Heat shock transcription factors (HSFs) are central elements in the regulatory network that controls plant heat stress response. They are involved in multiple transcriptional regulatory pathways and play important roles in heat stress signaling and responses to a variety of other stresses. We identified 41 members of the HSF gene family in moso bamboo, which were distributed non-uniformly across its 19 chromosomes. Phylogenetic analysis showed that the moso bamboo HSF genes could be divided into three major subfamilies; HSFs from the same subfamily shared relatively conserved gene structures and sequences and encoded similar amino acids. All HSF genes contained HSF signature domains. Subcellular localization prediction indicated that about 80% of the HSF proteins were located in the nucleus, consistent with the results of GO enrichment analysis. A large number of stress response–associated cis-regulatory elements were identified in the HSF upstream promoter sequences. Synteny analysis indicated that the HSFs in the moso bamboo genome had greater collinearity with those of rice and maize than with those of Arabidopsis and pepper. Numerous segmental duplicates were found in the moso bamboo HSF gene family. Transcriptome data indicated that the expression of a number of PeHsfs differed in response to exogenous gibberellin (GA) and naphthalene acetic acid (NAA). A number of HSF genes were highly expressed in the panicles and in young shoots, suggesting that they may have functions in reproductive growth and the early development of rapidly-growing shoots. This study provides fundamental information on members of the bamboo HSF gene family and lays a foundation for further study of their biological functions in the regulation of plant responses to adversity.

Background The BBX (B-box) family are zinc finger protein (ZFP) transcription factors that play an essential role in plant growth, development and response to abiotic stresses. Although BBX genes have been characterized in many model organisms, genome-wide identification of the BBX family genes have not yet been reported in Moso bamboo (Phyllostachys edulis), and the biological functions of this family remain unknown. Result In the present study, we identified 27 BBX genes in the genome of Moso bamboo, and analysis of their conserved motifs and multiple sequence alignments revealed that they all shared highly similar structures. Additionally, phylogenetic and homology analyses indicated that PeBBX genes were divided into three clusters, with whole-genome duplication (WGD) events having facilitated the expansion of this gene family. Light-responsive and stress-related cis-elements were identified by analyzing cis-elements in the promoters of all PeBBX genes. Short time-series expression miner (STEM) analysis revealed that the PeBBX genes had spatiotemporal-specific expression patterns and were likely involved in the growth and development of bamboo shoots. We further explored the downstream target genes of PeBBXs, and GO/KEGG enrichment analysis predicted multiple functions of BBX target genes, including those encoding enzymes involved in plant photosynthesis, pyruvate metabolism and glycolysis/gluconeogenesis. Conclusions In conclusion, we analyzed the PeBBX genes at multiple different levels, which will contribute to further studies of the BBX family and provide valuable information for the functional validation of this family.

Background Moso bamboo, the fastest growing plant on earth, is an important source for income in large areas of Asia, mainly cultivated in China. Lateral organ boundaries domain (LBD) proteins, a family of transcription factors unique to plants, are involved in multiple transcriptional regulatory pathways and play important roles in lateral organ development, pathogen response, secondary growth, and hormone response. The LBD gene family has not previously been characterized in moso bamboo (Phyllostachys edulis). Results In this study, we identified 55 members of the LBD gene family from moso bamboo and found that they were distributed non-uniformly across its 18 chromosomes. Phylogenetic analysis showed that the moso bamboo LBD genes could be divided into two classes. LBDs from the same class share relatively conserved gene structures and sequences encoding similar amino acids. A large number of hormone response–associated cis-regulatory elements were identified in the LBD upstream promoter sequences. Synteny analysis indicated that LBDs in the moso bamboo genome showed greater collinearity with those of O. sativa (rice) and Zea mays (maize) than with those of Arabidopsis and Capsicum annuum (pepper). Numerous segmental duplicates were found in the moso bamboo LBD gene family. Gene expression profiles in four tissues showed that the LBD genes had different spatial expression patterns. qRT–PCR assays with the Short Time-series Expression Miner (STEM) temporal expression analysis demonstrated that six genes (PeLBD20, PeLBD29, PeLBD46, PeLBD10, PeLBD38, and PeLBD06) were consistently up-regulated during the rapid growth and development of bamboo shoots. In addition, 248 candidate target genes that function in a variety of pathways were identified based on consensus LBD binding motifs. Conclusions In the current study, we identified 55 members of the moso bamboo transcription factor LBD and characterized for the first time. Based on the short-time sequence expression software and RNA-seq data, the PeLBD gene expression was analyzed. We also investigated the functional annotation of all PeLBDs, including PPI network, GO, and KEGG enrichment based on String database. These results provide a theoretical basis and candidate genes for studying the molecular breeding mechanism of rapid growth of moso bamboo.

Background The YABBY gene family is a family of small zinc finger transcription factors associated with plant morphogenesis, growth, and development. In particular, it is closely related to the development of polarity in the lateral organs of plants. Despite being studied extensively in many plant species, there is little information on genome-wide characterization of this gene family in Moso bamboo. Methods In the present study, we identified 16 PeYABBY genes, which were unequally distributed on 11 chromosomes, through genome-wide analysis of high-quality genome sequences of M oso bamboo by bioinformatics tools and biotechnological tools. Gene expression under hormone stress conditions was verified by quantitative real-time PCR (qRT-PCR) experiments. Results Based on peptide sequences and similarity of exon-intron structures, we classified the PeYABBY genes into four subfamilies. Analysis of putative cis-acting elements in promoters of these genes revealed that PeYABBYs contained a large number of hormone-responsive and stress-responsive elements. Expression analysis showed that they were expressed at a high level in Moso bamboo panicles, rhizomes, and leaves. Expression patterns of putative PeYABBY genes in different organs and hormone-treated were analyzed using RNA-seq data, results showed that some PeYABBY genes were responsive to gibberellin (GA) and abscisic acid (ABA), indicating that they may play an important role in plant hormone responses. Gene Ontology (GO) analyses of YABBY proteins indicated that they may be involved in many developmental processes, particularly high level of enrichment seen in plant leaf development. In summary, our results provide a comprehensive genome-wide study of the YABBY gene family in bamboos, which could be useful for further detailed studies of the function and evolution of the YABBY genes, and to provide a fundamental basis for the study of YABBY in Gramineae for resistance to stress and hormonal stress.

Dirigent-jacalin (D-J) genes belong to the plant chimeric lectin family, and play vital roles in plant growth and resistance to abiotic and biotic stresses. To explore the functions of the D-J family in the growth and development of Moso bamboo (Phyllostachys edulis), their physicochemical properties, phylogenetic relationships, gene and protein structures, and expression patterns were analyzed in detail. Four putative PeD-J genes were identified in the Moso bamboo genome, and microsynteny and phylogenetic analyses indicated that they represent a new branch in the evolution of plant lectins. PeD-J proteins were found to be composed of a dirigent domain and a jacalin-related lectin domain, each of which contained two different motifs. Multiple sequence alignment and homologous modeling analysis indicated that the three-dimensional structure of the PeD-J proteins was significantly different compared to other plant lectins, primarily due to the tandem dirigent and jacalin domains. We surveyed the upstream putative promoter regions of the PeD-Js and found that they mainly contained cis-acting elements related to hormone and abiotic stress response. An analysis of the expression patterns of root, leaf, rhizome and panicle revealed that four PeD-J genes were highly expressed in the panicle, indicating that they may be required during the formation and development of several different tissue types in Moso bamboo. Moreover, PeD-J genes were shown to be involved in the rapid growth and development of bamboo shoots. Quantitative Real-time PCR (qRT PCR) assays further verified that D-J family genes were responsive to hormones and stresses. The results of this study will help to elucidate the biological functions of PeD-Js during bamboo growth, development and stress response.