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Characterization of photomorphogenic responses and signaling cascades controlled by phytochrome‐A expressed in different tissues
Author(s) -
Kirchenbauer Daniel,
Viczián András,
Ádám Éva,
Hegedűs Zoltán,
Klose Cornelia,
Leppert Michael,
Hiltbrunner Andreas,
Kircher Stefan,
Schäfer Eberhard,
Nagy Ferenc
Publication year - 2016
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13941
Subject(s) - photomorphogenesis , phytochrome a , arabidopsis , microbiology and biotechnology , biology , phytochrome , arabidopsis thaliana , transcription factor , signal transduction , hypocotyl , morphogenesis , mutant , cotyledon , genetics , gene , botany , red light
Summary The photoreceptor phytochrome A acts as a light‐dependent molecular switch and regulates responses initiated by very low fluences of light ( VLFR ) and high fluences ( HIR ) of far‐red light. PhyA is expressed ubiquitously, but how phyA signaling is orchestrated to regulate photomorphogenesis is poorly understood. To address this issue, we generated transgenic Arabidopsis thaliana phyA‐201 mutant lines expressing the biologically active phyA‐ YFP photoreceptor in different tissues, and analyzed the expression of several reporter genes, including ProHY5: HY 5‐ GFP and Pro35S: CFP ‐ PIF 1 , and various FR ‐ HIR ‐dependent physiological responses. We show that phyA action in one tissue is critical and sufficient to regulate flowering time and root growth; control of cotyledon and hypocotyl growth requires simultaneous phyA activity in different tissues; and changes detected in the expression of reporters are not restricted to phyA‐containing cells. We conclude that FR ‐ HIR ‐controlled morphogenesis in Arabidopsis is mediated partly by tissue‐specific and partly by intercellular signaling initiated by phyA. Intercellular signaling is critical for many FR ‐ HIR induced responses, yet it appears that phyA modulates the abundance and activity of key regulatory transcription factors in a tissue‐autonomous fashion.