GLYCOALKALOID METABOLISM1 is required for steroidal alkaloid glycosylation and prevention of phytotoxicity in tomato

Maxim Itkin, Ilana Rogachev, Noam Alkan, Tally Rosenberg, Sergey Malitsky, Laura Masini, Sagit Meir, Yoko Iijima, Koh Aoki, Ric de Vos, Dov Prusky, Saul Burdman, Jules Beekwilder, Asaph Aharoni*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

173 Scopus citations

Abstract

Steroidal alkaloids (SAs) are triterpene-derived specialized metabolites found in members of the Solanaceae family that provide plants with a chemical barrier against a broad range of pathogens. Their biosynthesis involves the action of glycosyltransferases to form steroidal glycoalkaloids (SGAs). To elucidate the metabolism of SGAs in the Solanaceae family, we examined the tomato (Solanum lycopersicum) GLYCOALKALOID METABOLISM1 (GAME1) gene. Our findings imply that GAME1 is a galactosyltransferase, largely performing glycosylation of the aglycone tomatidine, resulting in SGA production in green tissues. Downregulation of GAME1 resulted in an almost 50% reduction in a-tomatine levels (the major SGA in tomato) and a large increase in its precursors (i.e., tomatidenol and tomatidine). Surprisingly, GAME1-silenced plants displayed growth retardation and severe morphological phenotypes that we suggest occur as a result of altered membrane sterol levels caused by the accumulation of the aglycone tomatidine. Together, these findings highlight the role of GAME1 in the glycosylation of SAs and in reducing the toxicity of SA metabolites to the plant cell.

Original languageAmerican English
Pages (from-to)4507-4525
Number of pages19
JournalPlant Cell
Volume23
Issue number12
DOIs
StatePublished - Dec 2011

Fingerprint

Dive into the research topics of 'GLYCOALKALOID METABOLISM1 is required for steroidal alkaloid glycosylation and prevention of phytotoxicity in tomato'. Together they form a unique fingerprint.

Cite this