Effect Of DA-6 On Sugarcane Plant Tillering And Its Mechanism

Tillering is a special agronomic trait for gramineous crop growth and development,it's occurring contains two stages:the formation of an axillary bud and it's elongation growth.The fist stage commonly isn't influenced by external factor,but multiple factors can affect it's subsequent growth.Plant hormone is one of the important factor for regulating the growth of axillary bud.Sugarcane(Saccharum officinarum),which is also belonging to the grass family,possesses the characteristic of tillering.However,as the main cultivar of sugarcane production area,ROC22 has a poor tillering ability.Given this situation,studying the molecular mechanism of plant growth regulator effecting sugarcane tillering,has a significant meaning for reasonably controlling sugarcane tillering in production management practice.In this study,the change of plant endogenous hormone and average tillering rate were counted through different concentrations of Nitrogen,DA-6 and 6-BA conducting sugarcane tissue culture seedling.on this basis,by high flux RNA sequencing researching a part of tissue culture seedling experiment material,sugarcane seeding gene function was studied at integral level.Morever,a kind of sugarcane tillering gene ScTB1 was cloned in present experiment,which was good for further studying the molecular mechanism of sugarcane tillering.The main results and conclusions are as follows:1.In the results of twentieth day treated samples,the average tillering rate of blank group is 1.1333,but the tiller number of samples which were treated by DA-6 increase obviously,and it's ideal concentration is 10mg/L,improving 1.53 times above the effect of blank group.2 mg/L is the ideal concentration of 6-BA.Howevevr,Nitrogen exerts an bad influence on sugarcane seedling tillering.What's more,the enhanced tillering of sugarcane seedling was accompanied by reduced plant height.2.During the earlier stage of treatment,the three factors's effects on improving the endogenous CTK content and promoting sugarcane seedling tillering were not obvious.During the middle stage,the endogenous CTK content of samples of treatment groups rose gradually,thereby promoting the occurrence of plant.Combining the hormone information and the average tillering rate of sugarcane,the average tillering rate care fell behind the hormone change.Namely,the endogenous hormone changed firstly,then the tillering number altered.On the whole,these results indicated that CTK maybe the key factor regulating the the formation of tillering bud.3.A part of treatment groups were used to analyze transcriptome by RNA-Seq.In total,170.93Gb date and 164,113 Unigenes were generated from 18 sugarcane samples.Comparing unigenes with a series of databases,99,247 unigenes with bioinformatics annotation were found,which involved cellular component,molecular function and biological process..Furthermore,this experiment result were compared with tillering relevant genes of other species in NCBI.A range of tillering relevant genes in sugarcane were mined,contributing to further study the molecular mechanism of sugarcane tillering.In this study,64,966 unigenes were not annotated with definite information.4.Combining RNA-Seq results and NCBI database,a kind of tillering related gene ScTB1(GeneBank:KJ865400)was cloned from ROC22.The full-length of cDNA was 1,167bp,encoding 382 AA.Bioinformatics analysis results reveal that the theoretical protein with no signal peptides is unstable,whose secondary structure elements is mostly random roil.Real-time quantitative PCR(qRT-PCR)Analysis showed ScTB1 gene was expressed in different sugarcane species as well as different tissues of same sugarcane species.Also,it's expression was highest in the axillary bud of base,which was 470 times of root,266 times of leaf.All above results were used to primarily analyze the effect of DA-6 on sugarcane plant tillering,and study the expression of sugarcane seedling growth related gene(especially gene relevant sugarcane plant tillering)at whole level by transcriptome RNA-Seq technology,thus digging the tillering relevant genes in sugarcane plant,which could lay a foundation for further studying the molecular mechanism of tillering of sugarcane plant.