Differential expression profiles and pathways of genes in sugarcane leaf at elongation stage in response to drought stress

Abstract

Water stress causes considerable yield losses in sugarcane. To investigate differentially expressed genes under water stress, a pot experiment was performed with the sugarcane variety GT21 at three water-deficit levels (mild, moderate, and severe) during the elongation stage and gene expression was analyzed using microarray technology. Physiological parameters of sugarcane showed significant alterations in response to drought stress. Based on the expression profile of 15,593 sugarcane genes, 1,501 (9.6%) genes were differentially expressed under different water-level treatments; 821 genes were upregulated and 680 genes were downregulated. A gene similarity analysis showed that approximately 62.6% of the differentially expressed genes shared homology with functional proteins. In a Gene Ontology (GO) analysis, 901 differentially expressed genes were assigned to 36 GO categories. Moreover, 325 differentially expressed genes were classified into 101 pathway categories involved in various processes, such as the biosynthesis of secondary metabolites, ribosomes, carbon metabolism, etc. In addition, some unannotated genes were detected; these may provide a basis for studies of water-deficit tolerance. The reliability of the observed expression patterns was confirmed by RT-PCR. The results of this study may help identify useful genes for improving drought tolerance in sugarcane.

De novo transcriptome assembly of sugarcane leaves submitted to prolonged water-deficit stress

“…The categories most expressed in the two cultivars and at all water-deficit times were binding and catalytic, followed by the categories cellular process, metabolic process, cell, and cell part. Our results agree with those obtained by Li et al (2016) who analyzed the expression of genes in only one drought-tolerant sugarcane cultivar (GT21) using microarray technology. The most expressed categories were the cell, cell part, organelle, cellular component organization, cellular process, catalytic activity, and binding.…”

“…Although these authors had subjected plants at 5 months of age to the water-deficit condition (total moisture content of 9 ± 2%), the response was only determined at 3, 7, and 9 days after stress application. These categories were the most representative in the cultivar tolerant to short-term water deficit (Li et al, 2016) and the two cultivars tolerant and sensitive to prolonged water deficit of this study (30, 60, and 90 days). These observations suggest that either the genes belonging to these categories are involved in basic events that are essential for the maintenance of sugarcane, regardless of its tolerant/sensitive nature, or the modulation of expression of these genes in one or the other cultivar is responsible for the different characteristics when subjected to water deficit.…”

“…Several transcriptome studies have tried to clarify the mechanisms used by sugarcane to overcome the difficulties encountered in water-deficit regions (Sugiharto et al, 2002;Rocha et al, 2007;Rodrigues et al, 2009;Iskandar et al, 2011;Kido et al, 2012;Andrade et al, 2015;Vantini, et al, 2015;Li et al, 2016). RNA sequencing (RNA-Seq) is one of the latest techniques used for the study of transcriptomes.…”

Physio‐biochemical assessment and expression analysis of genes associated with drought tolerance in sugarcane (Saccharum spp. hybrids) exposed to GA3 at grand growth stage

“…Li et al . () reported a significant decrease in GA 3 content in droughted plants, it is therefore possible that exposure of droughted plants to GA 3 led to a recovery of RWC and chlorophyll content. Cutler et al .…”

Temporal and spatial changes in gene expression, metabolite accumulation and phytohormone content in rice seedlings grown under drought stress conditions

“…Global analysis of transcripts altered by mild drought treatment in maize showed upregulation of genes involved in photosynthesis (Avramova et al ., ). Transcriptomic experiments in sugarcane treated with mild, moderate or severe drought stresses indicated that F v / F m decreased as water stress increased, with the most highly represented pathway categories being biosynthesis of secondary metabolites (Li et al ., 2016a). Tiling array analysis of Brachypodium seedlings treated with mild drought stress revealed that the stress did not change the expression level of genes related to cell division, despite the fact that leaf growth was decreased (Verelst et al ., ).…”