Arabidopsis AAL-toxin-resistant mutant atr1 shows enhanced tolerance to programmed cell death induced by reactive oxygen species

作者：Gechev Tsanko S^*; Ferwerda MargFiet A; Mehterov Nikolay; Laloi Christophe; Qureshi Muhammad K; Hille Jacques

来源：Biochemical and Biophysical Research Communications, 2008, 375(4): 639-644.

DOI：10.1016/j.bbrc.2008.08.056

• AAL-toxin
• Hydrogen peroxide
• Reactive oxygen species
• Sphingolipid metabolism
• Programmed cell death

The fungal AAL-toxin triggers programmed cell death (PCD) through perturbations of sphingolipid metabolism in AAL-toxin-sensitive plants. While Arabidopsis is relatively insensitive to the toxin, the loh2 mutant exhibits increased Susceptibility to AAL-toxin due to the knockout of a gene involved in sphingolipid metabolism. Genetic screening of mutagenized loh2 seeds resulted in the isolation of AAL-toxin-resistant mutant atr1. Atr1 displays a wild type phenotype when grown on soil but it develops less biomass than loh2 on media supplemented with 2% and 3% sucrose. Atr1 was also more tolerant to the reactive oxygen species-generating herbicides aminotriazole (AT) and paraquat. Microarray analyses of atr1 and loh2 under AT-treatment conditions that trigger cell death in loh2 and no visible damage in atr1 revealed genes specifically regulated in atr1 or loh2. In addition, most of the genes strongly down-regulated in both mutants were related to cell wall extension and cell growth, consistent with the apparent and similar AT-induced cessation of growth in both mutants. This indicates that two different pathways, a first controlling growth inhibition and a second triggering cell death, are associated with AT-induced oxidative stress.

• 出版日期2008-10-31