An estrogen receptor‐based transactivator XVE mediates highly inducible gene expression in transgenic plants

Abstract

SummaryWe have developed an estrogen receptor-based chemical-inducible system for use in transgenic plants. A chimeric transcription activator, XVE, was assembled by fusion of the DNA-binding domain of the bacterial repressor LexA (X), the acidic transactivating domain of VP16 (V) and the regulatory region of the human estrogen receptor (E; ER). The transactivating activity of the chimeric XVE factor, whose expression was controlled by the strong constitutive promoter G10-90, was strictly regulated by estrogens. In transgenic Arabidopsis and tobacco plants, estradiol-activated XVE can stimulate expression of a GFP reporter gene controlled by the target promoter, which consists of eight copies of the LexA operator fused upstream of the ±46 35S minimal promoter. Upon induction by estradiol, GFP expression levels can be eightfold higher than that transcribed from a 35S promoter, whereas the uninduced controls have no detectable GFP transcripts, as monitored by Northern blot analysis. Neither toxic nor adverse physiological effects of the XVE system have been observed in transgenic Arabidopsis plants under all the conditions tested. The XVE system thus appears to be a reliable and ef®cient chemical-inducible system for regulating transgene expression in plants.

The Arabidopsis Spontaneous Cell Death1 gene, encoding a ζ-carotene desaturase essential for carotenoid biosynthesis, is involved in chloroplast development, photoprotection and retrograde signalling

“…The SPC1 genomic clone included a 1.6-kb promoter sequence upstream of the 5' untranslated region (UTR) of At3g04870. The PCR product, digested with NheI and AscI (both sites were included in the primers), was cloned into the SpeI/AscI-digested pER14 vector that was derived from pER8 [49]. The resulting construct was transformed into the Agrobacterium tumefaciens strain GV3101, which was then used for the transformation of spc1-1/-and spc1-2/+ plants.…”

Arabidopsishomeodomain-leucine zipper IV proteins promote stomatal development and ectopically induce stomata beyond the epidermis

“…Plasmid pER8 (Zuo et al, 2000) was used for estradiol-inducible constructs. Generation and selection of transgenic plants were performed as described previously (Pillitteri et al, 2007).…”

“…CaMV35Spro::HDG2 plants were infertile (data not shown). For this reason, we subsequently used an induction system (Zuo et al, 2000), which specifically induced the transgenes after estradiol application (supplementary material Figs S3, S4). Both CaMV35Spro::HDG2 and inducible HDG2 seedlings develop narrow, dark-green leaves, suggesting that HDG2 ectopic overexpression (HDG2-OX) affects leaf growth (supplementary material Fig.…”

Controlled Expression of Recombinant Proteins in Physcomitrella patens by a Conditional Heat-shock Promoter: a Tool for Plant Research and Biotechnology

“…(3) The pattern of protein expression should be homogenous in all tissue of the organism and (4) inducing conditions should bare minimal consequences on the organism's physiology, fitness and viability (Gatz, 1997). In plants, prevalent conditional geneexpression systems use chemically regulated heterologous promoters (reviewed in (Padidam, 2003)) with chemical inducers such as tetracycline (Gatz, 1997), steroids (Aoyama and Chua, 1997;Zuo et al, 2000) and ethanol (Caddick et al, 1998;Roslan et al, 2001). These systems may reach up to a few hundred folds of induction, but there are major limitations such as promoter leakiness, non-uniform uptake and toxic effects of the inducing chemicals (reviewed in details in (Padidam, 2003)).…”