De novo transcriptome sequencing of two cultivated jute species under salinity stress

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.

土壤盐度作为一种主要的环境胁迫因子，可通过抑制植物的生长发育降低农业生产力。黄麻（Corchorus spp.）是一类具有重要商业价值的韧皮纤维作物，目前商业化栽培的黄麻包含两个物种：圆果黄麻（Corchorus capsularis）与长果黄麻（Corchorus olitorius）。本研究对盐胁迫下的24份圆果黄麻和长果黄麻样本开展了高通量转录组测序，共鉴定得到127个共有差异表达基因（differentially expressed genes, DEGs）；此外，在两个黄麻属物种的根组织与叶组织中，分别鉴定得到4489个与492个共有DEGs。进一步分析显示，在叶组织、根组织以及两类组织中分别检测到32个、196个与11个共有差异表达转录因子（differentially expressed transcription factors, DTFs）。多个基因本体（Gene Ontology, GO）条目在NY与YY样本中显著富集。京都基因与基因组百科全书（Kyoto Encyclopedia of Genes and Genomes）分析结果表明，两个物种中均存在大量差异表达基因。脱落酸（Abscisic acid）与细胞分裂素（cytokinin）信号通路分别在NY与YY的叶组织与根组织中富集了约20个差异表达基因。钙离子（Ca²+）信号通路、丝裂原活化蛋白激酶（mitogen-activated protein kinase）信号通路以及氧化磷酸化通路同样被证实与植物盐胁迫应答相关，这一结论得到了两个物种根组织中差异表达基因的佐证。本研究结果为解析植物盐胁迫应答机制提供了新的见解，同时也为未来耐盐品种的育种工作提供了理论基础。