Triticeae Genomics and Genetics, 2025, Vol.16, No.6, 262-268 http://cropscipublisher.com/index.php/tgg 263 2 Molecular Regulatory Basis of Wheat Spike Development 2.1 Main developmental stages and regulatory genes of spike development How do ears grow step by step? In fact, the process is not simple. From the initial double-ridge stage to the formation of small flower primordia and finally to the differentiation of spikelets, different things are happening at each stage, involving different genes "coming on stage". Genes like TaSPL15, WFZP, VRN1 and TaHOX4 have been repeatedly demonstrated by studies to play a crucial role in the development of floral organs and the formation of meristem (Figure 1). Once these genes mutate, the number of spikelets or the length of the spikelets may be problematic. Although these structural changes seem to be only "shape" changes, they actually directly affect the output behind them (Li et al., 2020; Ai et al., 2024). Figure 1 Landscape of gene transcription, OCRs, and histone modifications in young spikes at the DRS and FPS (Adopted from Ai et al., 2024) 2.2 Key pathways involved in floral organ formation and spike differentiation In the "behind-the-scenes system" that regulates the formation of wheat ears, not only individual genes are at play, but also many signaling pathways are working in coordination. For instance, the gibberellin pathway is not only related to the length of the spike but also affects the plant height. And behind this, there are also Q genes and others playing a role in regulation. However, this mechanism is far more than just hormones; a large number of transcription factors are also involved, such as TaMYB30, TaWRKY37, TaMYC2, etc. They not only regulate expression but are also "connected in series" with epigenetic mechanisms, acting like switches to control the
RkJQdWJsaXNoZXIy MjQ4ODYzNA==