Overexpression of Lilium formosanum MADS-box (LFMADS) Causing Floral Defects While Promoting Flowering in Arabidopsis thaliana, Whereas Only Affecting Floral Transition Time in Nicotiana tabacum

Abstract

The Formosa lily (Lilium formosanum) is one of the most common horticultural species in Taiwan. To explore gene regulation involved in this species, we used transcriptome analysis to generate PH-FB (mixed floral buds) and PH-LF (mature leaves) datasets. Combination of the PH-FB and PH-LF constructed a de novo assembly of the ALL dataset, including 18,041 contigs and 23,807 unigenes by Nr, GO, COG, and KEGG databases. The differential gene expression (DGE) analysis revealed 9937 genes were upregulated while 10,383 genes were downregulated in the developing floral buds compared to mature leaves. Seven putative genes (LFMADS1 to 7) encoding floral organ identity proteins were selected for further analysis. LFMADS1-6 genes were specifically expressed in the floral organ, while LFMADS7 in the floral buds and mature leaves. Phylogenetic analysis revealed that LFMADS1-3 is classified into B-class, LFMADS4 into C-class, LFMADS5 into D-class, and LFMADS6-7 into E-class, respectively. LFMADS-GFP fusion proteins appeared to localize in the nucleus, supporting their roles as transcription factors (TFs). Overexpression of the LFMADS2, LFMADS4, and LFMADS6 genes in Arabidopsis resulted in early flowering and floral defect, however, only early flowering in transgenic tobacco was observed. Highly expressed floral integrator genes, including AtFT, AtLFY, and AtFUL in transgenic Arabidopsis and NtFUL and NtSOC1 in transgenic tobacco, resulted in early flowering phenotype through qRT-PCR analysis. Yeast two-hybrid analysis suggested that LFMADSs may form higher order complexes with the B-, C-, D, and/or E-class proteins to determine the floral organ identity. Furthermore, E-class LFMADS proteins may function as a glue to mediate and strengthen the protein-protein interactions. Therefore, our de novo datasets would provide information for investigating other differentially expressed candidate transcripts. In addition, functional conservation of LFMADSs appears to be vital in floral transition and floral organ identity.

The Pomegranate Deciduous Trait Is Genetically Controlled by a PgPolyQ-MADS Gene

“…FCA is a RNA-binding protein which is an abscisic acid receptor that was reported to be involved in thermosensing of flowering (Razem et al, 2006). It is to note that overexpression of PgPolyQ-MADS in transgenic Arabidopsis dramatically shortens the time to flowering (Figure 8) as was shown for Arabidopsis AGL28 (Yoo et al, 2006) and for Lilium formosanum MADS-box gene (Liao et al, 2018). Pomegranate ELF3 (XP_031371603.1) does not contain the poly glutamine domain, neither the pomegranate agamous-like MADS-box protein MADS2 (XP_031407624.1), which was found to be most similar to AGL3, does not include the poly glutamine region.…”

The miR156-Targeted SQUAMOSA PROMOTER BINDING PROTEIN (PmSBP) Transcription Factor Regulates the Flowering Time by Binding to the Promoter of SUPPRESSOR OF OVEREXPRESSION OF CO1 (PmSOC1) in Prunus mume

“…The reaction with 10 µL volume (1 µL of cDNA, 5 µL of SYBR Premix ExTaq II (Takara), and 0.2 µL of each primer) were conducted as follow: 30 s in 95 °C, 40 cycles of 5 s in 95 °C and 30 s in 60 °C, and finally end in 20 °C, and each reaction was repeated in triplicate. The qRT-PCR primers of the housekeeping gene ( NtActin ) and eight endogenous flowering-related genes in tobacco used were also from the previous study [ 42 , 43 , 44 ]. The relative expression level was calculated by the 2 − ∆∆ Ct method [ 45 ].…”

Genome-Wide Identification of Mango (Mangifera indica L.) MADS-Box Genes Related to Fruit Ripening

“…MADS-box proteins are crucial transcription factors involved in the regulation of signal transduction [7], stress responses [8,9], and various aspects of plant development, including vernalization and flowering time control [10,11], floral organ (carpels, stamens, sepals, and petals) development [12][13][14][15][16], carpel identity and pollen development [17,18], reproductive development [19], seed development and pigmentation [20][21][22][23], root development [24,25], formation and dehiscence of fruit [26][27][28], and endosperm development [29]. In recent years, numerous MADS box TFs have been discovered to be associated with fruit ripening [30].…”