TITLE:
An Artemisia WD40-Repeat Gene Regulates Multiple Cellular Functions in Arabidopsis
AUTHORS:
Wei Wang, Qing Zhang, Dianjing Guo
KEYWORDS:
WD40 Repeat Protein, Glandular Trichome, Arabidopsis
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.4 No.5,
May
12,
2016
ABSTRACT: In this study, we
isolated a WD40-repeat gene from Artemisia annua glandular trichomes.
This gene shows 69.97% sequence similarity to Arabidopsis TTG1 at aminoacid
level. Sub-cellular localization study shows that AaWD40 protein diffuses in
both cell nucleus and cytosol. The correct nuclear localization of AaWD40 was
observed when co-expressed with AabHLH, a putative A. thaliana AtTTG1 homologue
cloned from Artemisia annua glandular trichomes. When AaWD40 gene was
ectopically over expressed in Arabidopsis transparent testa glabrous1-1 (ttg1-1) mutants of A. thaliana,
PAs production in seeds was restored, and the trichomeless phenotypes of mutant
were rescued. Real-time PCR analysis results revealed that ETC1, CPC, TTG2 and
BAN (the downstream targets of AtTTG1 depend on regulatory complex), which
regulate the epidermal differentiation and anthocyanin biosynthesis were
differentially expressed as a result of AaWD40 over expression. Furthermore,
the CLV1, CLV2, CLV3 and WUS, which are required to maintain the stem-cell
niche of Arabidopsis shoot apex, were also modulated by AaWD40 and Arabidopsis
TTG1. The transcriptions of AP2/ERF, bHLH, MYB, WRKY and NACs family proteins,
which are mostly involved in defense, stress response and development
regulation, were remarkably modulated by AaWD40 over expression. We hypothesize
that WD40 repeat proteins act as a crucial factor in regulating a wide variety
of cellular functions in A. thaliana.