Cell wall disassembly events in boysenberry (Rubus idaeus L. × Rubus ursinus Cham. & Schldl.) fruit development

2007 ◽  
Vol 34 (7) ◽  
pp. 614 ◽  
Author(s):  
Ariel Roberto Vicente ◽  
Ann Powell ◽  
L. Carl Greve ◽  
John M. Labavitch

Boysenberry fruit was harvested at five developmental stages, from green to purple, and changes in pectin and hemicellulose solubilisation and depolymerisation, polymer neutral sugar contents, and the activities of cell wall degrading enzymes were analysed. The high xylose to glucose ratio in the 4% KOH-soluble hemicellulose fraction suggests that xylans are abundant in the boysenberry cell wall. Although the cell wall changes associated with fruit development do not proceed in discrete stages and the cell wall disassembly is a consequence of highly regulated changes occurring in a continuum, the results suggest that the temporal changes in cell wall degradation in boysenberry account for at least three stages: an early stage (green to 75% red colour), associated with metabolism of cellulose and cross-linking glycans; an intermediate period (75 to 100% red colour), characterised by substantial pectin solubilisation without depolymerisation in which α-arabinofuranosidase increases markedly and 50% of the wall arabinose is lost; and a final stage (100% red colour to purple), characterised mainly by a reduction of pectic galactose content and a dramatic increase in pectin depolymerisation associated with higher polygalacturonase, pectin methylesterase, acetyl esterase and β-galactosidase activities. From a biotechnological perspective enzymes involved in pectin matrix disassembly seem to be the better candidates to affect boysenberry fruit late-softening by genetic intervention. A model for cell wall disassembly in boysenberry fruit is proposed.

2021 ◽  
Vol 23 (1) ◽  
pp. 243
Author(s):  
Tong Ning ◽  
Chengjie Chen ◽  
Ganjun Yi ◽  
Houbin Chen ◽  
Yudi Liu ◽  
...  

Though numerous studies have focused on the cell wall disassembly of bananas during the ripening process, the modification of homogalacturonan (HG) during fruit development remains exclusive. To better understand the role of HGs in controlling banana fruit growth and ripening, RNA-Seq, qPCR, immunofluorescence labeling, and biochemical methods were employed to reveal their dynamic changes in banana peels during these processes. Most HG-modifying genes in banana peels showed a decline in expression during fruit development. Four polygalacturonase and three pectin acetylesterases showing higher expression levels at later developmental stages than earlier ones might be related to fruit expansion. Six out of the 10 top genes in the Core Enrichment Gene Set were HG degradation genes, and all were upregulated after softening, paralleled to the significant increase in HG degradation enzyme activities, decline in peel firmness, and the epitope levels of 2F4, CCRC-M38, JIM7, and LM18 antibodies. Most differentially expressed alpha-1,4-galacturonosyltransferases were upregulated by ethylene treatment, suggesting active HG biosynthesis during the fruit softening process. The epitope level of the CCRC-M38 antibody was positively correlated to the firmness of banana peel during fruit development and ripening. These results have provided new insights into the role of cell wall HGs in fruit development and ripening.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 786B-786
Author(s):  
Guiwen W. Cheng ◽  
Donald J. Huber

Softening and liquefaction of `Solar Set' locules was studied by examining cell wall polysaccharides during fruit developmental stages (FDS) of immature green, mature green and breaker. Ethanol insoluble solids (EIS) were sequentially extracted by H2O, CDTA, and Na2CO3 solutions. The chromatograms of gel filtration among the same-solution extracts of EISs from three FDS were similar. Gradient DEAE also yielded similar patterns among FDS in each extraction solvent, even though the patterns of Na2CO3 extracts differed from those of H2O and CDTA extracts. The mole ratio of total polyuronides decreased for Gal, Ara, and Xyl at later FDS in both EIS and in all extracted polymers. Gal had the highest mole percentage of total neutral sugars, followed by Ara, Xyl, and Rha. While the mole percentage of neutral sugars for Gal, Rha, Ara, and Xyl were relatively similar among FDS in H2O extracts, those in CDTA and Na2CO3 extracts either increased or decreased, depending on individual neutral sugar. SDS-PAGE showed increased density in locule-tissue proteins, especially one with a molecular weight of less than 20 kDa, during later FDS. Results indicate that pectin depolymerization was limited and major neutral sugars commonly composing side chains showed a net decrease.


2007 ◽  
Vol 55 (10) ◽  
pp. 4119-4124 ◽  
Author(s):  
Ariel R. Vicente ◽  
Claudia Ortugno ◽  
Ann L. T. Powell ◽  
L. Carl Greve ◽  
John M. Labavitch

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 511D-511
Author(s):  
Alan B. Bennett

Fruit softening is integral to the ripening process. It is an important component of fruit quality, but also initiates deterioration and is a limiting determinant of shelf-life. Intensive research has attempted to elucidate the biochemical and genetic control of fruit softening with the goal of controlling this process as a means to enhance both fruit quality and shelf-life. Current models of fruit softening focus on cell wall disassembly as the major biochemical event regulating fruit softening. Examination of the sequence of cell wall disassembly in ripening Charentais melon fruit suggested that softening could be divided into two distinct phases. The early stage of fruit softening was associated with the regulated disassembly of xyloglucan polymers and the later softening that accompanies over-ripe deterioration was associated with pectin depolymerization. Characterization of cell wall changes in other fruit, including tomato, suggest that this may represent a general model of sequential cell wall disassembly in ripening fruit. Interestingly, the early events of xyloglucan disassembly were not associated with the activation or expression of xyloclucan hydrolases but were associated with the expression of a ripening-regulated expansin gene. Analysis of transgenic tomato fruit with suppressed expansin gene expression or with suppressed polygalacturonase gene expression supports a general model of sequential disassembly of xyloglucan and pectin that control the early and late phases of fruit softening, respectively.


2021 ◽  
Vol 22 (12) ◽  
pp. 6294
Author(s):  
Ricardo I. Castro ◽  
Ana González-Feliu ◽  
Marcelo Muñoz-Vera ◽  
Felipe Valenzuela-Riffo ◽  
Carolina Parra-Palma ◽  
...  

The role of auxin in the fruit-ripening process during the early developmental stages of commercial strawberry fruits (Fragaria x ananassa) has been previously described, with auxin production occurring in achenes and moving to the receptacle. Additionally, fruit softening is a consequence of the depolymerization and solubilization of cell wall components produced by the action of a group of proteins and enzymes. The aim of this study was to compare the effect of exogenous auxin treatment on the physiological properties of the cell wall-associated polysaccharide contents of strawberry fruits. We combined thermogravimetric (TG) analysis with analyses of the mRNA abundance, enzymatic activity, and physiological characteristics related to the cell wall. The samples did not show a change in fruit firmness at 48 h post-treatment; by contrast, we showed changes in the cell wall stability based on TG and differential thermogravimetric (DTG) analysis curves. Less degradation of the cell wall polymers was observed after auxin treatment at 48 h post-treatment. The results of our study indicate that auxin treatment delays the cell wall disassembly process in strawberries.


2005 ◽  
Vol 130 (4) ◽  
pp. 643-648 ◽  
Author(s):  
Rumphan Koslanund ◽  
Douglas D. Archbold ◽  
Kirk W. Pomper

Pawpaw fruit were harvested at the advent of the ripening process and were ripened at room temperature. Based on fruit firmness and respiration and ethylene production rates at harvest and during ripening, fruit were classified into one of four categories: preripening (no to very slight loss of firmness; preclimacteric), early ripening (some softening; increasing rates of ethylene and CO2 production), mid-ripening (soft; at or just past climacteric), and late ripening (very soft; postclimacteric). The activities of the cell-wall degrading enzymes polygalacturonase (PG), endo-(1→4)ß-D-glucanase (EGase), and endo-ß-1,4-mannanase (MAN) were low in the preripening and early ripening stages, increased dramatically by mid-ripening coincident with the respiratory and ethylene climacterics, and decreased at late ripening. However, pectin methylesterase (PME) activity per milligram protein was highest at the green stage when the fruit firmness was high and decreased as ripening progressed. Tissue prints indicated both EGase and MAN increased as ripening proceeded. The EGase activity was evident near the seeds and the surface of the fruit at preripening and eventually spread throughout, while MAN activity was evident near the fruit surface at preripening and was progressively expressed throughout the flesh as fruit ripened. The greatest decline in fruit firmness occurred between pre- and early ripening, before the peak activities of PG, EGase, and MAN, although MAN exhibited the greatest relative increase of the three enzymes in this period. The data suggest that PME may act first to demethylate polygalacturonate and may be followed by the action of the other enzymes resulting in cell wall disassembly and fruit softening in pawpaw.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vihang S. Thite ◽  
Anuradha S. Nerurkar

Abstract After chemical pretreatment, improved amenability of agrowaste biomass for enzymatic saccharification needs an understanding of the effect exerted by pretreatments on biomass for enzymatic deconstruction. In present studies, NaOH, NH4OH and H2SO4 pretreatments effectively changed visible morphology imparting distinct fibrous appearance to sugarcane bagasse (SCB). Filtrate analysis after NaOH, NH4OH and H2SO4 pretreatments yielded release of soluble reducing sugars (SRS) in range of ~0.17–0.44%, ~0.38–0.75% and ~2.9–8.4% respectively. Gravimetric analysis of pretreated SCB (PSCB) biomass also revealed dry weight loss in range of ~25.8–44.8%, ~11.1–16.0% and ~28.3–38.0% by the three pretreatments in the same order. Release of soluble components other than SRS, majorly reported to be soluble lignins, were observed highest for NaOH followed by H2SO4 and NH4OH pretreatments. Decrease or absence of peaks attributed to lignin and loosened fibrous appearance of biomass during FTIR and SEM studies respectively further corroborated with our observations of lignin removal. Application of commercial cellulase increased raw SCB saccharification from 1.93% to 38.84%, 25.56% and 9.61% after NaOH, H2SO4 and NH4OH pretreatments. Structural changes brought by cell wall degrading enzymes were first time shown visually confirming the cell wall disintegration under brightfield, darkfield and fluorescence microscopy. The microscopic evidence and saccharification results proved that the chemical treatment valorized the SCB by making it amenable for enzymatic saccharification.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shujuan Tian ◽  
Jiao Jiang ◽  
Guo-qi Xu ◽  
Tan Wang ◽  
Qiyan Liu ◽  
...  

Abstract Background Kinesin (KIN) as a motor protein is a versatile nano-machine and involved in diverse essential processes in plant growth and development. However, the kinesin gene family has not been identified in watermelon, a valued and nutritious fruit, and yet their functions have not been characterized. Especially, their involvement in early fruit development, which directly determines the size, shape, yield and quality of the watermelon fruit, remains unclear. Results In this study, we performed a whole-genome investigation and comprehensive analysis of kinesin genes in C. lanatus. In total, 48 kinesins were identified and categorized into 10 kinesin subfamilies groups based on phylogenetic analysis. Their uneven distribution on 11 chromosomes was revealed by distribution analysis. Conserved motif analysis showed that the ATP-binding motif of kinesins was conserved within all subfamilies, but not the microtubule-binding motif. 10 segmental duplication pairs genes were detected by the syntenic and phylogenetic approaches, which showed the expansion of the kinesin gene family in C. lanatus genome during evolution. Moreover, 5 ClKINs genes are specifically and abundantly expressed in early fruit developmental stages according to comprehensive expression profile analysis, implying their critical regulatory roles during early fruit development. Our data also demonstrated that the majority of kinesin genes were responsive to plant hormones, revealing their potential involvement in the signaling pathways of plant hormones. Conclusions Kinesin gene family in watermelon was comprehensively analyzed in this study, which establishes a foundation for further functional investigation of C. lanatus kinesin genes and provides novel insights into their biological functions. In addition, these results also provide useful information for understanding the relationship between plant hormone and kinesin genes in C. lanatus.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 794
Author(s):  
Luca M. Scolari ◽  
Robert D. Hancock ◽  
Pete E. Hedley ◽  
Jenny Morris ◽  
Kay Smith ◽  
...  

‘Crumbly’ fruit is a developmental disorder in raspberry that results in malformed and unsaleable fruits. For the first time, we define two distinct crumbly phenotypes as part of this work. A consistent crumbly fruit phenotype affecting the majority of fruits every season, which we refer to as crumbly fruit disorder (CFD) and a second phenotype where symptoms vary across seasons as malformed fruit disorder (MFD). Here, segregation of crumbly fruit of the MFD phenotype was examined in a full-sib family and three QTL (Quantitative Trait Loci) were identified on a high density GbS (Genotype by Sequencing) linkage map. This included a new QTL and more accurate location of two previously identified QTLs. A microarray experiment using normal and crumbly fruit at three different developmental stages identified several genes that were differentially expressed between the crumbly and non-crumbly phenotypes within the three QTL. Analysis of gene function highlighted the importance of processes that compromise ovule fertilization as triggers of crumbly fruit. These candidate genes provided insights regarding the molecular mechanisms involved in the genetic control of crumbly fruit in red raspberry. This study will contribute to new breeding strategies and diagnostics through the selection of molecular markers associated with the crumbly trait.


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