Abstract:

【Objective】 The purpose of this project was to study the early pollen-silk interaction in maize through proteomic analysis. 【Method】 Inbred line Ga25 was pollinated and total silk proteins were extracted after 1 h and 2 h pollination. Total proteins were extracted by TCA/acetone, separated by two-dimensional gel electrophoresis (2-DE) and analysed through MALDI-TOF-MS mass spectrometry. 【Result】 Compared with the pollen/silk proteome after 1 h pollination, the proteome after 2 h pollination contained 28 differentially expressed proteins, including 6 specifically expressed ones, 19 up-regulated and 3 down-regulated ones. And 23 of them were identified homologous to known proteins in various databases by MALDI-TOF-MS and MASCOT analysis. The predicted functions of the 23 proteins were related to cell wall biosynthesis (21.4%), defense/stress responses (17.9%), cellular organization, protein fate, protein synthesis and transcription. 【Conclusion】 The pollen/silk proteome profiles were different between the 1 h and 2 h pollination intervals. The majority of differentially expressed proteins were up-regulated; down-regulated and speciafically expressed proteins were also found in the 2 h pollination proteome profile. Secretory peroxidase, expansin, pectin methylesterase inhibitor, glutathione S-transferase and unknown protein 4 may play important roles in early pollen-silk interactions in maize.

Key words: maize (Zea mays L.), proteome profile, early pollen-silk interaction, 2-DE, MALDI-TOF-MS