Nitric oxide responses in Arabidopsis hypocotyls are mediated by diverse phytohormone pathways. (2nd August 2018)

• Record Type: Journal Article
• Authors: Castillo, Mari-Cruz; Coego, Alberto; Costa-Broseta, Álvaro; León, José
• Is Part Of: Journal of experimental botany. Volume 69:Number 21(2018)
• Page Start: 5265
• Page End: 5278
• Publication Date: 2018-08-02
• Subjects: ABA -- Arabidopsis thaliana -- brassinosteroids -- ethylene -- nitric oxide -- salicylate -- strigolactones -- transcription factors -- TRANSPLANTA lines; Botany -- Periodicals; Botany, Experimental -- Periodicals; Plant physiology -- Periodicals; 580
• DOI: 10.1093/jxb/ery286
• Languages: English
• ISSNs: 0022-0957

Abstract

Abstract : An NO-sensing mechanism controlling hypocotyl growth in etiolated seedlings requires the biosynthesis and/or signaling of ethylene, strigolactones, salicylate, abscisic acid, and brassinosteroids. Abstract: Plants are often exposed to high levels of nitric oxide (NO) that affects development and stress-triggered responses. However, the way in which plants sense NO is still largely unknown. Here we combine the analysis of early changes in the transcriptome of plants exposed to a short acute pulse of exogenous NO with the identification of transcription factors (TFs) involved in NO sensing. The NO-responsive transcriptome was enriched in hormone homeostasis- and signaling-related genes. To assess events involved in NO sensing in hypocotyls, we used a functional sensing assay based on the NO-induced inhibition of hypocotyl elongation in etiolated seedlings. Hormone-related mutants and the TRANSPLANTA collection of transgenic lines conditionally expressing Arabidopsis TFs were screened for NO-triggered hypocotyl shortening. These approaches allowed the identification of hormone-related TFs, ethylene perception and signaling, strigolactone biosynthesis and signaling, and salicylate production and accumulation that are essential for or modulate hypocotyl NO sensing. Moreover, NO inhibits hypocotyl elongation through the positive and negative regulation of some abscisic acid (ABA) receptors and transcripts encoding brassinosteroid signaling components thereby also implicating these hormones in NO sensing.