The schematic diagram of Hsp90 protein motifs of all Hsp90 genes and each species from MEME.

<p>The schematic diagram of Hsp90 protein motifs of all Hsp90 genes and each species from MEME.</p

Phylogenetic relationships of Hsp90 gene family.

<p>A total of 94 protein sequences of Hsp90 gene family identified from ten species vary from unicellular green algae to multicellular plants were aligned with MUSCLE program, and the phylogenetic tree was constructed based on Bayesian inference using Markov Chain Monte Carlo (MCMC) methods. The red arcs indicate different subgroups of Hsp90 genes. Hsp90 genes of B. distachyon are indicated by filled purple dots.</p

Chromosome distribution of Hsp90 genes in B. distachyon, A. thaliana and O. sativa.

<p>(A). The chromosome distribution of Hsp90 genes in B. distachyon. (B). The chromosome distribution of Hsp90 genes in A. thaliana. (C) The chromosome distribution of Hsp90 genes in Oryza sativa. The chromosome numbers are indicated at the top of each bar and size of a chromosome is indicated by its relative length.</p

The hierarchical cluster (HCA) analysis of seven B. distachyon Hsp90 genes in root and leaf tissues under drought and salt stresses (12h, 24h, 48h).

<p>Colorbar indicates the amounts of Hsp90 gene expression.</p

Segmental duplication events of some plant species.

<p>Segmental duplication events of some plant species.</p

Genome-wide analysis of the <i>Brachypodium distachyon</i> (L.) P. Beauv. <i>Hsp90</i> gene family reveals molecular evolution and expression profiling under drought and salt stresses

<div><p>The structure, evolution, and function of heat shock proteins 90 (Hsp90s) have been investigated in great detail in fungi and animals. However, studies on the <i>Hsp90</i> genes in plants are generally limited. <i>Brachypodium distachyo</i>n (L.) P. Beauv., as a model plant for cereal crops, has become a potential biofuel grass. During its long evolution, the <i>Hsp90</i> gene family in <i>Brachypodium</i> has developed some strategies to cope with adverse environments. How the <i>Hsp90</i> gene family in <i>Brachypodium</i> evolved in different plant lineages and what its role is in plant responses to drought and salt stresses remains to be elucidated. We used a set of different bioinformatics tools to identify 94 <i>Hsp90</i> genes from 10 species representing four plant lineages and classified into three subgroups. Eight <i>BdHsp90</i> genes were detected from <i>B</i>. <i>distachyo</i>n. The number of exon-intron structures differed in each subgroup, and the motif analysis revealed that these genes were relatively conservative in each group. The fragments duplication and tandem duplication, which are the prime powers for functional diversity, generally occurred during the duplication of the whole plant genome. Transcriptional analysis of the <i>BdHsp90</i> genes under salt and drought stress conditions indicated that the expression of these genes was delayed or increased at different stress time points; The expression was more affected in that of <i>Bradi3g39630</i>, <i>Bradi4g06370</i>, and <i>Bradi1g30130</i>. Our findings suggest the involvement of BdHsp90s in plant abiotic stress response, and further consolidate our views on the stress response mechanism of Hsp90 in general.</p></div

Subcellular localization of each subgroup and species by TargetP1.1, WoLF PSORT and Predotar v. 1.03 on-line tools.

<p>Subcellular localization of each subgroup and species by TargetP1.1, WoLF PSORT and Predotar v. 1.03 on-line tools.</p

Introns and the corresponding exon sequences within individual Hsp90 gene paralog listed in Neighbor-joining phylogenetic tree.

<p>Hsp90 genes of B. distachyon are indicated by filled purple dots. Hsp90 genes of A. thaliana are indicated by filled purple dots. Colorbar indicates the number of introns contained in Hsp90 genes.</p

Flow chart of the WTMM method for exon detection.

<p>Flow chart of the WTMM method for exon detection.</p

Detection plots for sequence BRCA1, in the range of 40,001–60,000 bp.

<p>Detection plots for sequence BRCA1, in the range of 40,001–60,000 bp.</p