Quantitative analysis of the grain amyloplast proteome reveals differences in metabolism between two wheat cultivars at two stages of grain development

Dongyun Ma,Dongyun Ma,Gege Hou,Gege Hou,Tiancai Guo,Xin Huang,Xin Huang,Chenyang Wang,Chenyang Wang,Ying Ma,Ying Ma,Junfeng Hou,Junfeng Hou,Qiaoxia Han

doi:10.1186/s12864-018-5174-z

Abstract

BackgroundWheat (Triticum aestivum L.) is one of the world’s most important grain crops. The amyloplast, a specialized organelle, is the major site for starch synthesis and storage in wheat grain. Understanding the metabolism in amyloplast during grain development in wheat cultivars with different quality traits will provide useful information for potential yield and quality improvement.ResultsTwo wheat cultivars, ZM366 and YM49–198 that differ in kernel hardness and starch characteristics, were used to examine the metabolic changes in amyloplasts at 10 and 15 days after anthesis (DAA) using label-free-based proteome analysis. We identified 523 differentially expressed proteins (DEPs) between 10 DAA and 15 DAA, and 229 DEPs between ZM366 and YM49–198. These DEPs mainly participate in eight biochemical processes: carbohydrate metabolism, nitrogen metabolism, stress/defense, transport, energetics-related, signal transduction, protein synthesis/assembly/degradation, and nucleic acid-related processes. Among these proteins, the DEPs showing higher expression levels at 10 DAA are mainly involved in carbohydrate metabolism, stress/defense, and nucleic acid related processes, whereas DEPs with higher expression levels at 15 DAA are mainly carbohydrate metabolism, energetics-related, and transport-related proteins. Among the DEPs between the two cultivars, ZM366 had more up-regulated proteins than YM49–198, and these are mainly involved in carbohydrate metabolism, nucleic acid-related processes, and transport.ConclusionsThe results of our study indicate that wheat grain amyloplast has the broad metabolic capability. The DEPs involved in carbohydrate metabolism, nucleic acids, stress/defense, and transport processes, with grain development and cultivar differences, are possibly responsible for different grain characteristics, especially with respect to yield and quality-related traits.

Highlights

IntroductionThe amyloplast, a specialized organelle, is the major site for starch synthesis and storage in wheat grain
Wheat (Triticum aestivum L.) is one of the world’s most important grain crops
The starch particle distribution in the grain at 10 days after anthesis (DAA) and 15 DAA is shown in Fig. 1, and it is clear that the volume distribution peak shifted from 15.65–17.18 μm at 10 DAA to 18.86–20.71 μm at 15 DAA

Summary

Introduction

The amyloplast, a specialized organelle, is the major site for starch synthesis and storage in wheat grain. Amyloplasts are a specialized type of leucoplast that serves as the major site of synthesis and long-term storage of starch in the endosperm [10]. The results of proteomics studies showed that amyloplasts play a central role in endosperm metabolism, and that the amyloplast may possess a regulatory mechanism that mediates the effect of interaction between genes and environment on protein and starch production [22]. Some important factors (timing, duration, and rate of grain filling) that determine the final protein yield are largely controlled by the amyloplasts present in the endosperm [21]. Amyloplasts play a role in kernel hardness, and lipids associated with the starch granule surface mainly originate from the amyloplast bilayer lipid membrane which is degraded during seed desiccation [23]

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Discussion

Conclusion