Heterologous expression of the BABY BOOM AP2/ERF transcription factor enhances the regeneration capacity of tobacco (Nicotiana tabacum L.)

Nicotine, the most abundant pyridine alkaloid in cultivated tobacco (Nicotiana tabacum L.), is a potent inhibitor of insect and animal herbivory and a neurostimulator of human brain function. Nicotine biosynthesis is controlled developmentally and can be induced by abiotic and biotic stressors via a jasmonic acid (JA)-mediated signal transduction mechanism involving members of the APETALA 2/ethylene-responsive factor (AP2/ERF) and basic helix-loop-helix (bHLH) transcription factor (TF) families. AP2/ERF and bHLH TFs work combinatorically to control nicotine biosynthesis and its subsequent accumulation in tobacco leaves. Here, we demonstrate that overexpression of the tobacco NtERF32, NtERF221/ORC1, and NtMYC2a TFs leads to significant increases in nicotine accumulation in T2 transgenic K326 tobacco plants before topping. Up to 9-fold higher nicotine production was achieved in transgenics overexpressing NtERF221/ORC1 under the control of a constitutive GmUBI3 gene promoter compared to wild-type plants. The constitutive 2XCaMV35S promoter and a novel JA-inducible 4XGAG promoter were less effective in driving high-level nicotine formation. Methyljasmonic acid (MeJA) treatment further elevated nicotine production in all transgenic lines. Our results show that targeted manipulation of NtERF221/ORC1 is an effective strategy for elevating leaf nicotine levels in commercial tobacco for use in the preparation of reduced risk tobacco products for smoking replacement therapeutics.

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A novel bHLH transcription factor, NtbHLH1, modulates iron homeostasis in tobacco (Nicotiana tabacum L.)

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2019.11.063 ◽

2020 ◽

Vol 522 (1) ◽

pp. 233-239

Author(s):

Yang-Yang Li ◽

Xiao-Yan Sui ◽

Jia-Shuo Yang ◽

Xiao-Hua Xiang ◽

Zun-Qiang Li ◽

...

Keyword(s):

Transcription Factor ◽

Nicotiana Tabacum ◽

Iron Homeostasis ◽

Bhlh Transcription Factor ◽

Nicotiana Tabacum L

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Heterologous expression of two Medicago truncatula putative ERF transcription factor genes, WXP1 and WXP2, in Arabidopsis led to increased leaf wax accumulation and improved drought tolerance, but differential response in freezing tolerance

Plant Molecular Biology ◽

10.1007/s11103-007-9150-2 ◽

2007 ◽

Vol 64 (3) ◽

pp. 265-278 ◽

Cited By ~ 109

Author(s):

Ji-Yi Zhang ◽

Corey D. Broeckling ◽

Lloyd W. Sumner ◽

Zeng-Yu Wang

Keyword(s):

Transcription Factor ◽

Drought Tolerance ◽

Heterologous Expression ◽

Medicago Truncatula ◽

Freezing Tolerance ◽

Differential Response ◽

Leaf Wax ◽

Transcription Factor Genes ◽

Erf Transcription Factor

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bHLH Transcription Factor NtMYC2a Regulates Carbohydrate Metabolism during the Pollen Development of Tobacco (Nicotiana tabacum L. cv. TN90)

Plants ◽

10.3390/plants11010017 ◽

2021 ◽

Vol 11 (1) ◽

pp. 17

Author(s):

Shiquan Bian ◽

Tian Tian ◽

Yongqiang Ding ◽

Ning Yan ◽

Chunkai Wang ◽

...

Keyword(s):

Transcription Factor ◽

Nicotiana Tabacum ◽

Transgenic Plants ◽

Carbohydrate Metabolism ◽

Pollen Development ◽

Starch Accumulation ◽

Bhlh Transcription Factor ◽

Pollen Maturation ◽

Nicotiana Tabacum L

Basic helix-loop-helix (bHLH) transcription factor MYC2 regulates plant growth and development in many aspects through the jasmonic acid (JA) signaling pathway, while the role of MYC2 in plant carbohydrate metabolism has not been reported. Here, we generated NtMYC2a-overexpressing (NtMYC2a-OE) and RNA-interference-mediated knockdown (NtMYC2a-RI) transgenic plants of tobacco (Nicotiana tabacum L. cv. TN90) to investigate the role of NtMYC2a in carbohydrate metabolism and pollen development. Results showed that NtMYC2a regulates the starch accumulation and the starch-sugar conversion of floral organs, especially in pollen. The RT-qPCR analysis showed that the expression of starch-metabolic-related genes, AGPs, SS2 and BAM1, were regulated by NtMYC2a in the pollen grain, anther wall and ovary of tobacco plants. The process of pollen maturation was accelerated in NtMYC2a-OE plants and was delayed in NtMYC2a-RI plants, but the manipulation of NtMYC2a expression did not abolish the pollen fertility of the transgenic plants. Intriguingly, overexpression of NtMYC2a also enhanced the soluble carbohydrate accumulation in tobacco ovaries. Overall, our results demonstrated that the bHLH transcription factor NtMYC2a plays an important role in regulating the carbohydrate metabolism during pollen maturation in tobacco.

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