Applying Differential Proteomics To Study The Weed-inhibition Of Rice Allelopathy Under Drought-stressed

Allelopathy denotes as a chemical-ecology phenomenon which means that living plants (donor) released some chemical substances into the environment to affect the growth and development of receptors through volatilization, leaching, root exudation, and plant residual decomposition. Using allelopathy to control field weeds is considered as a key technique for sustainable agriculture in the 21st century, and the mechanism of plant allelopathy has become one of the hot spots in plant biology research recently. Rice allelopathy and its regulation mechanism is an important field in plant allelopathy.A sensitive response of allelopathic rice to the drought-stressed was found in the previous study, the increasing of rice allelopathic potential, accompanying with sharply decreasing of rice production were found under drought-stress condition. Consequently, it is necessary to study the molecular mechanism of the increasing allelopathy effect under drought-stressed, which can promote rice breeding on higher resistance for drought stressed, the suppression of weed, characteristic of high-yielding and high-quality. Therefore, in this paper, the differential proteomics method was employed to clarify the response characteristics of allelopathic rice (PI312777) and non-allelopathic rice (Lemont) under drought stressed condition. Furthermore, the results were testified by fluorescence quantitative PCR (FQ-PCR) at the level of RNA expression. The results were mainly showed as follows:(1) Under drought-stressed condition, the allelopathic rice PI312777 and non-allelopathy rice Lemont showed significantly higher weed suppress effect than non drought-stressed treatment in the field. Simulatantly, allelopathy rice revealed a higher inhibition rate in weed biomass than non-allelopathic rice.(2) There were 23 proteins expressed differently between the roots of allelopathic rice PI312777 and non-allelopathic rice Lemont under drought-streesed determined by differential proteomics analysis, and 22 proteins in roots were identified by MALDI-TOF-TOF MS and database searching.These proteins involved in ATP synthase , heat shock protein 70, histidine kinase, glutathione S-transferase , hydroxycinnamoyl CoA transferase-like which were related to energy metabolism, stress-resistance and allelopathic and so on. (3) There were 24 proteins expressed differently in the leaves of allelopathic rice PI312777 and non-allelopathic rice Lemont under drought-streesed,determined by differential proteomics analysis. While 19 proteins in leaves were identified by MALDI-TOF-TOF MS and database searching. These proteins were mainly ribulose bisphosphate carboxylase/oxygenase activase, glycine hydroxymethyl transferase, cytochrome P450 monoxygenase, chalcone and stilbene synthases related to energy metabolism, stress-resistance and allelopathic and so on.(4) FQ-PCR technology was used to analyze the allelopathy related gene expression. The result showed that Chalcone and stilbene synthases and hydroxycinnamoyl transferase expressed increasingly in allelopathy rice but decreasingly in non-allelopathy, and it was in accordance with the result of protein expression.