Sugarcane is one of the world’s major C4 crops and mainly grown in tropical and sub-tropical regions for sugar and bioenergy. Climatological extremes including very high temperatures are predicted to have a catastrophic loss of crop productivity. Based on physiological and biochemical assays (data Unpublished), Co 99004 was selected as heat stress tolerant sugarcane variety. To investigate the differential expression of transcripts between control and heat stressed meristematic tissues of Co 99004, an RNA-Seq experiment was conducted. Meristematic tissues were collected from both control and treated samples at formative phase of the crop (150 days). Totally 2,308 transcripts were differentially expressed in the meristematic tissues of sugarcane in response to heat stress. About 458 transcripts and 305 transcripts were up and down regulated respectively in response to heat stress in sugarcane. There were common differential expressed transcripts detected between up and down regulated transcripts. Among the 458 up regulated transcripts, 328 transcripts were found to be commonly upregulated in both control and heat stress. Among the down regulated transcripts, 292 transcripts were down regulated in both treated and control. There were 130 transcripts exclusively upregulated during heat stress, while no transcripts were exclusively down regulated. The distribution of transcript expression level varied in different ranges of fold change. Transcripts coding for dehydration responsive element binding 1A like, grain softness protein, Malate synthase1, lipoxygenase and avenin were exclusively expressed during heat stress in sugarcane. These findings reveal novel target genes for subsequent research on the regulation of elevated temperature stress tolerance. .
Key Words: Sugarcane, Climate change, Elevated temperature, Transcripts, RNA-Seq.