Maize (Zea mays L.) is a vital crop worldwide, serving as a cornerstone for food security, livestock feed, and biofuel production. However, its cultivation is increasingly jeopardized by environmental challenges, notably soil salinization, which severely constrains growth, yield, and quality. To combat salinity stress, maize employs an array of adaptive mechanisms, including enhanced antioxidant enzyme activity and modulated plant hormone levels, which work synergistically to maintain reactive oxygen species (ROS) balance and ion homeostasis. This review explores the intricate interactions among ROS, antioxidant systems, plant hormones, and ion regulation in maize under salt stress, providing a comprehensive understanding of the physiological and molecular basis of its tolerance. By elucidating these mechanisms, this study contributes to the development of salt-tolerant maize varieties and informs innovative strategies to sustain agricultural productivity under adverse environmental conditions, offering significant theoretical insights into plant stress biology and practical solutions for achieving sustainable agriculture amidst global climate challenges.

SUMMARY: Cis ‐regulatory elements (CREs) are enriched in accessible chromatin regions (ACRs) of eukaryotes. Despite extensive research on genome‐wide ACRs in various plant tissues, the global impact of these changes on developmental processes in maize seeds remains poorly understood. In this study, we employed the assay for transposase‐accessible chromatin sequencing (ATAC‐seq) to reveal the chromatin accessibility profile throughout the genome during the early stages of maize seed development. We identified a total of 37 952 to 59 887 high‐quality ACRs in maize seeds at 0 to 8 days after pollination (DAP). Furthermore, we examined the correlation between the identified ACRs and gene expression. We observed a positive correlation between the open degree of promoter‐ACRs and the expression of most genes. Moreover, we identified binding footprints of numerous transcription factors (TFs) within chromatin accessibility regions and revealed key TF families involved in different stages. Through the footprints of accessible chromatin regions, we predicted transcription factor regulatory networks during early maize embryo development. Additionally, we discovered that DNA sequence diversity was notably reduced at ACRs, yet trait‐associated SNPs were more likely to be located within ACRs. We edited the ACR containing the trait‐associated SNP of NKD1 . Both NKD1 ^pro ‐1 and NKD1 ^pro ‐2 showed phenotypes corresponding to the trait‐associated SNP. Our results suggest that alterations in chromatin accessibility play a crucial role in maize seed development and highlight the potential contribution of open chromatin regions to advancements in maize breeding.

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.

Summary: Maize is a key biomass resource with wide agricultural applications. Anthocyanins, potent antioxidants, offer health benefits like reducing oxidative stress. The biosynthesis of anthocyanins competes with that of lignin for shared metabolic precursors, which can lead to trade‐offs in plant growth and feed quality. Higher lignin content can decrease silage digestibility, posing challenges for livestock feed. The maize brown midrib 6 (bm6) mutant, known for reduced lignin, has an unclear genetic basis. Here, we identify ZmGCH1 as the candidate gene for bm6 through fine mapping. Mutations in ZmGCH1 shift precursors from lignin to anthocyanin biosynthesis. Furthermore, we show that ZmGCH1 interacts with ZmPEBP15 to modulate chalcone synthase activity, thereby stabilizing the allocation of precursors between lignin and anthocyanin pathways. To evaluate the practical implications of our findings, we introduced the bm6 mutation into Zhengdan958 and Xianyu335. In vitro rumen digestion assays confirmed that the introduction of the bm6 mutation significantly improved silage digestibility. This discovery not only holds great potential for enhancing silage digestibility but also provides a broader strategy for optimizing maize production to better meet the increasing demands of both the food and livestock feed.

Recent advances in molecular studies on plant lipids have revealed novel functions, increasing interest in their roles in plant metabolic processes and food functionality. With evolving living standards, the demand for crop-derived polyunsaturated fatty acids (PUFAs) oil is increasing due to their benefits for cardiovascular health, brain function, and anti-inflammatory properties. Despite these benefits, there are gaps in comprehensive, integrated, and consolidated documents on recent advancements in crop biotechlogy, particularly concerning the biosynthesis of essential lipids. Such a document could provide valuable insights for researchers, breeders, and industry professionals seeking to enhance crop oil profiles and optimize the nutritional and functional qualities of plant-based foods. Therefore, this study aims to: (1) provide an updated review of crop lipid biosynthesis and (2) identify trending topics, key contributors, and institutions contributing to research on crop PUFAs, their health benefits, and genes associated with these functions. Methods: Systematic and mixed-method review approaches were used to gather the most recent evidence by identifying all relevant primary research studies on the specific review topic. Five databases were used in the process. Result and conclusion: 366 papers were identified, with 73 highly cited and recent ones focusing on crop PUFA biosynthesis and genetic engineering. Key genes involved in lipid biosynthesis include FAD, TMT, HGG, GhKAR, GhHAD, and transcription factors like MYB89, MYB96, WRI, LEC, GL2, FUS3, and HB2 all critical for enhancing PUFA biosynthesis. However, challenges such as poor transgene expression, reduced seed germination, and metabolic toxicity must be addressed to develop crops with improved oil profiles.