GATA transcription factor is crucial for plant growth and development, physiological metabolism, and environmental response, which has been reported in many plants. Although the identification of maize GATA genes has been reported previously, the number of maize GATA genes was incomplete, and the expression patterns of maize GATA genes were not analyzed. Therefore, in this study, the GATA gene family of maize (Zea mays L.) was systematically analyzed. Forty-one GATA family genes were identified in the maize and were divided into four groups. The gene structure of each subgroup was basically consistent with that of the motif. The maize GATA genes were distributed on 10 chromosomes, including 3 and 17 pairs of tandem and segmental duplication genes, respectively. Fourteen types of cis-acting elements were identified in the promoter sequences of maize GATA family genes, involving four categories: light response, stress, hormone, and growth and development. The tissue-specific expression analysis of maize GATA family genes revealed that 4 GATA genes were highly expressed in almost all the maize tissues, and 11 GATA genes were not expressed in almost all tissues. The other maize GATA family genes showed a tissue-specific expression pattern. The results of RNA-seq reanalysis of publicly available transcriptome sequencing big data revealed that the gene ZmGATA37 was significantly down-regulated in response to abiotic stresses including high temperature, low temperature, drought, waterlogging, and salt, and significantly up-regulated in response to biotic stresses including smut disease, Maize Iranian mosaic virus infection, beet armyworm and aphid infestations. This indicated that the ZmGATA37 gene plays an important role in maize growth and development. Our findings offer new insight into the potential role of GATA transcription factors in abiotic and biotic stresses and provide a theoretical groundwork for the molecular mechanisms underlying maize adaptation to such stress.

Maize is a critical crop for food, feed, and bioenergy worldwide. This study characterized the genetic diversity and population structure of 212 important inbred lines collected from the Southeast China breeding program using the Maize6H-60K single nucleotide polymorphism (SNP) array. To investigate the genetic architecture of plant height (PH) and ear height (EH), genome-wide association analysis (GWAS) was performed on this population in 2021 and 2022. Cluster analysis and population genetic structure analysis grouped the 212 maize inbred lines into 10 distinct categories. GWAS identified significant associations for PH, EH, and the EH/PH ratio. A total of 40 significant SNP (p < 8.55359 × 10⁻⁷) were detected, including nine associated with PH, with phenotypic variation explained (PVE) ranging from 3.42% to 25.92%. Additionally, 16 SNP were linked to EH, with PVE ranging from 2.49% to 38.49%, and 15 SNP were associated with the EH/PH ratio, showing PVE between 3.43% and 16.83%. Five stable SNP, identified across two or more environments, were further analyzed. Three of these SNP loci are reported for the first time in this study: two loci associated with the PH, AX-108020973, and AX-108022922, as well as one new locus, AX-108096437, which was significantly associated with the EH/PH ratio. Additionally, two other significant SNP (AX-247241325 and AX-108097244) were located within a 2 Mb range of previously identified QTL and/or related SNP. Within the 200 kb confidence intervals of these five stable SNP loci, 76 functionally annotated genes were identified. Further functional analysis indicated that 14 of these genes may play a role in regulating plant morphology, which is primarily involved in hormone synthesis, microtubule development, root growth, and cell division regulation. For instance, the homologous genes GRMZM2G375249 and GRMZM2G076029 in maize correspond to OsPEX1 in rice, a protein similar to extension proteins that are implicated in lignin biosynthesis, plant growth promotion, and the negative regulation of root growth through gibberellin-mediated pathways. The candidate gene corresponding to AX-108097244 is GRMZM2G464754; previous studies have reported its involvement in regulating EH in maize. These findings enhance the understanding of QTL associated with maize plant-type traits and provide a foundation for cloning PH, EH-related genes. Therefore, the results also support the development of functional markers for target genes and the breeding of improved maize varieties.

Seed reserve mobilization is a crucial physiological process during seed germination. Enhancing the reserve mobilization in sweet corn is vital for seed germination and seedling growth. In this study, a genome-wide association analysis (GWAS) was conducted to predict candidate genes for regulating the weight of mobilized reserved seeds (WMRS) and kernel weight (KW) in sweet corn. GWAS was performed using the BLINK model with the maize 56K SNP chip. The results indicated that there was a positive correlation between the WMRS and KW, with coefficients of variation of 68.18% and 44.63%. Association analysis identified thirteen SNPs associated with two traits, and linkage disequilibrium analysis revealed that eight of these SNPs were in strong linkage. A total of 298 candidate genes were identified within the confidence interval, of which 79 were annotated. About 20 candidate genes were identified through the comparison of homologous genes in Arabidopsis. These genes were enriched in regulating ribosome biogenesis, signal transduction, hormone synthesis, and RNA degradation processes. This study provides important insights into the genetic mechanisms governing germination traits in sweet corn, aiding further research into the localization and cloning of genes involved in the mobilization of reserve materials.

Silver nanoparticles were biosynthesized from Conyzacanadensis leaf extract with the help of a microwave oven. The UV-vis spectrum showed the maximum absorption at 441 nm, corresponding to the surface plasmon resonance of silver nanoparticles. Transmission electron microscope and scanning electron microscope images showed that the synthesized silver nanoparticles were spherical or near-spherical with an average diameter of 43.9 nm. X-ray diffraction demonstrated nanoparticles with a single-phase cubic structure. As-synthesized silver nanoparticles displayed prominent antifungal activity against Bipolaris maydis. The colony inhibition rate reached 88.6% when the concentration of nanosilver colloid was 100 μL·mL⁻¹ (v/v). At such a concentration, no colony formation was observed on the solid plate. The diameter of the inhibition zone was 13.20 ± 1.12 mm. These results lay the foundation for the comprehensive control of plant pathogens using an environmentally friendly approach.

In this study, dynamic quantitative trait loci (QTL) were mapped in a recombinant inbred line (F-2: 4) population derived from a BF3109 x Q267 cross. This was done during the unconditional (4, 7, and 10 days) and conditional (0 to 4, 4 to 7, and 7 to 10 days) germination stages in sh(2) sweet corn. The values of seedling dry weight, weight of mobilized seed reserve (WMSR), seed reserve depletion percentage (SRDP), seed reserve utilization efficiency (SRUE), and their heritability differed across the investigated stages. The heritabilities of these traits were lower at 7D/4D and 10D/7D compared with those at the 4- (4D/0D), 7- and 10-day (D) developmental stages. WMSR and SRDP were significantly negatively correlated with SRUE at the early stage. The unconditional QTL mapping can explain the accumulation of genetic effects of seed reserve utilization from the starting time, whereas the conditional QTL mapping can reveal genetic expression in the time intervals. Fifteen and fourteen additive QTLs were identified by the unconditional and conditional mapping, respectively. The number of additive QTLs and their effect values varied among the different stages. More additive QTLs were found at the later stage (7 to 10 days), based on the conditional mapping results. The identification of QTL mapping based on a combination of time-dependent measurements is important for a better understanding of the genetic bases of seed reserve utilization. It is also important for the improvement of relevant variety traits for subsequent sweet corn-breeding studies using marker-assisted selection.

Sweet corn is highly susceptible to low temperatures, especially during seed germination, which severely affects plant growth and crop yield. This study used 100 sweet corn micro-core germplasms to evaluate two key germination traits under cold stress: seed storage material utilization efficiency (SRUE) and mobilization weight (WMSR). To investigate the genetic basis of cold germination in sweet corn, we selected the BLINK model for GWAS due to its ability to minimize false positives. A total of nine SNPs were found to be significantly associated with cold germination. These SNPs explained between 9.8% and 17.2% of the phenotypic variance (PVE). Within the confidence interval, 63 functionally annotated genes were identified. Fourteen candidate genes associated with cold germination were identified through GO functional analysis and the functional expression of homologous genes. A literature analysis indicated that these genes are primarily involved in seed germination, cold tolerance, and responses to other abiotic stresses. These findings enhance our understanding of the genetic and molecular mechanisms underlying cold germination, establishing a theoretical foundation for breeding cold-tolerant sweet corn varieties.