The Arabidopsis thaliana mutant air1 implicates SOS3 in the regulation of anthocyanins under salt stress.
The accumulation of anthocyanins in plants exposed to salt stress has been largely documented. However, the functional link and regulatory components underlying the biosynthesis of these molecules during exposure to stress are largely unknown. In a screen of second site suppressors of the salt overly sensitive3-1 (sos3-1) mutant, we isolated the anthocyanin-impaired-response-1 (air1) mutant. air1 is unable to accumulate anthocyanins under salt stress, a key phenotype of sos3-1 under high NaCl levels (120 mM). The air1 mutant showed a defect in anthocyanin production in response to salt stress but not to other stresses such as high light, low phosphorous, high temperature or drought stress. This specificity indicated that air1 mutation did not affect anthocyanin biosynthesis but rather its regulation in response to salt stress. Analysis of this mutant revealed a T-DNA insertion at the first exon of an Arabidopsis thaliana gene encoding for a basic region-leucine zipper transcription factor. air1 mutants displayed higher survival rates compared to wild-type in oxidative stress conditions, and presented an altered expression of anthocyanin biosynthetic genes such as F3H, F3'H and LDOX in salt stress conditions. The results presented here indicate that AIR1 is involved in the regulation of various steps of the flavonoid and anthocyanin accumulation pathways and is itself regulated by the salt-stress response signalling machinery. The discovery and characterization of AIR1 opens avenues to dissect the connections between abiotic stress and accumulation of antioxidants in the form of flavonoids and anthocyanins.
Department of Agriculture, University of Naples "Federico II", Via Università 100, 80055, Portici, Italy.
Michael James
MJ
Van Oosten
Altanbadralt
A
Sharkhuu
Giorgia
G
Batelli
Ray Anthony
RA
Bressan
Albino
A
Maggio
D000872:Anthocyanins / Q000032:analysis / Q000378:metabolism*; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics* / Q000378:metabolism; D005419:Flavonoids / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008027:Light; D016254:Mutagenesis, Insertional; D010641:Phenotype; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000502:physiology / Q000528:radiation effects; D060888:Real-Time Polymerase Chain Reaction; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological
C584652:AIR1 protein, Arabidopsis; D000872:Anthocyanins; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D005419:Flavonoids; C112941:SOS3 protein, Arabidopsis; D012965:Sodium Chloride