Biochemical Analyses of Sorghum Varieties Reveal Differential Responses to Drought

Abstract

We have examined the biochemical responses of two sorghum cultivars of differing drought tolerance, Samsorg 17 (more drought tolerant) and Samsorg 40 (less drought tolerant), to sustained drought. Plants were exposed to different degrees of drought and then maintained at that level for five days. Responses were examined in terms of metabolic changes and the expression of drought induced proteins—Heat Shock Proteins (HSPs) and dehydrins (DHNs). Generalised phenotypic changes were studied using Fourier transform infrared (FT-IR) Spectroscopy and non-targeted Gas Chromatography Mass Spectrometry (GC-MS) was employed to detect changes in metabolites, while changes in protein expression were examined using Western blot analysis. Different response profiles of metabolites, HSPs and DHNs were observed in the two cultivars. Metabolic changes involved variation in amino acids, polysaccharides and their derivatives. A total of 188 compounds, with 142 known metabolites and 46 unknown small molecules, were detected in the two sorghum varieties. Under water deficit conditions, Samsorg 17 accumulated sugars and sugar alcohols, while in Samsorg 40 amino acids increased in concentration. This study suggest that the two Sorghum varieties adopt distinct approaches in response to drought, with Samsorg 17 being better able to maintain leaf function under severe drought conditions.

Transcriptome sequencing of okra (Abelmoschus esculentus L. Moench) uncovers differently expressed genes responding to drought stress

“…Studies have shown that drought-stress induce a series of physiological and morphological changes in plants, for example: growth inhibition and reduction in crop yields (Elagib 2014), enhancement of root systems and root-shoot ratios (Lu et al 2014), regulation of the closure of stomata (Wan et al 2009), disruption of photosynthesis (Zivcak et al 2013), activation of respiration (Sperlich et al 2016), accumulating compatible solutes and protective proteins (Ogbaga et al 2016;Sperdouli and Moustakas 2012), and the strengthening of anti-oxygenic enzyme activity (Bhaskara et al 2015;Hu et al 2015). These changes are controlled by gene expression, which is particularly affected by biotic and abiotic factors in the environment.…”

Transcriptome analysis of the tea oil camellia (Camellia oleifera) reveals candidate drought stress genes

“…In reality, plants developed a myriad of mechanisms to adapt or survive when exposed to drought stress, which could involve a series of molecular, biochemical, physiological, and morphological changes underlying the response of plants to water deprivation[ 13 ]. These strategies include reductions in growth rates and crop yields[ 14 ], enhancing root systems and root-shoot ratios to imbibe moisture[ 15 ], regulating the closure of stomata[ 16 ], disrupting photosynthetic pigments[ 17 ], activating respiration[ 18 ], accumulating compatible solutes and protective proteins[ 19 , 20 ], and increasing the level of antioxidants[ 21 , 22 ]. At the molecular level, the aforementioned changes will activate a range of responses, and most notably in drought-related genes that induce or inhibit gene expression.…”

Metabolomics: A Way Forward for Crop Improvement

“…With recent integrated applications of MS approaches, metabolomics has emerged as a more versatile strategy than genomics and proteomics. Indeed, metabolic profiling of various crops, such as wheat, rice, maize, sorghum, and soybean, showed remarkable applications of metabolomics in plant biology [4,[41][42][43][44].…”