De novo transcriptome analysis of Rhizophora mucronata Lam. furnishes evidence for the existence of glyoxalase system correlated to glutathione metabolic enzymes and glutathione regulated transporter in salt tolerant mangroves.

The accumulation of a metabolic by product - methylglyoxal above a minimal range can be highly toxic in all organisms. Stress induced elevation in methylglyoxal inactivates proteins and nucleic acids. Glutathione dependent glyoxalase enzymes like glyoxalase I and glyoxalase II together with glutathione independent glyoxalase III play inevitable role in methylglyoxal detoxification. Glyoxalase genes are generally conserved but with obvious exceptions. Mangroves being potent harsh land inhabitants, their internal organelles are constantly been exposed to elevated levels of methylglyoxal. First and foremost it is important to detect the presence of glyoxalases in mangroves. De novo transcriptome analysis of mangrove species Rhizophora mucronata Lam., identified eleven putative glyoxalase proteins (RmGLYI-1 to 5, RmGLYII-1 to 5 and RmGLYIII). Molecular characterization proposed PLN02300 or PLN02367 as the key domains of RmGLYI proteins. They possess molecular weight ranging from 26.45 to 32.53 kDa and may localize in cytosol or chloroplast. RmGLYII proteins of molecular weight 28.64-36 kDa, carrying PLN02398 or PLN02469 domains are expected to be localized in diverse cellular compartments. Cytosolic RmGLYIII with DJ-1/PfpI domain carries a molecular weight 26.4 kDa. Detailed structural analysis revealed monomeric nature of RmGLYI-1 and RmGLYII-1 whereas RmGLYIII is found to be homodimer. Molecular phylogenetic analysis and multiple sequence alignment specified conserved metal ion/substrate binding residues of RmGLY proteins. Estimation of relative expression of glyoxalases under salt stress indicated the prominence of RmGLYI and RmGLYII over RmGLYIII. The aforementioned prominence is supported by salt induced expression difference of glutathione metabolic enzymes and glutathione regulated transporter protein.

Leaf tissue specific transcriptome sequence and de novo assembly datasets of Asiatic mangrove Rhizophora mucronata Lam.

Transcriptome data is beneficial to explore molecular mechanisms of extreme adaptations in non- model organisms like mangroves. In this data article, five major datasets and two data sub sets of a salt secreting mangrove, Rhizophora mucronata Lam. were described. A combination of Illumina HiSeq 2500, Trinity, BLAST X, Bowtie 2 and BLAST 2GO was used for RNA Seq, de novo assembly, transcript annotation, gene expression estimation and gene ontology annotation respectively. The RNA Sequence (Read 1 and Read 2) in Sequence Read Archive amounting to 46,366,348 paired end raw reads is the first data set made open for de novo or comparative transcript assembly. Assembled sequences of 93960 gene transcripts constitute the second data set in Transcriptome Shotgun Assembly. The gene/protein annotations to the assembled transcripts give two sub data sets containing 93960 each of GenBank and GenPept entries with comprehensive cDNA and translated protein sequences of genes. Of these, predicted proteins for 87768 coding sequences, mapped to UniProtKB serve as the third data set. The gene expression levels of the annotated transcripts comprise the fourth data set in Gene Expression Omnibus. The fifth data set in Figshare includes 44,028 gene ontology terms extracted for 21,073 confident transcripts. The data sets provide a valuable resource for further analyses including transcriptomic changes in response to environmental stresses.