A Preliminary Study Of Rice Zinc Finger Protein Gene OsLSD1.1 On Rice Growth Regulation

In flooding paddy there is a little dissolved oxygen in rice rhizosphere environment.Oxygen from rice shoot would be transported by aerenchyma to root under waterlogged condition,then secreted into the rhizosphere.Therefore the formation and development of aerenchyma is a key process for rice growth.In the study a zinc finger protein gene OsLSD1.1 was used to study the relationship between aerenchyma formation and nitrogen use in rice.The main results obtained are as follows:1.Through the planar optodes techniques monitoring plant roots secrete oxygen conditions in situ,I found that root aerenchyma formation of oslsdl.1 mutant was inhibited and the rice growth and root development was reduced compared with wild type(WT).As a result the mutant showed a significant reduction of oxygen secreted from roots..Here we could make a conclusion that OsLSD1.1 is involved in regulation of the formation of rice roots aerenchyma and controls root secretion oxygen under anaerobic environmental conditions?2.In the field experiment,I found oslsd1.1 mutant appears leaf yellow at heading stage,and then I sampled the leaves of rice plants for observing chloroplast structure characteristic by TEM.Mutant chloroplast structure is undeveloped and loosely arranged.As well as,I detected gene expression in the cell through expression OsLSD1.1 protein and GFP fusion in the tobacco leaves.The results showed OsLSD1.1 expression in the nucleus,cell membrane and chloroplasts.The website(http://www.string-db.org)forecasted that zinc finger protein OsLSD1.1 might interact with chloroplast precursor,iron-sulfur protein.In a conclusion we can predict that OsLSD1.1 may be involved in chlorophyll synthesis metabolic pathways.3.The statistical analysis of agronomic traits,biomass,total N content showed that OsLSD1..deletion reduced the rice growth,yellowed leaf color,shortened plant height and increased tillering.The pollen fertility of oslsd1.1 mutant was poor.Statistical analysis of other agronomic traits showed significant differences between the mutant and WT.After calculating the proportion of total nitrogen distribution in various parts at maturity,we found that nitrogen accumulation in mutant grains is reduced,while the accumulation in stem and sheath is increased,compared with WT.4.Through the hydroponic experiment,I found that oslsdl.1 was not responsing to the ethylene,but to aeration treatment.,however the aeration treatment could affect the synthesis of ethylene in rice plants.Between oslsdl.l mutant and Dongjin WT,there is no significant differences in ethylene level,while the aeration and nitrogen treatments have significant interaction relations on ethylene content.In another words,the effect of different nitrogen treatments on ethylene synthesis depended on whether there is enough oxygen or not and this effect is independent of the mutant and WT difference.