VvSWEET10 Mediates Sugar Accumulation in Grapes

Area of Science:

• Plant Biology
• Molecular Biology
• Agricultural Science

Background:

• Grape berry ripening involves critical sugar accumulation, directly impacting market value.
• Sugar transporters are essential for berry cell sugar transport, but their specific roles in grapes are unclear.
• Understanding these transporters is key to improving grape quality.

Purpose of the Study:

• To investigate the role of the Sugars Will Eventually be Exported Transporter (SWEET) family, specifically VvSWEET10, in grape sugar accumulation.
• To determine the localization and transport function of VvSWEET10.
• To assess the potential of VvSWEET10 in enhancing grape sugar content.

Main Methods:

• Gene expression analysis of VvSWEET10 during grape ripening.
• Heterologous expression in yeast to characterize VvSWEET10's transport activity.
• Overexpression of VvSWEET10 in grapevine calli and tomato plants.
• RNA sequencing of transgenic grapevine calli.

Main Results:

• VvSWEET10 expression strongly increased at véraison, correlating with sugar accumulation.
• VvSWEET10 functions as a plasma membrane-localized hexose transporter with broad sugar specificity.
• Overexpression of VvSWEET10 led to significant increases in glucose, fructose, and total sugars in transgenic calli and tomatoes.
• RNA sequencing revealed upregulation of sugar transporter and invertase genes in VvSWEET10 overexpressing calli.

Conclusions:

• VvSWEET10 plays a crucial role in mediating sugar accumulation in grape berries.
• VvSWEET10's function in sugar transport and its positive effect on sugar levels provide a target for improving grape quality.
• This research offers valuable insights for enhancing grape berry quality through genetic manipulation of sugar transporters.