[Identification of HSP70 gene family members in Fritillaria cirrhosa and expression analysis in different tissues under high temperature stress].

The heat shock protein 70 family contains the stress proteins ubiquitous in plants. These proteins are involved in the responses to different abiotic stress conditions and have highly conserved gene sequences. However, little is known about the molecular mechanisms of Fritillaria cirrhosa in response to high-temperature stress. Here, 26 HSP70s, FcHSP70-1 to FcHSP70-26, were identified from the transcriptome data of root, bulb, stem, leaf, and fruit samples of F. cirrhosa. The proteins encoded by FcHSP70s had the lengths ranging from 560 aa to 944 aa, with the molecular weight of 61.64-100.01 kDa and the theoretical isoelectric point between 5.00 and 6.59. The secondary structural elements of HSP70s were mainly random coils and α-helixes. Subcellular localization prediction revealed that FcHSP70s were distributed in mitochondria, chloroplasts, nuclei, endoplasmic reticulum, and cytoplasm. The phylogenetic tree showed that 7 members of the HSP70 family belonged to the Dnak subfamily and 19 members belonged to the HSP110/SSE subfamily. In addition, the qRT-PCR results showed that the expression of FcHSP70-5, FcHSP70-8, FcHSP70-17, FcHSP70-18, and FcHSP70-23 in F. cirrhosa was significantly up-regulated at 35 ℃, which indicated that these genes might play a role in the response to high temperature stress. In addition, compared with other tissues, stems and leaves were sensitive to high temperature stress, with the expression of 18 genes up-regulated by 18.18 and 8.03 folds on average, respectively. These findings provide valuable information about the molecular mechanism of HSP70s of F. cirrhosa in response to high temperature stress.

Genome-wide identification and expression analysis of the C2H2-zinc finger transcription factor gene family and screening of candidate genes involved in floral development in Coptis teeta Wall. (Ranunculaceae).

Background: C2H2-zinc finger transcription factors comprise one of the largest and most diverse gene superfamilies and are involved in the transcriptional regulation of flowering. Although a large number of C2H2 zinc-finger proteins (C2H2-ZFPs) have been well characterized in a number of model plant species, little is known about their expression and function in Coptis teeta. C. teeta displays two floral phenotypes (herkogamy phenotypes). It has been proposed that the C2H2-zinc finger transcription factor family may play a crucial role in the formation of floral development and herkogamy observed in C. teeta. As such, we performed a genome-wide analysis of the C2H2-ZFP gene family in C. teeta. Results: The complexity and diversity of C. teeta C2H2 zinc finger proteins were established by evaluation of their physicochemical properties, phylogenetic relationships, exon-intron structure, and conserved motifs. Chromosome localization showed that 95 members of the C2H2 zinc-finger genes were unevenly distributed across the nine chromosomes of C. teeta, and that these genes were replicated in tandem and segmentally and had undergone purifying selection. Analysis of cis-acting regulatory elements revealed a possible involvement of C2H2 zinc-finger proteins in the regulation of phytohormones. Transcriptome data was then used to compare the expression levels of these genes during the growth and development of the two floral phenotypes (F-type and M-type). These data demonstrate that in groups A and B, the expression levels of 23 genes were higher in F-type flowers, while 15 genes showed higher expressions in M-type flowers. qRT-PCR analysis further revealed that the relative expression was highly consistent with the transcriptome data. Conclusion: These data provide a solid basis for further in-depth studies of the C2H2 zinc finger transcription factor gene family in this species and provide preliminary information on which to base further research into the role of the C2H2 ZFPs gene family in floral development in C. teeta.