Welcome to the Lai Lab
Welcome to the Lai lab in the Department of Plant Genetics and Breeding as well as the State Key Laboratory of Plant Physiology and Biochemistry and the National Maize Improvement Center at the China Agricultural University. The main focus of our maize breeding and genetics research group includes but not limited to: maize genomics, maize genetic engineering and molecular breeding, and gene imprinting in maize endosperm. Please explore to see who we are and what we do, check out the lab resources and lab news for latest happenings.
Selected Publications
High Temporal-Resolution Transcriptome Landscape of Early Maize Seed Development
The Plant Cell(2019)Here, we report a high temporal-resolution investigation of transcriptomes using 31 samples collected at an interval of 4 or 6 h within the first six days of seed development. These time-course transcriptomes were clearly separated into four distinct groups corresponding to the stages of double fertilization, coenocyte formation, cellularization, and differentiation.
Chromosome conformation capture resolved near complete genome assembly of broomcorn millet
NATURE COMMUNICATIONS(2019)We report here its genome assembly through a combination of PacBio sequencing, BioNano, and Hi-C (in vivo) mapping. The 18 super scaffolds cover ~95.6% of the estimated genome (~887.8Mb). There are 63,671 protein-coding genes annotated in this tetraploid genome. About ~86.2% of the syntenic genes in foxtail millet have two homologous copies in broomcorn millet, indicating rare gene loss after tetraploidization in broomcorn millet.
A barley stripe mosaic virus-based guide RNA delivery system for targeted mutagenesis in wheat and maize
Molecular Plant Pathology(2019)In this study, we engineered a barley stripe mosaic virus (BSMV)-based gRNA delivery system for clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9mediated targeted mutagenesis in wheat and maize. BSMVbased delivery of single gRNAs for targeted mutagenesis was first validated in Nicotiana benthamiana.
OS1 functions in the allocation of nutrients between the endosperm and embryo in maize seeds
JOURNAL OF INTEGRATIVE PLANT BIOLOGY(2019)Here, we cloned OS1 and show that it encodes a putative transcription factor containing an RWP-RKdomain. Transcriptional analysis indicated that OS1 expression is elevated in early endosperm development, especially in the basal endosperm transfer layer (BETL), conducting zone (CZ), and central starch endosperm (CSE) cells.
Long-range interactions between proximal and distal regulatory regions in maize
NATURE COMMUNICATIONS(2019)Here we report the generation of chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) data and the construction of extensive H3K4me3- and H3K27ac-centered chromatin interaction maps in maize. Results show that the interacting patterns between proximal and distal regulatory regions of genes are highly complex and dynamic.
Identification of minor effect QTLs for plant architecture related traits using super high density genotyping and large recombinant inbred population in maize (Zea mays)
BMC Plant Biology(2018)Here, we employed a genotyping-by-sequencing (GBS) strategy to construct a linkage map with 16,769 marker bins for 1021 recombinant inbred lines (RILs). Accurately mapping of well studied genes P1, pl1 and r1 underlying silk color demonstrated the map quality. After QTL analysis, a total of 51 loci were mapped for six PATs.
Defective Kernel 39 encodes a PPR protein required for seed development in maize
JOURNAL OF INTEGRATIVE PLANT BIOLOGY(2018)Here, we report the map-based cloning and molecular characterization of a defective kernel mutant dek39 in maize. Loss of Dek39 function leads to delayed embryogenesis and endosperm development, reduced kernelsize, and seedling lethality.
Effects of drought stress and water recovery on physiological responses and gene expression in maize seedlings
BMC PLANT BIOLOGY(2018)Many genes that are differentially expressed in responses to drought stress and water recovery conditions affect photosynthetic systems and hormone biosynthesis. The identified DEGs, especially those encoding transcription factors, represent potential targets for developing drought-tolerant maize lines.
ldentification and Fine-Mapping of a Major Maize Leaf Width QTL in a Re-sequenced Large Recombinant Inbred Lines Population
FRONTIERS IN PLANT SCIENCE(2018)Here, we constructed a bin map for 670 recombinant inbred lines (RILs) using∼1.2 billion 100-bp re-sequencingreads.QTL analysis of the LW trait directly narrowed the major effect QTL, qLW4, to a ∼270-kb interval. A fine-mapping population and near-isogenic lines (NILs) were quickly constructed using a key RIL harboring heterozygous genotypes across the qLW4 region.
Parent-of-origin-dependent nucleosome organization correlates with genomic imprinting in maize
GENOME RESEARCH(2018)We found that ∼2.3% of nucleosomes showed significant parental bias in maize endosperm. The parent-of-origin-dependent nucleosomes mostly exist as single isolated nucleosomes. Parent-of-origin-dependent nucleosomes were significantly associated with the allele-specific expression of imprinted genes, with nucleosomes positioned preferentially in the promoter of nonexpressed alleles of imprinted genes.
Extensive intraspecific gene order and gene structural variations between Mo17 and other maize genomes
NATURE GENETICS(2018)Comparative analysis revealed large gene-order and gene structural variations: approximately 10% of the annotated genes were mutually nonsyntenic, and more than 20% of the predicted genes had either large-effect mutations or large structural variations, which might cause considerable protein divergence between the two inbred lines. Our study provides a high-quality reference-genome sequence of an important maize germplasm, and the intraspecific gene order and gene structural variations identified should have implications for heterosis and genome evolution.
Genome-wide nucleosome occupancy and organization modulates the plasticity of gene transcriptional status in maize.
Molecular Plant(2017)Nucleosomes are fundamental units of chromatin that play critical roles in gene regulation by modulating DNA accessibility. However, their roles in regulating tissue-specific gene transcription are poorly understood. Here, we present genome-wide nucleosome maps of maize shoot and endosperm generated by sequencing the micrococcal nuclease digested nucleosomal DNA.
Dynamic and Antagonistic Allele-Specific Epigenetic Modifications Controlling the Expression of Imprinted Genes in Maize Endosperm
Molecular Plant(2017)Here, wereport the identification of 337 high-stringency allele-specific H3K4me3 and H3K36me3 peaks in maize endosperm. Paternally preferred H3K4me3 and H3K36me3 peaks mostly co-localized with paternally expressed genes (PEGs), while endosperm-specific maternally expressed genes (endo-MEGs) were associated with maternally preferred H3K4me3 and H3K36me3 peaks.
The coupled effect of nucleosome organization on gene transcription level and transcriptional plasticity
NUCLEUS(2017)Our recent study showed that nucleosome organization also plays an important role in modulating the plasticity of gene transcriptional status in maize. Here, we integrated our findings with previous studies on the role of nucleosome organization in regulation of gene transcription.