A comparison of the transcriptomes between diploid and autotetraploid Paulownia fortunei under salt stress
Paulownia is a tree species grown in many countries. Our previous study reveals that tetraploid Paulownia fortunei is more tolerant to salt stress than its corresponding diploid tree. To investigate the molecular mechanisms of salt stress tolerance in P. fortunei, the transcriptomes of normal and salt-stressed diploid and tetraploid were investigated. After assembling the clean reads, we obtained 130,842 unigenes. The unigenes were aligned against six public databases (Nr, Nt, Swiss-Prot, COG, KEGG, GO) to discover homologs and assign functional annotations. We retrieved 7983 and 15,503 differentially expressed unigenes (DEUs) between the normal and the salt-stressed diploid and tetraploid P. fortunei, respectively. We identified dozens of important DEUs including 3 related to photosynthesis, 10 related to plant growth and development and 11 related to osmolytes. Some of these DEUs were upregulated in tetraploid compared to diploid and others were upregulated under salt stress. Quantitative reverse transcriptase polymerase chain reaction verified the expression patterns of 15 unigenes. Our results provided insights into the molecular aspects why tetraploid is stronger and more energetic than diploid under saline environment. This study provides useful information for further studies on the molecular mechanisms of salt tolerance in other tree plants.
KeywordsPaulownia fortunei Transcriptome Salt stress Diploid Tetraploid
This work was supported by the Key Science and Technology Program of Henan Province of China (No. 152107000097), the Natural Science Foundation of Henan Province of China (No. 162300410158), and the Distinguished Talents Foundation of Henan Province of China (No. 174200510001).
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interests.
- Bi H, Wang M, Jiang Z, Dong X, Ai X (2011) Impacts of suboptimal temperature and low light intensity on the activities and gene expression of photosynthetic enzymes in cucumber seedling leaves. Chin J Appl Ecol 22:2894–2900Google Scholar
- Deng B, Du W, Liu C, Sun W, Tian S, Dong H (2011) Antioxidant response to drought, cold and nutrient stress in two ploidy levels of tobacco plants: low resource requirement confers polytolerance in polyploids? Plant Growth Regul 66:37–47. https://doi.org/10.1007/s10725-011-9626-6 CrossRefGoogle Scholar
- Deng M, Zhang X, Fan G, Zhao Z, Dong Y, Wei Z (2013) Physiological responses to salt stress of tetraploid Paulownia australis and Paulownia fortunei plants. J Henan Agric Univ 47:698–975Google Scholar
- Dong Y, Fan G, Zhao Z, Deng M (2014) Compatible solute, transporter protein, transcription factor, and hormone-related gene expression provides an indicator of drought stress in Paulownia fortunei. Funct Integr Genomics 14:479–491. https://doi.org/10.1007/s10142-014-0373-4 CrossRefPubMedPubMedCentralGoogle Scholar
- Essl F (2007) From ornamental to detrimental? The incipient invasion of Central Europe by Paulownia tomentosa. Preslia 79:377–389Google Scholar
- Fan G, Cao Y, Zhao Z, Yang Z (2007) Induction of Autotetraploid of Paulownia fortunei. Scientia Silvae Sinicae 43:31–35Google Scholar
- Fan G, Li X, Deng M, Zhao Z, Yang L (2016a) Comparative analysis and Identification of miRNAs and their target genes responsive to salt stress in diploid and tetraploid Paulownia fortunei seedlings. PLoS ONE 11:e0149617. https://doi.org/10.1371/journal.pone.0149617 CrossRefPubMedPubMedCentralGoogle Scholar
- Huang L et al (2018a) The ascorbate peroxidase APX1 is a direct target of a zinc finger transcription factor ZFP36 and a late embryogenesis abundant protein OsLEA5 interacts with ZFP36 to co-regulate OsAPX1 in seed germination in rice. Biochem Biophys Res Commun 495:339–345. https://doi.org/10.1016/j.bbrc.2017.10.128 CrossRefPubMedGoogle Scholar
- Huang L et al (2018b) An atypical late embryogenesis abundant protein OsLEA5 plays a positive role In ABA-induced antioxidant defense. In: Oryza Sativa L. Plant and Cell Physiology. https://doi.org/10.1093/pcp/pcy035
- Iseli C, Jongeneel CV, Bucher P (1999) ESTScan: a program for detecting, evaluating, and reconstructing potential coding regions in EST sequences. In: ISMB, pp 138–148Google Scholar
- Ismail AM, Horie T (2017) Genomics, Physiology, and Molecular Breeding Approaches for Improving Salt Tolerance. Annu Rev Plant Biol 68:405–434. https://doi.org/10.1146/annurev-arplant-042916-040936 CrossRefPubMedGoogle Scholar
- Li X, Chen W, Zhao Y, Xiang Y, Jiang H, Zhu S, Cheng B (2013) Downregulation of caffeoyl-CoA O-methyltransferase (CCoAOMT) by RNA interference leads to reduced lignin production in maize straw. Genet Mol Biol 36:540–546. https://doi.org/10.1590/S1415-47572013005000039 CrossRefPubMedPubMedCentralGoogle Scholar
- McDonagh B, Pedrajas JR, Padilla CA, Barcena JA (2013) Thiol redox sensitivity of two key enzymes of heme biosynthesis and pentose phosphate pathways: uroporphyrinogen decarboxylase and transketolase. Oxid Med Cell Longev Article ID 932472. https://doi.org/10.1155/2013/932472
- Wang X, Deng M, Shen L, Zhang X, Zhai X, Liu Y, Fan G (2014) Differential analysis of fiber characteristics and chemical properties between tetraploid Paulownia fortunei and its diploid. J Henan Agric Univ 5:585–589Google Scholar