Abstract:

The NAC transcription factors closely related to drought stress responses of Jerusalem artichoke（JA）（Helianthus tuberosus L.）leaves were screened by transcriptome method, which may lay a theoretical foundation for the cloning and functional verification of JA NAC gene in the future. In this study, the drought-resistant Qingyu No. 2 JA was used as experimental material. The leaves of JA were collected after treatment for 0, 18, 24 and 36 h, respectively, and the differentially expressed NAC transcription factors were screened and analyzed by transcriptomic sequencing. Referenced as RNA-Sequencing data, 70 NAC genes were identified in JA leaves with sequence length between 408-1 869 bp. The lengths of the detected motif ranged from 21 to 50 bases. Phylogenetic tree analysis showed that most HtNACs genes were clustered with other NAC genes. It was found that HtNAC90-3 was clustered with AtNAC72, HtNAC67-3 was clustered with AtNAC055, HtNAC2-1 was clustered with AtNAC019, HtNAC36 was clustered with SINAC6 through the clustering of NAC genes in other crops related to reported drought resistance. HtNAC83-1 was clustered with AtNAC96. Tissue-specific expression analysis showed relatively high HtNAC expression in seeds and petals. Drought-induced expression analysis showed that 38 and 11 HtNAC genes revealed the increasing expression trend after drought induction in JA leaves and roots, respectively. In this study, it was found that the expressions of HtNACs in seeds and petals was high, especially in petals. Subsequently, HtNACs of JA can be cloned from petals of JA and related functions can be verified.

Key words: Helianthus tuberosus L., NAC, transcription factor