Transient dissociation of polyribosomes and concurrent recruitment of calreticulin and calmodulin transcripts in gravistimulated maize pulvini

Citation
I. Heilmann et al., Transient dissociation of polyribosomes and concurrent recruitment of calreticulin and calmodulin transcripts in gravistimulated maize pulvini, PLANT PHYSL, 127(3), 2001, pp. 1193-1203
Citations number
47
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT PHYSIOLOGY
ISSN journal
0032-0889 → ACNP
Volume
127
Issue
3
Year of publication
2001
Pages
1193 - 1203
Database
ISI
SICI code
0032-0889(200111)127:3<1193:TDOPAC>2.0.ZU;2-G
Abstract
The dynamics of polyribosome abundance were studied in gravistimulated maiz e (Zea mays) stem pulvini. During the initial 15 min of gravistimulation, t he amount of large polyribosomes transiently decreased. The transient decre ase in polyribosome levels was accompanied by a transient decrease in polyr ibosome-associated mRNA. After 30 min of gravistimulation, the levels of po lyribosomes and the amount of polyribosome-associated mRNA gradually increa sed over 24 h up to 3- to 4-fold of the initial value. Within 15 min of gra vistimulation, total levels of transcripts coding for calreticulin and calm odulin were elevated 5-fold in maize pulvinus total RNA. Transcripts coding for calreticulin and calmodulin were recruited into polyribosomes within 1 5 min of gravistimulation. Over 4 h of gravistimulation, a gradual increase in the association of calreticulin and calmodulin transcripts with polyrib osomes was seen predominantly in the lower one-half of the maize pulvinus; the association of transcripts for vacuolar invertase with polyribosomes di d not change over this period. Our results suggest that within 15 min of gr avistimulation, the translation of the majority of transcripts associated w ith polyribosomes decreased, resembling a general stress response. Recruitm ent of calreticulin and calmodulin transcripts into polyribosomes occurred predominantly in the lower pulvinus one-half during the first 4 h when the presentation time for gravistimulation in the maize pulvinus is not yet com plete.