Poster: Oxidative Stress

Abs # 141: Identification of Novel Genes Involved in Oxidative Stress Responses in Arabidopsis

Presenter:	Shen, Yin , yin.shen@ttu.edu
Authors	Shen, Yin  (A)   Jing, Wang  (A)   Allen, Randy D (A)
Affiliations:	(A): Texas Tech University

In an attempt to identify novel Arabidopsis genes that are involved in the stress response signal transduction pathway a reporter gene construct that contains the glutathione S-transferase (GST) promoter fused with a luciferase gene was introduced into Arabidopsis (ecotype Columbia). One homozygous line with optimal luciferase expression was selected using a cooled CCD image system. Seeds from this transgenic line were mutagenized using EMS, and mutagenized seeds were allowed to self-pollinate to produce M2 seeds. Preliminary screening of M2 seedlings was carried out to select potential mutants that either have either elevated or reduced luciferase activity. These potential mutants were self-pollinated and offspring (M3) were assayed to determine if the apparent luciferase expression phenotypes are heritable. In this second round of screening, 10 day old M3 seedlings were treated with 400mM salicylic acid (SA) for two days prior to luciferase activity assays. Three distinct types of mutants have been identified. The first type is dominant with very weak luciferase activity both with and without SA treatment compared to the control plants. The second kind is recessive with higher luciferase activity without SA treatment. The third type has much higher luciferase activity both with and without SA treatment. M4 plants were crossed both with Columbia and Landsberg erecta (Le) plants and the F1 plants were self-pollinated to produce F2 plants. All of the F2 seedlings were assayed for their luciferase activity. F2 plants from crosses between mutants and Le plants will be used for mapping populations for positional cloning of the affected genes.