Cloning And Functional Analysis Of NAC Transcription Factor Genes In Rice

NAM, ATAF, and CUC (NAC) transcription factors comprise a large plantspecific gene family and a few members of this family have been characterized fortheir roles in plant growth, development, and stress tolerance.More recently, NACproteins were found to be involved in plant responses to pathogen and environmentalstimuli.In my study,147putative NAC or NAC-like genes (ONAC) in rice from thePlant Transcription Factor Database were found and57genes were cloned byRT–PCR.The plant two expression vectors pCAMBIA1301-NAC were constructedwith Gateway technology, which lay the foundations for research of genetictransformation in rice.Over-expressing vectors (VP64-pCambia1301-ONAC) and inhibit-expressingvectors (EAR-pCambia1301-ONAC) were used to infect rice callus by agrobacteriumtumefaciens.After several steps of screening and Western Blot, ONAC7over-expressing and inhibit-expressing rice plants and seeds of T3generation weresuccessfully obtained first.Real-time quantitative polymerase chain reaction was used to analyze theexpression pattern of NAC gene family under NAA and the expression pattern of NACgene family in different tissues under normal condition. The results showed that NACgenes in rice have different tissue-specific expression patterns under normal growthcondition, some were most abundant in leaves in flowers(ONAC28,ONAC62，ONAC24，ONAC22) and others had higher expression in maturedroots(ONAC42,ONAC7，ONAC39). ONAC7was the most interesting.RT-PCR andreal-time quantitative PCR showed that its expression was higher in roots than othertissues and induced obviously by NAA which may be a downstream gene in the auxin signal pathways.Over-expressing vectors (VP64-pCambia1301-ONAC7) and inhibit-expressingvectors (EAR-pCambia1301-ONAC7) were used to infect Arabidopsis by the floraldip method of Agrobacterium-mediated transformation. ONAC7has been insertedinto the genomic DNA of Arabidopsis. We obtained T3transgenic lines. TransgenicArabidopsis lines flowered earlier or later than the non-transgenic control, which hasthe potential as a target gene to change florescence.