encoding TFs, the percentage of TFs in each family is usually conserved (Fig. 1).
In woody plants, although their genome size and TF number are different, the patterns
of TF genes are similar. For example, Vitis vinifera contains 1,276 TF genes, Eucalyptus
grandis contains 1,731 and Populus trichocarpa contains 2,466 TFs. This number of
TF is higher than that reported for conifers (442–892), even though conifers have an
extremely large genome size (20–30 Gb) (Canales et al. 2014; De La Torre et al. 2014;
Jin et al. 2017b). In the maritime pine transcriptome, at least 877 TFs have been
identified and are distributed into 30 families, but some of these TF families contain
fewer members than do their counterparts in the genomes of several angiosperms.
The Dof family has 47 members in Arabidopsis, 62 in poplar and over 30 in eucalyptus but only ten in maritime and loblolly pines (Rueda-López et al. 2013). Similarly, the NAC TF family includes more than 100 members in Arabidopsis, poplar and
Eucalyptus but only 37 members in Pinus pinaster (Pascual et al. 2015) and 32 in
Picea glauca (Raherison et al. 2015) (Table 1). These findings suggest that, as has
occurred in other gene families, an expansion of the NAC family took place after
the divergence of tracheophytes through gene duplication or whole-genome duplication, resulting in the appearance of paralogous genes with a high sequence similarity
Table 1 Number of NAC proteins found in different species of the green plant linage
Species
Green Linage
No. of NAC TFs
Arabidopsis thaliana
Eudicots
113
Eucalyptus grandis
202
Vitis vinifera
71
Populus trichocarpa
167
Oryza sativa
Monocots
123
Picea glauca
Coniferophyta
32
Pinus pinaster
37
Psilotum nudum
Monilophytes
21
Selaginella moellendorffii
Lycophytes
22
Leucodon brachypus
Mosses
16
Physcomitrella patens
34
Ricciocarpos natans
Liverworts
9
Nothoceros aenigmaticus
Hornworts
4
Roya obtusa
Zygnematophyceae
4
Cylindrocystis brebissonii
6
Coleochaete irregularis
Coleochaetales
4
Nitella mirabilis
Charales
Klebsormidiales
1
Klebsormidium subtile
1
Klebsormidium flaccidum
3
Chlorokybus atmophyticus
Chlorokybales
0
Mesostigma viride
Mesostigmatales
0
Uronema sp.
Chlorophyta
0
Monomastix opisthostigma
0
The number of NAC proteins has been taken from Maugarny-Calès et al. (2016), Pascual et al.
(2015) and PlantTFDB database v4.0 (Jin et al. 2017b)
198
M. B. Pascual et al.
In woody plants, although their genome size and TF number are different, the patterns
of TF genes are similar. For example, Vitis vinifera contains 1,276 TF genes, Eucalyptus
grandis contains 1,731 and Populus trichocarpa contains 2,466 TFs. This number of
TF is higher than that reported for conifers (442–892), even though conifers have an
extremely large genome size (20–30 Gb) (Canales et al. 2014; De La Torre et al. 2014;
Jin et al. 2017b). In the maritime pine transcriptome, at least 877 TFs have been
identified and are distributed into 30 families, but some of these TF families contain
fewer members than do their counterparts in the genomes of several angiosperms.
The Dof family has 47 members in Arabidopsis, 62 in poplar and over 30 in eucalyptus but only ten in maritime and loblolly pines (Rueda-López et al. 2013). Similarly, the NAC TF family includes more than 100 members in Arabidopsis, poplar and
Eucalyptus but only 37 members in Pinus pinaster (Pascual et al. 2015) and 32 in
Picea glauca (Raherison et al. 2015) (Table 1). These findings suggest that, as has
occurred in other gene families, an expansion of the NAC family took place after
the divergence of tracheophytes through gene duplication or whole-genome duplication, resulting in the appearance of paralogous genes with a high sequence similarity
Table 1 Number of NAC proteins found in different species of the green plant linage
Species
Green Linage
No. of NAC TFs
Arabidopsis thaliana
Eudicots
113
Eucalyptus grandis
202
Vitis vinifera
71
Populus trichocarpa
167
Oryza sativa
Monocots
123
Picea glauca
Coniferophyta
32
Pinus pinaster
37
Psilotum nudum
Monilophytes
21
Selaginella moellendorffii
Lycophytes
22
Leucodon brachypus
Mosses
16
Physcomitrella patens
34
Ricciocarpos natans
Liverworts
9
Nothoceros aenigmaticus
Hornworts
4
Roya obtusa
Zygnematophyceae
4
Cylindrocystis brebissonii
6
Coleochaete irregularis
Coleochaetales
4
Nitella mirabilis
Charales
Klebsormidiales
1
Klebsormidium subtile
1
Klebsormidium flaccidum
3
Chlorokybus atmophyticus
Chlorokybales
0
Mesostigma viride
Mesostigmatales
0
Uronema sp.
Chlorophyta
0
Monomastix opisthostigma
0
The number of NAC proteins has been taken from Maugarny-Calès et al. (2016), Pascual et al.
(2015) and PlantTFDB database v4.0 (Jin et al. 2017b)
198
M. B. Pascual et al.