Proteomic analysis of heterotic seed germination in maize using F1 hybrid DHM 117 and its parental inbreds

Abstract

A number of differentially expressed proteins (DEPs) were identified in comparative two-dimensional gel electrophoresisanalysis of dry and 24-h water-imbibed seeds of maize F1 hybrid DHM 117 (BML 6 × BML 7) and its parental inbreds. Of the DEPs,53.4% (86/161) in dry seeds and 58% (127/219) in water-imbibed seeds exhibited a nonadditive pattern in the $F_1$ hybrid as comparedto parental inbreds. A total of 30 DEPs were categorized into different biological processes, most of which were related to metabolismand energy (34%), followed by storage proteins (27%), stress response (23%), transcription and translation (7%), cell cycle (3%), andhormone biosynthesis (3%). The transcript accumulation pattern of 8 selected genes corresponding to DEPs was examined using qRTPCR. Interestingly, LEA protein Rab28 showed higher accumulation in dry seeds at both protein and transcript levels, whereas indole3-acetaldehyde oxidase showed lower accumulation in water-imbibed seeds of the F1 hybrid than the female parent at the protein level.Thus, the DEPs particularly involved in metabolic and energy processes, as well as hormone biosynthesis in the $F_1$ hybrid, might beresponsible for heterotic seed germination in the $F_1$ hybrid. The DEPs identified in this study provide a scope for improving the seedgermination trait of agricultural crops.