https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Transcriptomic and metabolomics responses to elevated cell wall invertase activity during tomato fruit set https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:31530 Wed 11 Apr 2018 15:47:21 AEST ]]> Postharvest UV-C treatment combined with 1-methylcyclopropene (1-MCP), followed by storage in continuous low-level ethylene atmosphere, improves the quality of tomatoes https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33432 Solanum lycopersicum L. cv Neang Pich) were exposed to 13.6 kJ m-2 UV-C or 0.5 µL L-1 1-MCP or combination of 13.6 kJ m-2 UV-C and 0.5 µL L-1 1-MCP, with appropriate untreated controls. After treatment, tomatoes were stored in air containing 0.1 µL L-1 ethylene at 20°C and 100% RH. The untreated fruit ripened significantly faster than those of all other treatments. UV-C treatment alone was able to delay fruit ripening by up to 5 days longer compared to untreated fruits whilst the additional of 1-MCP further delayed fruit ripening. UV-C and 1-MCP treatments alone or in combination had significantly slower ethylene production rates throughout the storage period. The fruit treated with the combination of 1-MCP and UV-C was significantly firmer and had higher total phenolic content compared to that of the other treatments. However, there was no difference between treatments in soluble solids content/titratable acids ratio, chlorophyll content, lycopene content and total antioxidant activity. These results show that UV-C and 1-MCP treatment delay ripening and improve the quality of tomatoes in the presence of low-level ethylene during storage. This new treatment could be used to extend the shelf-life of mature green tomatoes through the supply chain without the use of refrigeration.]]> Wed 04 Sep 2019 09:56:41 AEST ]]> Evidence for a specific and critical role of mitogen-activated protein kinase 20 in uni-to-binucleate transition of microgametogenesis in tomato https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32990 SlMPK20 or its knockout using CRISPR/Cas9 significantly reduced or completely abolished pollen viability, respectively, with no effects on maternal fertility. Cell biology and gene expression analyses established that SlMPK20 exerts its role specifically at the uni-to-binucleate transition during microgametogenesis. This assertion is based on the findings that the transgenic pollen was largely arrested at the binucleate stage with the appearance of subcellular abnormality at the middle uninucleate microspore stage; and SlMPK20 mRNA and SlMPK20-GUS signals were localized in the tetrads, uninuclear microspores and binuclear pollen grains but not in microspore mother cells or mature pollen grains. Transcriptomic and proteomic analyses revealed that knockout of SlMPK20 significantly reduced the expression of a large number of genes controlling sugar and auxin metabolism and signaling in anthers. Finally, protein-protein interaction assays identified SlMYB32 as a putative target protein of SlMPK20. We conclude that SlMPK20 specifically regulates post-meiotic pollen development through modulating sugar and auxin metabolism and signaling.]]> Thu 28 Sep 2023 15:08:10 AEST ]]> Use of low-pressure storage to improve the quality of tomatoes https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:31216 Solanum lycopersicum cv. Neang Pich) were stored at low pressure (4 kPa) at 10°C for 11 days with 100% RH. Fruit quality was examined upon removal and after being transferred to normal atmosphere (101 kPa) at 20°C for 3 days. Weight loss was significantly lower in fruits which were stored at low pressure (4 kPa) than in fruits that were stored at regular atmosphere (101 kPa) at 10°C. Fruits that were stored at low pressure (4 kPa) reduced calyx browning by 12.5%, and calyx rots by 16%, compared to fruits that were stored at regular atmosphere (101 kPa) at 10°C. Fruit firmness was not significantly different between fruits stored at low pressures (4 kPa) and the normal atmosphere (101 kPa), with an average firmness of 14 N after fruits were stored at 10°C for 11 days. There was no difference in the SSC/TA ratio. The results suggest that a low pressure of 4 kPa at 10°C has potential as an alternative, non-chemical postharvest treatment to improve tomato quality during storage.]]> Mon 23 Sep 2019 12:38:29 AEST ]]>