Control of bolting and flowering in sugar beet · biology of flowering. 6 Transition from...
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1 Pierdomenico Perata Antonietta Santaniello Control of bolting and flowering in sugar beet Early flowering in sugar beet
Transcript of Control of bolting and flowering in sugar beet · biology of flowering. 6 Transition from...
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Pierdomenico Perata
Antonietta Santaniello
Control of bolting and flowering in sugar beet
Early flowering in sugar beet
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Early flowering in sugar beet
Troubles:
Lower yield
Difficult harvest
Increases seed dispersal (“wild beet”)
The physiology of flowering
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Pharbitis, short day plant Arabidopsis, long
day plant
Photoperiodic control of flowering
Beta vulgaris, long day plant
Vernalisation
cauliflower plant grown 5 years in a heated greenhouse
Vernalised cauliflower plant
=flowering
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Vernalisation in sugar beet
Sugar beet plants require vernalisationTemperature: 8°CLenght: ~ 70 gg
Early floweringSpring sowing (4-6 leaves stage)Fall sowingTemperature: 3-5°CLenght: few days
Low temperatures in southern Italy
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Molecular biology of flowering
Molecular biology of flowering
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Transition from vegetative to flowering meristem
Transition from vegetative to flowering meristem
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Flower and inflorescence
identity: “terminal flower” gene
tfl mutant
Mutations in CAL and AP1 results in a strong inflorescence phenoype
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The ABC model
The ABC modelAP1
AP3 PI
AG
Positive interaction between genes coding for the same
function.
A genes and C genes compete and the expression of one class excludes the expression of the
other class
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The ABC model
Vernalisation
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Physiology and genetics of flowering in sugar beet
VERNALISATION LONG DAY
GIBBERELLINS?
BOLTING
FLOWERING
B Gene
Early flowering in sugar beet
Flower differentiation
Flowering
“bolting”
inductionGibberellis
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Hormonal modulation of floweringGibberellins
Hormonal modulation of floweringGibberellins
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Gibberellins and flowering
Long dayvernalisation
gibberellins
vernalisation
bolting and flowering are distinct processes(bolting without flowering is possible) GA3 induces bolting(without vernalisation and long day conditions GA3 cannot induce flowering(unless vernalisation and long day conditions occur)
(Margara, 1960)
Long day
gibberellins
Gibberellins and flowering
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in Lolium temulentum:GA5 →→ flowering inductionGA1+GA4 →→ differentiation(King et al., 2001)
in some carrot CV GA3 induces flowering (replacing vernalisation)
In Vitis viniferagibberellins inhibit flowering
Gibberellins and flowering
VERNALISATION FLOWERING
GA1
GA8
GA5
Data: SORCE & LORENZI, UniPISA
Gibberellins and flowering in sugar beet
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Fitoregolatori e prefioritura
VERNALISATION FLOWERING
GA1
GA5
INHIBITION OF GA SYNTHESIS
REGALIS
H
H OH
COOH
O
CO
GA5
2,3-desaturasi
H
H OH
COOH
O
CO
GA20
H
H OHOH
COOH
O
CO
GA29
2β-idrossilasi
H
H OH
OH
COOH
O
CO
GA1
3β-idrossilasi
H
H OH
OH
OH
COOH
O
CO
GA8
H
H OH
OH
COOH
O
CO
GA3
PACLOBUTRAZOLE
BIOLOGICALLY ACTIVE GAs
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CONCLUSION:
Selection of CV with lower tendency to early flowering
Identification of genes responsible for the vernalisation response
Center for on Crop Physiology
Research
