תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםG. Hivert - The Hebrew University of Jerusalem, Department of Vegetable Crops, Rehovot, Israel
J. Hirschberg - The Hebrew University of Jerusalem, Department of Genetics, Jerusalem, Israel
N. Dudareva,
The tomato (Solanum lycopersicum L.) is the highest-value vegetable crop worldwide. Volatile compounds such as mono- and sesquiterpenes may contribute to the acceptable flavor of tomatoes but commercial tomatoes contain low amounts of such. In contrast, wild relatives of tomato display high content and variation in the mono- and sesquiterpene compositions in their fruit. Preliminary evidence indicates that the formation of monoterpenes in cultivated tomato fruit is limited by the availability of the precursor geranyl diphosphate (GPP). The structural genes involved in GPP synthesis have not been identified in tomato fruit. In other plants GPP is produced by the action of geranyl diphosphate synthase (GPPS). GPPS is often a heteromeric enzyme consisting of a small (GPPS.SSU) and a large subunit (GPPS.LSU). GPPS.LSU is similar to geranylgeranyl diphosphate (GGPP) synthases involved in diterpene and carotenoid biosynthesis. GPPS.SSU is usually inactive by itself but upon interaction with the GPPS.LSU directs the synthesis to GPP. We have isolated a gene (LeGPPS.SSU) that is homologous to other plant GPPS.SSU and is present in the tomato genome and its wild relatives, but almost not expressed in cultivated tomato fruits. We also demonstrated in enzymatic assays the ability of LeGPPS.SSU to support GPP formation with interaction of the tomato LeGGPPS2. In addition, the levels of the volatile terpenes of wild tomatoes generally correlated with the levels of expression of LeGPPS.SSU in the fruit. It seems that LeGPPS.SSU was down regulated during the domestication of tomato which resulted in the loss of the volatile terpenes.
G. Hivert - The Hebrew University of Jerusalem, Department of Vegetable Crops, Rehovot, Israel
J. Hirschberg - The Hebrew University of Jerusalem, Department of Genetics, Jerusalem, Israel
N. Dudareva,
The tomato (Solanum lycopersicum L.) is the highest-value vegetable crop worldwide. Volatile compounds such as mono- and sesquiterpenes may contribute to the acceptable flavor of tomatoes but commercial tomatoes contain low amounts of such. In contrast, wild relatives of tomato display high content and variation in the mono- and sesquiterpene compositions in their fruit. Preliminary evidence indicates that the formation of monoterpenes in cultivated tomato fruit is limited by the availability of the precursor geranyl diphosphate (GPP). The structural genes involved in GPP synthesis have not been identified in tomato fruit. In other plants GPP is produced by the action of geranyl diphosphate synthase (GPPS). GPPS is often a heteromeric enzyme consisting of a small (GPPS.SSU) and a large subunit (GPPS.LSU). GPPS.LSU is similar to geranylgeranyl diphosphate (GGPP) synthases involved in diterpene and carotenoid biosynthesis. GPPS.SSU is usually inactive by itself but upon interaction with the GPPS.LSU directs the synthesis to GPP. We have isolated a gene (LeGPPS.SSU) that is homologous to other plant GPPS.SSU and is present in the tomato genome and its wild relatives, but almost not expressed in cultivated tomato fruits. We also demonstrated in enzymatic assays the ability of LeGPPS.SSU to support GPP formation with interaction of the tomato LeGGPPS2. In addition, the levels of the volatile terpenes of wild tomatoes generally correlated with the levels of expression of LeGPPS.SSU in the fruit. It seems that LeGPPS.SSU was down regulated during the domestication of tomato which resulted in the loss of the volatile terpenes.
