Bulb onion (Allium cepa) is one of the second most widely cultivated and consumed vegetable crops in the world. During winter where the temperature can be as low, plant could get cold injury and limit the production of bulb onion. However, the genomic resources available for bulb onion are still very limited. To date, no studies about heritably durable cold and freezing tolerance were carried out in bulb onion genotypes using high-throughput sequencing technology was applied. We sequenced cold (2°C) freezing (-5 and -15°C) treated and control (25°C) samples of contrasting genotypes of A. cepa lines and obtained 4,52,194,370 total high quality reads. After de novo assembly reads were assembled into 54,047 genes finally generated with an average length of 1,331 bp. Based on the similarity search aligning all genes with known public non-redundant (NR) database, including Swiss-prot, KEGG and COG. Differentially expressed genes (DEGs) were investigated using FPKM method. Overall, 92,862 genes were differentially regulated in all libraries were identified. Additionally, increase our understanding of the DEGs, we performed GO and KEGG pathway enrichment analyses. Based on FDR<=0.01 value in cold freezing tolerant line candidate genes were selected and discussed. Finally 25 candidate genes were examined using qRT-PCR were differentially regulated and known to be associated with cold and freezing stresses. Moreover, in silico prediction of putative molecular marker 4,437 SSRs and 6,076 SNPs. Our study is the first to provide the transcriptome sequence resource of Allium spp., for cold and freezing stress. We identified large set of genes to determine its DEGs profile under cold and freezing condition using two different genotypes. These data provides a valuable resource of genetic and genomic studies of Allium spp.

To identify low temperature-induced genes of wheat chromosome substitution line 5D, suppression subtractive hybridization (SSH) was performed with mRNAs from leaf samples that treated with low temperature (4℃). A cDNA library was constructed using mRNA isolated from wheat chromosome substitution line 5D leaves treated with low temperature (4℃). The nucleotide and deduced amino acid sequences of the putative gene products were compared. wfr-9 and wfr-32 showed identity over 90% related to vernalization gene. Other two genes, wfr-77 and wfr-83 which is related to freezing-resistant gene have also identity over 90%. This result suggest that those genes may be transcribed into antifreeze proteins which are accumulated within leaf apoplasts, when wheat chromosome substitution line 5D is acclimated during low temperature treatment.

In this study, we present different physiological responses to cold acclimation between the freezing tolerant barley landrace, Jeonnamjaerae, and the freezing sensitive line, PI283398, chosen by the previous field test. We tried to identify some key facto