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Largely additive effects of gibberellin and strigolactone on gene expression in Arabidopsis thaliana seedlings
Author(s) -
Lantzouni Ourania,
Klermund Carina,
Schwechheimer Claus
Publication year - 2017
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13729
Subject(s) - gibberellin , strigolactone , biology , gene , arabidopsis , ubiquitin ligase , mutant , arabidopsis thaliana , microbiology and biotechnology , signal transduction , genetics , ubiquitin
Summary The phytohormones gibberellin ( GA ) and strigolactone ( SL ) are involved in essential processes in plant development. Both GA and SL signal transduction mechanisms employ α/β‐hydrolase‐derived receptors that confer E3 ubiquitin ligase‐mediated protein degradation processes. This suggests a common evolutionary origin of these pathways and possibly a molecular interaction between them. One such indication stems from rice, where the DELLA protein of the GA pathway was reported to interact with the SL receptor. Here, we examine the physiological interaction between both pathways through the analysis of GA ( ga1 ) and SL biosynthesis ( max1 and max3 ) mutants. In ga1 max double mutants, we find indications only for additive interactions when examining several phenotypic readouts. We further identify short‐term transcriptional responses to GA and the synthetic SL rac‐ GR 24 through next‐generation sequencing of poly‐adenylated RNA s ( RNA ‐seq) in ga1 max1 . Remarkably, both hormones lead to predominantly additive transcriptional changes of a largely overlapping set of genes. The expression of only a few genes was altered in a synergistic manner but, interestingly, these include the genes encoding the GA catabolic enzyme GA 2 OXIDASE 2 ( GA 2ox2 ) as well as the SL pathway regulators BRANCHED 1 ( BRC 1 ) and SUPPRESSOR OF max2 1‐ LIKE 8 ( SMXL 8 ). We conclude that GA and rac‐ GR 24 signaling in Arabidopsis seedlings converge at the level of transcription of a common gene‐set.