Plutella xylostella (L.) (Lepidoptera: Plutellidae), the major insect pest of cruciferous crops worldwide shows significant
resistance to almost all classes of insecticides. In order to effectively prevent and manage the insecticidal resistance,
it is crucial to understand the physiological adaptation of insects against insecticides. Identification of insect protein
that interacting with insecticides and characterization of their modification in resistant strains can be done by using
differential proteomics approach. This study focuses on optimizing a sensitive and rapid method for the extraction of
high quality protein of both larva and adult tissues of P. xylostella to be used in two-dimensional gel electrophoresis.
Five extraction methods were evaluated for protein concentration, yields and resolving patterns of one-dimensional
and two-dimensional electrophoresis. The results showed that trichloroacetic acid/acetone extraction methods with
two different concentrations of 2-mercaptoethanol produced the highest protein concentration and yield for both adult
and larva tissues, respectively. Meanwhile, trichloroacetic acid/acetone with dithiothreitol extraction method gave
better separation of spots and intensity for both larva and adult tissues compared to other methods tested. As such, we
concluded that trichloroacetic acid/acetone with dithiothreitol successfully yielded high total protein concentration and
good separation of two-dimensional electrophoresis gel spots in both adult and larva P. xylostella.
Microbial production of natural products using metabolic engineering and synthetic biology approaches often involves
the assembly of multiple gene fragments including regulatory elements, especially when using eukaryotes as hosts.
Traditional cloning strategy using restriction enzyme digestion and ligation are laborious and inflexible owing to the
high number of sequential cloning steps, limited cutting sites and generation of undesired ‘scar’ sequences. In this study,
a homology-based isothermal DNA assembly method was carried out for one-step simultaneous assembly of multiple DNA
fragments to engineer plant phenylpropanoid biosynthesis in Saccharomyces cerevisiae. Rapid construction of yeast
plasmid harboring dual gene expression cassettes was achieved via isothermal assembly of four DNA fragments designed
with 20 bp overlapping sequences. The rate-limiting enzyme of phenylpropanoid pathway, cinnamate 4-hydroxylase
encoded by C4H gene from Polygonum minus was cloned in tandem with yeast promoter and terminator elements of S.
cerevisiae for efficient construction of phenylpropanoid biosynthetic pathway in recombinant yeast. The assembled pAGCAT (C4H-ADH1t-TEF1p) shuttle plasmid and transformation of S. cerevisiae with the plant C4H gene were confirmed
via PCR analysis. Based on these findings, the yeast shuttle plasmid harboring P. minus phenylpropanoid biosynthesis
gene was efficiently constructed to be the starting platform for the production of plant natural products in geneticallyengineered S. cerevisiae.