TY - JOUR
T1 - Low glutathione regulates gene expression and the redox potentials of the nucleus and cytosol in Arabidopsis thaliana
AU - Schnaubelt, Daniel
AU - Queval, Guillaume
AU - Dong, Yingping
AU - Diaz-Vivancos, Pedro
AU - Makgopa, Matome Eugene
AU - Howell, Gareth
AU - De Simone, Ambra
AU - Bai, Juan
AU - Hannah, Matthew A.
AU - Foyer, Christine H.
PY - 2015/2
Y1 - 2015/2
N2 - Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress.
AB - Reduced glutathione (GSH) is considered to exert a strong influence on cellular redox homeostasis and to regulate gene expression, but these processes remain poorly characterized. Severe GSH depletion specifically inhibited root meristem development, while low root GSH levels decreased lateral root densities. The redox potential of the nucleus and cytosol of Arabidopsis thaliana roots determined using roGFP probes was between -300 and -320mV. Growth in the presence of the GSH-synthesis inhibitor buthionine sulfoximine (BSO) increased the nuclear and cytosolic redox potentials to approximately -260mV. GSH-responsive genes including transcription factors (SPATULA, MYB15, MYB75), proteins involved in cell division, redox regulation (glutaredoxinS17, thioredoxins, ACHT5 and TH8) and auxin signalling (HECATE), were identified in the GSH-deficient root meristemless 1-1 (rml1-1) mutant, and in other GSH-synthesis mutants (rax1-1, cad2-1, pad2-1) as well as in the wild type following the addition of BSO. Inhibition of auxin transport had no effect on organ GSH levels, but exogenous auxin decreased the root GSH pool. We conclude that GSH depletion significantly increases the redox potentials of the nucleus and cytosol, and causes arrest of the cell cycle in roots but not shoots, with accompanying transcript changes linked to altered hormone responses, but not oxidative stress.
KW - Auxin signalling
KW - Cell cycle
KW - Glutaredoxins
KW - Lateral root densities
KW - Nuclei
KW - Redox signalling
KW - Thioredoxins
KW - root meristem
UR - http://www.scopus.com/inward/record.url?scp=84921565222&partnerID=8YFLogxK
U2 - 10.1111/pce.12252
DO - 10.1111/pce.12252
M3 - Article
C2 - 24329757
AN - SCOPUS:84921565222
SN - 0140-7791
VL - 38
SP - 266
EP - 279
JO - Plant, Cell and Environment
JF - Plant, Cell and Environment
IS - 2
ER -