Flowering time in banana (Musa spp.), a day neutral plant, is controlled by at least three FLOWERING LOCUS T homologues

Abstract

Banana is an important day neutral food crop with a long flowering/fruiting cycle that is affected by hot summers or cold winters in different places. Manipulating its life cycle requires an understanding of its flowering time machinery to bypass these stresses. Twelve FLOWERING LOCUS T (FT) and two TWIN SISTER OF FT (TSF) members were isolated from banana and their organization and expression pattern studied during development in two varieties that differ in flowering time namely Grand Nain (AAA genotype) and Hill banana (AAB genotype). The expression of at least 3 genes namely MaFT1, MaFT2 and MaFT5 (and to some extent MaFT7) increases just prior to initiation of flowering. These four genes and five others (MaFT3, MaFT4, MaFT8, MaFT12 and MaTSF1 could suppress the delayed flowering defect in the Arabidopsis ft-10 mutant and induce early flowering upon over-expression in the Col-0 ecotype. Most genes are diurnally regulated and differentially expressed during development and in various vegetative and reproductive tissues suggesting roles besides flowering. Subtle amino acid changes in these FT/TSF-like proteins provide interesting insights into the structure/function relationships of banana FTs vis-à-vis Arabidopsis. The studies provide a means for manipulation of flowering in banana for better management of resources and to reduce losses through abiotic stresses.

Evolution and Expression of Reproductive Transition Regulatory Genes FT/TFL1 With Emphasis in Selected Neotropical Orchids

“…Within the FT/TFL1like clades we were able to identify a number of large scale as well as local duplications and the associated changes in protein sequences in the resulting paralogs. Some had been previously identified (Chardon and Damerval, 2005;Carmona et al, 2007;Danilevskaya et al, 2008;Hedman et al, 2009;Karlgren et al, 2011;Lee et al, 2013;Liu et al, 2016;Chaurasia et al, 2017;Leeggangers et al, 2018) while some are reported here for the first time.…”

“…Expression analyses of FT-like homologs from the FT2 clade have identified active transcription of MonFT2 members in leaves, SAM, IM, FBs, and fruits. These patterns are consistently found in Asparagales (Allium cepa), Liliales (Lilium longiflorum and Tulipa gesneriana), Orchidaceae (Cymbidium goeringii, Dendrobium "Chao Praya Smile, " Dendrobium nobile, Oncidium Gower Ramsey, Phalaenopsis aphrodite, Phalaenopsis "Thailin Red Angel V31, " Phalaenopsis "Fortune Saltzman"), Poales (Zea mays) and Zingiberales (Musa acuminata) (Danilevskaya et al, 2008;Hou and Yang, 2009;Li et al, 2012Li et al, , 2014Xiang et al, 2012;Lee et al, 2013;Jang et al, 2015;Manoharan et al, 2016;Chaurasia et al, 2017;Wang et al, 2017;Leeggangers et al, 2018;Zhou et al, 2018). In addition, FT2 homologs from A. cepa and Oncidium "Gower Ramsey" have also been detected in bulbs and pseudobulbs, respectively (Hou and Yang, 2009;Lee et al, 2013;Manoharan et al, 2016).…”

“…From the three PEBP subfamilies, the FT-like genes are by far the most diversified in terms of copy number (Chardon and Damerval, 2005;Danilevskaya et al, 2008;Lee et al, 2013;Chaurasia et al, 2017). Our ML analyses suggest that FT-like homologs have undergone a duplication event prior to the diversification of monocots and eudicots, giving rise to copies FT1 and FT2 (Figures 1-3).…”

“…Repositories used for Orchidaceae included Orchidbase 3.0 (Fu et al, 2011) 1 and Orchidstra 2.0 (Chao et al, 2017) 2 . Additionally, some of the FT/TFL1 genes previously reported in other orchids (Hou and Yang, 2009;Xiang et al, 2012;Li et al, 2014;Jang et al, 2015;Wang et al, 2017;Zhou et al, 2018) and monocots outside of the Orchidaceae, using databases like the Rice Genome Annotation Project web 3 , were included (Danilevskaya et al, 2008;Lee et al, 2013;Chaurasia et al, 2017;Leeggangers et al, 2018).…”

Mejoramiento genético acelerado de angiospermas perennes vía inducción floral por sobre-expresión del gen FT

“…El gen FT está muy conservado entre las angiospermas; participa en la transición a la floración en plantas neutrales a la extensión del día como tomate (Lifschitz et al, 2006) y banana (Chaurasia et al, 2017), así como en plantas que requieren de vernalización (Yan et al, 2006), por lo que se le considera como un integrador de rutas de señalización.…”