Transcriptomic analysis of Sorghum bicolor responding to combined heat and drought stress

Abstract

BackgroundAbiotic stresses which include drought and heat are amongst the main limiting factors for plant growth and crop productivity. In the field, these stress types are rarely presented individually and plants are often subjected to a combination of stress types. Sorghum bicolor is a cereal crop which is grown in arid and semi-arid regions and is particularly well adapted to the hot and dry conditions in which it originates and is now grown as a crop. In order to better understand the mechanisms underlying combined stress tolerance in this important crop, we have used microarrays to investigate the transcriptional response of Sorghum subjected to heat and drought stresses imposed both individually and in combination.ResultsMicroarrays consisting of 28585 gene probes identified gene expression changes equating to ~4% and 18% of genes on the chip following drought and heat stresses respectively. In response to combined stress ~20% of probes were differentially expressed. Whilst many of these transcript changes were in common with those changed in response to heat or drought alone, the levels of 2043 specific transcripts (representing 7% of all gene probes) were found to only be changed following the combined stress treatment. Ontological analysis of these ‘unique’ transcripts identified a potential role for specific transcription factors including MYB78 and ATAF1, chaperones including unique heat shock proteins (HSPs) and metabolic pathways including polyamine biosynthesis in the Sorghum combined stress response.ConclusionsThese results show evidence for both cross-talk and specificity in the Sorghum response to combined heat and drought stress. It is clear that some aspects of the combined stress response are unique compared to those of individual stresses. A functional characterization of the genes and pathways identified here could lead to new targets for the enhancement of plant stress tolerance, which will be particularly important in the face of climate change and the increasing prevalence of these abiotic stress types.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-456) contains supplementary material, which is available to authorized users.

Transcriptional networks — crops, clocks, and abiotic stress

“…stress-induced expression of orthologous PSR TFs are similar), conservation of all target gene regulation (regulon) is not implicit [49,50]. The bulk of abiotic stress expression data has been examined using paired (stress versus non-stress) differential gene expression analysis with limited time resolution [51][52][53][54]. Accordingly, the temporal dynamics of many PSR TF regulons remain unknown since identification of PSR TF targets often examines limited time resolution or relies on overexpression, which obfuscates temporal information.…”

The Difference of Physiological and Proteomic Changes in Maize Leaves Adaptation to Drought, Heat, and Combined Both Stresses

“…The evidence shows that crops exhibit unique physiological and molecular responses to combined stress, which cannot be directly inferred from plant responses to single stresses. Moreover, the simultaneous occurrence of several stresses brings about a complexity of plant responses that are highly controlled by different or opposing signaling pathways (Rollins et al, 2013; Johnson et al, 2014; Suzuki et al, 2014). …”

“…Thus, to meet food demand, it is necessary to develop crops with elevated endurance to drought, heat stress, and their combination. Some studies have looked specifically at the effects of drought, heat stress, and their combination on barley (Rollins et al, 2013; Ashoub et al, 2015), wheat (Rampino et al, 2012; Liu et al, 2015), Sorghum bicolor (Johnson et al, 2014), and maize (Hu et al, 2010, 2015). However, the functions of many proteins involved in crop responses to combined drought and heat stress remain unclear.…”

Proteome and Transcriptome Reveal Involvement of Heat Shock Proteins and Indoleacetic Acid Metabolism Process in Lentinula Edodes Thermotolerance

“…According to our results, it was documented that the expression of the HSF_DNA-bind gene was obviously downregulated in the thermotolerant strain S606 after heat stress, which indicated that L. edodes tolerance to heat stress could be negatively controlled by HSF_DNA-bind. Besides, many genes encoding other transcription factors including in bHLH, Myb and C 2 H 2 (Zinc finger family protein) regulated significantly in plant after heat stress [67,68], were among the up-or down-regulated (Table S5). Additionally, the gene expression and protein levels of the BAG gene were dramatically induced and upregulated.…”