Nitrogen (N) is a major macronutrient that is essential for plant growth. It is important for us to understand the key genes that are involved in the regulation of N utilization. In this study, we focused on a GARP-type transcription factor known as NSR1/MYR2, which has been reported to be induced under N-deficient conditions.
View Article and Find Full Text PDFIdentification of the factors involved in the regulation of senescence and the analysis of their function are important for both a biological understanding of the senescence mechanism and the improvement of agricultural productivity. In this study, we identified an gene termed " (EPI1) as a possible regulator of senescence in . We found that EPI1 possesses transcriptional repression activity and that the transgenic plants overexpressing and expressing its chimeric repressor, , commonly suppressed the darkness-induced senescence in their excised aerial parts.
View Article and Find Full Text PDFTo shed unfertilized flowers or ripe fruits, many plant species develop a pedicel abscission zone (AZ), a specialized tissue that develops between the organ and the main body of the plant. Regulation of pedicel abscission is an important agricultural concern because pre-harvest abscission can reduce yields of fruit or grain crops, such as apples, rice, wheat, etc. Tomato has been studied as a model system for abscission, as tomato plants develop a distinct AZ at the midpoint of the pedicel and several tomato mutants, such as jointless, have pedicels that lack an AZ.
View Article and Find Full Text PDFPedicel abscission occurs widely in fruit-bearing plants to detach ripe, senescent or diseased organs, and regulation of abscission plays a substantial role in regulating yield and quality in fruit crops. In tomato, development of pedicel abscission zones (AZs) requires the MADS-box genes JOINTLESS (J), MACROCALYX (MC) and SlMBP21. In other plants, however, the involvement of MADS-box genes in pedicel abscission remains unclear.
View Article and Find Full Text PDFBiosci Biotechnol Biochem
March 2015
Certain MADS-box transcription factors play central roles in regulating fruit ripening. RIPENING INHIBITOR (RIN), a tomato MADS-domain protein, acts as a global regulator of ripening, affecting the climacteric rise of ethylene, pigmentation changes, and fruit softening. Previously, we showed that two MADS-domain proteins, the FRUITFULL homologs FUL1 and FUL2, form complexes with RIN.
View Article and Find Full Text PDFIn plants, abscission removes senescent, injured, infected, or dispensable organs. Induced by auxin depletion and an ethylene burst, abscission requires pronounced changes in gene expression, including genes for cell separation enzymes and regulators of signal transduction and transcription. However, the understanding of the molecular basis of this regulation remains incomplete.
View Article and Find Full Text PDFThe tomato (Solanum lycopersicum) MADS box FRUITFULL homologs FUL1 and FUL2 act as key ripening regulators and interact with the master regulator MADS box protein RIPENING INHIBITOR (RIN). Here, we report the large-scale identification of direct targets of FUL1 and FUL2 by transcriptome analysis of FUL1/FUL2 suppressed fruits and chromatin immunoprecipitation coupled with microarray analysis (ChIP-chip) targeting tomato gene promoters. The ChIP-chip and transcriptome analysis identified FUL1/FUL2 target genes that contain at least one genomic region bound by FUL1 or FUL2 (regions that occur mainly in their promoters) and exhibit FUL1/FUL2-dependent expression during ripening.
View Article and Find Full Text PDFThe tomato MADS-box transcription factor RIN acts as a master regulator of fruit ripening. Here, we identified MADS-box proteins that interact with RIN; we also provide evidence that these proteins act in the regulation of fruit ripening. We conducted a yeast two-hybrid screen of a cDNA library from ripening fruit, for genes encoding proteins that bind to RIN.
View Article and Find Full Text PDFBackground: Detachment of plant organs occurs in abscission zones (AZs). During plant growth, the AZ forms, but does not develop further until the cells perceive abscission-promoting signals and initiate detachment. Upon signal perception, abscission initiates immediately; if there is no signal, abscission is not induced and the organ remains attached to the plant.
View Article and Find Full Text PDFThe fruit ripening developmental program is specific to plants bearing fleshy fruits and dramatically changes fruit characteristics, including color, aroma, and texture. The tomato (Solanum lycopersicum) MADS box transcription factor RIPENING INHIBITOR (RIN), one of the earliest acting ripening regulators, is required for both ethylene-dependent and -independent ripening regulatory pathways. Recent studies have identified two dozen direct RIN targets, but many more RIN targets remain to be identified.
View Article and Find Full Text PDFThe physiological and biochemical changes in fruit ripening produce key attributes of fruit quality including color, taste, aroma and texture. These changes are driven by the highly regulated and synchronized activation of a huge number of ripening-associated genes. In tomato (Solanum lycopersicum), a typical climacteric fruit, the MADS-box transcription factor RIN is one of the earliest-acting ripening regulators, required for both ethylene-dependent and ethylene-independent pathways.
View Article and Find Full Text PDFEthylene-responsive transcription factor (ERF) family genes, which are involved in regulation of metabolic pathways and/or are useful for metabolic engineering, were investigated in the cultured cells of Arabidopsis thaliana. The pectin content in the gelatinous precipitates after the ethanol precipitation of extracts derived from calli of a transgenic cell line, A17, overexpressing an ERF gene (At1g44830), increased in comparison with the control. Expression of genes involved in pectin biosynthesis was up-regulated in the A17 calli.
View Article and Find Full Text PDFAbscission in plants is a crucial process used to shed organs such as leaves, flowers, and fruits when they are senescent, damaged, or mature. Abscission occurs at predetermined positions called abscission zones (AZs). Although the regulation of fruit abscission is essential for agriculture, the developmental mechanisms remain unclear.
View Article and Find Full Text PDFBackground: During ripening, climacteric fruits increase their ethylene level and subsequently undergo various physiological changes, such as softening, pigmentation and development of aroma and flavor. These changes occur simultaneously and are caused by the highly synchronized expression of numerous genes at the onset of ripening. In tomatoes, the MADS-box transcription factor RIN has been regarded as a key regulator responsible for the onset of ripening by acting upstream of both ethylene- and non-ethylene-mediated controls.
View Article and Find Full Text PDFThe analysis of expression patterns of transcription-factor genes will be the basis for a better understanding of their biological functions in plants. In this study, we designed and developed an oligo-DNA macroarray consisting of gene-specific probes of 60-65 nucleotides for 288 transcription-factor genes, which cover COL, DOF, ERF, and NAC family genes. To investigate transcription-factor genes that are cooperatively regulated by jasmonate and ethylene in arabidopsis (Arabidopsis thaliana (L.
View Article and Find Full Text PDFIn this study, we showed that overexpression of ethylene-responsive transcription factor (ERF) 2 activated the expression of endogenous genes that have the GCC box in their promoter region, in tobacco plants. These include not only a defense-related gene, CHN50, encoding class I basic chitinase, but also a transcriptional repressor gene, ERF3. In tobacco plants constitutively expressing ERF2:glucocorticoid receptor fusion protein, treatment with dexamethazone induced a rapid increase of ERF3 mRNA and a slow increase of CHN50 mRNA.
View Article and Find Full Text PDFGenes in the ERF family encode transcriptional regulators with a variety of functions involved in the developmental and physiological processes in plants. In this study, a comprehensive computational analysis identified 122 and 139 ERF family genes in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa L. subsp.
View Article and Find Full Text PDFA putative elicitor responsive element with two W boxes (CTGACC/T) has been identified in the region between -125 and -69 of a tobacco class I basic chitinase gene CHN48. We generated transgenic tobacco calli that contained the -125/-69 region fused to a luciferase reporter gene. The expression of the reporter gene was induced upon treatment with an elicitor, xylanase from Trichoderma viride (TvX).
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