Overexpression of PslTIR1 in Tomato alters Fruit Shelf-life Characteristics

The release of auxin response factors (ARFs) from auxin repressors allows ARFs to mediate auxin-responsive changes in downstream gene transcription. To understand the role of auxin during fruit development, a plum auxin receptor, PslTIR1, was previously been characterized by researchers from the University of Guelph. The team used tomato (Solanum lycopersicum) to study the changes associated with the overexpression of PslTIR1.

PslTIR1 was found as a positive regulator of auxin-signalling in the development of leaves and fruits. This was manifested by the entire leaf morphology of transgenic tomato plants compared to the wild-types. Moreover, transgenic tomato plants produced parthenocarpic fruits, a characteristic property of auxin hypersensitivity.

Ethylene production associated with the ripening of fruits was not significantly altered in the transgenics. However, several genes encoding proteins involved in cell-wall degradation were upregulated, enhancing fruit softening rate leading to short shelf-life of transgenic tomatoes.

The study reveals the role of PslTIR1 in regulating leaf morphology, fruit development and fruit softening-associated ripening. These demonstrate that auxin accelerates fruit softening independently of ethylene action.

For more information, read the full article in BMC Plant Biology.