Abstract
Pre-harvest sprouting (PHS) is a worldwide problem for wheat production and transgene antisense-thioredoxin-s (anti-trx-s) facilitates outstanding resistance. To understand the molecular details of PHS resistance, we analyzed the metabonomes of the transgenic and wild-type (control) wheat seeds at various stages using NMR and GC-FID/MS. 60 metabolites were dominant in these seeds including sugars, organic acids, amino acids, choline metabolites and fatty acids. At day-20 post-anthesis, only malate level in transgenic wheat differed significantly from that in controls whereas at day-30 post-anthesis, levels of amino acids and sucrose were significantly different between these two groups. For mature seeds, most metabolites in glycolysis, TCA cycle, choline metabolism, biosynthesis of proteins, nucleotides and fatty acids had significantly lower levels in transgenic seeds than in controls. After 30-days post-harvest ripening, most metabolites in transgenic seeds had higher levels than in controls including amino acids, sugars, organic acids, fatty acids, choline metabolites and NAD+. These indicated that anti-trx-s lowered overall metabolic activities of mature seeds eliminating pre-harvest sprouting potential. Post-harvest ripening reactivated the metabolic activities of transgenic seeds to restore their germination vigor. These findings provided essential molecular phenomic information for PHS resistance of anti-trx-s and a credible strategy for future developing PHS resistant crops.
Highlights
Pre-harvest sprouting is a complex phenotype resulting from interactions between wheat genotypes[2] with biotic and/or abiotic environmental factors[3]
Our results showed that this anti-trx-s transgenic wheat seeds had lower trx-h expression and α -amylase activity but higher Pre-harvest sprouting (PHS) resistance compared with the corresponding wild-type wheat seeds as reported previously[13,14,15]
This was highlighted by up-regulation of protein disulfide isomerase (PDI), serpin, xylanase inhibitor protein I precursor (XIP-I) but down-regulation of glucose-6-phosphate isomeraseprecursor (GPI), aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoenolpyruvate carboxylase (PEPC), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), pullulanase, aspartate aminotransferase (AST), adenylylsulfate kinase (APK), α - and β -amylase[19]
Summary
Pre-harvest sprouting is a complex phenotype resulting from interactions between wheat genotypes[2] with biotic and/or abiotic environmental factors[3]. It was reported that anti-trx-s inhibited the endogenous trx-h expression and lowered α -amylase activity between day-30 post anthesis and 10 days post-harvest ripening resulting in high PHS resistance in the transgenic wheat[13,14,15]. Transgenic wheat showed differential gene expression in trx-h, serpin, heat shock protein 70 (hsp70), and WRKY transcription factor 6 (WRKY6) compared to wild-type[19]. These results imply that anti-trx-s gene may induce comprehensive metabolic changes in the transgenic wheat seeds. It remains unknown what metabolic changes such transgene causes, at which seed development stages and how these transgenic effects on seed metabolic activities are related to PHS
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
