Research On Sporangia Development And Phenylpropane Synthesis Pathway

Liverwort,as an early terrestrial plant,has important value in the study of a series of physiological processes from aquatic to terrestrial.Marchantia polymorpha,as a liverwort plant that has completed the whole genome sequencing,has gradually developed into a new model plant.In this paper,the laboratory culture conditions,the induction of reproductive development,and the establishment of a transgenic system were explored.We explored the vegetative propagation system of M.polymorpha and realized that under laboratory conditions,using gemma asexual propagation and subculture and culturing at about 22 ? can ensure the M.polymorpha will grow at the fastest rate.At the same time,an induction system of genitalia was established.In this system,it has been realized that when the mature thallus is illuminated by a fluorescent lamp,supplementary illumination of 20-30 lux far-red light can induce the formation of sexual reproductive organs,which is the genitalia,in about two weeks.By dropping water on the antheridiophore to separate the sperm,the swimming sperm can be observed on the made slide with a microscope.The archegonia in the archegoniophore can be visualized by tissue clearing.The structure of archegonia can be observed under confocal by washing off chlorophyll and other substances with a transparent agent and co-staining with Calcofluor white(CW),a dye-labeled with cellulose substances,and Basic fuchsin(BF),a dye that is labeled with lignin sporopollenin,and the archegonium can be observed under confocal.The liquid and solid transgenic methods to carry out the transgenic transformation of different tissues of M.polymorpha is referred to in this paper.And a simple and feasible laboratory transgenic system has been improved.In the process of M.polymorpha transgenic,we found that the transformation efficiency of the GWB series vector combined with Agrobacterium competent GV2260 was higher.Finally,a fluorescent protein system suitable for M.polymorpha has also been constructed.In this system,it was found that the expression of Venus,m T2,m Cherry,and RFP in fluorescent protein was stronger in M.polymorpha.As a result,this system should be more suitable for cytological observation of gene expression in M.polymorpha.As early as the period of algae,phenylpropane synthesis pathway began to appear.Phenylpropane has the functions of providing mechanical strength for cell walls,helping plants respond to abiotic stress,increasing flower color diversity,and absorbing ultraviolet light in higher plants.For lower plants,taking the moss Physcomitrium patens as an example,this pathway can resist environmental factors such as ultraviolet rays.There are homologous genes of this pathway in the liverwort M.polymorpha.However,the function of this pathway has not been studied in M.polymorpha.In this paper,the synthesis process of phenylpropane in early terrestrial plants was studied.By observing the expression of phenylpropane synthesis pathway genes such as PAL,C4 H,4CL,and CHS in M.polymorpha.We explore the stress resistance mechanism of early terrestrial plants taking M.polymorpha as an example.This paper verifies whether the protective effect of phenylpropane on terrestrial plants is conservative.The results showed that the gene CCR of lignin synthesis pathway was rarely expressed in the thallus,and the precursor of the flavonoid and lignin synthesis genes 4CL,as well as the flavonoid synthesis pathway genes CHS and CHI,were widely expressed in the thallus and gemma,suggesting that flavonoids in phenylpropanes play a broader role than lignin.The overexpression of CHS and CHI in M.polymorpha leads to a faster growth rate of gemma in the initial stage,more extended thallus,the earlier appearance of gemma cups,and affected branch growth.To a certain extent,it shows that flavonoids have an impact on the nutritional growth of M.polymorpha.