Analysis of gene expression by promoter reporter constructs and knockout plants: A case study under phosphorus stress

Abstract

Promoter reporter constructs were developed using Gateway Cloning Technology for plant non-specific lipid transport proteins (nsLTP1, AT4g12545 and nsLTP2, AT5g46900), MADS-Box (AT4g37940) and leucine rich repeat (LRR, AT2g28970) genes. The purpose of the construct was to investigate gene expression and function under phosphorus (P) stress. Agrobacterium tumefaciens was used to transform Arabidopsis thaliana. Transformed (T1), knockout and wild type ecotype Colombia-0 A. thaliana were investigated. To monitor the gene activity, plants were grown under different conditions: fully inside solid media, on the surface of solid media and hydroponically with 0.5 mM l-1 phosphorus and without phosphorus. Plants were also grown on MS media with selectable marker containing 50 mM l-1 Kanamycin. Morphological root assessment was also done by using knockout plants for the respective promoters. The promoters under study were induced promoter. GUS staining was observed on T1 plants when planted fully inside solid media and on the selectable marker for all the constructs regardless of phosphorus treatments. Mechanical impedance, oxygen deficiency and stress due to selectable marker were the probable reasons for the root specific gene expression. This suggests that these genes were involved in adaptation mechanism for plants under such stress conditions. © 2011 Academic Journals.