Whole‐genome expression patterns in LTP knockdown Arabidopsis plants

Abstract

AbstractOur lab studies the aging process in plants, using the plant model Arabidopsis thaliana. Arabidopsis’ small size and rapid life cycle make it an attractive model to study plant senescence. Previous research in our laboratory suggests that as Arabidopsis undergoes the developmental transition from vegetative growth to flowering, ascorbate peroxidase (APX) activity that is responsible for scavenging H2 O2 is repressed and 13‐lipoxygenase (LOX) is activated. LOX catalyzes the first reaction in oxylipin‐signaling pathways, which generate a multitude of lipid signaling molecules. We specifically focus on the possibility that lipid transfer proteins may carry signals during the aging process of the plant. Lipid transfer proteins are small, basic proteins present in the plant cell wall. Other data from our lab showed an up‐regulation of two lipid transfer proteins as the plant transitions from the vegetative to flowering stage. These data suggest that oxylipins may be involved as a signal between meristems and leaves during the vegetative to flowering transition in Arabidopsis. The purpose of this study is to compare gene expression patterns of Arabidopsis in wild type and LTP RNAi knockdown mutants, in meristems and flowers during different developmental stages and determine how gene expression patterns are altered in RNAi knockdowns. Our current RNAi knockdown mutants in Arabidopsis show uncontrolled growth producing an abundant number of flowers and seeds and live six times longer than an average wild type plant. Based on our knockdown phenotypes, we predict that downregulation of these genes may play a major role in the inhibition of meristem arrest.