Overexpression of AtDREB1D transcription factor improves drought tolerance in soybean
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Drought is one of the major abiotic stresses that affect productivity in soybean (Glycine max L.) Several genes induced by drought stress include functional genes and regulatory transcription factors. The Arabidopsis thaliana DREB1D transcription factor driven by the constitutive and ABA-inducible promoters was introduced into soybean through Agrobacterium tumefaciens-mediated gene transfer. Several transgenic lines were generated and molecular analysis was performed to confirm transgene integration. Transgenic plants with an ABA-inducible promoter showed a 1.5- to two-fold increase of transgene expression under severe stress conditions. Under well-watered conditions, transgenic plants with constitutive and ABA-inducible promoters showed reduced total leaf area and shoot biomass compared to non-transgenic plants. No significant differences in root length or root biomass were observed between transgenic and non-transgenic plants under non-stress conditions. When subjected to gradual water deficit, transgenic plants maintained higher relative water content because the transgenic lines used water more slowly as a result of reduced total leaf area. This caused them to wilt slower than non-transgenic plants. Transgenic plants showed differential drought tolerance responses with a significantly higher survival rate compared to non-transgenic plants when subjected to comparable severe water-deficit conditions. Moreover, the transgenic plants also showed improved drought tolerance by maintaining 17–24 % greater leaf cell membrane stability compared to non-transgenic plants. The results demonstrate the feasibility of engineering soybean for enhanced drought tolerance by expressing stress-responsive genes.
KeywordsDREB Drought tolerance Environmental stresses Cell membrane stability Soybean Transcription factor
We thank Dr. Zhanyuan Zhang, Plant Transformation Core Facility, University of Missouri for the soybean transformation and Dr. Thomas Clemente, University of Nebraska for providing sub-cloning vectors. This work was supported by the United Soybean Board and the Missouri Soybean Merchandising Council funding to HTN.
- 6.Krasensky J, Jonak C (2012) Drought, salt, and temperature stress-induced metabolic rearrangements and regulatory networks. J Exp Bot 63(4):1593–1608Google Scholar
- 27.Shen QX, Zhang PN, Ho THD (1996) Aba response complexes: composite promoter units which are necessary and sufficient for ABA induction of gene expression in barley, Hordeum vulgare. Plant Physiol 111(2):563-563Google Scholar
- 31.Lee JT, Prasad V, Yang PT, Wu JF, Ho THD, Charng YY, Chan MT (2003) Expression of Arabidopsis CBF1 regulated by an ABA/stress inducible promoter in transgenic tomato confers stress tolerance without affecting yield. Plant Cell Environ 26(7):1181–1190. doi: 10.1046/j.1365-3040.2003.01048.x CrossRefGoogle Scholar
- 34.Pellegrineschi A, Reynolds M, Pacheco M, Brito RM, Almeraya R, Yamaguchi-Shinozaki K, Hoisington D (2004) Stress-induced expression in wheat of the Arabidopsis thaliana DREB1A gene delays water stress symptoms under greenhouse conditions. Genome 47(3):493–500. doi: 10.1139/g03-140 CrossRefPubMedGoogle Scholar
- 41.Le DT, Aldrich DL, Valliyodan B, Watanabe Y, Van Ha C, Nishiyama R, Guttikonda SK, Quach TN, Gutierrez-Gonzalez JJ, Tran LSP, Nguyen HT (2012) Evaluation of candidate reference genes for normalization of quantitative rt-pcr in soybean tissues under various abiotic stress conditions. Plos One 7(9):ARTN e46487. doi: 10.1371/journal.pone.0046487 CrossRefGoogle Scholar
- 42.Liu Q, Kasuga M, Sakuma Y, Abe H, Miura S, Yamaguchi-Shinozaki K, Shinozaki K (1998) Two transcription factors, DREB1 and DREB2, with an EREBP/AP2 DNA binding domain separate two cellular signal transduction pathways in drought- and low-temperature-responsive gene expression, respectively, in Arabidopsis. Plant cell 10(8):1391–1406. doi: 10.2307/3870648 PubMedCentralCrossRefPubMedGoogle Scholar
- 47.Cushman JC (2001) Osmoregulation in plants: implications for agriculture. Am Zool 41(4):758–769Google Scholar
- 48.de Paiva Rolla AA, de Fatima Correa Carvalho J, Fuganti-Pagliarini R, Engels C, Do Rio A, Marin SR, de Oliveira MC, Beneventi MA, Marcelino-Guimaraes FC, Farias JR, Neumaier N, Nakashima K, Yamaguchi-Shinozaki K, Nepomuceno AL (2014) Phenotyping soybean plants transformed with rd29A:AtDREB1A for drought tolerance in the greenhouse and field. Transgenic Res 23:75–87. doi: 10.1007/s11248-013-9723-6 CrossRefPubMedGoogle Scholar