Dataset Information

Engineering ?-amylase levels in wheat grain suggests a highly sophisticated level of carbohydrate regulation during development.

ABSTRACT: Wheat starch degradation requires the synergistic action of different amylolytic enzymes. Our spatio-temporal study of wheat ?-amylases throughout grain development shows that AMY3 is the most abundant isoform compared with the other known ?-amylases. Endosperm-specific over-expression of AMY3 resulted in an increase of total ?-amylase activity in harvested grains. Unexpectedly, increased activity did not have a significant impact on starch content or composition but led to an increase of soluble carbohydrate (mainly sucrose) in dry grain. In AMY3 overexpression lines (A3OE), germination was slightly delayed and triacylglycerol (TAG) content was increased in the endosperm of mature grain. Despite increased AMY3 transcript and protein content throughout grain development, alterations of ?-amylase activity and starch granule degradation were not detected until grain maturation, suggesting a post-translational inhibition of ?-amylase activity in the endosperm during the starch filling period. These findings show unexpected effects of a high level of ?-amylase on grain development and composition, notably in carbon partitioning and TAG accumulation, and suggest the presence of a hitherto unknown regulatory pathway during grain filling.

SUBMITTER: Whan A

PROVIDER: S-EPMC4157717 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Engineering α-amylase levels in wheat grain suggests a highly sophisticated level of carbohydrate regulation during development.

Whan Alex A Dielen Anne-Sophie AS Mieog Jos J Bowerman Andrew F AF Robinson Hannah M HM Byrne Keren K Colgrave Michelle M Larkin Philip J PJ Howitt Crispin A CA Morell Matthew K MK Ral Jean-Philippe JP

Journal of experimental botany 20140722 18

Wheat starch degradation requires the synergistic action of different amylolytic enzymes. Our spatio-temporal study of wheat α-amylases throughout grain development shows that AMY3 is the most abundant isoform compared with the other known α-amylases. Endosperm-specific over-expression of AMY3 resulted in an increase of total α-amylase activity in harvested grains. Unexpectedly, increased activity did not have a significant impact on starch content or composition but led to an increase of solubl ...[more]

PMID: 25053646

Similar Datasets

Project description:BACKGROUND:MicroRNAs (miRNAs) play crucial roles in the regulation of plant development and growth, but little information is available concerning their roles during grain development under different nitrogen (N) application levels. Our objective was to identify miRNAs related to the regulation of grain characteristics and the response to different N fertilizer conditions. RESULTS:A total of 79 miRNAs (46 known and 33 novel miRNAs) were identified that showed significant differential expression during grain development under both high nitrogen (HN) and low nitrogen (LN) treatments. The miRNAs that were significantly upregulated early in grain development target genes involved mainly in cell differentiation, auxin-activated signaling, and transcription, which may be associated with grain size; miRNAs abundant in the middle and later stages target genes mainly involved in carbohydrate and nitrogen metabolism, transport, and kinase activity and may be associated with grain filling. Additionally, we identified 50 miRNAs (22 known and 28 novel miRNAs), of which 11, 9, and 39 were differentially expressed between the HN and LN libraries at 7, 17, and 27?days after anthesis (DAA). The miRNAs that were differentially expressed in response to nitrogen conditions target genes involved mainly in carbohydrate and nitrogen metabolism, the defense response, and transport as well as genes that encode ubiquitin ligase. Only one novel miRNA (PC-5p-2614_215) was significantly upregulated in response to LN treatment at all three stages, and 21 miRNAs showed significant differential expression between HN and LN conditions only at 27 DAA. We therefore propose a model for target gene regulation by miRNAs during grain development with N-responsive patterns. CONCLUSIONS:The potential targets of the identified miRNAs are related to various biological processes, such as carbohydrate/nitrogen metabolism, transcription, cellular differentiation, transport, and defense. Our results indicate that miRNA-mediated networks, via posttranscriptional regulation, play crucial roles in grain development and the N response, which determine wheat grain weight and quality. Our study provides useful information for future research of regulatory mechanisms that focus on improving grain yield and quality.

Dataset Information

Engineering ?-amylase levels in wheat grain suggests a highly sophisticated level of carbohydrate regulation during development.

Publications

Engineering α-amylase levels in wheat grain suggests a highly sophisticated level of carbohydrate regulation during development.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets