Dataset Information

A fatty acid desaturase modulates the activation of defense signaling pathways in plants.

ABSTRACT: Salicylic acid (SA) plays an important role in activating various plant defense responses, including expression of the pathogenesis-related (PR) genes and systemic acquired resistance. A critical positive regulator of the SA signaling pathway in Arabidopsis is encoded by the NPR1 gene. However, there is growing evidence that NPR1-independent pathways can also activate PR expression and disease resistance. To elucidate the components associated with NPR1-independent defense signaling, we isolated a suppressor of the npr1-5 allele, designated ssi2. The recessive ssi2 mutation confers constitutive PR gene expression, spontaneous lesion formation, and enhanced resistance to Peronospora parasitica. In contrast, a subset of defense responses regulated by the jasmonic acid (JA) signaling pathway, including expression of the defensin gene PDF1.2 and resistance to Botrytis cinerea, is impaired in ssi2 plants. With the use of a map-based approach, the SSI2 gene was cloned and shown to encode a stearoyl-ACP desaturase (S-ACP DES). S-ACP DES is an archetypical member of a family of soluble fatty acid (FA) desaturases; these enzymes play an important role in regulating the overall level of desaturated FAs in the cell. The activity of mutant S-ACP DES enzyme was reduced 10-fold, resulting in elevation of the 18:0 FA content in ssi2 plants. Because reduced S-ACP DES activity leads to the induction of certain defense responses and the inhibition of others, we propose that a FA-derived signal modulates crosstalk between different defense signaling pathways.

SUBMITTER: Kachroo P

PROVIDER: S-EPMC55441 | biostudies-literature | 2001 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A fatty acid desaturase modulates the activation of defense signaling pathways in plants.

Kachroo P P Shanklin J J Shah J J Whittle E J EJ Klessig D F DF

Proceedings of the National Academy of Sciences of the United States of America 20010701 16

Salicylic acid (SA) plays an important role in activating various plant defense responses, including expression of the pathogenesis-related (PR) genes and systemic acquired resistance. A critical positive regulator of the SA signaling pathway in Arabidopsis is encoded by the NPR1 gene. However, there is growing evidence that NPR1-independent pathways can also activate PR expression and disease resistance. To elucidate the components associated with NPR1-independent defense signaling, we isolated ...[more]

PMID: 11481500

Similar Datasets

Project description:BackgroundPolyunsaturated fatty acids (PUFAs) are associated with a lower risk of multiple diseases. Fatty acid desaturase 1 gene (FADS1) polymorphisms and dietary PUFA intake are both established determinants of circulating PUFA proportions.ObjectiveWe explored the joint effects of FADS1 polymorphisms and dietary PUFA intake on circulating PUFA proportions.DesignWe studied 2288 participants from a nested case-control study of coronary artery disease among participants who provided blood samples in the Nurses' Health Study and the Health Professionals Follow-Up Study. Dietary PUFA intake was obtained from semiquantitative food-frequency questionnaires. FADS1 rs174546 was genotyped by using the Affymetrix 6.0 platform, and circulating PUFA proportions were measured with gas-liquid chromatography. Linear regression models were used to examine the associations between rs174546 and circulating proportions of each fatty acid. Gene-diet interactions were tested by including a cross-product term of dietary intake of each PUFA by rs174546 genotype in the linear regression models.ResultsAfter adjustment for sex and ancestry, each copy of the C allele of rs174546 was associated with higher circulating proportions of arachidonic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and lower proportions of linoleic acid and α-linolenic acid. The magnitude of positive association between higher consumption of dietary EPA or DHA and circulating proportions of EPA increased with each copy of the rs174546_T allele (P-interaction = 0.01 and 0.007, respectively). Each 1-SD increment in EPA intake was associated with an average 3.7% increase in circulating EPA proportions among participants with the rs174546_CC genotype and an average 7.8% increase among participants with the TT genotype.ConclusionsCarriers of the T allele at FADS1 rs174546 may need higher doses of dietary EPA and DHA to achieve the same circulating proportions of EPA as carriers of the C allele. The implications of these findings on disease risk and dietary guidelines require further study.

Dataset Information

A fatty acid desaturase modulates the activation of defense signaling pathways in plants.

Publications

A fatty acid desaturase modulates the activation of defense signaling pathways in plants.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets