scholarly journals Evaluation of Cell Wall Modification in Two Strawberry Cultivars with Contrasted Softness

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1100
Author(s):  
Ricardo I. Castro ◽  
Marcelo Muñoz-Vera ◽  
Luis Morales-Quintana

During the ripening process of fruit, the solubilization and depolymerization of cell wall components takes place, which results in the loss of firmness or the softening of fruit. Recently, we reported that two different strawberry cultivars (“Cristal” and “Portola”) exhibit differences in their fruit softening values, with “Cristal” being the firmest and “Portola” being the softest. In the present work, we performed a comparative study of the changes in the physicochemical properties of the cell wall-associated polysaccharide contents of these two strawberry fruit cultivars via thermogravimetric analysis (TGA), combined with the first derivative of the thermogram (DTG) curves and morphological studies using scanning electron microscopy (SEM). The “Cristal” sample showed higher thermal stability than the “Portola” sample. Additionally, differences were observed between the “Cristal” and “Portola” samples at different stages, principally in Region II (temperatures between 200 °C and 350 °C), with a higher thermal stability evident in the green stage of the two cultivars. Notably, a higher thermal stability was observed in the green stage of the “Portola” sample. The highest percentage of cumulative depolymerization (PCD) was observed in the ripe stage of the “Portola” sample. The DTG curve showed four maximum peaks of degradation, which occurred between 170 °C and 350 °C. Finally, the existence of a relationship between fruit firmness and thermal stability was demonstrated for the two cultivars. This relationship was based on the morphological studies conducted using SEM, which provided new evidence through which to understand the changes within the cell wall polymers of these two strawberry cultivars during the ripening process.

1992 ◽  
Vol 117 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Elizabeth J. Mitcham ◽  
Roy E. McDonald

`Keitt' and `Tommy Atkins' mango (Mangifera indica L.) fruit were evaluated for selected ripening criteria at six ripening stages, from mature green to overripe. `Tommy Atkins' mangos developed more red and yellow pigmentation (CIE a* and b*) in peel and mesocarp tissues than `Keitt'. The outer mesocarp of `Keitt' remained firm longer than `Tommy Atkins', and the inner mesocarp was softer than the outer at each stage in both cultivars. Cell wall neutral sugars, particularly arabinosyl, rhamnosyl, and galactosyl residues, decreased with ripening in both cultivars. `Keitt' had more loosely associated, chelator-soluble pectin, accumulated more soluble polyuronides, and retained more total pectin at the ripe stage than `Tommy Atkins'. Both cultivars had similar polygalacturonase (EC 3.2.1.15) activity which increased with ripening. The amount and molecular weight of cell wall hemicellulose decreased with ripening in both cultivars. These data indicate that enzymatic and/or nonenzymatic processes, in addition to polygalacturonase activity, are involved in the extensive softening of mango fruit.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Guiming Deng ◽  
Fangcheng Bi ◽  
Jing Liu ◽  
Weidi He ◽  
Chunyu Li ◽  
...  

AbstractBackgroundBanana plant height is an important trait for horticultural practices and semi-dwarf cultivars show better resistance to damages by wind and rain. However, the molecular mechanisms controlling the pseudostem height remain poorly understood. Herein, we studied the molecular changes in the pseudostem of a semi-dwarf banana mutant Aifen No. 1 (Musaspp. Pisang Awak sub-group ABB) as compared to its wild-type dwarf cultivar using a combined transcriptome and metabolome approach.ResultsA total of 127 differentially expressed genes and 48 differentially accumulated metabolites were detected between the mutant and its wild type. Metabolites belonging to amino acid and its derivatives, flavonoids, lignans, coumarins, organic acids, and phenolic acids were up-regulated in the mutant. The transcriptome analysis showed the differential regulation of genes related to the gibberellin pathway, auxin transport, cell elongation, and cell wall modification. Based on the regulation of gibberellin and associated pathway-related genes, we discussed the involvement of gibberellins in pseudostem elongation in the mutant banana. Genes and metabolites associated with cell wall were explored and their involvement in cell extension is discussed.ConclusionsThe results suggest that gibberellins and associated pathways are possibly developing the observed semi-dwarf pseudostem phenotype together with cell elongation and cell wall modification. The findings increase the understanding of the mechanisms underlying banana stem height and provide new clues for further dissection of specific gene functions.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4976 ◽  
Author(s):  
Panpan Hu ◽  
Gang Li ◽  
Xia Zhao ◽  
Fengli Zhao ◽  
Liangjie Li ◽  
...  

Strawberry (Fragaria × ananassa) is an ideal plant for fruit development and ripening research due to the rapid substantial changes in fruit color, aroma, taste, and softening. To gain deeper insights into the genes that play a central regulatory role in strawberry fruit development and ripening characteristics, transcriptome profiling was performed for the large green fruit, white fruit, turning fruit, and red fruit stages of strawberry. A total of 6,608 differentially expressed genes (DEGs) with 2,643 up-regulated and 3,965 down-regulated genes were identified in the fruit development and ripening process. The DEGs related to fruit flavonoid biosynthesis, starch and sucrose biosynthesis, the citrate cycle, and cell-wall modification enzymes played important roles in the fruit development and ripening process. Particularly, some candidate genes related to the ubiquitin mediated proteolysis pathway and MADS-box were confirmed to be involved in fruit development and ripening according to their possible regulatory functions. A total of fiveubiquitin-conjugating enzymesand 10MADS-box transcription factorswere differentially expressed between the four fruit ripening stages. The expression levels of DEGs relating to color, aroma, taste, and softening of fruit were confirmed by quantitative real-time polymerase chain reaction. Our study provides important insights into the complicated regulatory mechanism underlying the fruit ripening characteristics inFragaria × ananassa.


2020 ◽  
Vol 71 (18) ◽  
pp. 5631-5644 ◽  
Author(s):  
Zhong Tang ◽  
Yijie Wang ◽  
Axiang Gao ◽  
Yuchen Ji ◽  
Baoyun Yang ◽  
...  

Abstract Straighthead disease is a physiological disorder in rice with symptoms of sterile spikelets, distorted husks, and erect panicles. Methylated arsenic species have been implicated as the causal agent of the disease, but direct evidence is lacking. Here, we investigated whether dimethylarsinic acid (DMA) causes straighthead disease and its effect on the transcriptome of young panicles. DMA addition caused typical straighthead symptoms in hydroponic culture, which were alleviated by silicon addition. DMA addition to soil at the tillering to flowering stages induced straighthead disease. Transgenic rice expressing a bacterial arsenite methyltransferase gene gained the ability to methylate arsenic to mainly DMA, with the consequence of inducing straighthead disease. Field surveys showed that seed setting rate decreased with increasing DMA concentration in the husk, with an EC50 of 0.18 mg kg−1. Transcriptomic analysis showed that 364 and 856 genes were significantly up- and down-regulated, respectively, in the young panicles of DMA-treated plants compared with control, whereas Si addition markedly reduced the number of genes affected. Among the differentially expressed genes, genes related to cell wall modification and oxidative stress responses were the most prominent, suggesting that cell wall metabolism is a sensitive target of DMA toxicity and silicon protects against this toxicity.


2019 ◽  
Vol 77 (9) ◽  
pp. 4469-4488 ◽  
Author(s):  
Umesh Somaji Waware ◽  
A. M. S. Hamouda ◽  
Dipanwita Majumdar

Abstract Polyaniline (PA), the versatile conducting polymer, owing to its tunable optoelectronic properties, facile preparation methodology and reversible redox behavior, has elicited much interest among current researchers, particularly in the fields of energy generation storage devices, protective coatings and electrochemical sensors. However, its commercialization has been much restricted due to low solution processability and thermal stability. Recent studies reveal that the above-mentioned challenges can effectively be addressed by copolymerization of PA with suitable components. In addition, the properties of copolymers could be modified and tuned by varying the monomer ratios. Thus, the present work is concerned with the fabrication of poly(aniline-co-3-nitroaniline) with varying compositions obtained by in situ oxidative copolymerization of aniline and 3-nitroaniline by altering the molar ratio of monomers. Optimization of the physicochemical properties such as UV–visible absorption, solubility, thermal stability, electrical conductivity and dielectric signatures, particle size and morphology was achieved by varying the composition of monomeric substituents in these copolymers. Smoother morphology of the copolymer films was revealed by morphological studies via AFM technique and supported by particle size distribution study. The physicochemical trends demonstrated that proper proportions of nitro (–NO2) group in the polymer chain are essential to achieve desired optimal physicochemical properties. Therefore, copolymers are ideally appropriate for multifaceted applications and would promote wider usage of conjugated polymers in various fields of organic-based optoelectronic as well as energy storage devices in the near future.


Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 755
Author(s):  
Angyan Ren ◽  
Rana Ahmed ◽  
Huanyu Chen ◽  
Linhe Han ◽  
Jinhao Sun ◽  
...  

Cell walls are basically complex with dynamic structures that are being involved in several growth and developmental processes, as well as responses to environmental stresses and the defense mechanism. Pectin is secreted into the cell wall in a highly methylesterified form. It is able to perform function after the de-methylesterification by pectin methylesterase (PME). Whereas, the pectin methylesterase inhibitor (PMEI) plays a key role in plant cell wall modification through inhibiting the PME activity. It provides pectin with different levels of degree of methylesterification to affect the cell wall structures and properties. The PME activity was analyzed in six tissues of Sorghum bicolor, and found a high level in the leaf and leaf sheath. PMEI families have been identified in many plant species. Here, a total of 55 pectin methylesterase inhibitor genes (PMEIs) were identified from S. bicolor whole genome, a more detailed annotation of this crop plant as compared to the previous study. Chromosomal localization, gene structures and sequence characterization of the PMEI family were analyzed. Moreover, cis-acting elements analysis revealed that each PMEI gene was regulated by both internal and environmental factors. The expression patterns of each PMEI gene were also clustered according to expression pattern analyzed in 47 tissues under different developmental stages. Furthermore, some SbPMEIs were induced when treated with hormonal and abiotic stress. Taken together, these results laid a strong foundation for further study of the functions of SbPMEIs and pectin modification during plant growth and stress responses of cereal.


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