Opposite roles of the Arabidopsis cytokinin receptors AHK2 and AHK3 in the expression of plastid genes and genes for the plastid transcriptional machinery during senescence.
Cytokinin membrane receptors of the Arabidopsis thaliana AHK2 and AHK3 play opposite roles in the expression of plastid genes and genes for the plastid transcriptional machinery during leaf senescence Loss-of-function mutants of Arabidopsis thaliana were used to study the role of cytokinin receptors in the expression of chloroplast genes during leaf senescence. Accumulation of transcripts of several plastid-encoded genes is dependent on the АНК2/АНК3 receptor combination. АНК2 is particularly important at the final stage of plant development and, unlike АНК3, a positive regulator of leaf senescence. Cytokinin-dependent up-regulation of the nuclear encoded genes for chloroplast RNA polymerases RPOTp and RPOTmp suggests that the hormone controls plastid gene expression, at least in part, via the expression of nuclear genes for the plastid transcription machinery. This is further supported by cytokinin dependent regulation of genes for the nuclear encoded plastid σ-factors, SIG1-6, which code for components of the transcriptional apparatus in chloroplasts.
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, Moscow, 127276, Russia.
Maria N
MN
Danilova
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, Moscow, 127276, Russia. nkudryakova@rambler.ru.
Natalia V
NV
Kudryakova
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, Moscow, 127276, Russia.
Anastasia S
AS
Doroshenko
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, Moscow, 127276, Russia.
Dmitry A
DA
Zabrodin
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, Moscow, 127276, Russia.
Zulfira F
ZF
Rakhmankulova
Institute of General Botany and Plant Physiology, Friedrich-Schiller University Jena, 07743, Jena, Germany.
Ralf
R
Oelmüller
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya 35, Moscow, 127276, Russia.
Victor V
VV
Kusnetsov
D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics*; D002467:Cell Nucleus / Q000235:genetics; D003583:Cytokinins / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D061125:Genes, Chloroplast / Q000235:genetics; D000071677:Histidine Kinase / Q000235:genetics*; D009154:Mutation; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D018087:Plastids / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000502:physiology; D012639:Seeds / Q000235:genetics / Q000502:physiology; D013997:Time Factors; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D003583:Cytokinins; D011956:Receptors, Cell Surface; D000071677:Histidine Kinase; C000605492:AHK2 protein, Arabidopsis; C000605493:AHK3 protein, Arabidopsis
Arabidopsis; Chloroplast gene expression; Cytokinin receptors; Senescence; Transcription