Transcriptional reprogramming and enhanced photosynthesis drive inducible salt tolerance in sugarcane mutant line M4209

Abstract

Sugarcane (Saccharum officinarum L.) is a globally-cultivated cash crop whose yield is negatively affected by soil salinity. In the present study, we have investigated the molecular basis of inducible salt tolerance in M4209, a sugarcane mutant generated through radiation-induced mutagenesis. Under salt-contaminated field conditions, M4209 exhibited 32% higher cane yield as compared with its salt-sensitive parent Co86032. In continuation, M4209 displayed significantly higher leaf biomass in post-sprouting phenotyping, as compared with Co86032, under both 50 and 200 mM NaCl. This was concomitant with 1.9- (50 mM) and 1.6- (200 mM) fold higher K+/Na+ ratio and 4- (50 mM) and 40- (200 mM) fold higher glutathione reductase activity in M4209 as compared with that in Co86032, suggesting better ionic and redox homeostasis. RNAseq based transcriptome profiling in M4209 indicated an extensive reprograming of stress responsive modules associated with photosynthesis, transmembrane transport and metabolic processes under 50 mM NaCl stress. Using ranking analysis, we identified PAL (Phenylalanine ammonia lyase), ATL (Acyl-transferase like gene) and SATA (Salt-activated transcriptional activator) as top-ranked genes associated with M4209’s salt tolerance. Additionally, M4209 exhibited 3-4-fold higher photosynthetic rate, as compared with Co86032 under NaCl stress conditions. Taken together, our study highlights the significance of transcriptional reprogramming coupled with photosynthetic efficiency for regulating salt tolerance in sugarcane.

Transcriptome profiling of genes regulated by phosphate-solubilizing bacteria Bacillus megaterium P68 in potato (Solanum tuberosum L.)

“… Li et al (2020) found that DEGs in potato were mostly enriched in functions such as transport activity and oxidoreductase activity under salt stress based on GO analysis and KEGG analysis. Similarly, the results reported by Negi et al (2020) found that when leaves of salt-tolerant and salt-sensitive sugarcane were subjected to transcriptome analysis and showed that sugarcane under salt stress induced genes related to metabolic processes, transmembrane transport, and photosynthesis expression, to reach a steady state in sugarcane production, thus increasing sugarcane yield under salt field conditions. Overall, genes of plants under inoculating with PSB may be regulated to cope with adverse growth conditions.…”

Antioxidant Defense and Ionic Homeostasis Govern Stage-Specific Response of Salinity Stress in Contrasting Rice Varieties

“…To assay the activities of antioxidant enzymes, total protein was extracted by homogenization of leaf/root tissue in chilled extraction buffer containing 100 mM potassium phosphate buffer (pH 7.0), 0.1 mM ethylene diamine tetra acetic acid (EDTA) and 1% polyvinyl pyrrolidone ( w / v ) and quantified. The activity of superoxide dismutase (SOD), ascorbate peroxidase (APX) Guaiacol peroxidase (GPX) and catalase (CAT) were estimated from the same extract according to protocol by [ 24 ].…”

Integrated approaches for increasing plant yield under salt stress

“…Salt stress is one of the most important environmental factors, significantly decreasing crop growth and yield worldwide ( Zörb et al., 2019 ; Negi et al., 2020 ). Salt stress affects approximately 20 percent of all agricultural lands and 33 percent of irrigated agricultural lands ( FAO, 2017 ).…”