Impact of exogenous salicylic acid treatment on the cell wall metabolism and ripening process in postharvest tomato fruit stored at ambient temperature

Abstract

Tomato is a climacteric fruit susceptible to rapid softening and ripening after harvest. In this study, the changes of physicochemical characters, cell wall‐degrading enzymes, cell wall compositions and ethylene production of ‘Hisar Arun’ and ‘BSS‐488’ tomato fruits were investigated under the influence of salicylic acid treatment. Salicylic acid treatment effectively delayed firmness decline and increase in PLW, TSS and lycopene content. The treated fruits maintained the integrity of cell wall composition by delay in increase in activities of cell wall‐degrading enzymes (pectin methylesterase, polygalacturonase and cellulose) and cell wall components (cellulose, hemicellulose, lignin and pectin) decline. Moreover, salicylic acid treatments significantly suppress expression level of ethylene‐producing genes (ACO1 and ACS2) and inhibited ethylene production during storage. Overall, the salicylic acid‐induced delay in the ripening process occurs via the strong inhibition of ethylene biosynthesis, lowered cell wall‐degrading enzyme activities and slowed cell wall degradation.

Molecular and Genetic Events Determining the Softening of Fleshy Fruits: A Comprehensive Review

“…The transient overexpression of FaAOC and FaAOS , two key genes involved in jasmonic acid synthesis, accelerated strawberry fruit softening [ 108 , 109 ]. Treatment with SA effectively delayed fruit firmness decline in tomato by strongly inhibiting the expression of ETH biosynthesis genes ( ACO1 and ACS2 ) and reducing the activity of cell-wall-degrading enzymes [ 110 ]. In summary, the softening process is controlled by phytohormones and also involves the co-regulation of other factors ( Figure 2 ).…”

“…RIN (ripening inhibitor) is an important MADS-Box TF involved in all aspects of fruit ripening and directly targets many ripening-related genes ( PG , TBG4 , EXP1 , CEL2 , etc.). Compared to the wild tomato fruit, the fruit of ripening inhibitor ( rin ), a tomato natural ripening mutant, softens slowly and has a long shelf life [ 110 ]. SlMBP8, MADS-Box TFs, has also been reported to play an important role in fruit softening.…”

Transcriptome Integrated with Metabolome Reveals the Molecular Mechanism of Phytoplasma Cherry Phyllody Disease on Stiff Fruit in Chinese Cherry (Cerasus pseudocerasus L.)

“…Up-accumulated phenylalanine metabolism pathway is directly connected to SA synthesis, and up-accumulated flavonoid biosynthesis is directly connected to pathogen resistance (Figure 5). SAR arouses the resistance genes to create phytoalexins and reinforce the cell wall [21,25,26]. DAMs analysis showed up-accumulated phytoalexins including chlorogenic acid, sakuranetin, wighteone, and capsidiol [27].…”

“…The cycle of homogenization and sonication was repeated for three times. The extracting solution was put on a constant temperature shaker over night at 4 • C before centrifugation at 12,000 rpm for 15 min at 4 • C. The supernatant liquid was carefully filtered through a 0.22 µm microporous membrane (BKMAM, China), and then the resulting supernatant liquid was diluted 5 times with mixture solution (containing internal standard, the proportion of methanol and pure water is 3:1) and vortexed at 60 Hz for 30 s. Then, 30 µL of sample from each vial were used as QC samples, which were stored at −80 • C before the ultra-performance liquid chromatographymass spectroscopy (UPLC-MS, UPLC: model ExionLC AD, AB Sciex Technologies, Umeå, Sweden; MS: model QTrap 6500+, AB Sciex Technologies, Umeå, Sweden) analysis [21].…”

“…The current study took the lower organic phase after 13,000 rpm centrifugation for them at 4 • C for 5 min and then dried the organic phase with nitrogen in dark condition. After that, 250 µL of them was used to dissolve in methanol (contained 0.1% formic acid), and they were finally detected by UPLC-MS [21].…”