Pumpkin (Cucurbita moschata) HSP20 Gene Family Identification and Expression Under Heat Stress

Pumpkin (Cucurbita moschata) is an important cucurbit vegetable crop that has strong resistance to abiotic stress. While heat shock protein 20 (HSP20) has been implicated in vegetable response to heat stress, little is known regarding activity of HSP20 family proteins in C. moschata. Here, we performed a comprehensive genome-wide analysis to identify and characterize the functional dynamics of the Cucurbita moschata HSP20 (CmoHSP20) gene family. A total of 33 HSP20 genes distributed across 13 chromosomes were identified from the pumpkin genome. Our phylogenetic analysis determined that the CmoHSP20 proteins fell into nine distinct subfamilies, a division supported by the conserved motif composition and gene structure analyses. Segmental duplication events were shown to play a key role in expansion of the CmoHSP20 gene family. Synteny analysis revealed that 19 and 18 CmoHSP20 genes were collinear with those in the cucumber and melon genomes, respectively. Furthermore, the expression levels of pumpkin HSP20 genes were differentially induced by heat stress. The transcript level of CmoHSP20-16, 24 and 25 were down-regulated by heat stress, while CmoHSP20-7, 13, 18, 22, 26 and 32 were up-regulated by heat stress, which could be used as heat tolerance candidate genes. Overall, these findings contribute to our understanding of vegetable HSP20 family genes and provide valuable information that can be used to breed heat stress resistance in cucurbit vegetable crops.

Genome-wide identification of small heat shock protein (HSP20) gene family in grape and expression profile during berry development

Background : Studies have shown that HSP20 (heat-shock protein 20) genes play important roles in regulating plant growth, development, and stress response. However, the grape HSP20 gene family has not been well studied. Results : A total of 48 VvHsp20 genes were identified from the grape genome, which were divided into 11 subfamilies (CI, CII, CIII, CV, CVI, CVII, MI, MII, ER, CP and PX/Po) based on a phylogenetic analysis and subcellular localization. Further structural analysis showed that most of the VvHsp20 genes (93.8%) had no intron or only one intron, while genes that clustered together based on a phylogenetic tree had similar motifs and evolutionarily conserved structures. The HSP20s share a conservedα-crystalline domain (ACD) and the different components of the ACD domain suggest the functional diversity of VvHSP20s. In addition, the 48 VvHSP20 genes were distributed on 12 grape chromosomes and the majority of VvHSP20 genes were located at the proximal or distal ends of chromosomes. Chromosome mapping indicated that four groups of VvHSP20 genes were identified as tandem duplication genes. Phytohormone responsive, abiotic and biotic stress-responsive, and plant development-related cis-elements were identified from the cis-regulatory elements analysis of VvHSP20s. The expression profiles of VvHSP20s genes (VvHsp20-1, 11, 14, 17, 18, 19, 20, 24, 25, 28, 31, 39, 42, and 43) were largely similar between RNA-Seq and qRT-PCR analysis after hydrogen peroxide (H 2 O 2 ) treatment. The results showed that most VvHSP20s were down-regulated by H 2 O 2 treatment during fruit development. VvHSP20s genes were indeed found to be involved in the grape berry development and differences in their transcriptional levels may be the result of functional differentiation during evolution. Conclusions : Our results provide valuable information on the evolutionary relationship of genes in the VvHSP20 family, which is useful for future studies on the functional characteristics of VvHSP20 genes in grape.

Genome-wide identification of small heat shock protein (HSP20) gene family in grape and expression profile during berry development

Background : Studies have shown that HSP20 (heat-shock protein 20) genes play important roles in regulating plant growth, development, and stress response. However, the grape HSP20 gene family has not been well studied. Results : A total of 48 VvHsp20 genes were identified from the grape genome, which were divided into 11 subfamilies (CI, CII, CIII, CV, CVI, CVII, MI, MII, ER, CP and PX/Po) based on a phylogenetic analysis and subcellular localization. Further structural analysis showed that most of the VvHsp20 genes (93.8%) had no intron or only one intron, while genes that clustered together based on a phylogenetic tree had similar motifs and evolutionarily conserved structures. The HSP20s share a conservedα-crystalline domain (ACD) and the different components of the ACD domain suggest the functional diversity of VvHSP20s. In addition, the 48 VvHSP20 genes were distributed on 12 grape chromosomes and the majority of VvHSP20 genes were located at the proximal or distal ends of chromosomes. Chromosome mapping indicated that four groups of VvHSP20 genes were identified as tandem duplication genes. Phytohormone responsive, abiotic and biotic stress-responsive, and plant development-related cis-elements were identified from the cis-regulatory elements analysis of VvHSP20s. The expression profiles of VvHSP20s genes (VvHsp20-1, 11, 14, 17, 18, 19, 20, 24, 25, 28, 31, 39, 42, and 43) were largely similar between RNA-Seq and qRT-PCR analysis after hydrogen peroxide (H 2 O 2 ) treatment. The results showed that most VvHSP20s were down-regulated by H 2 O 2 treatment during fruit development. VvHSP20s genes were indeed found to be involved in the grape berry development and differences in their transcriptional levels may be the result of functional differentiation during evolution. Conclusions : Our results provide valuable information on the evolutionary relationship of genes in the VvHSP20 family, which is useful for future studies on the functional characteristics of VvHSP20 genes in grape.

Genome-wide identification of small heat shock protein (HSP20) gene family in grape and expression profile during berry development

Background : Studies have shown that HSP20 (heat-shock protein 20) genes play important roles in regulating plant growth, development, and stress response. However, the grape HSP20 gene family has not been well studied. Results : A total of 48 VvHsp20 genes were identified from the grape genome, which were divided into 11 subfamilies (CI, CII, CIII, CV, CVI, CVII, MI, MII, ER, CP and PX/Po) based on a phylogenetic analysis and subcellular localization. Further structural analysis showed that most of the VvHsp20 genes (93.8%) had no intron or only one intron, while genes that clustered together based on a phylogenetic tree had similar motifs and evolutionarily conserved structures. The HSP20s share a conservedα-crystalline domain (ACD) and the different components of the ACD domain suggest the functional diversity of VvHSP20s. In addition, the 48 VvHSP20 genes were distributed on 12 grape chromosomes and the majority of VvHSP20 genes were located at the proximal or distal ends of chromosomes. Chromosome mapping indicated that four groups of VvHSP20 genes were identified as tandem duplication genes. Phytohormone responsive, abiotic and biotic stress-responsive, and plant development-related cis-elements were identified from the cis-regulatory elements analysis of VvHSP20s. The expression profiles of VvHSP20s genes (VvHsp20-1, 11, 14, 17, 18, 19, 20, 24, 25, 28, 31, 39, 42, and 43) were largely similar between RNA-Seq and qRT-PCR analysis after hydrogen peroxide (H 2 O 2 ) treatment. The results showed that most VvHSP20s were down-regulated by H 2 O 2 treatment during fruit development. VvHSP20s genes were indeed found to be involved in the grape berry development and differences in their transcriptional levels may be the result of functional differentiation during evolution. Conclusions : Our results provide valuable information on the evolutionary relationship of genes in the VvHSP20 family, which is useful for future studies on the functional characteristics of VvHSP20 genes in grape.

Genome-wide identification of small heat shock protein (HSP20) gene family in grape and expression profile during berry development

Background : Studies have shown that HSP20 (heat-shock protein 20) genes play important roles in regulating plant growth, development, and stress response. However, the grape HSP20 gene family has not been well studied. Results : A total of 48 VvHsp20 genes were identified from the grape genome, which were divided into 11 subfamilies (CI, CII, CIII, CV, CVI, CVII, MI, MII, ER, CP and PX/Po) based on a phylogenetic analysis and subcellular localization. Further structural analysis showed that most of the VvHsp20 genes (93.8%) had no intron or only one intron, while genes that clustered together based on a phylogenetic tree had similar motifs and evolutionarily conserved structures. The HSP20s share a conservedα-crystalline domain (ACD) and the different components of the ACD domain suggest the functional diversity of VvHSP20s. In addition, the 48 VvHSP20 genes were distributed on 12 grape chromosomes and the majority of VvHSP20 genes were located at the proximal or distal ends of chromosomes. Chromosome mapping indicated that four groups of VvHSP20 genes were identified as tandem duplication genes. Phytohormone responsive, abiotic and biotic stress-responsive, and plant development-related cis-elements were identified from the cis-regulatory elements analysis of VvHSP20s. The expression profiles of VvHSP20s genes (VvHsp20-1, 11, 14, 17, 18, 19, 20, 24, 25, 28, 31, 39, 42, and 43) were largely similar between RNA-Seq and qRT-PCR analysis after hydrogen peroxide (H 2 O 2 ) treatment. The results showed that most VvHSP20s were down-regulated by H 2 O 2 treatment during fruit development. VvHSP20s genes were indeed found to be involved in the grape berry development and differences in their transcriptional levels may be the result of functional differentiation during evolution. Conclusions : Our results provide valuable information on the evolutionary relationship of genes in the VvHSP20 family, which is useful for future studies on the functional characteristics of VvHSP20 genes in grape.

Genome-wide identification and expression profile analysis of the Hsp20 gene family in Barley (Hordeum vulgare L.)

In plants, heat shock proteins (Hsps) play important roles in response to diverse stresses. Hsp20 is the major family of Hsps, but their role remains poorly understood in barley (Hordeum vulgare L.). To reveal the mechanisms of barley Hsp20s (HvHsp20s) response to stress conditions, we performed a comprehensive genome-wide analysis of the HvHsp20 gene family using bioinformatics-based methods. In total, 38 putative HvHsp20s were identified in barley and grouped into four subfamilies (C, CP, PX, and MT) based on predicted subcellular localization and their phylogenetic relationships. A sequence analysis indicated that most HvHsp20 genes have no intron or one with a relatively short length. In addition, the same group of HvHsp20 proteins in the phylogenetic tree shared similar gene structure and motifs, indicating that they were highly conserved and might have similar function. Based on RNA-seq data analysis, we showed that the transcript levels of HvHsp20 genes could be induced largely by abiotic and biotic stresses such as heat, salt, and powdery mildew. Three HvHsp20 genes, HORVU7Hr1G036540, HORVU7Hr1G036470, and HORVU3Hr1G007500, were up-regulated under biotic and abiotic stresses, suggesting their potential roles in mediating the response of barley plants to environment stresses. These results provide valuable information for further understanding the complex mechanisms of HvHsp20 gene family in barley.