic stress process. ANAC084gene, one of the NAC transcription factors, hasn’t been extensively studied in Arabidopsis yet. Overexpression of ANAC084in Arabidopsis induces a series of phenotypes, including dwarf、accumulation of leaf pigments、later flowering、longer life cycle,etc. The content of anthocyanins in35S::ANAC084transgenic plants increases significantly in comparison with Wild-type plants, Anthocyanins and other flavonoids could absorb UV to protect plants from UV radiation.Using RT-PCR analysis, we found that a relatively higher expession level of mRNAs of four flavonoid enzymes, PAL1(phenylalanine ammonia-lyase)、CHI (chalcone isomerase)、CHS (chalcone synthase)、DFR (dihydroflavonol reductase) in ANAC084overexpression seedlings. We found that35S::ANAC084transgenic plants show higher resistance of UV-B radiation.On the contrary, amiR172-ANAC084seedlings in which the expression of ANAC084was interfered are more sensitive to UV-B radiation.In addition, there’s no difference in anthocyanins content between Wild-type seedlings and amiR172-ANAC084plants, which means that ANAC084not only increases anthocyanins content, maybe also involved in DNA repair. After treatment with the radiomimetic drug zeocin, using confocal microscope we obversed that overexpression of ANAC084enhanced DNA repair ability in root stem cells, while root stem cells of amiR172-ANAC084plants are more sensitive to zeocin treatment than Wild-type. The results suggested that ANAC084plays important roles in anthocyanins metabolism and DNA repair.