A strong canopy structure is central to maximizing yield. The canopy microenvironment, which is related to crop growth and development, reflects changes in a crop’s microclimate. In this study, with the uniform sowing of winter wheat (Triticun aestivum L.), five planting densities (in 10⁴ plants·ha⁻¹: 123, 156, 204, 278, and 400) were established to examine how the planting density affected filling stage spikes, canopy structures, microenvironments, yields, and yield components. The large-spike Xindong 50 and multi-spike Sangtamu 4 varieties were used. The experiment was conducted over 263 days in the Xinjiang province, in a warm continental arid desert-type climate, with low precipitation. The study aimed to determine the optimal parameters for cultivation on limited land and improve the production potential. For both varieties, from anthesis to filling, increases in planting density were associated with a rapid reduction in the leaf area index of the lower and middle parts of the leaves. Canopy temperature and canopy CO₂ concentration also decreased, whereas relative humidity increased. The number of grains per spike and the thousand-grain weight of both varieties decreased with increased planting density. Yields were maximized at densities of 278 × 10⁴ and 156 × 10⁴ plants·ha⁻¹ for the large- and multi-spike varieties, respectively, indicating that uniform sowing improves plant uniformity, and adjusting planting density optimizes canopy structure and microenvironment. Our study provides valuable data for optimizing planting densities to ensure high yields.

Wheat production is often impacted by pre-winter freezing damage and cold spells in later spring. To study the influences of cold stress on wheat seedlings, unstressed Jing 841 was sampled once at the seedling stage, followed by 4 °C stress treatment for 30 days and once every 10 days. A total of 12,926 differentially expressed genes (DEGs) were identified from the transcriptome. K-means cluster analysis found a group of genes related to the glutamate metabolism pathway, and many genes belonging to the bHLH, MYB, NAC, WRKY, and ERF transcription factor families were highly expressed. Starch and sucrose metabolism, glutathione metabolism, and plant hormone signal transduction pathways were found. Weighted Gene Co-Expression Network Analysis (WGCNA) identified several key genes involved in the development of seedlings under cold stress. The cluster tree diagram showed seven different modules marked with different colors. The blue module had the highest correlation coefficient for the samples treated with cold stress for 30 days, and most genes in this module were rich in glutathione metabolism (ko00480). A total of eight DEGs were validated using quantitative real-time PCR. Overall, this study provides new insights into the physiological metabolic pathways and gene changes in a cold stress transcriptome, and it has a potential significance for improving freezing tolerance in wheat.

Tillering ability is a key agronomy trait for wheat (Triticum aestivum L.) production. Studies on a dwarf monoculm wheat mutant (dmc) showed that ARF11 played an important role in tillering of wheat. In this study, a total of 67 ARF family members were identified and clustered to two main classes with four subgroups based on their protein structures. The promoter regions of T. aestivum ARF (TaARF) genes contain a large number of cis-acting elements closely related to plant growth and development, and hormone response. The segmental duplication events occurred commonly and played a major role in the expansion of TaARFs. The gene collinearity degrees of the ARFs between wheat and other grasses, rice and maize, were significantly high. The evolution distances among TaARFs determine their expression profiles, such as homoeologous genes have similar expression profiles, like TaARF4-3A-1, TaARF4-3A-2 and their homoeologous genes. The expression profiles of TaARFs in various tissues or organs indicated TaARF3, TaARF4, TaARF9 and TaARF22 and their homoeologous genes played basic roles during wheat development. TaARF4, TaARF9, TaARF12, TaARF15, TaARF17, TaARF21, TaARF25 and their homoeologous genes probably played basic roles in tiller development. qRT-PCR analyses of 20 representative TaARF genes revealed that the abnormal expressions of TaARF11 and TaARF14 were major causes constraining the tillering of dmc. Indole-3-acetic acid (IAA) contents in dmc were significantly less than that in Guomai 301 at key tillering stages. Exogenous IAA application significantly promoted wheat tillering, and affected the transcriptions of TaARFs. These data suggested that TaARFs as well as IAA signaling were involved in controlling wheat tillering. This study provided valuable clues for functional characterization of ARFs in wheat.

Background: Seed germination is a critical developmental process in plants, regulated by numerous genetic factors. The delay of germination 1 ( DOG ) gene family plays a pivotal role in controlling seed dormancy and germination in various species. However, as a heterohexaploid (AABBDD), the genome structure of wheat ( Triticum aestivum L.) is complex, and the evolutionary process, functional differentiation and association mechanism of the DOG gene family with pre-harvest sprouting (PHS) have not been clarified, which urgently needs to be systematically analyzed. Results: In this study, we conducted a comprehensive genome-wide analysis of the DOG gene family in wheat, identifying 53 DOG family members (designated TaDOG1 ~ TaDOG53 ). Phylogenetic analysis grouped wheat, Arabidopsis, rice, and maize DOG proteins into three clades, with wheat genes showing closer relationships to monocots (rice/maize) than to Arabidopsis. Structural diversity, including motif composition and exon-intron organization, suggested functional specialization: Group Ⅰ genes (8 ~ 12 exons) harbored more regulatory motifs, while Group Ⅲ (1 ~ 2 exons) had minimal structures. Promoter analysis revealed abundant ABA (22.52%) and MeJA responsive (36.56%) cis -elements, consistent with hormone-treated expression dynamics: Synteny analysis indicated segmental duplications drove wheat DOG expansion, with 124 intra-genomic events and strong synteny with rice/maize. RT-PCR showed distinct temporal patterns under ABA/MeJA, with early (1 ~ 4 h) and delayed (12 h) responders mediating phased signaling. RNA-seq shows TaDOG genes have diverse expressions in 8 wheat tissues, clustered into 4 groups with distinct expression and roles, with grain-specific genes ( TaDOG3 ) highlighting potential roles in seed dormancy. It was found that there is a negative correlation between TaDOG3 expression and PHS rate, and TaDOG3 can be used as a marker gene to detect the degree of spike germination. Conclusion: This study systematically analyzed the evolutionary history and functional differentiation of the wheat TaDOG gene family, confirming that the TaDOG genes play a multi-level role in seed dormancy regulation through differentiated hormone response patterns and tissue expression characteristics. Among them, TaDOG3 , as a potential molecular marker of PHS resistance, provides a theoretical basis and practical target for wheat anti-spike germination breeding.

Tillering is a key agronomy trait for wheat (Triticum aestivum L.) production. Previously, we have reported a dwarf-monoculm wheat mutant (dmc) obtained from cultivar Guomai 301 (wild type, WT), and found growth regulating factors (GRFs) playing important roles in regulating wheat tillering. This study is to systematically investigate the roles of all the wheat GRFs (T. aestivum GRFs, TaGRFs) in regulating tillering, and screen out the key regulators. A total of 30 TaGRFs were identified and their physicochemical properties, gene structures, conserved domains, phylogenetic relationships and tissue expression profiles were analyzed. The expression levels of all the TaGRFs were significantly lower in dmc than those in WT at early tillering stage, and the abnormal expressions of TaGRF2-7(A, B, D), TaGRF5-7D, TaGRF10-6(A, B, D) and TaGRF11-2A were major causes constraining the tillering of dmc. The transcriptions of TaGRFs were significantly affected by exogenous indole acetic acid (IAA) and gibberellin acid (GA3) applications, which suggested that TaGRFs as well as IAA, GA signaling were involved in controlling wheat tillering. This study provided valuable clues for functional characterization of GRF genes in wheat.

Background: The tiller number is a key agronomic trait for increasing the yield potential of wheat (Triticum aestivum L.). A number of quantitative trait loci (QTLs) and key genes controlling tillering have been identified, but the regulatory mechanisms remain unclear. Methods: In this study, we utilized the dwarf-monoculm mutant (dmc) obtained from the ethyl methane sulfonate (EMS)-treated wheat cultivar Guomai 301. The F₂ populations were constructed using the dmc mutant crossed to multiple tiller parents. The F₂ populations were surveyed for tillering traits at the critical fertility stage for genetic analyses. The extreme-tillering-phenotype plants from the F₂ population were used to construct mixing pools that were analyzed by a wheat 55K SNP array. The tillering genes of dmc were mapped using the wheat 55K SNP array combined with transcriptomic data. Results: The results showed that the genetic phenotype of dmc is controlled by two dominant genes. The tillering genes of dmc were mapped on the 60–100 Mb region of chromosome 5B and the 135–160 Mb region of chromosome 7A. A total of sixteen candidate genes associated with the tillering trait of dmc were identified. Two candidate genes, TraesCS5B02G058800 and TraesCS7A02G184200, were predicted to be involved in indole acetic acid (IAA) response and transport, which were considered as potential regulatory genes. Conclusions: This study elucidated the genetic basis of the dmc mutant and provided two valuable reference genes for studying the development and regulatory mechanisms of wheat tillering.