The infective cycle of Cabbage leaf curl virus (CaLCuV) is affected by CRUMPLED LEAF (CRL) gene in Arabidopsis thaliana

<p>Abstract</p> <p>Background</p> <p>Geminiviruses are single-stranded DNA viruses that cause serious crop losses worldwide. Successful infection by these pathogens depends extensively on virus-host intermolecular interactions that allow them to express their gene products, to replicate their genomes and to move to adjacent cells and throughout the plant.</p> <p>Results</p> <p>To identify host genes that show an altered regulation in response to <it>Cabbage leaf curl virus </it>(CaLCuV) infection, a screening of transposant <it>Arabidopsis thaliana </it>lines was carried out. Several genes were identified to be virus responsive and one, <it>Crumpled leaf </it>(<it>CRL) </it>gene, was selected for further characterization. <it>CRL </it>was previously reported by Asano et al., (2004) to affect the morphogenesis of all plant organs and the division of plastids. We report here that <it>CRL </it>expression, during CaLCuV infection, shows a short but strong induction at an early stage (3-5 days post inoculation, dpi). To study the role of <it>CRL </it>in CaLCuV infection, <it>CRL </it>over-expressing and silenced transgenic plants were generated. We compared the replication, movement and infectivity of CaLCuV in transgenic and wild type plants.</p> <p>Conclusion</p> <p>Our results showed that CRL over-expressing plants showed an increased susceptibility to CaLCuV infection (as compared to wt plants) whereas <it>CRL</it>-silenced plants, on the contrary, presented a reduced susceptibility to viral infection. The possible role of <it>CRL </it>in the CaLCuV infection cycle is discussed.</p

Gradual domestication of root traits in the earliest maize from Tehuacan

Efforts to understand the phenotypic transition that gave rise to maize from teosinte have mainly focused on the analysis of aerial organs, with little insights into possible domestication traits affecting the root system. Archeological excavations in San Marcos cave (Tehuacan, Mexico) yielded two well-preserved 5,300 to 4,970 calibrated y B.P. specimens (SM3 and SM11) corresponding to root stalks composed of at least five nodes with multiple nodal roots and, in case, a complete embryonic root system. To characterize in detail their architecture and anatomy, we used laser ablation tomography to reconstruct a three-dimensional segment of their nodal roots and a scutellar node, revealing exquisite preservation of the inner tissue and cell organization and providing reliable morphometric parameters for cellular characteristics of the stele and cortex. Whereas SM3 showed multiple cortical sclerenchyma typical of extant maize, the scutellar node of the SM11 embryonic root system completely lacked seminal roots, an attribute found in extant teosinte and in two specific maize mutants: root with undetectable meristem1 (rum1) and rootless concerning crown and seminal roots (rtcs). Ancient DNA sequences of SM10—a third San Marcos specimen of equivalent age to SM3 and SM11—revealed the presence of mutations in the transcribed sequence of both genes, offering the possibility for some of these mutations to be involved in the lack of seminal roots of the ancient specimens. Our results indicate that the root system of the earliest maize from Tehuacan resembled teosinte in traits important for maize drought adaptation

Taxonomic distribution of non-maize HiSeq 2000 reads from cDNA and DNA sets:

<p>(<b>a</b>) represents cDNA sample 935130, (<b>b</b>) represents cDNA sample 935230, and (<b>c</b>) represents a DNA shotgun sample from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050961#pone.0050961-Bannister1" target="_blank">[25]</a> 100,00 randomly sampled unmapped reads were used to perform BLAST searches and MEGAN was for taxonomic characterization of non-maize reference genome (non-B73) reads.</p

Histogram showing fragment length distribution of maize GS FLX sequence reads from 3 Arizonan DNA (FLX4-6) samples (blue) in comparison to 3 Arizonan cDNA (FLX1-3) samples (red).

<p>Histogram showing fragment length distribution of maize GS FLX sequence reads from 3 Arizonan DNA (FLX4-6) samples (blue) in comparison to 3 Arizonan cDNA (FLX1-3) samples (red).</p

Dominant elements represented in repeat content profiles of cDNA and DNA sequences using RepeatMasker.

<p>Dominant elements represented in repeat content profiles of cDNA and DNA sequences using RepeatMasker.</p

Positive correlation matrix of contig read content from cDNA (935130 and 935230) and DNA [25].

<p>Positive correlation matrix of contig read content from cDNA (935130 and 935230) and DNA <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050961#pone.0050961-Bannister1" target="_blank">[25]</a>.</p

Kernel and sample information and names.

<p>A total of 6 kernels were utilized for either RNA or DNA extraction only, or co-extracted for DNA and RNA. After nucleic acids were co-extracted, samples were divided into 2 aliquots, and RNA samples were DNase treated and DNA samples were RNase treated (see Methods and Supplementary Methods S1), and labeled with unique sample names.</p

Top 50 exon hits with functional annotation from cDNA (935130 and 935230) HiSeq 2000 maize reads (for a detailed version of the table see Supplementary Table S4).

<p>Top 50 exon hits with functional annotation from cDNA (935130 and 935230) HiSeq 2000 maize reads (for a detailed version of the table see Supplementary <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050961#pone.0050961.s010" target="_blank">Table S4</a>).</p