Biology subjects

Bie, X.

Publications and source records attributed to Bie, X..

3 recordsLinked to original sources

bioRxiv2022

Systematic mining and genetic characterization of regulatory factors for wheat spike development

The spike architecture of wheat plays a crucial role in determining grain number, making it a key trait to optimize in wheat breeding programs. In this study, through a multi-omic approach, we analyzed the transcriptome and epigenome profiles of the shoot apex at eight developmental stages, revealing coordinated changes in chromatin accessibility and H3K27me3 abundance during the flowering transition. We constructed a core transcriptional regulatory network (TRN) that drives wheat spike formation, and experimentally validated a multi-layer regulatory module involving TaSPL15, TaAGLG1, and TaFUL2. By integrating the TRN with genome-wide association analysis (GWAS), we identified 227 transcription factors (TFs), including 42 with known functions and 185 with unknown functions. Further investigation of 61 novel TFs using multiple homozygous mutant lines uncovered 36 TFs with altered spike architecture or flowering time, such as TaMYC2-A1, TaMYB30-A1, and TaWRKY37-A1. Of particular interest, TaMYB30-A1, downstream and repressed by WFZP, was found to regulate fertile spikelet number. Notably, during the domestication and breeding process in China, the excellent haplotype of TaMYB30-A1 containing a C allele at the WFZP binding site was enriched, leading to improved agronomic traits. Our study presents novel and high-confidence regulators and offers an effective strategy for understanding the genetic basis of wheat spike development, with practical impact for wheat breeding applications.

plant biology↗

bioRxiv2022

Uncovering transcriptional regulatory network during regeneration for boosting wheat transformation

Genetic transformation is important for gene functional study and crop breeding. Though it is available in many plant species, the transformation efficiency in wheat is generally low, which greatly restricts the genetic manipulation in wheat. Here, we use multi-omic analysis strategy to uncover core transcriptional regulatory network (TRN) driving wheat shoot regeneration and identify key factors that boost the transformation efficiency. RNA-seq, ATAC-seq and CUT&Tag were used to profile the transcriptome and chromatin dynamic during regeneration process from immature embryo of wheat variety Fielder. Sequential expression of gene clusters that mediating cell fate transition during regeneration is induced by auxin signaling, in coordination with changes of chromatin accessibility, H3K27me3 and H3K4me3 status. The TRN driving wheat shoot regeneration was built-up and 446 key transcriptional factors (TFs) occupied the core of network were identified, including functionally tested regeneration factors in other species. We further compared the regeneration process between wheat and Arabidopsis and found that DNA binding with one finger (DOF) TFs show distinct patterns in two species. Furthermore, we found that TaDOF5.6 (TraesCS6A02G274000) and TaDOF3.4 (TraesCS2B02G592600) can significantly improve the transformation efficiency of different wheat varieties. Thus, our data uncovers the molecular regulatory insights for wheat shoot regeneration process and provides potential novel targets for improving transformation efficiency in wheat.

developmental biology↗

bioRxiv2022

Chromatin reprogramming and transcriptional regulation orchestrate embryogenesis in hexaploid wheat

Embryogenesis represents the beginning of life cycle, but our understanding of the regulatory circuitry in plants is far lagged to animals. Here, we draw a transcriptome trajectory and chromatin landscape profile during embryogenesis of most cultivated crop hexaploid wheat, highlighting large-scale chromatin reconfiguration and distinct proximal and distal transcriptional regulation in defining cell fate transition. Upon fertilization, H3K27ac and H3K4me3 resetting were correlated with maternal genome silence, while de novo building of chromatin accessibility activated zygotic genome. Global depletion of H3K27me3 in pre-embryo results in a permissive chromatin environment with gain-of-chromatin accessibility, allowing subsequent hierarchical cis- and trans-regulation network mediated by key factors, such as LEC1, MYB, ZHD, LEC2, governing embryo pattern formation. By contrast, H3K27me3 restoration coordinating with chromatin compaction in developmental genes attenuated totipotency and prohibited extensive organogenesis during embryo maturation. In addition, dynamic biased expression of homeolog triads and diverse expression profiles after polyploidization were observed. This is correlated with asymmetric transposon elements insertion in accessible proximal and distal regions. Thus, our study revealed a plant-specific chromatin reprogramming process in facilitating the hierarchical transcription regulation circuits mediated "inverse hourglass model" and unveiled epigenetic regulation of evolutionary divergence among different sub-genome in shaping embryogenesis in polyploidy wheat.

plant biology↗