Response to darkness of late-responsive dark-inducible genes is positively regulated by leaf age and negatively regulated by calmodulin-antagonist-sensitive signalling in Arabidopsis thaliana.
Induction after prolonged darkness distinguishes the late-responsive genes din2 and din9 from the early-responsive gene din3 in Arabidopsis. The former genes were coincidently induced with the senescence marker gene YLS4 in rosette leaves of different ages and in the early-senescence mutant hys1. The calmodulin antagonists W-7, trifluoperazine, and fluphenazine accelerated the expression of the former genes in darkness but not in light, and had little effect on the latter gene. Our results suggest that Ca(2+)/calmodulin signalling conveys a negative signal that suppresses the responses of late-responsive din genes to prolonged darkness. The results are discussed in relation to natural senescence.
Fujiki
Yuki
Y
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Hongo, Japan.
Nakagawa
Yuka
Y
Furumoto
Tsuyoshi
T
Yoshida
Satoko
S
Biswal
Basanti
B
Ito
Masaki
M
Watanabe
Akira
A
Nishida
Ikuo
I
D017360:Arabidopsis / Q000235:genetics*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D003624:Darkness; D017343:Genes, Plant; D006571:Heterocyclic Compounds / Q000494:pharmacology; D018515:Plant Leaves / Q000378:metabolism*; D015398:Signal Transduction; D013449:Sulfonamides / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
D002147:Calmodulin; D006571:Heterocyclic Compounds; D013449:Sulfonamides; D014268:Trifluoperazine; C017967:W 7; C417227:flufenzine