The Microbial Characteristics Analysis Of Rice Rhizosphere Soil Under Nitrogen Regulation

Nitrogen is very important for the growth of rice and the effective regulation of nitrogenfertilizer can improve the yield of rice. Along with more and more large-spike and high-yieldingrice cultivar were bred and planted, the traditional regulation of nitrogen can't certify the yield ofthis rice. The regulation of nitrogen fertilizer that was moved to late period was demonstrated tobe suit for the development of high-yielding of these rice cultivars. But these research works thatwere done to explore the different physiological functions, e.g., the NUE (nitrogen useefficiency).The aim of this study is to unveil the characteristics of microbial of rhizosphere underdifferent nitrogen regulation. For this aim a large-spike rice cultivar "Jinhui809'(indica) was usedin this study, and physiological function upland, activity of soil enzyme, structure of microbialcommunity, the correlation between soil enzyme and microbial community and difference ofmicrobial function were researched under two different regulation of nitrogen. The one regulationwas the traditional regulation of nitrogen fertilizer, basal fertilizer was applied heavily in thismethod, and the ratio of basal fertilizer to tiller fertilizer to panicle fertilizer was6:3:1, toabbreviate for NT. In the other one the nitrogen fertilizer was moved lately, and the ratio of basalfertilizer to tiller fertilizer to panicle fertilizer to grain fertilizer was5:1:3:1, to abbreviate for NP.Hereby this study focus on the community and diversity of rhizosphere microbial and differenceof microbial function under two different regulation of nitrogen fertilizer by modern molecularmethod terminal restrain fragment length polymorphism (T-RFLP) and metaproteomics, The mainresults were summarized as follows:(1) the results of physiological functions upland showed that the NP regulation wasadvantageous for the improvement of yield of rice cultivar Jinhui. The chlorophyll SPAD values,the leaf area index, the effective spike rate and grain yield and yield components of rice wereimproved under this regulation. The activity of soil urinary enzyme and invertase under NPregulation were higher than NT in the same period.(2) the results of T-RFLP showed that there was different diversity of rhizosphere microbialunder two different regulation. the diversity of microorganisms under NP regulation was higherthan that under NT regulation. The number of microbial species of NP regulation was175and117in booting stage and gain-filling period, whereas the number was84and1970f NT regulation.These species belong to129species. For all of these, Butyrivibrio, Frankia, Rhizobium,Paenibacillus ect.12species were present in four treatments, accounting for8%of the totalidentified species. Leptospira, Streptomyces, Planctomyces ect.18species were present in threetreatment when Clavibacter, Brevibacterium ect27species were only present in two treatment.The others were special species of every treatment. Those were indicated that the impact ofnitrogen fertilizer on the rhizosphere microbial is high complicated. The result of correlationanalysis between T—RFLP and soil enzyme showed that the activity of urinary enzyme andinvertase were improved under NP regulation, but they were exhibited in different styles. Forinvertase, the species of positive correlation were increased especially in grain-filling period. For urinary enzyme, the species of negative correlation were decreased under NP regulation,especially in the grain-filling period too.(3) Four different maps of Expression shape of soil proteins were set up. Differentialproteomic analysis showed that180proteins were differentially expressed.134proteins weresuccessly identified, they were from soil microorganisms, plants and animals. The functionanalysis of these proteins found that the impact of nitrogen on rhizosphere microbial were affectedby the metabolism of protein and amino, the development and motility of microbial cells, signaltransduction and material transport, C cycle and energy metabolism.All in all, under different regulations NT and NP, the NP regulation was profit for theformation of yield and yield components of rice and the diversity of rice rhizosphere microbialwas improved at booting stage. The correlation analysis showed that the relationship between soilmicroorganisms and soilenzyme was complicated. The activity of urinary enzyme and invertasewere improved by raising the number of species of negative correlation and positive correlation.The metaproteimic analysis showed that proteins in soil were from microorganisms, plants andanimals. And the impact of nitrogen on rhizosphere microbial were affected by the metabolism ofprotein and amino, the development and motility of microbial cells, signal transduction andmaterial transport, C cycle and energy metabolism.