From metabolome to phenotype: GC-MS metabolomics of developing mutant barley seeds reveals effects of growth, temperature and genotype

Abstract

The development of crop varieties tolerant to growth temperature fluctuations and improved nutritional value is crucial due to climate change and global population growth. This study investigated the metabolite patterns of developing barley seed as a function of genotype and growth temperature for ideal vegetable protein production and for augmented β-glucan production. Seeds from three barley lines (Bomi, lys3.a and lys5.f) were sampled eight times during grain filling and analysed for metabolites using gas chromatography-mass spectrometry (GC-MS). The lys3.a mutation disrupts a regulator gene, causing an increase in proteins rich in the essential amino acid lysine, while lys5.f carries a mutation in an ADP-glucose transporter gene leading to a significant increase in production of mixed-linkage β-glucan at the expense of α-glucan. Unique metabolic patterns associated with the tricarboxylic acid cycle, shikimate-phenylpropanoid pathway, mevalonate, lipid and carbohydrate metabolism were observed for the barley mutants, whereas growth temperature primarily affected shikimate-phenylpropanoid and lipid metabolism. The study applied recently developed GC-MS metabolomics methods and demonstrated their successful application to link genetic and environmental factors with the seed phenotype of unique and agro-economically important barley models for optimal vegetable protein and dietary fibre production.

Proteome and Nutritional Shifts Observed in Hordein Double-Mutant Barley Lines

“…, C-hordein-mutant line ( Figure 1 ). In this barley lys3 mutant, three intermediates of lipid metabolism, including 2-hydroxyheptanoate, 9,10-dihydroxy-octadecanoic acid methyl ester and dimethyl ester of threo-9,10-dihydroxy-octadecanedioic acid, were found to be more abundant ( Khakimov et al, 2017 ). This mutant may use excess lysine to convert to acetyl-CoA and thus provide more precursors for fatty acid synthesis leading to increased abundance of FA and TAG.…”

Temporal Control of Seed Development in Dicots: Molecular Bases, Ecological Impact and Possible Evolutionary Ramifications

“…First, analogs of the heterochronic pathway controlling meristem initiation found in monocots suggest that the comparative approach could be exploited to elucidate the actual mechanisms underlying seed temporal plasticity. Because of the definitive differences between monocots and dicots regarding both their seed development [256,257] and the peculiarities of their vegetative heterochronic pathways [258], we deliberately restrained ourselves from drawing any examples from monocot species in this review; however, several reports indicate that processes denoted here as type I temporal alterations may arise in cereals to adjust their seed developmental timing to heat [259][260][261][262][263][264][265][266], moderate cold [267], drought [268], and mycorrhiza formation [269]. Second, these mechanisms may control a multitude of processes and act through numerous mediating components, which raises the necessity for large-scale gene expression studies involving the techniques of modern transcriptomics and proteomics.…”

The unreasonable effectiveness of near infrared spectroscopy explained. Introducing the era of NIRS integrated functional fingerprinting

“…The question is now: how can soft modelling in real life itself supply a base for a theorem/reference? The regularities in compositional chemical and NIRS fingerprints from ripe (Figures 2, 3A, B, 4B) and developing seeds 5,15 indeed reflect a decision interface of the coordinated organism that can serve as provisional theorem/reference in real time. The key point is to advance back from Albert Einstein's deterministic standpoint in macro cosmos that "God does not play dice" to the fluctuating probabilistic/stochastic quantum reality in micro cosmos that has to be extremely fast and coordinative to support Life.…”