Genome-Wide Characterization and Evolutionary Expansion of Poplar NAC Transcription Factors and Their Tissue-Specific Expression Profiles under Drought
The NAC (NAM, ATAF1/2 and CUC2) is a large gene family of plant-specific transcription factors that play a pivotal role in various physiological processes and abiotic stresses. Due to the lack of genome-wide characterization, intraspecific and interspecific synteny, and drought-responsive expression...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-12-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/1/253 |
| Summary: | The NAC (NAM, ATAF1/2 and CUC2) is a large gene family of plant-specific transcription factors that play a pivotal role in various physiological processes and abiotic stresses. Due to the lack of genome-wide characterization, intraspecific and interspecific synteny, and drought-responsive expression pattern of <i>NAC</i> genes in poplar, the functional characterization of drought-related <i>NAC</i> genes have been scarcely reported in <i>Populus</i> species. Here, we identified a total of 170 <i>NAC</i> domain-containing genes in the <i>P. trichocarpa</i> genome, 169 of which were unevenly distributed on its nineteen chromosomes. These <i>NAC</i> genes were phylogenetically divided into twenty subgroups, some of which exhibited a similar pattern of exon–intron architecture. The synteny and Ka/Ks analysis indicated that the expansion of <i>NAC</i> genes in poplar was mainly due to gene duplication events occurring before and after the divergence of <i>Populus</i> and <i>Salix</i>. Ten <i>PdNAC</i> (<i>P. deltoids × P. euramericana</i> cv.’Nanlin895’) genes were randomly selected and cloned. Their drought-responsive expression profiles showed a tissue-specific pattern. The transcription factor PdNAC013 was verified to be localized in the nucleus. Our research results provide genomic information for the expansion of <i>NAC</i> genes in the poplar genome, and for further characterizing putative poplar <i>NAC</i> genes associated with water-deficit. |
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| ISSN: | 1661-6596 1422-0067 |