Genome-wide identification and expression analyses of genes involved in raffinose accumulation in sesame

Abstract

Sesame (Sesamum indicum L.) is an important oilseed crop. However, multiple abiotic stresses severely affect sesame growth and production. Raffinose family oligosaccharides (RFOs), such as raffinose and stachyose, play an important role in desiccation tolerance of plants and developing seeds. In the present study, three types of key enzymes, galactinol synthase (GolS), raffinose synthase (RafS) and stachyose synthase (StaS), responsible for the biosynthesis of RFOs were identified at the genome-wide scale in sesame. A total of 7 SiGolS and 15 SiRS genes were identified in the sesame genome. Transcriptome analyses showed that SiGolS and SiRS genes exhibited distinct expression profiles in different tissues and seed developmental stages. Comparative expression analyses under various abiotic stresses indicated that most of SiGolS and SiRS genes were significantly regulated by drought, osmotic, salt, and waterlogging stresses, but slightly affected by cold stress. The up-regulation of several SiGolS and SiRS genes by multiple abiotic stresses suggested their active implication in sesame abiotic stress responses. Taken together, these results shed light on the RFOs-mediated abiotic stress resistance in sesame and provide a useful framework for improving abiotic stress resistance of sesame through genetic engineering.

Characterization of raffinose metabolism genes uncovers a wild Arachis galactinol synthase conferring tolerance to abiotic stresses

“…The phylogenetic analysis of putative RFO-related proteins from Fabaceae, including these five enzyme families identified in wild Arachis, showed a clear subdivision within each family, supported by high bootstrap values. This clustering, based on phylogenetic proximity, was related to the intron/exon organization of the corresponding Arachis genes, as previously observed for other plant species [8][9][10] . Similarly to the conservation of gene structure, amino acid sequences were highly conserved too, for example, the hydrophobic pentapeptide (APSAA), characteristic of the GolS family 42 , was found for all the proteins from A. duranensis and A. ipaënsis, as well as other conserved motifs in the different enzyme families.…”

“…Conversely, the genes from the GolS family have undergone duplication mostly by WGD and can be observed in gene blocks in two different chromosomes. Other studies also found that segmental duplications were the driving force for the expansion of GolS genes in S. indicum and Rosaceae genomes, being associated with a possible subfunctionalization 10,12 .…”

“…RFOs are part of the molecular network activated by plants in response to a range of environmental stresses and currently emerge as key components in stress tolerance, acting as osmoprotectants, antioxidants and signaling molecules 2,4 . Due to their importance, the principal enzymes involved in the first steps of RFO biosynthesis (GolS, RS and STS) have been thoroughly studied at the genome-wide scale in many plant species [8][9][10][11][12]15 . However, little attention has been given to the enzymes involved in RFO catabolism, such as AGAL and BFLUCT.…”

Identification and characterization of the bZIP transcription factor family and its expression in response to abiotic stresses in sesame

“…13 cultivar were grown hydroponically in a growth chamber (16 h light/8 h dark cycle at 28°C). Two-week old seedlings were exposed to different abiotic stresses including osmotic, salt, and cold treatments as described in our previous study [ 52 ]. The shoots of seedlings with different treatments were harvested at 0, 2, 6 and 12 h after treatment.…”

Genome-wide characterization and expression analysis of the Dof gene family related to abiotic stress in watermelon

“…The chromosomal location information of watermelon Dof genes was obtained from the watermelon genome database, and MapChart was used to display the physical positions of all ClDof genes along each chromosome. Gene duplications were examined using multiple collinear scanning toolkits (MCScanX) software with the default parameters as previously reported (You et al, 2018).…”