Spike development inhibition in the ftin mutant is associated with
multiple phenotypic characteristics and regulated multiple biological
pathways
Abstract
Spike development of wheat line 3558M was strongly inhibited by low
temperature stress in spring. The fertile tiller inhibition (ftin) gene
in the wheat line 3558M is associated with multiple phenotypes,
including the production of fewer tillers, delayed floral transition,
and death of the shoot apical meristem. In order to study the
relationship between spike development inhibition and response to cold
stress, we systematically investigated the genes and pathways underlying
the differences using ITRAQ proteomics and RNA-sequencing technologies.
The results showed that the cold acclimation pathway and multiple
defence responses, including reactive oxygen species-mediated
hypersensitive response, salicylic acid-mediated systemic acquired
resistance, are activated and led to apex death of the wheat line 3558M
under cold stress. Meanwhile, the cold acclimation pathway inhibited the
SVP-SCO1-LFY flowering pathway and led to delayed floral transition. Two
TaPIN proteins were significantly downregulated, and multiple auxin
signalling genes were also differentially expressed. Particularly,
knocking down the two TaPIN genes using RNAi technology significantly
reduced the tiller number. The cold stress might disrupt the
distribution of auxin and reduce the tillers of 3558M. Taken together,
the ftin gene might be a cold-sensitive mutation and that is the cause
of multiple biological pathways and phenotypic changes.