Functional Analysis Of ONAC055 And Transcriptome Analysis Of ONAC055 Transgenic Rice Plants

NAC(NAM, ATAF, CUC) is a plant specific transcription factor family in many different plants. NAC protein contains approximately 160 N-terminal amino acid residues that are highly conserved. The C-term is not quite conserved, but has very important role in transcriptional activation activity. The plant NAC transcription factors have many functions and play important roles in plant growth and development such as regulation of plant secondary growth, plant lateral root growth and plant senescence and cell division as well as the abiotic stress and plant disease resistance.As an important crop in the world and the model plant of monocotyledon, research on rice has a great significance. Currently, there are about 151 NAC genes in rice genome. According to bioinformatic analysis, ONAC055 may be involved in the regulation of rice root growth. Plants root system architecure absorbs water and minerals, and directly affects the growth and yield of the plant.In this study, we preliminary investigated the biological functions of ONAC055 and mainly analyzed the transcriptome in root tissue of ONAC055 transgenic plants. The main results were as follows:(1) Transgenic experiments indicated that in the transgenic seedlings of T1 progeny, the primay root length, average length of three longest adventitious roots as well as density of lateral root in both ONAC055-RNAi and 35S::ONAC055 transgenic plants were significantly decreased compared with the counterparts of the wild type, while the adventitious root number and shoot length in 35S::ONAC055 transgenic plants were drastically increased compared with that of the wild type.(2) Transcriptome analysis indicated that most of the differentially expressed genes related to metabolic process and cellular process in the biological process classification. In the cellular component classification, most of the differentially expressed genes are related to cell part and organelle. In the molecular function classification, most of the differentially expressed genes are related to binding and catalytic activity. Most of the differentially expressed genes are involved in metabolic pathway followed by biosynthesis of secondary metabolism and plant-pathogen interaction. Most importantly, many genes related to auxin response and polar transport, nitrate affinity and transport and drought stress displayed differential expression.(3) Protein physical interaction analysis indicated that ONAC055 do not showed the transcriptional activation activity in yeast. Five candidate proteins were obained from yeast two hybrid cDNA library by using ONAC055 as a bait.