Rhythmic expression of mitogen activated protein kinase activity in rice.
Mitogen activated protein kinase (MAPK) are known to get activated during various stress signals and transduce the message from the cell membrane to the nucleus for appropriate cellular reorganization. Though, a certain basal activity of MAPK is often observed in the control plants. Prolonged exposure of rice plants to lowered or elevated temperature exhibited a rhythm in the activation of MAPKs. We analyzed existence of a possible endogenous rhythm in the activity of MAPKs in rice plants. The plants growing at constant temperature entrained in 16/8 h day-night cycle showed diurnal rhythm in activity. When the activation of MAPK was tested under continuous conditions by shifting plants to continuous darkness for a period of 72 h, the periodic rhythm persisted and followed a circadian pattern. Analysis of the transcripts of group A, B and C members of MAPKs under above conditions by quantitative real time PCR revealed that the members of group C exhibit periodic rhythm. Our data indicates that the MAP kinase activity in rice follows rhythmic expression in a circadian manner.
National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.
Kudupudi Prabhakara
KP
Rao
Gubbala
G
Vani
Kundan
K
Kumar
Alok Krishna
AK
Sinha
D002940:Circadian Rhythm / Q000235:genetics*; D004789:Enzyme Activation; D018506:Gene Expression Regulation, Plant; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000201:enzymology* / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013696:Temperature
D012333:RNA, Messenger; D020928:Mitogen-Activated Protein Kinases