The Alfin-like transcription factor family is one of the important gene families in eukaryotic plants. They are involved in many biological processes, such as lignocellulosic wall biosynthesis, meristem development, metabolite transport, and responses to biotic and abiotic stresses. But the regulatory mechanism of these genes involved in stresses responses is still unrevealed. In this study, we identified a total of 16 Alfin-like genes from Brassica rapa database. The 16 putative Alfin-like proteins were divided into four groups (group I-IV) based on structural and phylogenetic analyses. Accordingly, this study analyzed stress resistance-related functions of all B. rapa Alfin-like (BrAL) genes through a homology study with existing biotic and abiotic stress resistance-related Alfin-like genes of other plant species and found a high degree of similarity with them. Subsequently, these genes were further investigated by real-time quantative PCR under cold, salt and drought stresses and after infection with Fusarium oxysporum f. sp. conglutinans in B. rapa. These genes showed an organ specific expression and all genes differentially expressed in Chiifu compared to Kenshin under cold stress. Ten and seven BrALs responded highly in Kenshin compared to Chiifu under salt and drought stresses respectively. In addition, six BrAL genes showed responsive expression after Fusarium oxysporum f. sp. conglutinans infection in B. rapa. Interestingly, four BrAL genes showed responses against both biotic and abiotic stress factors. Thus, our result provides a useful reference data set as the basis for functional analysis and utilization in the resistance molecular breeding of B. rapa.

Heterosis is very important for breeding hybrid cultivars and is intensively used to increase the productivity of crop plants. But the molecular basis of heterosis is still unrevealed to the scientists. This study selected 51 heterosis associated genes of Arabidopsis of different family on the basis of their high differential expression in a hybrid compared to its midparent value and identified their orthologues in Brassica oleracea. Then the selected B. oleracea genes were characterized based on their structural properties, recognized functions and expression patterns in a cabbage hybrid progeny (Cabbage-36) of crosses between Cabbage-34 and Cabbage-35 accessions. Among these genes, a good number were found to express highly in the hybrid then the midparent value and better parent in some cases. Moreover, these highly expressed genes are mostly related to the yield contributing characters. Cotyledon and young leaf sizes of these three genotypes also well correlated with gene expression. Thus, it can be said that, the identified genes might be associated with the mechanism of heterosis of B. oleracea hybrid and provide a foundation for the exploration of gene regulatory networks associated with the specification of the phenomenon heterosis in the plant life cycle. Subsequently, these genes would be useful resources for molecular hybrid breeding in Brassica crops as well.

Flavonoids are divided into several structural classes, including anthocyanins, which provide flower and leaf colors and other derivatives with diverse roles in plant development and interactions with the environment. This study characterized four Anthocyanidin Synthase (ANS) genes of Brassica rapa, a structural gene of anthocyanin biosynthetic pathway, and investigated their association with cold and freezing tolerance in B. rapa. Sequences of these genes were analyzed and compared with similar types of gene sequences of other species and found a high degree of homology with their respective functions. In the organ specific expression analysis, these genes showed expression only in the colored portion of leaves of different lines of B. rapa. On the other hand, BrANS genes also showed differential expression with certain time course of cold stress treatment in B. rapa. Thus, the above results suggest probable association of these genes with anthocyanin biosynthesis and cold and freezing tolerance and might be useful resources for developing cold resistant Brassica crops with desirable colors as well. The present work may help explore the molecular mechanism that regulates anthocyanin biosynthesis and its response to abiotic stress at the transcriptional level in plants.

sequence and more than fifty thousand proteins have been obtained to date. Transcription factors (TFs) are important regulators involved in plant development and physiological processes and the AP2/ERF protein family contains TFs that also plays a crucial role as well and response to biotic and abiotic stress conditions in plants. However, no detailed expression profile of AP2/ERF-like genes is available for B. oleracea. In the present study, 226 AP2/ERF TFs were identified from B. oleracea based on the available genome sequence. Based on sequence similarity, the AP2/ERF superfamily was classified into five groups (DREB, ERF, AP2, RAV and Soloist) and 15 subgroups. The identification, classification, phylogenetic construction, conserved motifs, chromosome distribution, functional annotation, expression patterns and interaction network were then predicted and analyzed. AP2/ERF TFs expression levels exhibited differences in response to varying abiotic stresses based on expressed sequence tags (ESTs). BoCBF1a, 1b, 2, 3 and 4, which were highly conserved in Arabidopsis and B. rapa CBF/DREB genes families were well characterized. Expression analysis enabled elucidation of the molecular and genetic level expression patterns of cold tolerance (CT) and susceptible lines (CS) of cabbage and indicated that all BoCBF genes responded to abiotic stresses. Comprehensive analysis of the physiological functions and biological roles of AP2/ERF superfamily genes and BoCBF family genes in B. oleracea is required to elucidate AP2/ERF, which will provide rich resources and opportunities to understand abiotic stress tolerance in crops.

Cabbage (Brassica oleracea) is one of the most important vegetable crops in the world. Yet, its sensitivity to cold stress, especially at the seedling stage, could limit the production. Until now, only, few studies about heritably durable cold tolerance were carried out in cabbage. Hence this study was done to characterize the transcriptome profiles of two cabbage genotypes with contrasting responses to cold stress using Illumina Hiseq short read (paired-end) sequencing technology. MicroRNAs (miRNAs) represent a class of short, non-coding, endogenous RNAs which play important roles in post-transcriptional regulation of gene expression. Thisstudy,wesoughttoprovideamorecomprehensivepredictionofB. oleracea cold responsive miRNAs based on high through put sequencing using two contrasting genotypes. The raw sequences were processed for removal of poor-quality and adaptor sequences. Then, the high quality unigenes (58,094) reads were applied for length filtering. Then, unigenes reads were used in a BLASTN search against of Rfam database and known miRNA database (miRBase 18.0) to removal of non-coding RNA’s and identifies conserved miRNA’s in B. oleracea. Further, novel reads were searched against B. oleracea genome. Their flanking sequences in the genome were used to predict their secondary structures, target prediction, and functional analysis. This is first report to identify novel miRNAs for cold stress through high throughput techniques. Our findings will provide an overview of potential miRNAs involved in cold stress, which may provide important clues on the function of miRNAs in from B. oleracea and other closely related Brassica species.

MADS-box transcription factor (TF), primarily involved in the floral organ specification with other several aspects of plant growth and development. Whole genome survey of B. rapa revealed 167 MADS-box genes and categorized into MIKCc, MIKC*, Mα, Mβ and Mγ groups based on phylogeny, protein motif structure and exon-intron organizations. MIKCc group belongs 89 genes, which is the highest in number than in any other crops till date. The MIKCc group has further classified into 13 sub-families. In case of chromosomal localization, remarkably 57 MIKCc type MADS-box genes were found in the duplicated segments of B. rapa genome, whereas only 4 M-type genes have resulted from tandem duplications. Besides floral and vegetative tissue expression we also identified MADS-box genes with their male and female gametophyte specific expression in different stages of flower bud development. Furthermore, from a low temperature treated whole genome microarray data set 19 BrMADS genes were found to show variable transcript abundance in two contrasting double haploid lines of B. rapa. Subsequently, the responsive genes were investigated under three abiotic stresses where they showed differential and corresponsive expression patterns. An extensive annotation and transcriptome profiling undertaken in this study might be useful for understanding the involvement of MADS-box genes in stress resistance besides their growth and developmental functions, which ultimately will provide the basis for functional characterization and exploitation of the candidate genes in the genetic engineering study of B. rapa

Flavonoids including anthocyanins provide flower and leaf colors and other derivatives that play diverse roles in plant development and interactions with the environment and dihydroflavonol 4-reductase (DFR) is part of an important step in the flavonoid biosynthesis pathway of anthocyanins. This study characterized 12 DFR genes of Brassica rapa and investigated their association with anthocyanin coloration, cold and freezing tolerance in several genotypes of B. rapa. Sequences of these genes were analyzed and compared with DFR gene sequences from other species and a high degree of homology was found. Constitutive expression of them in several pigmented and non-pigmented lines of B. rapa showed a correlation with anthocyanin accumulation only for BrDFR8 and 9. Conversely, BrDFR genes also showed responses to cold and freezing stress treatment in B. rapa. BrDFRs were also shown to be regulated by two transcription factors, BrMYB2-2 and BrTT8, contrasting with anthocyanin accumulation and cold and freezing stress. Thus, the above results suggest the association of these genes with anthocyanin biosynthesis and cold and freezing stress tolerance and might be useful resources for development cold and/or freezing resistant Brassica crops with desirable colors as well. The findings presented here may also help explore the molecular mechanism that regulates anthocyanin biosynthesis and its response to abiotic stress at the transcriptional level in plants.

Numerous environmental stresses, such as abiotic and biotic stresses, cause significant yield loss in crops and can significantly affect their development. Un the field conditions, crops are exposed to a variety of concurrent stresses. Combined high temperature and linked diseases can cause considerable damage that eventually leads to crop death. Hence, this study was conducted to characterize the genes encoding the nucleotide-binding site (NBS) motif obtained from transcriptome profiles of two cabbage genotypes with contrasting responses to heat stress. We selected 80 up-regulated genes form a total of 264 loci, among which 17 were confirmed to be complete and incomplete members of the TIR-NBS-LRR (TNL) class families, and another identified as a NFYA-HAP2 family member. Expression analysis using qRT-PCR revealed that 8 genes showed significant responses to heat shock treatment and F. oxysporum infection. Additionally, in the commercial B. oleracea cultivars with resistance to F. oxysporum, Bol007132, Bol016084, and Bol030522 genes showed dramatically higher expression levels in the F. oxysporum resistant line than the intermediate and susceptible lines. The results of this study may facilitate the identification and development of molecular markers based on multiple stress resistance genes related to heat and fungal stress under field conditions in B. oleracea.

Calcium-binding proteins, like calcineurin B-like (CBL) proteins, represent important roles in plant calcium signaling. Calcium signals mediate a multitude of plant responses to external stimuli and regulate a wide range of physiological processes including pathogens, abiotic stresses and hormones. These proteins form a complex network with their target kinases being the CBL-interacting protein kinases (CIPKs). CBL genes play vital roles in multiple abiotic stress response pathways whereas some of these are more specifically involved in mediating ABA signaling. In this study, we collected 17 CBL genes designated as B. rapa CBL (BrCBL) from the Brassica database and analyzed the sequences. In comparison analysis, these genes showed high homology with published CBL genes of other species. An organ specific expression of these genes was observed in different organs of chinese cabbage plants. In addition, six BrCBL genes showed responsive expression after cold and drought stress treatments at certain time courses. All these data revealed that these CBL genes might be useful resources in developing abiotic stresses resistance Brassica.