Drought stress results in significant crop yield losses. Comparative transcriptome analysis between tolerant and sensitive species can provide insights into drought tolerance mechanisms in jute. We present a comprehensive study on drought tolerance in two jute species—a drought tolerant species (Corchorus olitorius L., GF) and a drought sensitive species (Corchorus capsularis L., YY). In total, 45,831 non-redundant unigenes with average sequence length of 1421 bp were identified. Higher numbers of differentially expressed genes (DEGs) were discovered in YY (794) than in GF (39), implying that YY was relatively more vulnerable or hyper-responsive to drought stress at the molecular level; the two main pathways, phenylpropanoid biosynthesis and peroxisome pathway, significantly involved in scavenging of reactive oxygen species (ROS) and 14 unigenes in the two pathways presented a significant differential expression in response to increase of superoxide. Our classification analysis showed that 1769 transcription factors can be grouped into 81 families and 948 protein kinases (PKs) into 122 families. In YY, we identified 34 TF DEGs from and 23 PK DEGs, including 19 receptor-like kinases (RLKs). Most of these RLKs were downregulated during drought stress, implying their role as negative regulators of the drought tolerance mechanism in jute.

High salinity is a major environmental stressor for crops. To understand the regulatory mechanisms underlying salt tolerance, we conducted a comparative transcriptome analysis between salt-tolerant and salt-sensitive jute (Corchorus spp.) genotypes in leaf and root tissues under salt stress and control conditions. In total, 68,961 unigenes were identified. Additionally, 11,100 unigenes (including 385 transcription factors (TFs)) exhibited significant differential expression in salt-tolerant or salt-sensitive genotypes. Numerous common and unique differentially expressed unigenes (DEGs) between the two genotypes were discovered. Fewer DEGs were observed in salt-tolerant jute genotypes whether in root or leaf tissues. These DEGs were involved in various pathways, such as ABA signaling, amino acid metabolism, etc. Among the enriched pathways, plant hormone signal transduction (ko04075) and cysteine/methionine metabolism (ko00270) were the most notable. Eight common DEGs across both tissues and genotypes with similar expression profiles were part of the PYL-ABA-PP2C (pyrabactin resistant-like/regulatory components of ABA receptors-abscisic acid-protein phosphatase 2C). The methionine metabolism pathway was only enriched in salt-tolerant jute root tissue. Twenty-three DEGs were involved in methionine metabolism. Overall, numerous common and unique salt-stress response DEGs and pathways between salt-tolerant and salt-sensitive jute have been discovered, which will provide valuable information regarding salt-stress response mechanisms and help improve salt-resistance molecular breeding in jute.

Soil salinity, a major environmental stress, reduces agricultural productivity by restricting plant development and growth. Jute (Corchorus spp.), a commercially important bast fiber crop, includes two commercially cultivated species, Corchorus capsularis and Corchorus olitorius. We conducted high-throughput transcriptome sequencing of 24 C. capsularis and C. olitorius samples under salt stress and found 127 common differentially expressed genes (DEGs); additionally, 4489 and 492 common DEGs were identified in the root and leaf tissues, respectively, of both Corchorus species. Further, 32, 196, and 11 common differentially expressed transcription factors (DTFs) were detected in the leaf, root, or both tissues, respectively. Several Gene Ontology (GO) terms were enriched in NY and YY. A Kyoto Encyclopedia of Genes and Genomes analysis revealed numerous DEGs in both species. Abscisic acid and cytokinin signal pathways enriched respectively about 20 DEGs in leaves and roots of both NY and YY. The Ca²⁺, mitogen-activated protein kinase signaling and oxidative phosphorylation pathways were also found to be related to the plant response to salt stress, as evidenced by the DEGs in the roots of both species. These results provide insight into salt stress response mechanisms in plants as well as a basis for future breeding of salt-tolerant cultivars.

Jute (Corchorus spp.) is the second most important global natural fiber crop after cotton. Analyses of the genetic diversity and population structure of the germplasm are useful for improving Corchorus breeding. Recently, limited studies on genetic diversity and population structure in jute have been carried out. In the present study, the genetic diversity and population structure of 453 accessions in Corchorus olitorius L., including cultivars, landraces, genetic materials and wild germplasm, were analyzed using 39 SSR markers. The results showed that C. olitorius populations have moderate genetic diversity with an average gene diversity (h_e) value of 0.322 and polymorphic information content (PIC) value of 0.270 in all accessions. Regarding the geographic distribution, the average h_e and PIC values were highest in Kenya (0.332, 0.273), followed by Nepal (0.307, 0.259), and China (0.303, 0.253). Among the different germplasm types, the wild germplasm showed higher genetic diversity with an average h_e value of 0.362 and PIC value of 0.299. The population structure analysis revealed two populations, Pop1 and Pop2; Pop1 was further divided into three subpopulations, and Pop2 was further divided into two subpopulations. These populations were verified by F_ST statistics, principal coordinate analysis (PCoA) and neighbour-joining trees. This study contributes to the knowledge about levels and distribution of genetic diversity of C. olitorius worldwide and provides clues about the origin of C. olitorius.