Ectopic expression of Triticum polonicum VRT-A2 underlies elongated glumes and grains in hexaploid wheat in a dosage-dependent manner: Additional data (images, phylogenetic alignments and trees)

Flower development is an important determinant of grain yield in crops. In
wheat, natural variation for the size of spikelet and floral organs is
particularly evident in Triticum polonicum, a tetraploid subspecies of
wheat with long glumes, lemmas, and grains. Using map-based cloning, we
identified VRT2, a MADS-box transcription factor belonging to the SVP
family, as the gene underlying the P1 locus. The causal P1 mutation is a
sequence substitution in intron-1 that results in both increased and
ectopic expression of the T. polonicum VRT-A2 allele. Based on allelic
variation studies, we propose that the intron-1 mutation in VRT-A2 is the
unique T. polonicum species defining polymorphism, which was later
introduced into hexaploid wheat via natural hybridizations. Near-isogenic
lines differing for the T. polonicum long-glume (P1) locus revealed a
gradient effect of P1 across florets. Transgenic lines of hexaploid wheat
carrying the T. polonicum VRT-A2 allele show that expression levels of
VRT-A2 are highly correlated with spike, glume, grain, and floral organ
length. These results highlight how changes in expression profiles,
through variation in cis-regulation, can impact on agronomic traits in a
dosage-dependent manner in polyploid crops. Here, we deposit additional
data that did not fit into the manscurpt itself. These are images of whole
spikes and of spikelets of Triticum polonicum, Triticum petropavlovskyi,
Triticum aestivum 'Arrancada' landrace group, the hexaploid and
tetraploid near-isogenic lines described in the manuscript, as well as
imags from the CSxPol F2 population. We also upload a phylogenetic tree,
including the protein sequences and where they were sourced from, as well
as a description of the methods used.