title: Interplay between sucrose and folate modulates auxin signaling in Arabidopsis.
abstract: As sessile organisms growing in an ever-changing environment, plants must integrate multiple regulatory inputs to promote the appropriate developmental responses. One such nutritional signal is cellular sugar levels, which rise and fall throughout the day and affect a variety of developmental processes. To uncover signaling pathways that modulate sugar perception, compounds from the Library of Active Compounds in Arabidopsis were screened for the ability to perturb developmental responses to sucrose (Suc) in Arabidopsis (Arabidopsis thaliana) seedlings. This screen found that sulfonamides, which inhibit folate biosynthesis in plants, restrict hypocotyl elongation in a sugar-dependent fashion. Transcriptome analysis identified a small set of transcripts that respond to the interaction between sulfonamide and Suc, including a number of transcripts encoding Auxin/Indole-3-Acetic Acids, negative regulators of auxin signal transduction. Chemical inhibition of auxin transport or genetic disruption of auxin signaling relieved this interaction, suggesting that responses to these two nutritional stimuli are mediated by auxin. Reporter systems used to track auxin signaling and distribution showed enhanced activity in the vascular region of the hypocotyl in response to cotreatment of Suc and sulfonamide, yet no change in auxin abundance was observed. Taken together, these findings suggest that the interplay between Suc and folates acts to fine-tune auxin sensitivity and influences auxin distribution during seedling development.
authors.affiliation: Department of Cell and Systems Biology , University of Toronto, Toronto, Ontario, Canada M5S 3B2.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Stokes
authors.forename: Abhishek
authors.initials: A
authors.lastname: Chattopadhyay
authors.forename: Olivia
authors.initials: O
authors.lastname: Wilkins
authors.forename: Eiji
authors.initials: E
authors.lastname: Nambara
authors.forename: Malcolm M
authors.initials: MM
authors.lastname: Campbell
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001692:Biological Transport; D004094:Dihydropteroate Synthase / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D005492:Folic Acid / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018546:Hypocotyl / Q000254:growth & development / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D030821:Plants, Genetically Modified; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction; D013395:Sucrose / Q000378:metabolism* / Q000494:pharmacology; D013420:Sulfamethoxazole / Q000494:pharmacology
chemical_list: D007210:Indoleacetic Acids; D013395:Sucrose; C030737:indoleacetic acid; D005492:Folic Acid; D004094:Dihydropteroate Synthase; D013420:Sulfamethoxazole