Cyp Proteins In Fusarium:
The highlights of the taxonomic distribution of the putative cyps of the 320 selected protein sequences from the selected Fusarium species (Table 1), shows F. pisi has the highest protein entry of 34, followed by F. oxysporum 5176 with 32 entries, on the other hand, F. cucurbiticola has the least protein entry of 4. F.oxysporum Fo5176 and F, melonis are the two species that have some families with no matches in the fungal cytochrome P450 database. F. oxysporum Fo5176 has 13 families while F. melonis has 3 families with no matches in the fungal cytochrome P450 database.
Evolutionary Relationship Of Taxa
The phylogenetic analysis of the P450s present in the seventeen selected Fusarium species (Figure 1) revealed the presence of several branches, which suggest a strong evolutionary divergence over time. CYPs belonging to the same family irrespective of the Fusarium species were clustered on the same monophyletic clade on the phylogenetic tree. The CYPs across all the selected species were grouped into seventeen (17) clades based on their phylogenetic relationship. Clades III and IX have the highest branches with a total P450 of 33 and 37, respectively. The lowest number of branches (6 CYPs) was recorded in clade XVI. Clan CYP531 was the most expanded with members across four clades (IV, IX, X and XIV). Eighteen (CYPs) with no matches in the fungal cytochrome P450 database (FCDP) for family classification were found to be clustered in just four clades; four (4) each in clades VI and VII, while five (5) each in clades VIII and IX. Based on the phylogenetic clustering, three (3) of these unmatched CYPs from Fusarium oxysporum melonis were classified alongside CYP61 (clade VIII), CYP5085 in clade IX and clan CYP61 in clade VI. Moreover, the result obtained from Fusarium oxysporum 5176, three (3) CYPs were closely related to CYP61 (clade VII), four (4) with CYP505 and one (1) CYP645 in clades VIII, also one (1) with CYP5111 and three (3) with CYP5085 in clades IX, finally, one (1) with CYP61 and two (2) with CYP61/CYP621/CYP637.
The phylogenetic clustering of these CYPs across the seventeen Fusarium species is shown in Table 2; All the selected species were represented in clade V except for F. cucurbiticola, clade I has CYPs from 14 species out of the seventeen selected species, clades III, VI, IX, XII and IV have CYPs from 13 selected species each. Clades with the least number of species are; XVI, XV, XIII and VIII with 4,5,6 and 6 respectively.
All the species selected were found to have CYPs that spread across at least nine (9) clades out of the seventeen identified clades except F. cucurbiticola and F. graminearum that were found to appear in just 2 and 6 clades respectively (Table 2).
Table 1
Taxonomic Distributions of Cytochrome P450 in Seventeen (17) Fusarium spp.
Fusarium Species
|
Genome size (Mb)
|
Number of predicted genes
|
Total proteins
Sequences
|
Total Cyp proteins
|
Sequences with e value ≥7
|
Family type
|
Clan type
|
Families with no FCPD matches
|
F. oxysporum Fo5176
|
67,983,296
|
19,130
|
297
|
185
|
32
|
16
|
15
|
13
|
F.o. melonis
|
54,034,280
|
26,719
|
344
|
201
|
21
|
13
|
13
|
3
|
F.o. conglutinans
|
53,575,352
|
26,246
|
345
|
210
|
20
|
13
|
12
|
-
|
F.o. lycopersici
|
48,637,398
|
24,733
|
319
|
189
|
24
|
21
|
18
|
-
|
F.o. vasinfectum
|
52,914,414
|
25,216
|
320
|
196
|
21
|
18
|
13
|
-
|
F.o.pisi
|
55,188,216
|
26,378
|
355
|
217
|
34
|
25
|
21
|
-
|
F.o.cubense
|
46,553,780
|
22,487
|
293
|
172
|
16
|
14
|
14
|
-
|
F. verticillioides
|
41,776,161
|
20,553
|
288
|
148
|
19
|
17
|
15
|
-
|
F. fujikuroi
|
43,832,314
|
14,813
|
276
|
143
|
13
|
11
|
9
|
-
|
F. pseudograminearum
|
36,330,246
|
12,395
|
173
|
108
|
17
|
16
|
13
|
-
|
F. graminearum
|
36,446,046
|
13,322
|
209
|
110
|
9
|
8
|
7
|
-
|
F. mangiferae
|
46,292,722
|
15,804
|
261
|
158
|
20
|
20
|
17
|
-
|
F. langsethiae
|
37,543,021
|
11,940
|
184
|
119
|
17
|
16
|
14
|
-
|
F. poae
|
46,476,831
|
14,740
|
201
|
125
|
18
|
18
|
18
|
-
|
F. proliferatum
|
45,210,324
|
16,143
|
285
|
181
|
20
|
19
|
14
|
-
|
F.solani
|
52,932,111
|
17,656
|
279
|
158
|
15
|
13
|
12
|
-
|
F. cucurbiticola
|
42,448,309
|
12,147
|
150
|
81
|
4
|
4
|
4
|
-
|
Total
|
|
|
4,579
|
2,701
|
320
|
|
|
|
Families And Clan Classification
A total of eighty-six (86) Cyp families and forty-eight (48) CYP clans were identified across the seventeen (17) selected Fusarium species as shown in figure 2. Twenty-seven (27) of these Cyp families were found to be unique to only a specie. Fusarium oxysporum 5176 has five (5) families unique to it alone (not found in other selected species). Other families unique to only a single specie out of the selected species are; Cyp506 and Cyp5111 are unique to F. conglutinans, Cyp504 in F.cucurbiticola, Cyp 5156 was found only in F. lycopersici, Cyp633 only in F. lansetheaie, Cyp636 in F.melonis, Cyp503, Cyp530, and Cyp573 in F.o. pisi, Cyp62, Cyp631 and Cyp673 were found only in F.poae, Cyp547, Cyp622, Cyp5078, Cyp5104, Cyp640, in F.O. 5176, Cyp644 and Cyp540 only in F. graminearum, Cyp 629 only in F. vasifectum, Cyp587 and Cyp625 in F. verticilloides, Cyp583 in F. proliferatum, Cyp534 in F. pseudograminearum, Cyp675, Cyp683 and Cyp5109 were found only in F. solani. These twenty-seven unique families were spread across thirteen Fusarium species. The largest clan (both in terms of the number of P450s and number of families) is CYP531, with 17 P450s and eight (8) different families (Figure 2). The most consolidated clan is CYP505, with 16 P450s all belonging to one family.
Subcellular Localization
The distribution of the CYPs across the subcellular organelles was found to be majorly localized in the endoplasmic reticulum, as seen in (Figure 3a). In contrast, very few sequences were found scattered across the other organelles except for F. oxysporum 5176, which has 8 cyps localized in the cytoplasm after the major localization in the endoplasmic reticulum (Figure 3b).
The Distribution of Secondary Metabolic Related Gene Clusters
The secondary metabolic-related gene clusters of CYPs present in the selected Fusarium species were presented in Figure 4a. The non-ribosomal peptide synthetase-like (NRPS-like) gene cluster was the predominant gene cluster across all the seventeen selected Fusarium species except in F. cucurbiticola and F. solani, which have PolyKetide Synthase (PKS) as the predominant gene clusters. Figure 4b showed the distribution of all the secondary metabolism gene clusters in each specie. F. cucurbiticola and F. lansatheiae have no HYBRID gene clusters, like-wise F. graminearum, F. poae and F. pseudograminearum contain no DMATS.