Elucidating the role of SlXTH5 in tomato fruit softening

Wang, Duoduo; Lu, Qianhui; Wang, Xiaomin; Hui, Lisa; Huang, Ning

doi:10.1016/j.hpj.2022.12.005

Cited by 13 publications

(5 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to previous studies, overexpressing SlXTH1 or knockout of SlXTH5 in tomato can increase fruit firmness, while silencing of SlPME2.1 in tomato fruit resulted in an increased rate of softening during ripening, which is consistent with our transcriptome data related to cell wall synthesis and degradation (Fig. 7E) (Miedes et al, 2010; Wang et al, 2023). Moreover, simultaneous inhibition of SlPG and SlEXP1 , or inhibition of SlPL , has been demonstrated to reduce cell wall disassembly and elevate levels of cellulose and hemicellulose.…”

Section: Discussionsupporting

confidence: 92%

A vacuolar invertase geneSlVImodulates sugar metabolism and postharvest fruit quality and resistance in tomato

Wu,

Chen,

et al. 2024

Preprint

View full text Add to dashboard Cite

Sugars act as signaling molecules to modulate various growth processes and enhance plant tolerance to various abiotic and biotic stresses. Moreover, sugars contribute to the post-harvest flavor in fleshy fruit crops. To date, the regulation of sugar metabolism and its effect in plant growth, fruit ripening, postharvest quality and resistance remains not fully understood. In this study, we investigated the role of tomato gene encoding a vacuolar invertase, hydrolyzing sucrose to glucose and fructose.SlVIis specifically expressed during the tomato fruit ripening process. We found that overexpression ofSlVIresulted in increased leaf size and early flowering, while knockout ofSlVIled to increased fruit sucrose content, enhanced fruit firmness, elevated resistance of postharvest fruit toBotrytis cinerea.Moreover, the content of naringenin and total soluble solids was significantly increased inSlVIknockout fruit at postharvest stage. Transcriptome analysis showed a negative feedback regulation triggered by sucrose accumulation inSlVIknockout fruit resulting in a downregulation ofBAM3andAMY2,which are critical for starch degradation. Moreover, genes associated with cell wall, cutin, wax, and flavonoid biosynthesis and pathogen resistance were upregulated inSlVIknockout fruit. Conversely, the expression levels of genes involved in cell wall degradation were decreased in knockout fruit. These results are consistent with the enhanced postharvest quality and resistance. Our findings not only provide new insights into the relationship between tomato fruit sucrose content and postharvest fruit quality, but also suggest new strategies to enhance fruit quality and extend postharvest shelf life.

show abstract

Section: Discussionsupporting

confidence: 92%

A vacuolar invertase geneSlVImodulates sugar metabolism and postharvest fruit quality and resistance in tomato

Wu,

Chen,

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…However, the contribution of xyloglucan depolymerization to fruit softening is still unclear. Recently, SlXTH5 , the dominant XTH expressed during tomato fruit ripening, was knocked out by CRISPR/Cas9, which showed a more intensive LM25 labeling signal than WT but only resulted in slightly firmer fruit ( Wang et al 2023 ). Meanwhile, less cell separation was observed in exp1 cel2 and exp1 mutants, which was also noticed in SlPL and SlPG2a knockout fruit ( Wang et al 2019 ), suggesting that loss of SlExp1 and SlCel2 or SlExp1 alone may affect the function of HG pectin modifiers or lytic enzymes in the TCJ and ML regions.…”

Section: Discussionmentioning

confidence: 99%

“…However, the studies of cell wall genes associated with metabolism of the xyloglucan–cellulose networks have been limited compared to that of pectin, possibly due to reported limited changes in cellulose content and molecular weight and because the molecular basis of xyloglucan depolymerization during fruit ripening is not well characterized ( Maclachlan and Brady 1994 ; Brummell 2006 ; Saladié et al 2006 ; Wang et al 2023 ). The role of xyloglucan and cellulose microfibrils in fruit softening is still obscure.…”

Section: Introductionmentioning

confidence: 99%

Expansin SlExp1 and endoglucanase SlCel2 synergistically promote fruit softening and cell wall disassembly in tomato

Su,

Lin,

Wang

et al. 2023

The Plant Cell

View full text Add to dashboard Cite

Fruit softening, an irreversible process that occurs during fruit ripening, can lead to losses and waste during postharvest transportation and storage. Cell wall disassembly is the main factor leading to loss of fruit firmness, and several ripening-associated cell wall genes have been targeted for genetic modification, particularly pectin modifiers. However, individual knockdown of most cell wall–related genes has had minimal influence on cell wall integrity and fruit firmness, with the notable exception of pectate lyase. Compared to pectin disassembly, studies of the cell wall matrix, the xyloglucan–cellulose framework, and underlying mechanisms during fruit softening are limited. Here, a tomato (Solanum lycopersicum) fruit ripening–associated α-expansin (SlExpansin1/SlExp1) and an endoglucanase (SlCellulase2/SlCel2), which function in the cell wall matrix, were knocked out individually and together using clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9-mediated genome editing. Simultaneous knockout of SlExp1 and SlCel2 enhanced fruit firmness, reduced depolymerization of homogalacturonan-type pectin and xyloglucan, and increased cell adhesion. In contrast, single knockouts of either SlExp1 or SlCel2 did not substantially change fruit firmness, while simultaneous overexpression of SlExp1 and SlCel2 promoted early fruit softening. Collectively, our results demonstrate that SlExp1 and SlCel2 synergistically regulate cell wall disassembly and fruit softening in tomato.

show abstract

“…SlXTH5 recombinant protein can depolymerize xyloglucan rapidly in the presence of an acceptor (xyloglucan oligosaccharides), but cannot induce cucumber ( Cucumis sativus ) hypocotyl wall creep nor affect elastic or plastic extensibilities, suggesting that SlXTH5 is not a CW loosening agent ( Saladié et al 2006 ). More recently, Wang et al (2022) showed that knockout of SlXTH5 by CRISPR resulted in slightly firmer fruit with increased paste viscosity and higher level of LM25 interaction (antibody to xyloglucan), and extracts from SlXTH5 knockout fruit showed lower xyloglucan-degrading activity compared to WT fruit, indicating SlXTH5 is involved in xyloglucan depolymerization. When SlXTH1 , which is expressed during fruit growth, was overexpressed in tomato fruit, however, the firmness was higher and polymerization of hemicelluloses and xyloglucan extractable by a strong alkali solution was reduced compared to WT fruit ( Miedes et al 2010 ).…”

Section: Insights Into Fruit Softening-related Cw Changes From Gene-m...mentioning

confidence: 99%

Insights into cell wall changes during fruit softening from transgenic and naturally occurring mutants

Shi

Grierson

et al. 2023

Plant Physiology

View full text Add to dashboard Cite

Excessive softening during fleshy fruit ripening leads to physical damage and infection that reduce quality and cause massive supply chain losses. Changes in cell wall (CW) metabolism, involving loosening and disassembly of the constituent macromolecules, are the main cause of softening. Several genes encoding CW metabolizing enzymes have been targeted for genetic modification to attenuate softening. At least nine genes encoding CW modifying proteins have increased expression during ripening. Any alteration of these genes could modify CW structure and properties and contribute to softening, but evidence for their relative importance is sparse. The results of studies with transgenic tomato (Solanum lycopersicum), the model for fleshy fruit ripening, investigations with strawberry (Fragaria spp.) and apple (Malus domestica), and results from naturally occurring textural mutants provide direct evidence of gene function and the contribution of CW biochemical modifications to fruit softening. Here we review the revised CW structure model and biochemical and structural changes in CW components during fruit softening and then focus on and integrate the results of changes in CW characteristics derived from studies on transgenic fruits and mutants. Potential strategies and future research directions to understand and control the rate of fruit softening are also discussed.

show abstract

Elucidating the role of SlXTH5 in tomato fruit softening

Cited by 13 publications

References 48 publications

A vacuolar invertase geneSlVImodulates sugar metabolism and postharvest fruit quality and resistance in tomato

A vacuolar invertase geneSlVImodulates sugar metabolism and postharvest fruit quality and resistance in tomato

Expansin SlExp1 and endoglucanase SlCel2 synergistically promote fruit softening and cell wall disassembly in tomato

Insights into cell wall changes during fruit softening from transgenic and naturally occurring mutants

Contact Info

Product

Resources

About