argyi by specific PCR of leaves and non-glandular trichomes]

Artemisia stolonifera is a relative of A. argyi. The two species are difficult to be distinguished due to the similarity in leaf shape and have even less distinctive features after processing. This study aims to establish a method to quickly distinguish between them. At the same time, we examined the reasonability and applicability of the specific polymerase chain reaction(PCR) method. The C/T single nucleotide polymorphism was detected at the position 202 of the sequence, based on which specific primers were designed to identify these two species. The PCR with the specific primer JNC-F and the universal primer ITS3R produced a specific band at 218 bp for A. argyi and no band for A. stolonifera, which can be used to detect at least 3% of A. argyi samples mixed in A. stolonifera samples. The PCR with the specific primer KY-F and the universal primer ITS3R produced a specific band at 218 bp for A. stolonifera and no band for A. argyi, which can be used to detect at least 5% of A. stolonifera samples mixed with A. argyi. The limit of detection of the established method was 5 ng DNA. The established PCR method can accurately distinguish between A. stolonifera and A. argyi, which provides an experimental basis for the quality control of A. stolonifera and determines whether the herbs are adulterated.

Promoters of AaGL2 and AaMIXTA-Like1 genes of Artemisia annua direct reporter gene expression in glandular and non-glandular trichomes

Herein, we report cloning and analysis of promoters of GLABRA2 (AaGL2) homolog and a MIXTA-Like (AaMIXTA-Like1) gene from Artemisia annua. The upstream regulatory regions of AaGL2 and AaMIXTA-Like1 showed the presence of several crucial cis-acting elements. Arabidopsis and A. annua seedlings were transiently transfected with the promoter-GUS constructs using a robust agro-infiltration method. Both AaGL2 and AaMIXTA-Like1 promoters showed GUS expression preferentially in Arabidopsis single-celled trichomes and glandular as well as T-shaped trichomes of A. annua. Transgenic Arabidopsis harboring constructs in which AaGL2 or AaMIXTA-Like1 promoters would control GFP expression, showed fluorescence emanating specifically from trichome cells. Our study provides a fast and efficient method to study trichome-specific expression, and 2 promoters that have potential for targeted metabolic engineering in plants.