DTA

Digital Theses Archive

 

Tesi etd-01232019-130435

Type of thesis
Dottorato
Author
PRASETYANINGRUM, PUTRI
URN
etd-01232019-130435
Title
Temporal and carbon dependent patterns in gibberellin biosynthesis and growth
Structure
BIO/04
Course
SCIENZE AGRARIE E BIOTECNOLOGIE - Agrobiodiversity
Committee
relatore Prof. PERATA, PIERDOMENICO
Membro Dott.ssa GIUNTOLI, BEATRICE
Membro Prof.ssa SMITH, ALISON
Membro Prof. TONUTTI, PIETRO
Keywords
  • Growth
  • Gibberellin
  • Circadian clock
  • Light
  • Resource availability
Exam session start date
;
Availability
completa
Abstract
Plant growth shows rhythmic behaviour during day/night cycles and is highly dependent on environmental conditions. Gibberellin (GA) plays a key role in growth control. However, a lot remains unclear regarding how GAs interplay with light, sugar availability and the circadian clock, to ensure proper timing and magnitude of plant growth. Therefore, this study explores how these cues regulate GA biosynthesis. First, we identified GA biosynthetic genes that showed rhythmic transcriptional behaviour throughout the day-night cycle in adult Arabidopsis rosettes. Of these, KAURENE SYNTHASE (KS) was the only GA biosynthesis gene that retained rhythmicity under continuous light conditions. However, GA20OX1 and GA3OX1, the genes that encoded final enzymatic steps of GA biosynthesis required a shift to light or darkness respectively for their induction. We present data that supports a model of rhytmic GA biosynthesis where GA precursors are made during the day and converted to bioactive GA during the night in a resource, light and clock dependent way. This thesis highlights the importance of timing of growth and synchronization between external (day-night rhythm) and internal cues (circadian clock and sugar availability).
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