Project description:Study of changes in the plastid genome sequence could arise during maize development from proplastids in the basal meristem to mature chloroplasts in the leaf blade. Comparison of ptDNA sequences from light-grown and dark-grown leaves.
Project description:Drought represents a major constraint on maize production worldwide. Understanding the genetic basis for natural variation in drought tolerance of maize may facilitate efforts to improve this trait in cultivated germplasm. Here, using a genome-wide association study, we show that a miniature inverted-repeat transposable element (MITE) inserted in the promoter of a NAC gene (ZmNAC111) is significantly associated with natural variation in maize drought tolerance. For maize RNA-seq analysis, pooled tissues from three, eight-day-old maize seedlings were collected from transgenic and wild-type plants, prior to or after 2-hour dehydration, to conduct the RNA-seq analysis.
Project description:All above ground organs of higher plants are ultimately derived from specialized organogenic structures called shoot apical meristems (SAMs). It is comprised of pluripotent stem cells, which divide to regenerate themselves as well as to provide cells to form other organs such as leaves and stems. To study global gene expression in maize SAM and very young primordia (P0 and P1), RNA was extracted from both SAMs (SAMs per se plus P0 and P1) and above-ground portions of seedlings collected from 14-day old B73 seedlings. These RNA samples were labeled and hybridized with cDNA microarrays that have over 37,000 informative spots from maize. Statistical analyses showed that approximately 7.4% and 6.0% of the tested genes were significantly (p <0.0001) up- and down-regulated, respectively. Several control genes, whose expressions were confirmed in the maize SAM in the previous studies, were also up-regulated (p <0.01). The significantly up-regulated genes involved many novel transcription factor genes and regulatory genes as well as some kinds of enzymes, suggesting these genes play important roles in meristem maintenance and the early stage of leaf development in maize. Interestingly, several retrotransposon-related genes were greatly up-regulated in the SAM. This finding raised the possibility that retrotransposons are involved in regulatory mechanisms of maize SAM. Keywords: cell type comparison design
Project description:Using the RL-SAGE method (Gowda et al. 2004), a maize leaf longSAGE library (cv. inbred line B73) was constructed. Leaf tissues were harvested from 4-week old B73 plants for RNA isolation. The conditions in the growth chamber were 12 h light (500 µmol photons m-2 sec-1), 20oC at night, 26oC in the day and 85% relative humidity. A total of 44,870 unique tags (17 bases +CATG) were identified from 232,948 individual tags in the maize leaf library.
Project description:Large scale transcriptomics study to establish gene expression in leaf tissue of W22 inbred line in Zea Mays. RNA was extracted from leaf tissue when the plants were at V6. Sequencing library was produced following the protocol mentioned in the following publication PMID:22039485
Project description:Photosynthesis supports life on Earth but the regulatory architecture associated with photosynthesis gene expression is poorly understood. Most crops use either C3 or C4 photosynthesis with the latter allowing significantly higher efficiencies as well as improved water and nitrogen use. Here we use DNAse-SEQ to define >1 million transcription factor binding sites in leaves of grasses that either operate C3 or C4 photosynthesis and that are consistent with significant differences in the modes of gene regulation between the kingdoms of life. Leaf samples were collected from seedlings to allow for comparison of regulatory interactions between species from the same (Zea mays and Sorghum bicolor) and different (Setaria italica) C4 lineages, as well as a C3 grass (Brachypodium distachyon) in order to investigate evolution of C4 photosynthetic gene expression. Additionally bundle sheath tissues were mechanically isolated from C4 species and analysed by DNAse-SEQ to identify DNA regulatory elements controlling cell-specific gene expression patterns.
Project description:Insect elicitors, in particular fatty acid amides like volicitin, have been known to induce defense-related gene expression. Here we investigated transcriptional changes in response to volicitin 60min after treatment locally and in distal parts of the treated leaf. 3-Week old Zea mays seedling (inbred line B73) were treated with pure volicitin (1nmol per plant). Controls were untreated. Plants were for 60 min. The second leaf was then taken and a segment of 1 cm cut around the damage site and shock-frozen in liquid N2. 3 segments from 3 individual leaves were pooled for one biological replicate and then stored at -85M-BM-0prior to RNA extraction. For distal gene expression analysis a 1cm segment was cut about 3 cm leaf upwards from the volicitin application site and also frozen in liquid N2. 3 segments from 3 individual leaves were pooled for one biological replicate and then stored at -85M-BM-0prior to RNA extraction. 2 biological replicates were performed for each treatment with one dye swap (second sample).
Project description:Small RNAs (21-24 nt) are pivotal regulators of gene expression that guide both transcriptional and post-transcriptional silencing mechanisms in diverse eukaryotes, including most if not all plants. MicroRNAs (miRNAs) and short interfering RNAs (siRNAs) are the two major types, both of which have a demonstrated and important role in plant development, stress responses and pathogen resistance. In this work, we used a deep sequencing approach (Sequencing-By-Synthesis, or SBS) to develop sequence resources of small RNAs from different maize tissues (including leaves, ears and tassels) collected from wild-type plants of the B73 variety. The high depth of the resulting datasets enabled us to examine in detail critical small RNA features as size distribution, tissue-specific regulation and sequence conservation between different organs in this species. We also developed database resources and a dedicated website (http://smallrna.udel.edu/) with computational tools for allowing other users to identify new miRNAs or siRNAs involved in specific regulatory pathways, verify the degree of conservation of these sequences in other plant species and map small RNAs on genes or larger regions of the maize genome under study.