Peer Review #2 of "iTRAQ-based quantitative proteome analysis reveals metabolic changes between a cleistogamous wheat mutant and its wild-type wheat counterpart (v0.2)"

Abstract

Background: Wheat is one of the most important staple crops worldwide. Fusarium head blight severely affects wheat yield and quality. A novel bread wheat mutant, ZK001, characterised as cleistogamic was isolated from a non-cleistogamous variety (YM18) through static magnetic field mutagenesis. Cleistogamy is a promising strategy for controlling Fusarium head blight. However, little is known about the mechanism of cleistogamy in wheat. Methods: We performed a Fusarium head blight resistance test to identify the Fusarium head blight infection rate of ZK001. We also measured the agronomic traits of ZK001 and the starch and total soluble sugar contents of lodicules in YM18 and ZK001. Finally, we performed comparative studies at the proteome level between YM18 and ZK001 based on the proteomic technique of isobaric tags for relative and absolute quantification. Results: The infection rate of ZK001 was lower than that of its wild type and AK58. The abnormal lodicules of ZK001 lost the ability to push the lemma and palea apart during the flowering stage. Proteome analysis showed that the main differentially abundant proteins were related to carbohydrate metabolism, protein transport, and calcium ion binding. These differentially abundant proteins may work together to regulate cellular homeostasis, osmotic pressure and the development of lodicules. This hypothesis is supported by the analysis of starch, soluble sugar content in the lodicules as well as the results of qRT-PCR. Conclusions: Proteomic analysis has provided comprehensive information that should be useful for further research on the lodicule development mechanism in wheat. The ZK001 mutant is optimal for studying flower development in wheat and could be very important for Fusarium head blight resistant projects via conventional crossing.