Plant grows in nature facing various types of abiotic stresses for their normal growth and development. During abiotic stress, plants evolve different types of mechanisms to survive in a hostile environment. Phospholipase D (PLD) plays important role in the regulation of diverse cellular processes including stress responses in plants. Member of PLD genes are well studied in different model plants; however, their functions in the jute are not clear yet. In the present study, a total of 12 and 11 PLD genes were identified in the genome of C. capsularis and C. olitorius, respectively. The presence of the two conserved HKD motifs in PLD genes except for CoPLDδ-2 in jute suggests their strong lipase activity. Twenty different motifs were found in the identified PLD genes, and PLD-β1, PLD-γ1, and all members of PLD-δ1 of both jute species contained the highest number of motifs. Phylogenetic analysis showed the close evolutionary relationship among the five groups of jute PLD proteins along with the PLD proteins from Arabidopsis. Tissue-specific expression pattern of PLDα1-2, PLD-α2, PLDβ1, PLDγ1, and PLDδ1 of two jute species suggested their involvement in plant growth and development. However, the expression pattern of PLDα1-2, PLDα1-3, PLD-α4, PLDδ1, and PLDδ3 indicated their association during waterlogging stress. In addition, PLD-α2, PLDβ1, and PLDδ2 seemed to be involved in drought stress as well as salinity stress. This genome-wide identification of jute PLD genes from C. capsularis and C. olitorius will help to further functional characterization of the PLD genes for developing stress-tolerant jute variety.

Sucrose non-fermenting-1 (SNF1)-related protein kinase 2 (SnRK2), a plant-specific serine/threonine kinase family, is associated with metabolic responses, including abscisic acid signaling under biotic and abiotic stresses. So far, no information on a genome-wide investigation and stress-mediated expression profiling of jute SnRK2 is available. Recent whole-genome sequencing of two Corchorus species prompted to identify and characterize this SnRK2 gene family. We identified seven SnRK2 genes of each of Corchorus olitorius (Co) and C. capsularis (Cc) genomes, with similar physico-molecular properties and sub-group patterns of other models and related crops. In both species, the SnRK2 gene family showed an evolutionarily distinct trend. Highly variable C-terminal and conserved N-terminal regions were observed. Co- and CcSnRK2.3, Co- and CcSnRk2.5, Co- and CcSnRk2.7, and Co- and CcSnRK2.8 were upregulated in response to drought and salinity stresses. In waterlogging conditions, Co- and CcSnRk2.6 and Co- and CcSnRK2.8 showed higher activity when exposed to hypoxic conditions. Expression analysis in different plant parts showed that SnRK2.5 in both Corchorus species is highly expressed in fiber cells providing evidence of the role of fiber formation. This is the first comprehensive study of SnRK2 genes in both Corchorus species. All seven genes identified in this study showed an almost similar pattern of gene structures and molecular properties. Gene expression patterns of these genes varied depending on the plant parts and in response to abiotic stresses.

Na ⁺ /H ⁺ exchangers (NHXs) are secondary ion transporter to exchange H+ and transfer Na ⁺ or K ⁺ across membrane plays crucial role in cellular pH and Na ⁺ and K ⁺ homeostasis in plant. In the present study, we have performed genomewide identification, characterization and comparative analysis of NHXs genes in two cultivated jute species and found seven Co and Cc NHXs in each genome. Subsequently phylogenetic analysis demonstrated that Co and Cc NHXs have three sub-group that correlate with other plant species containing 10-12 transmembrane helices (TMH) and a hydrophilic C-terminal domain in the cytoplasmic region, the TMH compose a hollow cylinder to provide the channel for Na ⁺ and H ⁺ transport. Promoter profiling of both species NHXs genes revealed in enrichment of cis element involved in stress responsiveness reflecting their potential involvement against abiotic stress. Transcriptome data and real time PCR of Co and Cc NHXs gene expression analysis under saline and drought condition showed significant differences, which suggest their potential role in abiotic stress conditions. This is the first comprehensive analysis providing baseline information of Co and Cc NHXs genes in abiotic stress condition which can be used for the development of abiotic stress tolerant jute variety.

Mitogen activated protein kinase (MAPK) cascade is evolutionary conserved universal signal transduction module that plays central role in the growth and development of plants as well as in biotic and abiotic stress response. Although, MAPKs have been investigated in several model plants, no systematic analysis has been conducted in jute species ( Corchorus olitorius and C. capsularis ) even though, their genome sequencing has been completed. In the present study we identified 11 and 12 putative MAPKs in C. olitorius and C. capsularis using their genomic database, respectively. Here we provide a comprehensive bioinformatics analysis of the MAPK family from both Corchorus species including identification and nomenclature, chromosomal localization, sequence alignment, domain and Motif, gene structure, phylogenetic, functional analysis and investigation of expression analysis in response to abiotic stress and fiber cell development. The phylogenetic analysis of predicted MAPKs were clustered into four different clades and assigned with specific name based on their orthology based evolutionary relationship with Arabidopsis . Structural analysis of the MAPK genes revealed that there was a large variation among the exon number in both Corchorus species ranged from 2 to 11 but genes with the same clade had similar exon-intron structure. The sequence alignment analysis concede the presence of several conserved domain and motif including crucial signature phosphorylation motif TDY or TEY where first one is harbor in group D sequence and rest of the sequence contain TEY motif in their activation loop. Transcriptome analysis against salinity, drought along with fiber cell formation showed that MAPK4-1 genes in both jute genome highly expressed and may play a potential role in jute on adverse condition as well as jute fiber formation. These findings yielded new insights into the transcriptional control of MAPK gene expression, provide an improved understanding of abiotic stress responses and signaling transduction in jute, that lead to potential applications in the genetic improvement of jute cultivars.