Abstract:
Cembranoids and sucrose esters are the main secretions of glandular trichomes. In order to explore the characteristics of chemical components in different tobacco glandular trichome secretions, tobacco varieties TI1068 and TI35 (
Nicotiana tabacum), which have different types of glandular trichomes, were used to analyze the morphological structure of trichomes, the chemical components on leaf surface, the expression level of genes related to cembranoid biosynthesis and aphid preference. Trichome morphological observations showed that TI1068 and TI35 had three types of trichomes:long stalk glandular trichomes, short stalk glandular trichomes, and protective trichomes. TI1068 mainly had long stalk glandular trichomes and few protective trichomes, while TI35 mainly had protective trichomes and few long stalk glandular trichomes. There was no significant difference in the number of short stalk glandular trichomes between TI1068 and TI35. Leaf surface chemical analysis indicated that both TI1068 and TI35 contained cembranoids, sucrose esters and alkanes, while the total content of the three chemicals in TI1068 was 10 times as that of TI35. The main components on the leaf surface of TI1068 were cembranoids and sucrose esters, while those of TI35 were alkanes. There was no obvious difference in the types and total amount of alkanes between TI1068 and TI35. The expression levels of
GGPPS,
CBTS and
CYP71D16 related to cembranoid biosynthetic were higher in TI1068 than those in TI35. Aphid preference test showed that aphids significantly preferred TI35 rather than TI1068.