Molecular responses of genetically modified maize to abiotic stresses as determined through proteomic and metabolomic analyses

Abstract

Some genetically modified (GM) plants have transgenes that confer tolerance to abiotic stressors. Meanwhile, other transgenes may interact with abiotic stressors, causing pleiotropic effects that will affect the plant physiology. Thus, physiological alteration might have an impact on the product safety. However, routine risk assessment (RA) analyses do not evaluate the response of GM plants exposed to different environmental conditions. Therefore, we here present a proteome profile of herbicide-tolerant maize, including the levels of phytohormones and related compounds, compared to its near-isogenic non-GM variety under drought and herbicide stresses. Twenty differentially abundant proteins were detected between GM and non-GM hybrids under different water deficiency conditions and herbicide sprays. Pathway enrichment analysis showed that most of these proteins are assigned to energetic/carbohydrate metabolic processes. Among phytohormones and related compounds, different levels of ABA, CA, JA, MeJA and SA were detected in the maize varieties and stress conditions analysed. In pathway and proteome analyses, environment was found to be the major source of variation followed by the genetic transformation factor. Nonetheless, differences were detected in the levels of JA, MeJA and CA and in the abundance of 11 proteins when comparing the GM plant and its non-GM near-isogenic variety under the same environmental conditions. Thus, these findings do support molecular studies in GM plants Risk Assessment analyses.

Evaluating maize phenotypic variance, heritability, and yield relationships at multiple biological scales across agronomically relevant environments

“…Most of the metabolites, however, show a relatively low repeatability, with the mean of 0.11. Metabolites are well known for their sensitivity to environment (Asiago et al, ; Baniasadi et al, ; Benevenuto et al, ; Sun, Gao, Li, Fu, & Zhang, ; Sun, Li, et al, 2016b; Tang et al, ). Nevertheless, there is still substantial amount of genetic variation for some of metabolites observed in this and other studies, including high levels of genetic control of trans ‐chlorogenic acid and galactinol (Andrew, Wallis, Harwood, Henson, & Foley, ) (Table ).…”

“…There have been some analyses that explore a maize plant's response to specific environmental conditions such as salinity, heat, and drought (Sun, Li, et al, 2016b;Witt et al, 2012), nitrogen (Amiour et al, 2012;Brusamarello-Santos et al, 2017;Simons et al, 2014) and low phosphorus (Ganie et al, 2015) by monitoring the relationships of these environmental factors to those of metabolites and transcripts. Further examinations have begun to characterize the breadth of diversity of various inbreds and hybrids across typical agronomic environments particularly emphasizing these effectors on grain and forage composition (Asiago, Hazebroek, Harp, & Zhong, 2012;Baniasadi, Vlahakis, Hazebroek, Zhong, & Asiago, 2014;Benevenuto et al, 2017;Hall et al, 2016;Tang et al, 2017;Venkatesh et al, 2016). There have also been several "omic" analyses to understand the relationship of transcripts and metabolites to critical phenotypic traits including: yield (Asiago et al, 2012;Hazebroek, Janni, & Lightner, 2012;Wang, Xue, & Wang, 2014;Xu, Xu, & Xu, 2017), dry matter accumulation (Westhues et al, 2017), and silking (Yesbergenova-Cuny et al, 2016).…”

Stacked genetically modified soybean harboring herbicide resistance and insecticide rCry1Ac shows strong defense and redox homeostasis disturbance after glyphosate-based herbicide application

“…Jasmonic acid derives from fatty acid biosynthesis and increased levels have been also observed after GBH and drought stress application in NK603 herbicide resistant GM maize [20]. GBH was also shown to affect other hormones, such as ethylene [39] and abscisic acid [12].…”

Crop metabolomics: from diagnostics to assisted breeding

“…Metabolomic analyses have been recognized as a valuable tool in risk assessment of genetically modified plants (Harrigan et al 2016). Recently, Benevenuto et al (2017) challenged the presumption of molecular stability of commercially approved GM maize cultivars through a proteomic and metabolomic approach under different environmental conditions.…”