scholarly journals A tomato LATERAL ORGAN BOUNDARIES transcription factor, SlLOB1, predominantly regulates cell wall and softening components of ripening

2021 ◽  
Vol 118 (33) ◽  
pp. e2102486118
Author(s):  
Yanna Shi ◽  
Julia Vrebalov ◽  
Hui Zheng ◽  
Yimin Xu ◽  
Xueren Yin ◽  
...  
Keyword(s):  
Cell Wall ◽  
Tomato Fruit ◽  
35S Promoter ◽  
Protein Levels ◽  
Physiological Processes ◽  
Tomato Fruit Ripening ◽  
Lateral Organ ◽  
Textural Changes ◽  
Late Maturation

Fruit softening is a key component of the irreversible ripening program, contributing to the palatability necessary for frugivore-mediated seed dispersal. The underlying textural changes are complex and result from cell wall remodeling and changes in both cell adhesion and turgor. While a number of transcription factors (TFs) that regulate ripening have been identified, these affect most canonical ripening-related physiological processes. Here, we show that a tomato fruit ripening–specific LATERAL ORGAN BOUNDRIES (LOB) TF, SlLOB1, up-regulates a suite of cell wall–associated genes during late maturation and ripening of locule and pericarp tissues. SlLOB1 repression in transgenic fruit impedes softening, while overexpression throughout the plant under the direction of the 35s promoter confers precocious induction of cell wall gene expression and premature softening. Transcript and protein levels of the wall-loosening protein EXPANSIN1 (EXP1) are strongly suppressed in SlLOB1 RNA interference lines, while EXP1 is induced in SlLOB1-overexpressing transgenic leaves and fruit. In contrast to the role of ethylene and previously characterized ripening TFs, which are comprehensive facilitators of ripening phenomena including softening, SlLOB1 participates in a regulatory subcircuit predominant to cell wall dynamics and softening.

scholarly journals 926 PB 497 SOFTENING OF GAMMA-IRRADIATED TOMATO FRUITS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 566g-567
Author(s):  
N. El-Assi ◽  
D. J. Huber ◽  
J. K. Brecht
Keyword(s):  
Cell Wall ◽  
Tomato Fruit ◽  
Pectic Polysaccharides ◽  
Tomato Fruits ◽  
Biochemical Basis ◽  
Cell Wall Polymers ◽  
Textural Changes ◽  
Gamma Irradiated

The use of irradiation to increase longevity and quality of horticultural commodities often results in undesirable softening. The biochemical basis of irradiation-induced softening is not well understood. In this study, we investigated the role of the pectic polysaccharides in irradiation-induced textural changes of `Sunny' tomato fruit. `Sunny' mature-green and pink fruit subjected to 84 or 240 Krad experienced a dosage-dependent decrease in firmness, an increase in electrolyte leakage, and an increase in chelator-soluble pectins. Additionally, pectins prepared from 240 Krad-irradiated fruit were of markedly lower mol wt compared to those from nonirradiated fruit. Irradiation-induced downshifts in pectin mol wt were also noted for preripe fruit that lack PG activity. Mol wt decreases noted for pectins from 240 Krad-treated fruit exceeded those observed for fully ripe, nonirradiated fruit The role of other cell wall polymers in irradiation-induced textural changes is currently being addressed.

scholarly journals Light and ripening-regulated BBX protein-encoding genes in Solanum lycopersicum

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bruno Silvestre Lira ◽  
Maria José Oliveira ◽  
Lumi Shiose ◽  
Raquel Tsu Ay Wu ◽  
Daniele Rosado ◽  
...  
Keyword(s):  
Tomato Fruit ◽  
Protein Family ◽  
Tomato Genome ◽  
Physiological Processes ◽  
Fruit Development And Ripening ◽  
Protein Encoding ◽  
Ripening Inhibitor ◽  
Encoding Genes ◽  
Signalling Cascade

Abstract Light controls several aspects of plant development through a complex signalling cascade. Several B-box domain containing proteins (BBX) were identified as regulators of Arabidopsis thaliana seedling photomorphogenesis. However, the knowledge about the role of this protein family in other physiological processes and species remains scarce. To fill this gap, here BBX protein encoding genes in tomato genome were characterised. The robust phylogeny obtained revealed how the domain diversity in this protein family evolved in Viridiplantae and allowed the precise identification of 31 tomato SlBBX proteins. The mRNA profiling in different organs revealed that SlBBX genes are regulated by light and their transcripts accumulation is directly affected by the chloroplast maturation status in both vegetative and fruit tissues. As tomato fruits develops, three SlBBXs were found to be upregulated in the early stages, controlled by the proper chloroplast differentiation and by the PHYTOCHROME (PHY)-dependent light perception. Upon ripening, other three SlBBXs were transcriptionally induced by RIPENING INHIBITOR master transcriptional factor, as well as by PHY-mediated signalling and proper plastid biogenesis. Altogether, the results obtained revealed a conserved role of SlBBX gene family in the light signalling cascade and identified putative members affecting tomato fruit development and ripening.

scholarly journals Corrigendum to: Re-evaluation of the nor mutation and the role of the NAC-NOR transcription factor in tomato fruit ripening

2020 ◽  
Vol 71 (12) ◽  
pp. 3759-3759
Author(s):  
Ying Gao ◽  
Wei Wei ◽  
Zhongqi Fan ◽  
Xiaodan Zhao ◽  
Yiping Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Fruit Ripening ◽  
Tomato Fruit ◽  
Tomato Fruit Ripening

scholarly journals Contribution of cell wall modifying enzymes on the texture of fleshy fruits: The example of apple

2013 ◽  
Vol 78 (3) ◽  
pp. 417-427 ◽  
Author(s):  
Estelle Bonnin ◽  
Marc Lahaye
Keyword(s):  
Cell Wall ◽  
Fruit Ripening ◽  
Consumer Choice ◽  
Fruit Production ◽  
Cell Wall Polysaccharides ◽  
Structural Reorganization ◽  
Fleshy Fruits ◽  
Textural Changes ◽  
Transformation Processes

Cell walls consist of polysaccharide assemblies (pectin, hemicelluloses and cellulose), whose structure and interactions vary depending on fruit genetic, and its stage and conditions of development. The establishment and the structural reorganization of the assemblies result from enzyme/protein consortia acting in muro. The texture of fleshy fruits is one of the major criteria for consumer choice. It impacts also post-harvest routes and transformation processes. Disassembly of fruit cell wall polysaccharides largely induces textural changes during ripening but the precise role of each polysaccharide and each enzyme remains unclear. The changes of cell wall polysaccharides during fruit ripening have mainly emphasized a modulation of the fine chemical structure of pectins by hydrolases, lyases, and esterases. This restructuring also involves a reorganization of hemicelluloses by hydrolases/transglycosydases and a modulation of their interactions with the cellulose by non-catalytic proteins such as expansin. Apple is the third fruit production in the world and is the subject of studies about fruit quality. This paper presents some of the results to date about the enzymes/proteins involved in this fruit ripening with a particular emphasis on apple.

scholarly journals (472) Yeast Expressed Tomato β-Galactosidases 1, 4, and 5 Have Activity against Synthetic and Plant-derived Cell Wall Substrates

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1092B-1092 ◽  
Author(s):  
Megumi Ishimaru ◽  
David L. Smith ◽  
Kenneth C. Gross
Keyword(s):  
Cell Wall ◽  
Tomato Fruit ◽  
Wall Material ◽  
Wall Structure ◽  
Fruit Softening ◽  
Pectic Polysaccharides ◽  
Wide Range ◽  
Fruit Pericarp ◽  
Galactosyl Residues

Fruit softening occurs by several mechanisms, including modifications of cell wall structure by wall degrading enzymes. The most prominent change in tomato fruit pericarp wall composition is the loss of galactosyl residues throughout development and especially during ripening. In order to understand the role of galactosyl turnover in fruit softening, we successfully produced three recombinant tomato β-galactosidase/exo-galactanase (TBG) fusion proteins in yeast. TBG1, 4 and 5 enzyme properties and substrate specificities were assessed. Optimum pH of TBG1, 4 and 5 was 5.0, 4.0, and 4.5 and optimum temperature was 40∼50, 40, and 40 °C, respectively. The K ms for TBG1, 4 and 5 were 7.99, 0.09, and 2.42 mm, respectively, using p-nitrophenyl-β-D-galactopyranoside as substrate. Using synthetic and plant-derived substrates, TBG1 and 5 released galactosyl residues from 1 → 4 linkages. TBG4 released galactosyl residues from a wide range of plant-derived oligosaccharides and polysaccharides. Using tomato fruit cell wall material, TBG1, TBG4 and TBG5 released galactosyl residues from a variety of fruit stages and cell wall fractions. TBG4 released the most galactosyl residues from the ASP fraction and especially the ASP fraction from fruit at the turning stage. Interestingly, even though walls from Turning fruit stage contain less total galactosyl residues than at the Mature Green stage, TBG4 released 3–4 fold more galactose from the CSP and ASP fractions from Turning fruit. These results suggest that changes in structure of wall pectic polysaccharides leading up to the Turning stage may cause the wall to become more susceptible to hydrolysis by the TBG4 product.

scholarly journals Brassinosteroid signaling component SlBES1 promotes tomato fruit softening through transcriptional repression of PMEU1

2021 ◽  
Author(s):  
Haoran Liu ◽  
Lihong Liu ◽  
Dongyi Liang ◽  
Min Zhang ◽  
Chengguo Jia ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Tomato Fruit ◽  
Fruit Softening ◽  
Loss Of Function ◽  
Postharvest Storage ◽  
Nutrition Quality ◽  
Transcriptional Inhibition ◽  
Tomato Fruit Ripening ◽  
Brassinosteroid Signaling

ABSTRACTFirmness is one of the most important factors that affect postharvest properties of tomato fruit. However, the regulatory mechanism underlying firmness formation in tomato fruit is poorly understood. Here, we report a novel role of SlBES1, a transcriptional factor (TF) mediating brassinosteroid (BR) signaling, in tomato fruit softening. We first found that SlBES1 promotes fruit softening during tomato fruit ripening and postharvest storage. RNA-seq analysis suggested that PMEU1, which encodes a pectin de-methylesterification protein, might participate in SlBES1-mediated fruit softening. Biochemical and immunofluorescence assays in SlBES1 transgenic fruits indicated that SlBES1 inhibited PMEU1-related pectin de-methylesterification. Further molecular and genetic evidence verified that SlBES1 directly binds to the E-box in the promoter of PMEU1 to repress its expression, leading to the softening of the tomato fruits. Loss-of-function SlBES1 mutant generated by CRISPR/cas9 showed firmer fruits and longer shelf life during postharvest storage without the color, size and nutritional quality alteration. Collectively, our results indicated the potential of manipulating SlBES1 to regulate fruit firmness via transcriptional inhibition of PMEU1 without negative consequence on visual and nutrition quality.

scholarly journals 45Ca mobility and distribution during ripening and maturation of Rutgers and RIN tomatoes

1986 ◽  
Vol 58 (1) ◽  
pp. 27-32
Author(s):  
L. R. Howard ◽  
A. Uusi-Rauva ◽  
J. J. Laine
Keyword(s):  
Cell Wall ◽  
Fruit Ripening ◽  
Early Stage ◽  
Tomato Fruit ◽  
Tissue Levels ◽  
Tomato Fruit Ripening ◽  
Soluble Calcium ◽  
Low Levels

Radioisotope 45Ca was used to examine changes in levels of bound and soluble calcium during tomato fruit ripening, and the distribution of calcium in different regions of Rutgers and Rin (non-ripening) tomato tissue. Levels of cell wallmiddle lamella bound 45Ca decreased readily in pericarp tissue during ripening of Rutgers tomatoes with only as mall decrease being observed in RIN fruit. No significant increase in soluble 45Ca was observed for either genotype during ripening. Decreasing levels of bound and soluble 45Ca were observed from calyx to blossom end of pericarp tissue in Rutgers and RIN fruits. Low levels of bound 45Ca were found in the inner locular walls at an early stage of tomato ripening. The implication of low levels of cell wall bound calcium in relation to catabolic changes associated with ripening are discussed.

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