Jean-Philippe Pichaut1, Benoît Farinas1, Marie Umber1, Matthieu Chabannes2, Nathalie Laboureau2, Pierre Olivier Duroy2, Lydiane Bonheur1, Frédéric Salmon1, Christophe Jenny1,
Marie-Line Iskra-Caruana2 & Pierre-Yves Teycheney1 Marie-Line Iskra-Caruana2 & Pierre-Yves Teycheney1
1 CIRAD, UMR AGAP, F-97130 Capesterre Belle-Eau, Guadeloupe, France
2 CIRAD, UMR BGPI, F-34398 Montpellier Cedex 5, France
Horizontal gene transfer is a very important process in eukaryotic evolution and viruses are prominent DNA donors
• Plant genomes contain sequences of viruses with dsDNA (Caulimoviridae) and ssDNA (Geminiviridae) genomes which have
• Animal genomes contain retroviruses and LTR retrotransposons
(Caulimoviridae) and ssDNA (Geminiviridae) genomes which have no obligatory integration step in their replication cycle.
Teycheney P-Y & Geering ADW (2011) Endogenous viral sequences in plant genomes. Recent Advances in Plant Virology, eds Caranta C, Aranda MA, Tepfer M, & Lopez- Moya JJ (Caister Academic Press), pp 347-366.
Some endogenous Caulimoviridae sequences of banana, petunia
and Nicotiana edwardsonii are infectious and can lead to the
release of viral particles through stress-induced activation.
Musa acuminata (A) Musa balbisiana (B)
•
Fruit organoleptic qualities
• Disease resistance traits
•
Rusticity and robustness
•
Partial or total resistance to
biotic and abiotic stresses
Interspecific hybrid
Infectious eBSV integrated into the genome of the M.
balbisiana parent
Activating stress
Viral particles
© J. Vo, QAAFI
Dallot S., Acuna P., Rivera C., Ramirez P., Côte F., Lockhart B.E.L., Caruana M.L. (2001). Archives of virology, 146: 2179-2190.
Lheureux F., Carreel F., Jenny C., Lockhart B.E.L., Iskra Caruana M.L. (2003). Theoretical and applied genetics, 106 : 594-598 Côte F, Galzi S., Folliot M., Lamagnère Y., Teycheney P.-Y., Iskra-Caruana M.-L. (2010). Mol. Plant Pathol.11: 137–144
Interspecific hybrid (AAB / AAAB)
Known activating stresses:
• interspecific crosses
• temperature differences
• micropropagation
Viral particles Risk of
outbreak
Yellow leaf streaks Pseudostem splitting
Abnormal
inflorescence and bunch emergence
• Improved banana hybrid varieties with disease resistance traits are the key to increased sustainability through the reduction of pesticide usage
• Breeding strategies rely on a narrow genetic basis, and only on 2 families of progenitors : Musa acuminata (A) and Musa balbisiana (B)
AAw x AAcv colchicine
AAcv AAAAcv
• CIRAD’s breeding scheme:
AAcv AAAAcv
AAcv x AAcv
colchicine
AAcv x BBw ABcv AABBcv
AAcv x AAAAcv AAAcv
AAw x AAAAcv AAAcv
BBw x AAAAcv AABcv
AAcv x AABBcv AABcv
AAw x AABBcv AABcv
Tetraploid parents
Triploid hybrids
Tetraploid parents
AAw x AAcv colchicine
AAcv AAAAcv
AAcv x AAcv
colchicine
AAcv x BBw ABcv AABBcv
Triploid hybrids
AAcv x AAAAcv AAAcv
AAw x AAAAcv AAAcv
BBw x AAAAcv AABcv
AAcv x AABBcv AABcv
AAw x AABBcv AABcv
• Only M. acuminata progenitors are used since 2001, which narrows down the genetic basis available for breeding new varieties
• Research efforts have been focused on the creation of M. balbisiana ressources
devoid of infectious eBSVs for breeding purposes
eBSGFV-7
(BAC 71C19)
eBSGFV-9
(BAC 94I16)
13.3 kb
15.6 kb
eBSOlV -1 (BAC 310O7) 22.9 kb
23.2 kb eBSOlV-2 (BAC 73B22)
ORF1 ORF2
ORF3
Viral genome
✖ 1 locus / di allélic
✖ 1 locus / mono allélic eBSImV
(BAC 68C24) 15.8 kb
eBSMysV-1
(BAC 29H14) 11.3 kb
eBSMysV-2
(BAC 86I03) 12 kb
Infectious allele Non infectious allele
✖ 1 locus / mono allélic
✖ 2 loci / mono-allélic
15.8 kb
Gayral P, Noa-Carrazana JC, Lescot M, Lheureux F, Lockhart BE, Matsumoto T, Piffanelli P, Iskra-Caruana M-L. (2008) J Virol. 82: 6697-710.
Iskra-Caruana M-L, Baurens FC, Gayral P, Chabannes M. (2010). Mol. Plant Micr. Interact 23: 1394-402 Gayral P, Blondin L, Guidolin O, Carreel F, Hippolyte I, Perrier X, Iskra-Caruana M-L (2010) J. Virol 84: 7346-59
PCR Markers
OBINO L’EWAI
eBSOlV-1 eBSOlV-2
GOLDFINGER
eBSGFV-7 eBSGFV-9
eBSImV-1
IMOVE
eBSImV-2
- Structures - Integration
- Allèles
eBSMysV-1
IMOVE
eBSImV-2
eBSMysV-2
MYSORE
eBSV specific signature for each BSV species
Internal structure definition is ongoing
GF OL Im
PKW BBw GF7/GF9 OL1/OL2 Im
B. Honduras BBw GF7/GF9 OL1/OL2 n
Pisang Batu BBw GF7/GF9 OL1/OL2 Im
B. Cameroun BBw GF? OL? Im
Pisang Klutuk BBw GF7/GF9 OL1/OL2 Im
Porp (Popoulou) AABcv n OL? Im?
Langka AABcv n OL? n
Safet Velchi ABcv GF? OL1 n
Ney Poovan ABcv GF? OL1 n
Figue Pomme (Ekona) ABcv GF? OL1 n
Accessions with M. balbisiana genetic background were screened by PCR, using primer pairs differentiating infectious and non infectious eBSVs
OL1, GF7, Im: infectious OL2, GF9: non infectious n : no eBSV
Figue Pomme (Ekona) ABcv GF? OL1 n
FlhorBan 902 AAAcv n n n
IDN 110T AAAA n n n
Kunnan D ABcv n OL? Im?
Kunnan T AABB n OL? Im?
FlhorBan 914 AABhyb GF9 OL2 Im
FlhorBan 910 AABhyb GF7 OL2 Im
French Clair AABcv GF7 OL1 n
Kelong Mekintu AABcv GF? OL1 n
Burro (CEMSA) ABBcv GF7/GF9 OL2/OL2 Im
Pelipita ABBcv GF7/GF9 OL1/OL2 Im
Bunga Oisan AABcv GF7 OL1 n
Several accessions harbour both infectious and non infectious eBSOLV and eBSGFV alleles
Modified alleles are present in some cultivars (Cameroun, Kunnan, Kelong Mekintu…)
cv Honduras is free of eBSImV
Breeding ♂ X ♀
Seeds No seeds
Embryo rescue Failed
Plantlets
Plants weaning
eBSV signatures
B. HondurasBBw GF7/GF9 OL1/OL2 n
X
B. HondurasBBw GF7/GF9 OL1/OL2 n• Progeny of 70 screened by PCR
OL1/OL2 OL1/OL1 OL2/OL2
GF7/GF9 30 13 7
Allelic signatures (%)
GF7/GF7 7 6 3
GF9/GF9 10 3 4
• eBSV signature results fit expected segregation ratios
• 4 % of plants are devoid of all infectious alleles
B. Cameroun BBw GF ? OL? Im B. HondurasBBw GF7/GF9 OL1/OL2 n
X
• Progeny of 153 screened by PCR
OL1/OL2 OL1 OL2 ND
Allelic signatures (%)
GF7/GF9 7 13 7 2
GF7 3 14 4 2
GF9 1 14 14 4
ND 0 3 2 11
• 24 % harbour modified eBSOLV and eBSGFV alleles
B. Cameroun BBw GF ? OL? Im B. HondurasBBw GF7/GF9 OL1/OL2 n
X
• Progeny of 153 screened by PCR
OL1/OL2 OL1 OL2 ND
GF7/GF9 - - - -
Allelic signatures (%) Imové -
GF7 - - - -
GF9 - - 1.3 1.3
ND - - - 7.2
• 1.3 % are devoid of all infectious alleles
Molecular screening tools allow:
the study of eBSV alleles segregation
the search for individuals devoid of infectious eBSV alleles
Molecular screening tools allow:
the study of eBSV alleles segregation
the search for individuals devoid of infectious eBSV alleles
M .balbisiana genitors devoid of infectious eBSV alleles
were created and are being used for breeding improved
banana interspecific hybrids
Unravel the structure of modified eBSV alleles
Southern-blot
Sequencing
Unravel the structure of modified eBSV alleles
Southern-blot
Sequencing
Study the infectious status of modified alleles
Study the infectious status of modified alleles
Optimize molecular screening tools specific of modified eBSV alleles
Optimize molecular screening tools specific of modified eBSV alleles
Study the infectious status of modified alleles
CMR X IDN110 (AAB) progeny is being assessed for the expression of infectious eBSVs
Study the infectious status of modified alleles
CMR X IDN110 (AAB) progeny is being assessed
for the expression of infectious eBSVs
Lydiane Bonheur Isabelle Acina
Mambole Marie Umber
Jean-Philippe Pichaut
Pierre-Yves Teycheney