Overexpression of EaALDH7, an aldehyde dehydrogenase gene from Erianthus arundinaceus enhances salinity tolerance in transgenic sugarcane (Saccharum spp. Hybrid).

Aldehyde Dehydrogenases (ALDH), a group of enzymes, are associated with the detoxification of aldehydes, produced in plants during abiotic stress conditions. Salinity remains a pivotal abiotic challenge that poses a significant threat to cultivation and yield of sugarcane. In this study, an Aldehyde dehydrogenase gene (EaALDH7) from Erianthus arundinaceus was overexpressed in the commercial sugarcane hybrid cultivar Co 86032. The transgenic lines were evaluated at different NaCl concentrations ranging from 0 mM to 200 mM for various morpho-physiological and biochemical parameters. The control plants, subjected to salinity stress condition, exhibited morphological changes in protoxylem, metaxylem, pericycle and pith whereas the transgenic events were on par with plants under regular irrigation. The overexpressing (OE) lines showed less cell membrane injury and improved photosynthetic rate, transpiration rate, and stomatal conductance than the untransformed control plants under stress conditions. Elevated proline content, higher activity of enzymatic antioxidants such as sodium dismutase (SOD), catalase (CAT), glutathione reductase (GR) and ascorbate peroxidase (APX) and low level of malondialdehyde MDA and hydrogen peroxide (H2O2) in the transgenic lines. The analysis of EaALDH7 expression revealed a significant upregulation in the transgenic lines compared to that of the untransformed control during salt stress conditions. The current study highlights the potentials of EaALDH7 gene in producing salinity-tolerant sugarcane cultivars.

Comparative genome-wide characterization of salt responsive micro RNA and their targets through integrated small RNA and de novo transcriptome profiling in sugarcane and its wild relative Erianthus arundinaceus.

Soil salinity and saline irrigation water are major constraints in sugarcane affecting the production of cane and sugar yield. To understand the salinity induced responses and to identify novel genomic resources, integrated de novo transcriptome and small RNA sequencing in sugarcane wild relative, Erianthus arundinaceus salt tolerant accession IND 99-907 and salt-sensitive sugarcane genotype Co 97010 were performed. A total of 362 known miRNAs belonging to 62 families and 353 miRNAs belonging to 63 families were abundant in IND 99-907 and Co 97010 respectively. The miRNA families such as miR156, miR160, miR166, miR167, miR169, miR171, miR395, miR399, miR437 and miR5568 were the most abundant with more than ten members in both genotypes. The differential expression analysis of miRNA reveals that 221 known miRNAs belonging to 48 families and 130 known miRNAs belonging to 42 families were differentially expressed in IND 99-907 and Co 97010 respectively. A total of 12,693 and 7982 miRNA targets against the monoploid mosaic genome and a total of 15,031 and 12,152 miRNA targets against the de novo transcriptome were identified for differentially expressed known miRNAs of IND 99-907 and Co 97010 respectively. The gene ontology (GO) enrichment analysis of the miRNA targets revealed that 24, 12 and 14 enriched GO terms (FDR < 0.05) for biological process, molecular function and cellular component respectively. These miRNAs have many targets that associated in regulation of biotic and abiotic stresses. Thus, the genomic resources generated through this study are useful for sugarcane crop improvement through biotechnological and advanced breeding approaches. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03867-7.