Large-scale analysis of full-length cDNAs from the tomato (Solanum lycopersicum) cultivar Micro-Tom, a reference system for the Solanaceae genomics

<p>Abstract</p> <p>Background</p> <p>The Solanaceae family includes several economically important vegetable crops. The tomato (<it>Solanum lycopersicum</it>) is regarded as a model plant of the Solanaceae family. Recently, a number of tomato resources have been developed in parallel with the ongoing tomato genome sequencing project. In particular, a miniature cultivar, Micro-Tom, is regarded as a model system in tomato genomics, and a number of genomics resources in the Micro-Tom-background, such as ESTs and mutagenized lines, have been established by an international alliance.</p> <p>Results</p> <p>To accelerate the progress in tomato genomics, we developed a collection of fully-sequenced 13,227 Micro-Tom full-length cDNAs. By checking redundant sequences, coding sequences, and chimeric sequences, a set of 11,502 non-redundant full-length cDNAs (nrFLcDNAs) was generated. Analysis of untranslated regions demonstrated that tomato has longer 5'- and 3'-untranslated regions than most other plants but rice. Classification of functions of proteins predicted from the coding sequences demonstrated that nrFLcDNAs covered a broad range of functions. A comparison of nrFLcDNAs with genes of sixteen plants facilitated the identification of tomato genes that are not found in other plants, most of which did not have known protein domains. Mapping of the nrFLcDNAs onto currently available tomato genome sequences facilitated prediction of exon-intron structure. Introns of tomato genes were longer than those of Arabidopsis and rice. According to a comparison of exon sequences between the nrFLcDNAs and the tomato genome sequences, the frequency of nucleotide mismatch in exons between Micro-Tom and the genome-sequencing cultivar (Heinz 1706) was estimated to be 0.061%.</p> <p>Conclusion</p> <p>The collection of Micro-Tom nrFLcDNAs generated in this study will serve as a valuable genomic tool for plant biologists to bridge the gap between basic and applied studies. The nrFLcDNA sequences will help annotation of the tomato whole-genome sequence and aid in tomato functional genomics and molecular breeding. Full-length cDNA sequences and their annotations are provided in the database KaFTom <url>http://www.pgb.kazusa.or.jp/kaftom/</url> via the website of the National Bioresource Project Tomato <url>http://tomato.nbrp.jp</url>.</p

Dynamic behavior and flame acceleration of spherically expanding hydrogen flames under the low-pressure conditions

To investigate the dynamic behavior and flame acceleration of spherically expanding hydrogen flames under the low-pressure conditions, the deflagration experiments were conducted in a closed combustion chamber. The dynamic behavior of hydrogen flames was observed by high-speed Schlieren imaging, and the flame radius and propagation velocity were measured by analyzing the Schlieren photography. When the flame radius was sufficiently small, smooth flame surface was observed, where flame stretching affected strongly the propagation velocity. From the correlation between the flame stretch rate and the propagation velocity, we estimated the Markstein length and Markstein number. When the flame radius was large, on the other hand, cellular surface was observed and the flame acceleration was confirmed. As a result, the critical flame radius corresponding to the occurrence of flame acceleration and the increment coefficient of propagation velocity were obtained. Under the low-pressure conditions, the dynamic behavior of hydrogen flames became weaker and the increment coefficient of propagation velocity became smaller. This was because the intrinsic instability was weakened by increasing the preheat zone thickness. It was also found that the increment coefficient became larger at lower equivalence ratios, which was because the diffusive-thermal instability became stronger. Moreover, the effects of preheat zone thickness on the flame acceleration was elucidated. We obtained the correlation between the normalized increment coefficient of propagation velocity and the preheat zone thickness. Based on the characteristics of dynamic behavior of hydrogen flames, the parameters of flame acceleration model depending on the initial pressure was obtained, and then the flame propagation velocity under the low-pressure conditions were predicted