Natural modifiers of seed longevity in the Arabidopsis mutants abi3 ...
Natural modifiers of seed longevity in the Arabidopsis mutants abi3 ...
Natural modifiers of seed longevity in the Arabidopsis mutants abi3 ...
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<strong>Natural</strong> <strong>modifiers</strong> <strong>of</strong> <strong>seed</strong> <strong>longevity</strong> <strong>in</strong> <strong>the</strong><br />
<strong>Arabidopsis</strong> <strong>mutants</strong> <strong>abi3</strong>-5 and lec1-3<br />
Wim Soppe<br />
ISTA Köln<br />
17 June 2010
Seed <strong>longevity</strong><br />
‣Def<strong>in</strong>es life span <strong>of</strong> <strong>seed</strong>s<br />
‣Crucial for germplasm conservation<br />
‣Influences uniformity <strong>of</strong> germ<strong>in</strong>ation<br />
‣Determ<strong>in</strong>es crop establishment<br />
Knowledge about <strong>the</strong> molecular regulation is limited
How can we study <strong>the</strong> molecular regulation <strong>of</strong> <strong>seed</strong><br />
<strong>longevity</strong>?<br />
We use:<br />
•Model plant <strong>Arabidopsis</strong> thaliana<br />
•Mutants with reduced <strong>seed</strong> <strong>longevity</strong><br />
•<strong>Natural</strong> variation
<strong>abi3</strong>-5 and lec1-3 <strong>mutants</strong> have reduced <strong>longevity</strong><br />
ABI3 = ABSCISIC ACID INSENSITIVE<br />
LEC1 = LEAFY COTYLEDON<br />
<strong>abi3</strong>-5<br />
Wild-type<br />
Ler<br />
lec1-3<br />
• reduced accumulation <strong>of</strong> storage prote<strong>in</strong>s<br />
• <strong>in</strong>tolerance to desiccation<br />
• absence <strong>of</strong> dormancy<br />
• Rapid loss <strong>of</strong> viability
<strong>Natural</strong> variation <strong>in</strong> <strong>Arabidopsis</strong><br />
Accessions:<br />
An-1 C24 Cvi Eri Col-0 Ler Hog Sha<br />
Kyo<br />
<strong>Arabidopsis</strong> accessions differ <strong>in</strong> phenotype and physiological traits
Selection <strong>of</strong> modifier l<strong>in</strong>es that improve <strong>longevity</strong><br />
20 <strong>Arabidopsis</strong> accessions X <strong>abi3</strong>-5 / lec1-3 (<strong>in</strong> Ler accession)<br />
F1<br />
Selection for <strong>abi3</strong>-5 / lec1-3 l<strong>in</strong>es<br />
with high <strong>longevity</strong> <strong>in</strong> F2<br />
X Ler<br />
F1<br />
4X<br />
Selection for <strong>abi3</strong>-5 / lec1-3 l<strong>in</strong>es<br />
with high <strong>longevity</strong> <strong>in</strong> F2
Seis am Schlern modifier <strong>of</strong> <strong>abi3</strong>-5<br />
1 2 3 4 5<br />
<strong>abi3</strong>-5<br />
abi/Sei<br />
= Ler<br />
= Sei
Germ<strong>in</strong>ation %<br />
Seis am Schlern <strong>modifiers</strong> <strong>of</strong> <strong>abi3</strong>-5<br />
100<br />
80<br />
= Ler<br />
= <strong>abi3</strong>-5<br />
60<br />
= abi/Sei<br />
40<br />
20<br />
0<br />
0 10 20 30 40 50 60 70 80<br />
Time <strong>of</strong> <strong>seed</strong> storage (days)
Shadara <strong>modifiers</strong> <strong>of</strong> lec1-3<br />
1 2 3 4 5<br />
lec/Sha1<br />
= Ler<br />
lec1-3<br />
lec/Sha3<br />
= Sha<br />
lec/Sha2
Germ<strong>in</strong>ation%<br />
Shadara <strong>modifiers</strong> <strong>of</strong> lec1-3<br />
100<br />
80<br />
60<br />
40<br />
= Ler<br />
= lec1-3<br />
= lec/Sha1<br />
= lec/Sha2<br />
20<br />
0<br />
0 10 20 30 40<br />
Time <strong>of</strong> <strong>seed</strong> storage (days)<br />
= lec/Sha3<br />
= lec/Sha1+2+3
Controlled deterioration <strong>of</strong> Ler, Sei and Sha<br />
Germ<strong>in</strong>ation%<br />
100<br />
80<br />
60<br />
40<br />
= Ler<br />
= Sei<br />
= Sha<br />
20<br />
0<br />
0 5 10 15<br />
17<br />
Time <strong>of</strong> controlled deterioration (days)<br />
Sha is most resistant to artificial ag<strong>in</strong>g
Sha <strong>modifiers</strong> promote hypocotyl development
Proteomic pr<strong>of</strong>iles <strong>of</strong> dry <strong>seed</strong>s<br />
pI<br />
3 5 5,8 6,6 8,7<br />
3 5 5,8 6,6 8,7<br />
3 5 5,8 6,6 8,7<br />
96,5<br />
96,5<br />
96,5<br />
73,0<br />
73,0<br />
73,0<br />
58,9<br />
58,9<br />
58,9<br />
MW<br />
(kDa)<br />
42,5<br />
34,9<br />
42,5<br />
34,9<br />
42,5<br />
34,9<br />
27,2<br />
27,2<br />
27,2<br />
18,0<br />
18,0<br />
18,0<br />
13,3<br />
13,3<br />
13,3<br />
Ler lec1-3 lec/Sha1+2<br />
= 12S α globul<strong>in</strong>s<br />
= 12S β crucifer<strong>in</strong>s
Changes <strong>in</strong> prote<strong>in</strong> abundance<br />
Prote<strong>in</strong><br />
lec1-3<br />
<br />
Ler<br />
lec/Sha1+2+3<br />
/<br />
lec1-3<br />
Storage <br />
Germ<strong>in</strong>ation <br />
Chloroplast <br />
Stress<br />
response
Map based clon<strong>in</strong>g <strong>of</strong> lec/Sha1<br />
18 Kb region, conta<strong>in</strong><strong>in</strong>g <strong>the</strong> lec/Sha1 modifier<br />
1 2<br />
3<br />
A s<strong>in</strong>gle nucleotide<br />
deletion <strong>in</strong> Sha, creat<strong>in</strong>g<br />
a longer prote<strong>in</strong><br />
A 245 bp deletion <strong>in</strong> Ler,<br />
remov<strong>in</strong>g <strong>the</strong> start<br />
codon<br />
5 Kb<br />
Three candidate genes have been amplified from Sha<br />
and are transformed <strong>in</strong>to lec1-3 plants
Future prospects<br />
‣ Molecular identification <strong>of</strong> <strong>the</strong> lec/Sha1 modifier<br />
‣ Introduction <strong>of</strong> <strong>the</strong> lec/Sha1 modifier <strong>in</strong> <strong>Arabidopsis</strong><br />
l<strong>in</strong>es with poor <strong>seed</strong> <strong>longevity</strong><br />
‣ Identification <strong>of</strong> homologues <strong>of</strong> <strong>the</strong> lec/Sha1 modifier<br />
<strong>in</strong> o<strong>the</strong>r (crop) species<br />
‣ Improve <strong>seed</strong> <strong>longevity</strong> <strong>in</strong> various crops by<br />
<strong>in</strong>troduction <strong>of</strong> improved alleles <strong>of</strong> <strong>the</strong> lec/Sha1 modifier
Acknowledgements<br />
MPIPZ Cologne:<br />
Matteo Sugliani<br />
Wagen<strong>in</strong>gen University (NL):<br />
Maarten Koornneef<br />
Emile Clerkx<br />
INRA Versailles / AgroParisTech (F):<br />
Loïc Rajjou<br />
The <strong>seed</strong> dormancy group at <strong>the</strong> MPIPZ
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