Search Results (197)

Transgenic insect-resistant maize can effectively control insect pests, which is of great significance to improve maize yield and quality. Transgenic maize LD05 is an insect-resistant and herbicide-tolerant maize independently developed by Shandong Academy of Agricultural Sciences and highly resistant to major lepidopteran pests. In order to study the pest resistance of transgenic maize LD05 in different ecological areas of China, this study conducted a laboratory bioassay, and artificial inoculation test and natural pest investigation in field were carried out in one pilot of each of five maize ecological zones in China. The results of laboratory bioassay showed that transgenic maize LD05 had high resistance to Ostrinia furnacalis (Guenée), Mythimna separata (Walker), Helicoverpa armigera (Hübner) and Spodoptera frugiperda (J. E. Smith), the main lepidopteran pests threatening maize production in China. The results of artificial inoculation test and natural pest investigation in field showed that transgenic maize LD05 had high resistance to major lepidopteran pests in different ecological areas of China, which was consistent with the pest resistance management strategy, and can provide important theoretical basis and technical support for the industrialization of transgenic maize LD05 in the future. Full article

This paper examines various aspects of maize plant height. Firstly, it emphasizes that maize is a significant food and forage crop with considerable research significance, and that its plant height is influenced by multiple factors, including biotic elements such as genes and plant hormones, as well as abiotic factors such as soil, water, and climate. Secondly, the paper explores the complex relationship between maize plant height and yield, noting that moderate plant height can improve photosynthetic efficiency, reduce lodging risk, and enhance yield, although it may also affect kernel quality. Additionally, the paper reviews the application of modern biotechnological methods in maize plant height research, such as genome-wide linkage analysis, gene editing, transgenic technology, and epigenetic studies, which aid in elucidating the genetic mechanisms underlying plant height. Finally, it outlines future research directions for improving maize plant height and yield, highlighting key challenges that require urgent attention, such as the advancement of gene editing techniques, the integration of multiple biotechnologies, and strategies to address climate change, with the ultimate goal of achieving precision breeding for high-yielding, stress-resistant, and broadly adaptable maize varieties. Full article

While genetically modified crops bring significant economic benefits, the environmental safety issues they may pose have also received increasing attention. To study the impact of planting genetically modified insect-resistant crops on soil ecosystems, this research employed methods such as 16S rDNA amplicon full-length sequencing, using transgenic Cry1Ah insect-resistant corn HGK60 and its conventional counterpart Zheng 58 as subjects for a three-year continuous survey to analyze the effects of planting transgenic Cry1Ah insect-resistant corn HGK60 on the rhizosphere bacterial community. The following results were obtained. (1) A total of 216 corn rhizosphere soil samples were annotated to 51 phyla, 119 orders, 221 families, and 549 genera. (2) Overall, there was no significant difference in the composition of the rhizosphere bacterial community between HGK60 and Zheng 58 at the phylum, class, order, or family levels (p > 0.05), and the planting of HGK60 did not significantly affect the relative abundance of rhizosphere probiotics (p > 0.05). Some differences appeared only briefly and were not reproducible. (3) Alpha and beta diversity analyses showed that overall, the planting of HGK60 had no significant impact on the structure of the rhizosphere bacterial community (p > 0.05). (4) Significant changes in the rhizosphere bacterial community were observed across different growth stages of corn. It can be concluded that the planting of HGK60 has no significant impact on the rhizosphere bacteria. This study provides valuable data support for the environmental safety assessment of genetically modified crops. Full article

The fall armyworm (Spodoptera frugiperda (J.E. Smith)), which invaded China in 2018, has caused severe corn yield losses and increased pesticide application frequency. Bacillus thuringiensis (Bt)-based genetically modified corn represents an environmentally friendly and effective strategy for managing S. frugiperda. The transgenic corn LD05 harbors the m2cryAb-vip3A insect-resistant fusion gene, which has demonstrated potent inhibitory effects against fall armyworm and is currently in the phase of applying for safety certification. Here, we evaluated the inhibitory efficacy of LD05 against S. frugiperda through laboratory and field experiments during 2022–2024. The LC₅₀ and LC₉₅ of M2CryAb-VIP3A against fall armyworm were 0.024 μg/cm² and 0.508 μg/cm², respectively; and the GLC₅₀ and GLC₉₅ were 0.142 μg cm⁻² and 0.556 μg cm⁻², respectively. M2CryAb-VIP3A expression of LD05 varied significantly across tissues, and remained stable between generations. Bioassays revealed significant tissue-specific differences in fall armyworm larval mortality for LD05 corn tissues, ranked as V5-stage leaves > R3-stage kernels > R1-stage silks. Field trials demonstrated that LD05 corn significantly reduced fall armyworm larval populations, leaf damage incidence, and plant damage incidence compared to non-Bt control Zheng58. Agronomic trait analysis showed no significant differences between LD05 and Zheng58. These results indicate that LD05 has a significant inhibitory effect on fall armyworm, which is an effective strategy for the comprehensive management of fall armyworm in China. Full article

Nitrogen use efficiency remains the primary bottleneck for sustainable maize production. This study elucidates the functional mechanisms of the amino acid transporter ZmAAP1 in nitrogen absorption and stress resilience. Through systematic evolutionary analysis of 55 maize inbred lines, we discovered that the ZmAAP1 gene family exhibits distinct chromosomal localization (Chr7 and Chr9) and functional domain diversification (e.g., group 10-specific motifs 11/12), indicating species-specific adaptive evolution. Integrative analysis of promoter cis-elements and multi-omics data confirmed the root-preferential expression of ZmAAP1 under drought stress, mediated via the ABA-DRE signaling pathway. To validate its biological role, we generated transgenic maize lines expressing Arabidopsis thaliana AtAAP1 via Agrobacterium-mediated transformation. Three generations of genetic stability screening confirmed the stable genomic integration and root-specific accumulation of the AtAAP1 protein (Southern blot/Western blot). Field trials demonstrated that low-N conditions enhanced the following transgenic traits: the chlorophyll content increased by 13.5%, and the aboveground biomass improved by 7.2%. Under high-N regimes, the gene-pyramided hybrid ZD958 (AAP1 + AAP1) achieved a 12.3% yield advantage over conventional varieties. Our findings reveal ZmAAP1’s dual role in root development and long-distance nitrogen transport, establishing it as a pivotal target for molecular breeding. This study provides actionable genetic resources for enhancing NUE in maize production systems. Full article

Chaperonin 60 proteins plays an important role in plant growth and development as well as the response to abiotic stress. As part of the protein homeostasis system, molecular chaperones have attracted increasing attention in recent years due to their involvement in the folding and assembly of key proteins in photosynthesis. However, little is known about the function of maize chaperonin 60 protein. In the study, a gene encoding the chaperonin 60 proteins was cloned from the maize inbred line B73, and named ZmCpn60-3. The gene was 1, 818 bp in length and encoded a protein consisting of 605 amino acids. Phylogenetic analysis showed that ZmCpn60-3 had high similarity with OsCPN60-1, belonging to the β subunits of the chloroplast chaperonin 60 protein family, and it was predicted to be localized in chloroplasts. The ZmCpn60-3 was highly expressed in the stems and tassels of maize, and could be induced by exogenous plant hormones, mycotoxins, and pathogens; Overexpression of ZmCpn60-3 in Arabidopsis improved the resistance to Pst DC3000 by inducing the hypersensitive response and the expression of SA signaling-related genes, and the H₂O₂ and the SA contents of ZmCpn60-3-overexpressing Arabidopsis infected with Pst DC3000 accumulated significantly when compared to the wild-type controls. Experimental data demonstrate that flg22 treatment significantly upregulated transcriptional levels of the PR1 defense gene in ZmCpn60-3-transfected maize protoplasts. Notably, the enhanced resistance phenotype against Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) in ZmCpn60-3-overexpressing transgenic lines was specifically abolished by pretreatment with ABT, a salicylic acid (SA) biosynthetic inhibitor. Our integrated findings reveal that this chaperonin protein orchestrates plant immune responses through a dual mechanism: triggering a reactive oxygen species (ROS) burst while simultaneously activating SA-mediated signaling cascades, thereby synergistically enhancing host disease resistance. Additionally, yeast two-hybrid assay preliminary data indicated that ZmCpn60-3 might bind to ZmbHLH118 and ZmBURP7, indicating ZmCpn60-3 might be involved in plant abiotic responses. The results provided a reference for comprehensively understanding the resistance mechanism of ZmCpn60-3 in plant responses to abiotic or biotic stress. Full article

The control of gene expression by cis-regulatory DNA sequences is a conserved genomic feature. The maize booster1 gene (b1) is a naturally occurring locus that serves as a mechanistic model for the control of gene expression from a distal cis element and a form of allelic interactions called paramutation. Two epi-alleles of b1 produce distinct pigmentation phenotypes correlated with transcriptional enhancement and the silencing of b1. These transcriptional dynamics depend on a hepta-tandem repeat sequence located 100 kb upstream of the b1 locus. In the heterozygous condition, the B′ epi-allele paramutates B-I, heritably converting the B-I epi-allele to the epigenetic state and expression level of B′, producing lightly pigmented plants. To identify b1TR-associated proteins, we used a targeted chromatin immunoprecipitation approach with a stably integrated transgenic b1TR locus. Applying a conservative filtering strategy, we detected several expected factors, including RNA Polymerase II, as well as the novel putative DNA-binding proteins ZAG4 and DDT4. ZAG4 and DDT4 activated GAL expression using b1TR as bait in yeast one-hybrid, supporting their potential interaction with this sequence. The identification of proteins uniquely associated with the UAS::b1TR chromatin provides insight into potential b1 regulatory factors and offers a foundation for future studies to investigate their roles in gene regulation. Full article

Meeting the rising demand for staple grains now requires cultivars that combine high yield, enhanced nutritional value, and strong chemical resilience. Blue-kernel landraces from central Mexico are rich in anthocyanins yet remain highly susceptible to post-emergence herbicides, whereas modern hybrids detoxify these compounds through cytochrome P450 (CYP450) enzymes. We crossed the anthocyanin-rich variety Polimaize with a CYP450-tolerant hybrid and evaluated the two parents and their F₁ segregants (designated “White” and “Yellow”) under greenhouse applications of mesotrione (75 g a.i. ha⁻¹), nicosulfuron (30 g a.i. ha⁻¹), and their mixture. Across 160 plants, the hybrid retained 95% of control dry matter and showed ≤7% foliar injury under all treatments, whereas Polimaize lost 28% biomass and exhibited 36% injury after nicosulfuron. The Yellow class matched hybrid performance while maintaining a blue pericarp and a β-carotene-rich endosperm, demonstrating that nutritional and agronomic traits can be stacked. The White class displayed heterosis-driven compensatory growth, exceeding its untreated biomass by 60% with nicosulfuron and by 82% with the mixture despite transient bleaching. Chlorophyll and carotenoid fluorescence revealed rapid, zeaxanthin-linked photoprotection in all tolerant genotypes, consistent with accelerated CYP450-mediated detoxification. These findings show that broad-spectrum herbicide tolerance can be introgressed into pigment-rich germplasm through conventional breeding, providing a non-transgenic path to herbicide-ready, anthocyanin-rich maize. The strategy preserves local biodiversity while delivering cultivars suited to intensive, weed-competitive agriculture and offers a template for integrating metabolic resilience into other native crops. Full article

Alkaline stress limits crop productivity by causing osmotic and oxidative damage. This study investigated the new gene LcTprxII, a type II peroxiredoxin encoded by Leymus chinensis, and its role in enhancing alkaline stress tolerance in transgenic maize. The gene was cloned, overexpressed, and characterized using RT-PCR, phylogenetic analysis, and motif identification. Transgenic maize lines were generated via Agrobacterium-mediated transformation and subjected to physiological, biochemical, and transcriptomic analyses under alkaline stress. Under alkaline stress, the results revealed that LcTprxII overexpression significantly preserved chlorophyll content, mitigated oxidative damage, and maintained growth compared to wild-type plants, as evidenced by elevated activities of antioxidant enzymes (APX, CAT, SOD, and POD) and reduced malondialdehyde (MDA) content. Transcriptomic profiling identified 3733 differentially expressed genes and the upregulation of ABA and MAPK signaling pathways, highlighting the role of these genes in stress signaling and metabolic adaptation. Hormonal analysis indicated reduced ABA and increased GA levels in the transgenic lines. This study identified WRKY, bHLH, and MYB transcription factors as key regulators activated under alkaline stress, contributing to transcriptional regulation in transgenic maize. Field trials confirmed the agronomic potential of LcTprxII-overexpressing maize, with yield maintained under alkaline conditions. The present study revealed that LcTprxII enhances antioxidant defenses and stress signaling, which trigger tolerance to abiotic stress. Future studies should explore the long-term effects on growth, yield, and molecular interactions under diverse environmental conditions. Full article

Drought stress severely impacts maize productivity, necessitating the exploration of molecular mechanisms underlying drought responses. In maize, while Class I members of the LBD family have been extensively studied for their essential functions in developmental regulation and environmental stress responses, the potential involvement of Class II LBD genes in abiotic stress tolerance mechanisms remains poorly characterized. This study characterizes ZmLBD33, a maize Class II LBD gene, to elucidate its role in drought responses. Promoter analysis identified ABA-responsive cis-elements (AREB); ZmLBD33 expression was strongly induced in roots under drought and ABA treatments, localized to the nucleus, and exhibited dimerization via yeast two-hybrid despite lacking intact leucine zipper motifs. ZmLBD33-overexpressed plants showed later germination, shorter roots, and decreased survival rates than wild-type plants under osmotic stress and soil drought. Compared to wild-type plants, ZmLBD33-overexpressed plants showed significantly faster water loss, a greater stomatal density, and reduced stomatal closure efficiency. Histochemical analysis using DAB and NBT showed attenuated reactive oxygen species accumulation in transgenic Arabidopsis overexpressing ZmLBD33. Quantitative enzymatic activity analyses further indicated that SOD and POD levels were significantly elevated in ZmLBD33-overexpressing plants compared to wild-type plants. These findings indicate that ZmLBD33 negatively regulates drought tolerance by modulating stomatal aperture and H₂O₂ signaling. This study highlights the divergent roles of Class II LBD genes in stress adaptation and positions ZmLBD33 as a potential target for engineering drought-resilient crops. Full article

Monolepta hieroglyphica Motschulsky, a major agricultural pest in China, causes considerable economic damage to crops, such as maize. In this study, a Bacillus thuringiensis (Bt) strain was discovered to exhibit insecticidal activity against M. hieroglyphica. A novel Bt gene, vpb4Fa1, with toxicity against both adults and larvae of M. hieroglyphica was cloned. The Vpb4Fa1 protein causes damage to the midgut of adult M. hieroglyphica, disrupting their normal growth and development and ultimately leading to death. To further enhance the insecticidal activity of the vpb4Fa1 gene, a random mutation library was established. A total of 75 mutants with amino acid mutations were generated, among which 7 mutants demonstrated significantly enhanced activity relative to the wild-type gene. Notably, three mutants, C9, 6C2, and 6A7, exhibited the highest activity, with LC₅₀ values for adult M. hieroglyphica of 10.21, 9.45, and 9.83 µg/g, respectively. The mutants C9, 6C2, and 6A7 each harbored nine, three, and six amino acid mutations, respectively, mainly located in Domains I, II, and III. The novel insecticidal gene vpb4Fa1 and its mutants offer valuable genetic resources for the biological control of M. hieroglyphica and the development of Bt transgenic maize. Full article

Maize is highly sensitive to water deficit but has high transpiration and biomass production, leading to a substantial water demand. Genetic engineering can overcome reproductive isolation and utilize drought-tolerant genes from distant species. Ammopiptanthus nanus is a relic of the Tertiary glaciation that can adapt to harsh environmental conditions. In our previous study, five maize homozygous T₈ lines overexpressing the AnVP1 gene from Ammopiptanthus nanus were generated and showed the enhancement of drought tolerance. However, the recipient inbred line Zh-1 was poor in yield and agronomic performance. In the present study, the AnVP1 gene was backcrossed from donor parent L10 (one of the five T₈ lines) into recurrent parent Chang 7-2 (one of the elite parents of the commercial hybrid Zhengdan 958). In total, 103 InDel markers were developed and used for assisted background selection. After two generations of foreground selection through glufosinate spraying, the detection of CP4 EPSP MAb1 strips, and the PCR amplification of the AnVP1 gene, along with the similarity of agronomic traits to the recurrent parent, and background selection assisted by these InDel markers, the transgenic AnVP1 gene became homozygous in the BC₂ lines. The average recovery rate of the genetic background of the recurrent parent reached 74.80% in the BC₁ population and 91.93% in the BC₂ population, respectively. The results of RT-PCR and RT-qPCR indicated the stable expression of the AnVP1 gene in the two ultimately selected BC₂F₃ lines, BC₂-36-12 and BC₂-5-15. The drought tolerance of these two BC₂F₃ lines were significantly improved compared to the recurrent parent Chang 7-2, as revealed by their wilting phenotype and survival rate of seedlings. This improvement was related to the enhancement of water-retention ability, as indicated by higher RWC and the reduction in damage, as shown by the decrease in REL, MDA, and H₂O₂ under drought stress. The result of field evaluation in two arid and semi-arid environments indicated that the drought tolerance of Chang 7-2 was significantly improved. This study suggests that the improved Chang 7-2 can be crossed with Zheng 58 to develop the transgenic commercial hybrid Zhengdan 958. Full article

ZDRF-8 is a transgenic maize event created via Agrobacterium-mediated transformation for insect resistance and glyphosate tolerance by expressing Cry1Ab, Cry2Ab, and G10evo-epsps. A Southern blot analysis suggested that it is a single-copy T-DNA insertion event. The flanking genomic sequences of the T-DNA insertion suggested that its T-DNA was inserted at the terminal region of the long arm of chromosome 7 without interrupting any known or predicted genes. Event-specific PCRs based on the flanking sequence were able to detect this event specifically. Laboratory bioassays and field trials of multiple generations demonstrated that ZDRF-8 is highly active against major corn pests in China, including Asian corn borers (ACB, Ostrinia furnacalis), cotton bollworms (CBW, Helicoverpa armigera), and oriental armyworm (OAW, Mythimna separata), and meanwhile confers glyphosate tolerance up to two times the recommended dose. The expression of the transgenes and the efficacy of insect resistance and glyphosate tolerance were stable over more than 10 generations. ZDRF-8 has been granted with a safety certificate in China, and its commercial release is expected in the coming years. Full article

Dendrobine, a significant medicinal compound, typically accumulates at low concentrations within several Dendrobium species, including Dendrobium nobile, Dendrobium catenatum, and Dendrobium moniliforme. As D. nobile and D. catenatum are established ingredients in traditional Chinese medicine and have been cultivated extensively, they present ideal plant chassis for upscaling dendrobine production for industrial and research applications. This study employed two approaches: the ectopic overexpression of seven genes through multigene stacking and the activation of multiple key endogenous genes in the dendrobine synthesis pathway using CRISPR/Act3.0 in either D. nobile or D. catenatum. These methods enhanced dendrobine production in transiently infiltrated leaves by 30.1% and transgenic plants by 35.6%. The study is the first to apply CRISPR/Act3.0 to Dendrobium orchids, enhancing dendrobine production, and thus laying a solid foundation for further improvements. CRISPR/Act3.0 is a recently developed technique that demonstrates high efficiency in model plant species, including rice, maize, and Arabidopsis. By combining CRISPR with transcriptional regulatory modules, activation of multiple endogenous genes in the metabolic pathway can be achieved. The successful application in orchid molecular breeding reveals promising potential for further exploration. Full article

The phyllosphere is one of the largest habitats for microorganisms, and host genetic factors play an important role during the interaction between microorganisms and the phyllosphere. Therefore, the transgene may also lead to changes in the maize phyllosphere. ZmMYB3R was identified as a drought-tolerant gene in Arabisopsis. Here, we employed metagenomic sequencing to analyze the microbiome of the adaxial and abaxial leaf surfaces on ZmMYB3R-overexpressing (OE) and wild-type (WT)·maize, aiming to dissect the possible associations between ZmMYB3R and changes in phyllosphere microbiome functioning. Our results revealed that overexpressing ZmMYB3R altered the alpha and beta diversity of the phyllosphere microbiome. In OE plants, more beneficial microbes accumulated on the phyllosphere, while pathogenic ones diminished, especially on the abaxial surface of ZmMYB3R leaves. Further analysis of disease resistance-related metabolic pathways and abundances of disease resistance genes revealed significant differences between OE and WT. The inoculation experiment between OE and WT proved that ZmMYB3R increased the disease resistance of maize. In conclusion, the results reveal that transgenes affect the phyllosphere microbiome, and ZmMYB3R might alter leaf disease resistance by reshaping the phyllosphere microbiome structure. These findings help us understand how ZmMYB3R regulates leaf disease resistance and may facilitate the development of disease control by harnessing beneficial microbial communities. Full article