Acylsugar biosynthetic pathway diversity in tomato species. (a) The acylsugar biosynthetic pathways characterized from the cultivated tomato S. lycopersicum and wild relative S. pennellii. IPMS3, isopropylmalate synthase-like 3; ASAT, acylsucrose acyltransferase; ASFF1, acylsucrose fructofuranosidase 1. (b) Left, recruitment of the feedback insensitive and trichome gland cell expressed SlIPMS3 in cultivated tomato S. lycopersicum for biosynthesis of acylsugar isoC5-CoA acyl chain precursor. Right, the IPMS3 allele is further truncated at the C-terminus and inactivated in S. pennellii LA0716, diverting the acyl CoA precursor pathway to produce more isoC4-CoA derived acylsugars. (c) Examples of how small numbers of amino acid differences influence ASAT2 and ASAT3 enzyme acyl CoA donor and sugar core substrate preference and promiscuity. The tomato species from which the ASAT alleles are derived are labeled beneath the product(s). (d) Functional diversification of ASAT3 through gene duplication, neofunctionalization, and loss in the tomato clade.