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Polyamine oxidase 5 loss‐of‐function mutations in Arabidopsis thaliana trigger metabolic and transcriptional reprogramming and promote salt stress tolerance
Author(s) -
Zarza Xavier,
Atanasov Kostadin E.,
Marco Francisco,
Arbona Vicent,
Carrasco Pedro,
Kopka Joachim,
Fotopoulos Vasileios,
Munnik Teun,
GómezCadenas Aurelio,
Tiburcio Antonio F.,
Alcázar Rubén
Publication year - 2017
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12714
Subject(s) - arabidopsis , spermine , spermidine , polyamine , polyamine oxidase , jasmonate , putrescine , mutant , biochemistry , biology , arabidopsis thaliana , metabolic pathway , biosynthesis , microbiology and biotechnology , chemistry , gene , enzyme
The family of polyamine oxidases (PAO) in Arabidopsis ( AtPAO1–5 ) mediates polyamine (PA) back‐conversion, which reverses the PA biosynthetic pathway from spermine and its structural isomer thermospermine (tSpm) into spermidine and then putrescine. Here, we have studied the involvement of PA back‐conversion in Arabidopsis salinity tolerance. AtPAO5 is the Arabidopsis PAO gene member most transcriptionally induced by salt stress. Two independent loss‐of‐function mutants ( atpao5‐2 and atpao5‐3 ) were found to exhibit constitutively higher tSpm levels, with associated increased salt tolerance. Using global transcriptional and metabolomic analyses, the underlying mechanisms were studied. Stimulation of abscisic acid and jasmonate (JA) biosynthesis and accumulation of important compatible solutes, such as sugars, polyols and proline, as well as TCA cycle intermediates were observed in atpao5 mutants under salt stress. Expression analyses indicate that tSpm modulates the transcript levels of several target genes, including many involved in the biosynthesis and signalling of JA, some of which are already known to promote salinity tolerance. Transcriptional modulation by tSpm is isomer‐dependent, thus demonstrating the specificity of this response. Overall, we conclude that tSpm triggers metabolic and transcriptional reprogramming that promotes salt stress tolerance in Arabidopsis .