US EPA

4309506 

Journal Article 

The flavonoid biosynthetic enzyme chalcone isomerase modulates terpenoid production in glandular trichomes of tomato 

Kang, JH; Mcroberts, J; Shi, F; Moreno, JE; Jones, AD; Howe, GA 

2014 

1 

Plant Physiology
ISSN: 0032-0889
EISSN: 1532-2548 

164 

3 

1161-1174 

English 

24424324 

10.1104/pp.113.233395 

WOS:000332475000006 

Flavonoids and terpenoids are derived from distinct metabolic pathways but nevertheless serve complementary roles in mediating plant interactions with the environment. Here, we show that glandular trichomes of the anthocyanin free (af) mutant of cultivated tomato (Solanum lycopersicum) fail to accumulate both flavonoids and terpenoids. This pleiotropic metabolic deficiency was associated with loss of resistance to native populations of coleopteran herbivores under field conditions. We demonstrate that Af encodes an isoform (SlCHI1) of the flavonoid biosynthetic enzyme chalcone isomerase (CHI), which catalyzes the conversion of naringenin chalcone to naringenin and is strictly required for flavonoid production in multiple tissues of tomato. Expression of the wild-type SlCHI1 gene from its native promoter complemented the anthocyanin deficiency in af. Unexpectedly, the SlCHI1 transgene also complemented the defect in terpenoid production in glandular trichomes. Our results establish a key role for SlCHI1 in flavonoid production in tomato and reveal a link between CHI1 and terpenoid production. Metabolic coordination of the flavonoid and terpenoid pathways may serve to optimize the function of trichome glands in dynamic environments.