Scientists Discover the Role of Isopentenyltransferase in Lycopene Synthesis in Tomato

Lycopene is an important carotenoid pigment in fruits and vegetables, especially in tomato. While lycopene synthesis is known to be regulated by multiple factors, little is known about their regulation. Isopentenyltransferases (IPTs) are known to catalyze the initial rate-limiting step in the synthesis of cytokinin, an important hormone involved in various aspects of plant growth. However, the other roles of IPTs remain unclear.

A research team led by Yong Zhang from Chongqing University in China studied the function of the SlIPT4 gene, which encodes an isopentenyltransferase, using RNAi-mediated gene silencing in tomato. As expected, silencing of SlIPT4 resulted in accelerated leaf senescence. However, silencing of SlIPT4 also generated never-red orange fruits, suggesting a dramatic reduction in lycopene. Among the lycopene synthesis-related genes, the ZISO gene was found to have significantly reduced expression.

This study revealed that SlIPT4 positively regulates lycopene biosynthesis by affecting the expression of the ZISO gene. SlIPT4 also has crucial roles in leaf senescence. This provides a new light on lycopene biosynthesis in tomato.

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