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ARS Home » Midwest Area » Columbia, Missouri » Plant Genetics Research » Research » Publications at this Location » Publication #179089
Title: FUNCTIONAL CHARACTERIZATION OF ATLCB1 AS AN ESSENTIAL SUBUNIT OF THE ARABIDOPSIS SERINE PALMITOYLTRANSFERASE

Author
item CHEN, MING - DONALD DANFORTH PLANT SCI
item DIETRICH, CHARLES
item CAHOON, EDGAR

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/18/2005
Publication Date: 3/18/2005
Citation: Chen, M., Dietrich, C.R., Cahoon, E.B. 2005. Functional characterization of atlcb1 as an essential subunit of the arabidopsis serine palmitoyltransferase [abstract]. 2005 Midwest American Society of Plant Biologists Sectional Meeting. p. 26.

Interpretive Summary:

Technical Abstract: Sphingolipids are one of the major components of the plasma membrane and tonoplast of plant cells. In contrast to mammals and yeast, only a few genes associated with sphingolipid synthesis and metabolism have been isolated and characterized in plants. Serine palmitoyltransferase, which catalyzes the first step of de novo sphingolipid synthesis, is believed to be a heterodimer consisting of LCB1 and LCB2 subunits in yeast and mammalian cells. The gene for LCB1 in plants, however, has yet to be functionally demonstrated. Evidence presented here demonstrates that the predicted AtLCB1 (At4g36480) gene encodes a genuine subunit of the serine palmitoyltransferase in Arabidopsis. Most compelling, down-regulation of mRNA levels of AtLCB1 by RNAi resulted in decreases in the total sphingolipid long-chain base (LCB) content of Arabidopsis leaves. These plants displayed distinct phenotypes including sporadic lesion-like spots on all leaves, premature senescence of old leaves and curled young leaves. AtLCB1-RNAi suppressed lines were also subjected to different stress conditions to study the effect of reduced sphingolipid content on the response of plants to environmental stresses. In addition, T-DNA mutant analysis indicated AtLCB1 is essential for seed development since homozygous T-DNA plants are embryo lethal. This result indicates that sphingolipids are essential to plant viability, which is consistent with results from studies of mammalian and yeast cells.