Identification of Key Proteins and Networks Related to Grain Development in Wheat (Triticum aestivum L.) by Comparative Transcription and Proteomic Analysis of Allelic Variants in TaGW2-6A.

Dengfeng Du,Xin Gao,Qingyan Li,Juan Geng,Liqun Li,Qian Lv,Xuejun Li

doi:10.3389/fpls.2016.00922

Dengfeng Du, Xin Gao + Show 5 more

Open Access

https://doi.org/10.3389/fpls.2016.00922

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Abstract

In wheat, coding region allelic variants of TaGW2-6A are closely associated with grain width and weight, but the genetic mechanisms involved remain unclear. Thus, to obtain insights into the key functions regulated by TaGW2-6A during wheat grain development, we performed transcriptional and proteomic analyses of TaGW2-6A allelic variants. The transcription results showed that the TaGW2-6A allelic variants differed significantly by several orders of magnitude. Each allelic variant of TaGW2-6A reached its first transcription peak at 6 days after anthesis (DAA), but the insertion type TaGW2-6A allelic variant reached its second peak earlier than the normal type, i.e., at 12 DAA rather than 20 DAA. In total, we identified 228 differentially accumulated protein spots representing 138 unique proteins by two-dimensional gel electrophoresis and tandem MALDI-TOF/TOF-MS in these three stages. Based on the results, we found some key proteins that are closely related to wheat grain development. The results of this analysis improve our understanding of the genetic mechanisms related to TaGW2-6A during wheat grain development as well as providing insights into the biological processes involved in seed formation.

Highlights

Wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) is an allohexaploid species and one of the most important and widely cultivated crops throughout the world
The BC6F2 population were derived from a cross between the Chinese winter wheat cultivar Lankaodali (LK, thousand kernel weight (TKW) = 57.49 ± 0.88 g, with the insertion of a T nucleotide base at the 977-bp position in the eighth exon of the TaGW2 allele compared with Chinese Spring) and Chinese Spring (CS, TKW = 27.75 ± 0.62 g), where recurrent backcrossing with the parent CS was performed for six generations, which was accompanied by marker-assisted selection with single nucleotide polymorphisms (SNPs) (Yang et al, 2012) to allow the rapid and efficient recovery of the recurrent parent genome
These results showed that the insertion type allelic variant of TaGW2-6A was closely related to the grain size and kernel weight

Summary

Introduction

Several single nucleotide polymorphisms (SNPs) were found in its promoter region, which have significant associations with the kernel width (KW) and thousand kernel weight (TKW; Su et al, 2011; Zhang et al, 2013; Jaiswal et al, 2015). Further transcription analysis has shown that TaGW26A is negatively associated with grain width (Yang et al, 2012; Hong et al, 2014; Jaiswal et al, 2015). A single-base insertion in the eighth exon of TaGW2-6A causes premature termination in a large-kernel variety (Lankaodali), which leads to increases in the grain width and weight (Yang et al, 2012)

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