Abstract
BackgroundPlant TRANSPARENT TESTA GLABRA (TTG) proteins regulate various developmental activities via the auxin signaling pathway. Recently, we elucidated the developmental role of tobacco (Nicotiana tabacum L.) NtTTG2 in association with 12 genes that putatively encode AUXIN RESPONSIVE FACTOR (ARF) proteins, including NtARF8, NtARF17, and NtARF19. Here we show that NtTTG2 regulates tobacco growth and development by involving the NtARF8, NtARF17, and NtARF19 genes, with the NtARF8 gene playing a predominant contribution.ResultsIndependent silencing of the NtARF8 gene more strongly repressed tobacco growth than silencing the NtARF17 or NtARF19 gene and more effectively eradicated the growth enhancement effect of NtTTG2 overexpression. In contrast, plant growth was not affected by silencing additional nine NtTTG2-regulated NtARF genes. In double and triple gene silencing combinations, silencing the NtARF8 gene was more effective than silencing the NtARF17 or NtARF19 gene to repress growth as well as nullify growth enhancement. Therefore, the NtARF8 predominantly cooperated with the NtARF17 and NtAFR19 of the NtTTG2 functional pathway. NtARF8 also contributed to NtTTG2-regulated seed production as concurrent NtTTG2 and NtARF8 overexpression played a synergistic role in seed production quantity, whereas concurrent silencing of both genes caused more severe seed abortion than single gene silencing. In plant cells, the NtTTG2 protein facilitated the nuclear import of NtARF8 as well as increased its function as a transcription activator.ConclusionsNtARF8 is an integral component of the NtTTG2 functional pathway, which regulates tobacco growth and development.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0815-3) contains supplementary material, which is available to authorized users.
Highlights
Plant TRANSPARENT TESTA GLABRA (TTG) proteins regulate various developmental activities via the auxin signaling pathway
NtTTG2 responds to auxin but does not affect endogenous auxin levels To infer the functional relationship between NtTTG2 and auxin, we analyzed NtTTG2 expression in leaves of WT tobacco treated with an aqueous solution containing a surfactant and a synthetic auxin, 1-naphthaleneacetic acid (NAA), and with the surfactant solution as control
The NAA treatment highly induced NtTTG2 expression based on quantitative real-time Reverse transcriptasepolymerase chain reaction (RT-PCR) (RT-qPCR) analysis performed at a 10-min interval in 60 h after plant treatment
Summary
Plant TRANSPARENT TESTA GLABRA (TTG) proteins regulate various developmental activities via the auxin signaling pathway. TRANSPARENT TESTA GLABRA (TTG) proteins are essential regulators of plant trichome and seed development [1, 2] and have been extensively studied in terms of the functional regulation [3,4,5]. The WD40 domain enables NtTTG1 to interact with elicitin protein ParA1, which is produced by an oomycete pathogen and induces hypersensitive cell death in plants [10]. The NtTTG1-ParA1 interaction is essential for the induction of programmed cell death initially in leaf trichomes and in mesophylls, which in turn results in plant resistance to different pathogens [10].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
