Genome-Wide Analysis of the <i>NAC</i> Gene Family in Physic Nut (<i>Jatropha curcas</i> L.)

<div><p>The NAC proteins (NAM, ATAF1/2 and CUC2) are plant-specific transcriptional regulators that have a conserved NAM domain in the N-terminus. They are involved in various biological processes, including both biotic and abiotic stress responses. In the present study, a total of 100 <i>NAC</i> genes (<i>JcNAC</i>) were identified in physic nut (<i>Jatropha curcas</i> L.). Based on phylogenetic analysis and gene structures, 83 <i>JcNAC</i> genes were classified as members of, or proposed to be diverged from, 39 previously predicted orthologous groups (OGs) of NAC sequences. Physic nut has a single intron-containing <i>NAC</i> gene subfamily that has been lost in many plants. The <i>JcNAC</i> genes are non-randomly distributed across the 11 linkage groups of the physic nut genome, and appear to be preferentially retained duplicates that arose from both ancient and recent duplication events. Digital gene expression analysis indicates that some of the <i>JcNAC</i> genes have tissue-specific expression profiles (e.g. in leaves, roots, stem cortex or seeds), and 29 genes differentially respond to abiotic stresses (drought, salinity, phosphorus deficiency and nitrogen deficiency). Our results will be helpful for further functional analysis of the <i>NAC</i> genes in physic nut.</p></div

Cranial x-ray showing an asymmetrical skull, abnormal wormian bone, poor pneumatization of the sinuses, no eruption of third teeth, and a hypoplastic third tooth of the right upper jaw

<p><b>Copyright information:</b></p><p>Taken from "A novel RUNX2 missense mutation predicted to disrupt DNA binding causes cleidocranial dysplasia in a large Chinese family with hyperplastic nails"</p><p>http://www.biomedcentral.com/1471-2350/8/82</p><p>BMC Medical Genetics 2007;8():82-82.</p><p>Published online 31 Dec 2007</p><p>PMCID:PMC2241583.</p><p></p> Chest x-ray reveals a cone-shaped chest, high position of the scapular bone, aplasia of the lateral and middle thirds of the clavicle, and mild scoliosis between T6–T10. Vertebral x-ray showing mild dislocation of L5/S1. Pelvic x-ray showing a widening sacroiliac joint, wide pubic symphysis, hypoplastic pubic bone and normal hips

Relative expression levels of <i>JcNAC</i> genes, divided into different orthologous groups.

<p>The relative expression levels of all of the <i>JcNAC</i> genes were the average value of 6 biological repeats of digital expression profile tags. NA, not available; R, roots; St, stem cortex; L, leaves; S1, seed 1; S2, seed 2.</p

Gene structure and motif locations of <i>JcNAC</i> genes.

<p>(A), Exon/intron arrangements of <i>JcNAC</i> genes. Exons and introns are represented by black boxes (open reading frame in black, untranslated region (UTR) in gray), and black lines, respectively, and their sizes are indicated by the scale at the bottom. *, intron in the UTR. (B), Schematic representation of conserved motifs in the JcNAC proteins predicted by MEME. Each motif is represented by a number in the colored box. The black lines represent non-conserved sequences. The relationships between motifs and conserved domains (A-E) are shown on the right. The lengths of JcNAC proteins can be estimated from the scale at the bottom.</p

Chromosomal localization of physic nut <i>NAC</i> genes.

<p>Chromosomal localization of <i>JcNAC</i> genes based on the linkage map. In total, 98 <i>JcNAC</i> genes were mapped to the 11 linkage groups (LGs). The scale is in centimorgan. T, tandem duplication; A, ancient segmental duplication based on the genome synteny [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0131890#pone.0131890.ref026" target="_blank">26</a>].</p