It is demonstrated that COM2 and WFZP exert dosage‐dependent regulatory influence on the inflorescence and root architecture in Triticeae cereals.
Abstract
SUMMARY The distinctive spike‐shaped inflorescence architecture in temperate cereals is governed by a complex interplay of genetic factors, including the orthologous WHEAT FRIZZY PANICLE (WFZP) and barley COMPOSITUM 2 (COM2), whose products belong to the APETALA 2/ ETHYLENE RESPONSE FACTOR (AP2/ERF) family of transcription factors. However, the precise regulatory mechanism driving their function as well as the influence of allele dosage on spike formation and fertility remain to be elucidated specifically in wheat. A comprehensive analysis of the phenotype and gene function was conducted to unravel the genetic and molecular mechanisms underlying the peculiar rattail 1 (rtt1) barley phenotype. In wheat, new WFZP alleles were generated, including knockouts and in‐frame mutations in all three homoeoalleles. Our genetic analysis revealed that the rtt1 phenotype is caused by a conserved COM2 mutation. The subsequent analysis of the transcriptome data elucidated the molecular mechanisms of rtt1 for spikelet meristem identity, underscored by a predicted compromised DNA‐binding capacity of rtt1. The combination of our newly generated mutant alleles in wheat has revealed the intricate regulation of inflorescence, grain, and root development, which is controlled by WFZP. This provides evidence of the indispensable role of functional WFZP proteins, with a particular focus on the WFZP‐B allele, which has hitherto received limited attention. This study also demonstrates the allele‐specific impact of WFZP on root development, influencing branching and length. The findings of this study demonstrate that COM2 and WFZP exert dosage‐dependent regulatory influence on the inflorescence and root architecture in Triticeae cereals.
It is found that Rht5 reduces plant height through inhibition of cell proliferation while it promotes cell elongation during wheat stem elongation, providing new insights into the molecular mechanism of the Rht5-mediated plant height regulatory pathway and valuable gene resource for the genetic improvement of wheat plant architecture.
Xianglan Kong, Yuxin Lei, Aozhe Wang et al.· Theoretical and Applied Gene...· 0 citations
The Growth-Regulating Factor (GRF) family and their co-activators, GRF-Interacting Factors (GIFs), are key players in the trade-off between plant development and stress adaptation, functioning as canonical targets of the highly conserved miR396 family, which mediates responses to environmental stressors including high temperatures and water deficits. The “starlet” phenomenon in the allotetraploid Coffea arabica L. is a developmental disorder that results in malformed flowers, frequently associated with environmental stress and floral sterility. Since their underlying molecular mechanisms remain uncharacterized, we performed a genome-wide identification of the CaGRF and CaGIF families and quantified their transcriptional profiles in shoot apical meristems (SAMs) and across multiple stages of floral bud development. Our findings reveal significant differential expression of the GRF-GIF module between typical and starlet tissues throughout development, including the SAM. Intriguingly, these results do not correlate with the levels of a representative member of the miR396 family, indicating that the GRF-GIF expression shifts in starlet-flowers may be uncoupled from miR396 levels. This work provides the first molecular insights into the enigmatic starlet phenomenon in Coffea arabica L., addressing an understudied aspect of coffee reproductive development and its implications for the reproductive stability (and productivity) of this important tropical crop species.
Gabriel de Campos Rume, R. R. de Oliveira, Isabel Marques et al.· International Journal of Mol...· 0 citations
This study identified sidt1, a semi‐dwarf, high‐tillering mutant exhibiting a compact architecture and enhanced lodging resistance, and identified SiDT1 as a key regulator of plant architecture and establish a semi‐dwarf ideotype reminiscent of the rice Green Revolution.
Jianzhen Lv, Jinjin Cheng, Zhen Hu et al.· Advancement of science· 0 citations
Wheat (Triticum aestivum), a key global crop, faces rising drought stress that limits root growth and water uptake. Root meristem growth factors (RGFs) are small peptides that regulate root stem cell maintenance, meristem activity, and lateral root formation in model plants, yet the RGF gene family remains unexplored in wheat. Here, we performed a comprehensive genome-wide analysis of the TaRGF gene family, identifying 15 genes distributed across the A, B, and D subgenomes and classified into five homeologous groups (TaRGF1–TaRGF5), predominantly located on chromosomes 2 and 6. All TaRGFs contained a characteristic RGF motif, with dibasic cleavage sites and Asp–Tyr motifs indicating conserved maturation mechanisms. Based on the phylogenetic analysis, the TaRGF5 homeologs showed the highest similarity to Arabidopsis thaliana RGF5. Tested RNA-seq data revealed predominantly root-enriched expression for all TaRGF genes, with TaRGF5 exhibiting the most root-preferential and downregulation under drought stress. Quantitative real-time PCR (qRT-PCR) confirmed that drought stress suppressed the expression of TaRGF5A, TaRGF5B, and TaRGF5D in roots of wheat cultivar Sids-13 across all time points, unlike the higher accumulation seen in controls. Promoter analysis predicted a unique BES1 transcription factor binding site exclusively in TaRGF5B, linking brassinosteroid signaling to peptide-mediated root regulation. Structural modeling and molecular docking predicted an interaction between wheat TaRGF5 homeologs and root growth factor-insensitive receptor kinase (TaRGI3), characterized by conserved sulfotyrosine-mediated binding and favorable interaction energetics. Based on this characterization of the wheat RGF gene family, particularly the potential role of TaRGF5 in root development and drought-adaptation signaling, we propose targeting this gene for functional analysis to improve wheat resilience under water-limited conditions.
H. Khalil, Haidar A. Alsahoud, Abdulrahman Darwish Mostafa et al.· International Journal of Mol...· 0 citations
The domestication of maize from teosinte involved dramatic remodeling of the ear, yet the cellular and genetic bases of this transformation remain unclear. Here, we generate a single-nucleus and spatial transcriptome atlas of developing maize and teosinte ears. Comparative analysis reveals divergence in cob-associated cell types, with enhanced cytokinin signaling and reduced growth-inhibitory signals collectively driving cob thickening and enlargement in maize. We further demonstrate that domestication expanded the spatial expression domain of key transcription factors in maize meristem cells, enhancing the potential for increasing kernel number. Additionally, we verified a major domestication gene, ZmSPD1, in which two nonsynonymous SNPs differentiate maize from teosinte and alter jasmonic acid (JA) levels in the ear, thereby suppressing spikelet abortion to effectively double kernel production. These findings provide a cell-resolved mechanistic framework for how cob architecture and kernel number were shaped during maize domestication, offering new insights into the formation of key agronomic traits.
Yuebin Wang, Ruijie Mao, Yu Liu et al.· bioRxiv· 0 citations
Wheat is a globally important staple crop, whose growth and yield formation rely on the precise regulation of phytohormone signaling. The PR10/Bet v 1 (Pathogenesis-related protein 10/Betula verrucosa 1) family consists of conserved small-molecule ligand-binding proteins that participate in phytohormone signaling and plant development; however, systematic investigations of this family in wheat remain limited. Here, we performed a genome-wide identification of 75 PR10/Bet v 1 members in wheat, which were phylogenetically classified into three subfamilies: 21 known members belonging to the PYL (Pyrabactin resistance 1-like) subfamily, and 54 members assigned to two previously uncharacterized subfamilies. Bioinformatic analyses revealed that whole-genome/segmental duplication has driven the expansion of this gene family, which has evolved under strong purifying selection. Expression profiling and promoter analysis revealed differential expression patterns, along with abundant cis-acting elements responsive to multiple hormones. Quantitative RT-PCR (qRT-PCR) of 12 representative genes revealed marked transcriptional changes in several members within 1 h of treatment with BR (Brassinosteroid), ABA (Abscisic acid), CK (Cytokinin), or SA (Salicylic acid) suggesting that these genes may be directly involved in hormone-regulated processes. This study provides a fundamental framework for exploring the regulatory functions of the wheat PR10/Bet v 1 family, and valuable hormone-responsive candidate genes for the genetic improvement of wheat agronomic traits.