Plant architecture is a crucial influencing factor of wheat yield and adaptation. In this study, we cloned and characterized TaSPL14, a homologous gene of the rice ideal plant architecture gene OsSPL14 in wheat. TaSPL14 homoeologs (TaSPL14-7A, TaSPL14-7B and TaSPL14-7D) exhibited similar expression patterns, and they were all preferentially expressed in stems at the elongation stage and in young spikes. Moreover, the expression level of TaSPL14-7A was higher than that of TaSPL14-7B and TaSPL14-7D. Overexpression of TaSPL14-7A in wheat resulted in significant changes in plant architecture and yield traits, including decreased tiller number and increased kernel size and weight. Three TaSPL14-7A haplotypes were identified in Chinese wheat core collection, and haplotype-based association analysis showed that TaSPL14-7A-Hap1/2 were significantly correlated with fewer tillers, larger kernels and higher kernel weights in modern cultivars. The haplotype effect resulted from a difference in TaSPL14-7A expression levels among genotypes, with TaSPL14-7A-Hap1/2 leading to higher expression levels than TaSPL14-7A-Hap3. As favorable haplotypes, TaSPL14-7A-Hap1/2 underwent positive selection during global wheat breeding over the last century. Together, the findings of our study provide insight into the function and genetic effects of TaSPL14 and provide a useful molecular marker for wheat breeding.

Drought stress seriously affects the growth, development, yield, and quality of maize. This study aimed to investigate the effects of exogenous 5-ALA on root morphology and physiological changes in maize seedlings and to detect its regulatory network. The results showed that adding 25 mg/L 5-ALA accelerated root morphogenesis (root average diameter, main root length, total root length, and root surface area) and promoted dry matter accumulation and free radical removal. Transcriptome analysis showed that after applying exogenous 5-ALA, differently expressed genes (DEGs) were mainly involved in histidine metabolism, amino acid biosynthesis, plasma membrane components, secondary active sulfate transmembrane transporter activity, and anion reverse transporter activity. Two inbred lines specifically responded to organelle and structural molecular activity, and 5-ALA may regulate maize roots to achieve drought tolerance through these two pathways. In addition, candidate genes that may regulate maize root growth were screened by weighted gene co-expression network analysis (WGCNA). These genes may play important roles in alleviating drought stress through lignin synthesis, heat shock proteins, iron storage and transport, calcium binding proteins, and plasma membrane regulation of exogenous regulator 5-ALA. Our results may provide a theoretical basis for clarifying the response of maize seedling roots to drought and the mechanism of exogenous hormones in alleviating drought.

Ubiquitin/proteasome-mediated proteolysis (UPP) plays a crucial role in almost all aspects of plant growth and development, proteasome subunit RPN10 mediates ubiquitination substrate recognition in the UPP process. The recognition pathway of ubiquitinated UPP substrate is different in different species, which indicates that the mechanism and function of RPN10 are different in different species. However, the homologous ZmRPN10 in maize has not been studied. In this study, the changing of leaf angle and gene expression in leaves in maize wild-type B73 and mutant rpn10 under exogenous brassinosteroids (BRs) were investigated. The regulation effect of BR on the leaf angle of rpn10 was significantly stronger than that of B73. Transcriptome analysis showed that among the differentially expressed genes, CRE1, A-ARR and SnRK2 were significantly up-regulated, and PP2C, BRI1 AUX/IAA, JAZ and MYC2 were significantly down-regulated. This study revealed the regulation mechanism of ZmRPN10 on maize leaf angle and provided a promising gene resource for maize breeding.

Deep sowing, as a method to mitigate drought and preserve soil moisture and seedlings, can effectively mitigate the adverse effects of drought stress on seedling growth. The elongation of the hypocotyl plays an important role in the emergence of maize seeds from deep-sowing stress. This study was designed to explore the function of exogenous methyl jasmonate (MeJA) in the growth of the maize mesocotyl and to examine its regulatory network. The results showed that the addition of a 1.5 μ mol L⁻¹ MeJA treatment significantly increased the mesocotyl length (MES), mesocotyl and coleoptile length (MESCOL), and seedling length (SDL) of maize seedlings. Transcriptome analysis showed that exogenous MeJA can alleviate maize deep-sowing stress, and the differentially expressed genes (DEGs) mainly include ornithine decarboxylase, terpene synthase 7, ethylene responsive transcription factor 11, and so on. In addition, candidate genes that may regulate the length of maize hypocotyls were screened by Weighted Gene Co-expression Network Analysis (WGCNA). These genes may be involved in the growth of maize hypocotyls through transcriptional regulation, histones, ubiquitin protease, protein binding, and chlorophyll biosynthesis and play an important role in maize deep-sowing tolerance. Our research findings may provide a theoretical basis for determining the tolerance of maize to deep-sowing stress and the mechanism of exogenous hormone regulation of deep-sowing stress.

Maize ear rot is an important fungal disease in maize production, mainly caused by pathogens such as Fusarium graminearum, which seriously affects the yield and quality of maize. This study investigated the changes in the activity of defense-related enzymes in maize grains and their transcriptome response characteristics after exogenous SA treatment under Fusarium graminearum stress. The results showed that treatment with 0.01 mmol/L salicylic acid (SA) significantly inhibited the growth of Fusarium graminearum hyphae, while enhancing the activities of phenylalanine ammonia-lyase (PAL), superoxide dismutase (SOD), β-1,3-glucanase (β-1,3-GA), and polyphenol oxidase (PPO) in maize grains, and reducing the content of malondialdehyde (MDA), effectively alleviating the damage of Fusarium graminearum to the maize grain membrane system. Transcriptome analysis identified multiple key genes involved in SA-mediated disease resistance pathways, including disease-related proteins (PR10), acidic terpenoids, aspartic proteases, proteins containing BTB/POZ and MATH domains (BPM4), and PPT3 transporters. This study reveals the physiological and molecular mechanisms by which exogenous SA enhances maize resistance to ear rot, providing an important theoretical basis for further understanding the regulatory network of SA in plant disease resistance.

Maize common smut is a common disease caused by Ustilago maydis, can cause serious damage to the yield and quality of maize. To elucidate the genetic mechanism of resistance to maize smut disease, and to discover the relevant resistance genes, which have important scientific implications for maize resistance breeding. This study used the high-resistance maize variety Qi319 and the high-susceptibility variety Ye478 as materials, and constructed different segregating populations through hybridization, backcrossing, and other methods. Through field artificial inoculation and disease resistance identification, the six population (P1, P2, F1, F2, BC1P1, BC1P2) constructed was subjected to genetic and correlation analysis using a plant "quantitative trait main gene + multi gene mixed genetic model". The results showed that the optimal genetic model for maize resistance of U. maydis is MX2-ADI-ADI, the resistance of maize to U. maydis was mainly controlled by two pairs of additive-dominant-superior main genes + additive-dominant-superior polygenic genes. The heritabilities of major genes of F2, BC1P1 and BC1P2 were 69.24%, 57.89% and 54.09%, respectively, indicating that the resistance of the variety Qi319 to U. maydis was transmitted steadily to the progeny. The resistance/susceptibility pool was constructed from F2 population constructed by parents, a total of 6 candidate intervals were located on chromosomes 4, 6, 7 and 10, with a total length of 51.23Mb and containing 3723 genes by BSA-seq analysis. Transcriptome sequencing analysis showed that photosynthesis, plant pathogen interaction, carbon sequestration of photosynthetic organisms, plant hormone signal transduction, MAPK signal transduction and other pathways may be involved in the metabolic regulation of Qi319 resistance to U. maydis. The results laid a theoretical foundation for analyzing the molecular mechanism of maize resistance to powdery mildew and cloning the resistance gene.