Figure 2 : maximum likelihood phylogeny constructed with PhyML (after alignment of 534pb of the first part of ORF3). Using the 80% nucleotide identity threshold in the RT/RNase H domain for discriminating badnavirus species, groups B-C, A, D, F, G, and E correspond to different CSSV species.
Citrus mosaic virus
is used as outgroup Figure 3: Geographic repartition of CSSV groups in different foci in West Africa (Togo, Côte d’Ivoire). In Ghana, only few isolates were studied.
Figure 1: A, CSSV genome showing the 5 ORFs and the position of the
primers used for variability studies. B, History of the appearance of the disease in West Africa. C et D, Characteristic symptoms of the disease, red vein banding of the young leaves et swellings on stems or chupons.
Figure 4 : A, Phylogeny
obtained from all currently available complete badnavirus genomic sequences. BSV is a complex of viruses showing a polyphyletic structure divided into two groups (sequences presented in green). B, Foliar symptoms of BSV. A B C D B-C1 B-C2 B-C3 B-C4 B-C5 B-C6 E F
Cacao swollen shoot virus (CSSV) and Banana streak virus (BSV) are two members of the family Caulimoviridae, genus Badnavirus. CSSV and BSV
are naturally transmitted to their respective hosts, cacao (Theobroma cacao) and banana (Musa sp.), in a semi-persistent manner by several mealybug species.
Do the primary and recent CSSV outbreaks have the same origin: host shift versus contamination by pods bearing infected mealybugs?
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Nathal
ie Le Gal
l
We cannot answer the question on the basis of these results.
- The hypothesis that each homogeneous diversity group could originate from a different original host species should be tested.
- We now need to study additional isolates from Ghana, the first country where CSSV was reported, to have a more complete idea of the geographical repartition of CSSV populations.
Analysis of CSSV populations is based on sequence comparisons of the first part of ORF3 (Figure 1A). Their spatial repartition in Togo and Côte d’Ivoire are presented in Figure 2 and 3.
Adzopé Kloto Litimé Abengourou Agnibilekrou Bouaflé Issia Sinfra Group B ubiquist: Togo, Ghana and Côte d’Ivoire
0 2. CI260 CI259 CI214 CI251 CI464 CI266 CI127 CI102 CI364 CI474_ORF3 CI490_ORF3 CI109 CI269 CI271 Ci344 CI343 CI346 CI347 CI268 CI208 CI275 CI190 GHANA11 CI604_CSSV CI323 CI316 CI322 CI320 CI645_CS GHANA23 CI641_CS CI454_ORF3 CI460_ORF3 CI196 CI44 CI32 CI68 CI54 CI181 GHANA5 Peki17 GHANA24 GHANA12 NJ10 'G27-2' CI71 CI77 CI261 CI258 CI335 CI331 CI336 CI470_ORF3 CI184 CI475 CI476 Ci337 CI338 CI210 'OBI-1-6B' 'OBI-1-3' 'OBI-2-8' 'OB1-1' 'OB2-6' 'DZ2A-10' 'DZ1-3' 'DZ4-1' 'ODO-2-6' 'ODO-1-12' 'DZ3-1' 'ABO-1-4' 'OBK-2-7' DN1_16 'DAN-2-4' 'DAN-2-3' 'DAN-3-5' 'GHANA9-200' CI85 N1A14 CI94 CI273 CI603_CSSV CI636_CSSV CI611_CSSV CI643_CS CI248 CI5 CI30 CI444_ORF3 CI23 CI431_CSSV CI437_ORF3 CI16 CI8 CI443_CSSV CI543_CSSV CI544_CSSV CI551_CSSV CI552_CSSV CI556_CSSV CI559_CSSV 'CI299-OR' CI303 CI302 CI529 CI531_CSSV CI522 CI386_ORF3 CI528 CI175 CI285 CI281 CI401_CSSV CI402_CSSV CI407_CSSV CI411_CSSV CI568_CSSV CI569_CSSVCI291CI288 CI286 CI561_CSSV CI563_CSSV CI279 CI293 CI228 CI230 CI247 CI548_CSSV CI168 CI424_CSSV CI596_CSSV CI597_CSSV CI583_CSSV CI585_CSSV CI592_CSSV CI218 CI423_CSSV CI573_CSSV CI572_ORF3 'KeDa-181' Agou 'T26-2' 'Wli-225' 'A4-4' 'KeT-221' NB2 ANA6_6 AH14 GHANA30_ 'ANA4-7' 'ANA1-1' TI1_14 Maflo28 W8B4 W12_1 GHANA10 CI163 CI152 CI141 CI636_CS CI638_CS CI642_CS CI232 CI538 CI539 CI523 CI524_CSSV CI533 CI532_CSSV CI530 CI525_CSSV CI515_CSSV CI508_CSSV CI540 CI150 'Ghana9-10'
Citrus mosaic virus CI617_ORF3CI631_ORF3CI632_ORF3GHANA26
60 20 5 0 10 17 71 39 30 16 9 0 65 68 95 28 1 12 14 1 16 61 74 60 12 8 33 1 0 75 27 42 38 14 13 22 0 6834 22 34 1 00 0 76 63 38 0 0 55 39 10017 0 29 41 55 42 42 42 23 32 31 21 12 31 67 42 49 26 0 0 0 0 4 9 38 81 46 80 51 57 41 94 62 61 97 52 52 100 100 98 100 83 74 86 89 30 63 26 68 61 12 98 100 45 100 38 89 64 100 94 100 84 98 77 15 100 89 73 23 96 71 79 39 76 31 88 40 100 33 61 56 100 69 87 30 20 22 23 67 97 54 92 10036 34 33 35 99 99 96 84 100 85 78 95 100 39 46 82 67 1 0 20 20 31 97 58 55 98 97 44 45 4394
Group C only Kloto, Togo Group A Litimé, Togo + Ghana Group D: Center of Côte d’Ivoire
Group E East of Côte d’Ivoire + Ghana Group F: East of Côte d’Ivoire
Origin of isolates: Ghana Côte d’Ivoire Togo
Groups inter B-C 1, 2, 3, 4, 5,and 6
Group G Ghana
100 km
Akoupé
Cacao swollen shoot disease(CSSD) occurs in all the main cacao growing areas of West Africa where it has caused enormous economic damage. Despite numerous “cutting out“ campaigns specially in Ghana, the virus is still a serious constraints to cocoa production in West Africa and renewed outbreaks of CSSD caused problems in Ghana, Togo and Côte d’Ivoire. As this disease only exists in Africa and appeared soon after the introduction of cacao from America to West Africa, it is likely that CSSV came by host shift from indigenous hosts
Banana streak virus recently became emergent in East Africa. The biodiversity of BSV higher than for the other badnaviruses is the consequence of two phenomena: the epidemic process of the disease -contamination of plant to plant by vector- and the release of infectious viral genomes by the banana genome harboring endogenous sequences.
0 0.2 RTBV-Phi GVBV-BC DrMV TaBV ComYMV CLNV SCBMOV SCBIMV BSUMV BSULV BSUIV BSGFV BCVBV DBV DBSNV CMBV CSSV-CI152 CSSV-Wobe12 CSSV-N1A CSSV-Agou1 BSMYV SCBGDV KTSV BSIMV BSYUV BSVNV BSUAV BSOLV BSCAV SCBGAV-B51129 SCBGAV-R570 51 60 99 100 10097 100 100 100 100 100100 99 99 100 100 100 100 100 100 100 100 100 75 82 70 98 64
Could the second group of BSV originate from integrated equivalent within alternative host genome?
Work in progress
Group 1, BSV identified in epidemics worldwide and having for most of them an integrated equivalent within the host genome Group 2, BSV only identified in East Africa without integrated equivalent.
Cacao swollen shoot virus
3: Côte d’Ivoire East 1946 2:Nigéria 1944 4: Togo Kloto 1949 1: Ghana 1922 B C D A Orf3ACSSVF Orf3ACSSVR 534pb CSSV 7-7.3 kb 3 12 A B ORF III ORF I ORF II BSV IR ORF III ORF I ORF II BSV IR episomal endogenous episomal
Origin of the emergence of badnaviruses
such as Cacao swollen shoot virus (CSSV)
and Banana streak virus (BSV)
Emmanuelle Muller 1, Koffie Kouakou2, Christian Cilas3, Marie-Line Iskra-Caruana1
1 CIRAD/UMR BGPI F-34398 Montpellier cedex 5, emmanuelle.muller@cirad.fr, 2 Station de Recherche du CNRA, BP 808 Divo, COTE D’IVOIRE, 3 CIRAD/UPR 106, F-34398 Montpellier cedex 5
