Summary: Lignin is a crucial component of the cell wall, providing mechanical support and protection against biotic and abiotic stresses. However, little is known about wheat lignin‐related mutants and their roles in pathogen defence. Here, we identified an ethyl methanesulfonate (EMS)‐derived Aegilops tauschii mutant named brown glume and internode 1 (bgi1), which exhibits reddish‐brown pigmentation in various tissues, including internodes, spikes and glumes. Using map‐based cloning and single nucleotide polymorphism (SNP) analysis, we identified AET6Gv20438400 (BGI1) as the leading candidate gene, encoding the TaCAD1 protein. The mutation occurred in the splice acceptor site of the first intron, resulting in a premature stop codon in BGI1. We validated the function of BGI1 using loss‐of‐function EMS and gene editing knockout mutants, both of which displayed reddish‐brown pigmentation in lignified tissues. BGI1 knockout mutants exhibited reduced lignin content and shearing force relative to wild type, while BGI1 overexpression transgenic plants showed increased lignin content and enhanced disease resistance against common root rot and Fusarium crown rot. We confirmed that BGI1 exhibits CAD activity both in vitro and in vivo, playing an important role in lignin biosynthesis. BGI1 was highly expressed in the stem and spike, with its localisation observed in the cytoplasm. Transcriptome analysis revealed the regulatory networks associated with BGI1. Finally, we demonstrated that BGI1 interacts with TaPYL‐1D, potentially involved in the abscisic acid signalling pathway. The identification and functional characterisation of BGI1 significantly advance our understanding of CAD proteins in lignin biosynthesis and plant defence against pathogen infection in wheat.

Phytohormone synergies and signaling interdependency are important topics in plant developmental biology. Physiological and genetic experimental evidence for phytohormone crosstalk has been accumulating and a genome-scale enzyme correlation model representing the Arabidopsis metabolic pathway has been published. However, an integrated molecular characterization of phytohormone crosstalk is still not available. A novel modeling methodology and advanced computational approaches were used to construct an enzyme-based Arabidopsis phytohormone crosstalk network (EAPCN) at the biosynthesis level. The EAPCN provided the structural connectivity architecture of phytohormone biosynthesis pathways and revealed a surprising result; that enzymes localized at the highly connected nodes formed a consecutive metabolic route. Furthermore, our analysis revealed that the transcription factors (TFs) that regulate enzyme-encoding genes in the consecutive metabolic route formed structures, which we describe as circular control units operating at the transcriptional level. Furthermore, the downstream TFs in phytohormone signal transduction pathways were found to be involved in the circular control units that included the TFs regulating enzyme-encoding genes. In addition, multiple functional enzymes in the EAPCN were found to be involved in ion and pH homeostasis, environmental signal perception, cellular redox homeostasis, and circadian clocks. Last, publicly available transcriptional profiles and a protein expression map of the Arabidopsis root apical meristem were used as a case study to validate the proposed framework. Our results revealed multiple scales of coupled mechanisms in that hormonal crosstalk networks that play a central role in coordinating internal developmental processes with environmental signals, and give a broader view of Arabidopsis phytohormone crosstalk. We also uncovered potential key regulators that can be further analyzed in future studies.

The aim was to improve the fertilizer utilization efficiency and alleviate environmental pollution risk under a wheat-maize rotation system. Here, the combinations of different nitrogen stabilizers and phosphorus activators were used to reduce nitrogen loss and phosphorus fixation in the field experiment. Compared to the control, the combination of 1.5%HQ + 0.5%DMPP + biochar showed the most significant effect on the retention of alkali-hydrolysable nitrogen (Nah), the highest with an increase of 22.6% at the 0~20 cm layer soil; and the combination of 1.5%HQ + 3.5%DCD + CMFs (compound microbial fertilizers) showed the most significant effect on the maintenance of available phosphorus (Pa), with the highest increase of 41.3%. N, P synergists combined with a basal fertilizer could effectively slow down the transformation from ${\mathrm{N}\mathrm{H}}_4^{+}$ to ${\mathrm{N}\mathrm{O}}_3^{-}$, and keep ${\mathrm{N}\mathrm{H}}_4^{+}$ at an increase of 7.38%~19.6%. Moreover, the N, P synergists could efficiently lock the available nutrients around the roots, preventing the migration of ${\mathrm{N}\mathrm{O}}_3^{-}$, ${\mathrm{N}\mathrm{H}}_4^{+}$, Nah, and Pa to the deeper layers. Especially for ${\mathrm{N}\mathrm{O}}_3^{-}$, the total accumulation at 0~60 cm decreased by 32.1%, and the activation of Pa was mainly concentrated at 0~40 cm. Under the same nutrient inputs, the combination of 0.3%NBPT + 0.5%DMPP + CMFs obtained the highest wheat yield. The combination of 1.5%HQ + 0.5%DMPP+ biochar gained the highest maize yield. Overall, the application of N, P synergists could increase the effective duration of Nah, Pa, and ${\mathrm{N}\mathrm{H}}_4^{+}$ in the surface soil, and reduce the accumulation of ${\mathrm{N}\mathrm{O}}_3^{-}$ in the 0~60 cm soil layer. The capacity of holding and keeping nutrients from leaching rose obviously; simultaneously, the assimilative capacity of crops for nitrogen and phosphorus increased distinctly, which could lower the eutrophia risks from nitrogen and phosphorus.

Lignin is a crucial component of the cell wall, providing mechanical support and protection against biotic and abiotic stresses. However, little is known about wheat lignin-related mutants and their roles in pathogen defense. In this study, we identified an ethyl methanesulfonate (EMS)-derived Aegilops tauschii mutant named brown glume and internode 1 ( bgi1 ), which exhibits reddish-brown pigmentation in various tissues, including internodes, spikes, and glumes. Using map-based cloning and single nucleotide polymorphism (SNP) analysis, we identified AET6Gv20438400 ( BGI1 ) as the leading candidate gene, encoding the TaCAD1 protein. The mutation occurred in the splice acceptor site of the first intron, resulting in a premature stop codon in BGI1 . We validated the function of BGI1 using loss-of-function EMS and gene editing knockout mutants, both of which displayed reddish-brown pigmentation in lignified tissues. BGI1 knockout mutants exhibited reduced lignin content and shearing force relative to wild type, while BGI1 overexpression transgenic plants showed increased lignin content and enhanced disease resistance against common root rot and Fusarium crown rot. We confirmed that BGI1 exhibits CAD activity both in vitro and in vivo , playing an important role in lignin biosynthesis. BGI1 was highly expressed in the stem and spike and localized in the cytoplasm. Transcriptome analysis revealed the regulatory networks associated with BGI1 . Finally, we demonstrated that BGI1 interacts with TaPYL-1D, potentially involved in the abscisic acid signaling pathway. The identification and functional characterization of BGI1 significantly advance our understanding of CAD proteins in lignin biosynthesis and plant defense against pathogen infection in wheat.

Soil salinization is a major abiotic stress limiting wheat production. Although transcriptional responses to salt stress are well-studied, the role of post-transcriptional regulation, particularly through RNA modifications, remains unclear in wheat (Triticum aestivum L.). Here, we present an integrated analysis of the early salt stress response using Nanopore direct RNA sequencing (DRS) and quantitative proteomics. We generated genome-wide maps of N6-methyladenosine (m6A) modifications, concurrently profiling alternative polyadenylation (APA) events and poly(A) tail length (PAL) dynamics. This multi-omics approach characterizes coordinated epitranscriptomic reprogramming and enabled the construction of a regulatory network linking m6A marks to proteomic changes. Furthermore, we identified and functionally validated the putative m6A reader protein TaECT5 as a positive regulator of wheat salt tolerance. Our study provides a systems-level view of post-transcriptional regulation during salt stress in wheat and identifies potential targets for enhancing salt tolerance.