Indica And Japonica Rice Heterosis Proteomics Research

Rice, which is widely cultivated in China, plays important roles in the agricultural production. Besides, it is a model plant for genome study. Great successes have been made in structural genomics, which would drive the life science forward unprecedentedly. In the post-genomic era, proteomics is becoming a hotspot. It concerns about both the dynamic expression and the interaction of proteins.The heterosis of hybird between subspecies in leaf photosynthetic rate, relative content of chlorophyll and photosynthetic photochemical activity (chlorophyll fluorescence) of 93-11 (Oryza sativa L. ssp indica), Nippon bare (Oryza sativa L. ssp japonica) and F1 generation of their reciprocal cross were investigated. Classical proteomics approaches including high resolution two-dimensional electrophoresis (2-DE), matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and bioinformatics techniques were used in this study.Comparative proteomics of the rice leaves at tillering stage were studied using this strategy, in order to identify some proteins closely related to heterosis of hybrid between subspecies. It would benefit to both production and theory.Proteome maps were constructed for the rice leaves at tillering stage. Totally, 42 different expressing proteins were analyzed through MALDI-TOF-MS and database searching. Among them, 22 proteins were identified. Most of these identified proteins were involved in photosynthetic metabolism and energy production.Among those proteins accumulated in F1 generation, the expression of the photosynthesis- and energy production-associated proteins, such as ATPase beta subunit, ribulose-1,5-bisphosphate carboxylase large subunit, ATP synthase subunit gamma, chloroplast precursor, chlorophyll a/b-binding protein CP26 precursor-maize, were significantly higher than those in their parents, which indicated a higher photosynthetic activities in these hybrid rice.Meanwhile, antiviral protein S (PAP-S) showed relatively greater abundance in the F1 generation. It could be deduced that the hybrid rice between subspecies had relatively higher resistance to some diseases than their parents.We applied proteome method to study the proteins expression pattern of the rice leaves of different species and the F1 generation of their reciprocal cross. Valuable information of some proteins was acquired. This would contribute to the understanding of the growth and function of hybrid rice between different subspecies, and the heterosis of hybrid rice between subspecies.