Comparison of fruit texture and aquaporin gene expression in papaya “Khak Nual” cultivated under varying conditions

ABSTRACT

The effects of cultivation conditions on the texture of unripe papaya fruit ‘Khak Nual’ were investigated. Fruit from papaya cultivated using raised bed conditions were crisper than those cultivated under open field conditions. Conversely, fruit cultivated under open field conditions were firmer. In all cases, mesocarp cells and intercellular spaces were larger in papaya fruit cultivated in raised beds, reflecting the higher relative humidity (RH) of the cultivation conditions and greater water availability. At harvest, TIP2–1, TIP4–1, SIP1 and PIP1–3 expression was significantly higher in fruit cultivated under raised bed conditions, which correlated with the larger cells of the mesocarp, the RH and the ready availability of water. There also appeared to be a link between aquaporin gene expression and crispness in papaya fruit from both conditions. Expression of TIP2–1 and TIP4–1 correlated with papaya fruit under open field conditions while SIP1 and PIP2–5 correlated with papaya fruit under raised bed conditions. The results clearly demonstrate the effect of cultivation conditions on fruit texture, with water availability being critical in the production of market-preferred crisp fruit with the optimal conditions. These conditions are reflected in the higher expression of the water transport aquaporins which likely control crispness.

KEYWORDS:

• Carica papaya L
• unripe fruit
• water turgor
• firmness
• crispness
• cultivation conditions

Acknowledgements

This work was financially supported by the Agricultural Research Development Agency (Public Organization) (ARDA). We would like to thank the Department of Horticulture, Faculty of Agriculture at Kamphaengsaen, Kasetsart University Kamphaengsaen, Thailand, Center for Agriculture Biotechnology, Kasetsart University, Kamphaengsaen, Nakhon Pathom, and Center of Excellence on Agricultural Biotechnology, Office of the Permanent Secretary, Ministry of Higher Education, Science, Research and Innovation (AG-BIO/MHESI) for support of both laboratory and equipment.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14620316.2023.2206396

Authors’ contributions

PB and WU initiated and designed methodology, investigation, data curation. KT and UD carried out cultivated papaya resources. PS carried out the data analysis. PB wrote, revised the paper. JS and AT supervised the study. All authors have read and agreed to the published version of the manuscript

Data availability statement

Not applicable.

Compliance with ethical standards

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was funded by Agricultural Research Development Agency (Public Organization) (ARDA) [PRP6205031790]