Identification and characterization of a biphasic/bidirectional wound-inducible RHA3B gene promoter from Arabidopsis thaliana

Conditional promoters such as wound inducible are important tools for plant biotechnology to selectively express agronomically important genes. From a set of Enhancer trap (DsE-uidA) transposant lines we identified wound inducible ET1075 line by injuring leaf blade and screening for Ds linked GUS gene expression. Earliest GUS stain detected at petiolar region at 2hrs post injury with a progressive attainment of maximum visual intensity between 12 and 24hrs wherein, the transcript expression induced in a bidirectional manner. DsE was found to be inserted in the intergenic region between AT4G35480 and AT4G35490. To find the essential transcriptional regulatory region, deletion constructs comprising upstream sequences of pRHA3B fused to GUS reporter gene were functionally tested in Arabidopsis plants by generating stable transgenics. A 481 bp of upstream sequence from ATG is found to be sufficient to promote wound inducible gene expression. Sequence analysis revealed the presence of several regulatory elements implicated in wound inducible gene expression. Comparative analysis with similar wound inducible promoters revealed the presence of common cis-regulatory elements. This promoter can essentially be used in pest control and in molecular pharming to conditionally express agronomically/commercially important genes in plants.HighlightsDsE enhancer trap transposant lines were generated.Identified a novel wound inducible promoter line ET1075.Wound inducible promoter pRHA3B is bidirectional and induces the expression of RHA3B and MRPL11 genes.Wound responsive key cis-elements WRKY, W-box, FORCA are present in the pRHA3B promoter.

GAL4/GFP enhancer-trap lines for identification and manipulation of cells and tissues in developing Arabidopsis leaves

Understanding developmental processes requires the unambiguous identification of cells and tissues, and the selective manipulation of the properties of those cells and tissues. Both requirements can most efficiently be satisfied through the use of GAL4/GFP enhancer-trap lines. No such lines are available, however, for the study of leaf development in the Columbia-0 reference genotype of Arabidopsis. Here we address this limitation by identifying and characterizing a set of GAL4/GFP enhancer-trap lines in the Columbia-0 background for the specific labeling of cells and tissues during leaf development, and for the targeted expression of genes of interest in those cells and tissues. By using one line in our set to resolve outstanding problems in leaf vein patterning, we show that these lines can be used to address key questions in plant developmental biology.

An Interscholastic Network to Generate LexA Enhancer Trap Lines in Drosophila

Binary expression systems like the LexA-LexAop system provide a powerful experimental tool kit to study gene and tissue function in developmental biology, neurobiology and physiology. However, the number of well-defined LexA enhancer trap insertions remains limited. In this study, we present the molecular characterization and initial tissue expression analysis of nearly 100 novel StanEx LexA enhancer traps, derived from the StonEx1 index line. This includes 76 insertions into novel, distinct gene loci not previously associated with enhancer traps or targeted LexA constructs. Additionally, our studies revealed evidence for selective transposase-dependent replacement of a previously-undetected KP element on chromosome III within the StanEx1 genetic background during hybrid dysgenesis, suggesting a molecular basis for the over-representation of LexA insertions at the NK7.1 locus in our screen. Production and characterization of novel fly lines were performed by students and teachers in experiment-based genetics classes within a geographically diverse network of public and independent high schools. Thus, unique partnerships between secondary schools and university-based programs have produced and characterized novel genetic and molecular resources in Drosophila for open-source distribution, and provide paradigms for development of science education through experience-based pedagogy.