in many plants and in many plant cell types, as the
products of these reactions are intermediates for a
wide range of plant secondary products. cDNA
and in some cases, genomic clones have been
characterized from many plants for three of these
enzymes: phenylalanine ammonia lyase (PAL)
[12–16], cinnamate 4-hydroxylase (Ca4H) [17–21]
and caffeic O-methyl transferase, (COMT) [22–
24]. In this report we describe the transcript abundance
for Pal, Ca4h, and Comt as a function of
fruit developmental stage, fruit tissue type, and
degree of pungency in Capsicum spp. cDNA clones
for Pal, Ca4h, and Comt were isolated from a
library of C. chinense c.v. haban˜ero placental transcripts
using heterologous probes. The haban˜ero
cDNA clones were then used to monitor transcript
levels in chile fruit. Based on the differential patterns
of expression of these three genes, we devised
a screening strategy to isolate cDNAs for additional
capsaicinoid biosynthetic enzymes.