ChIFN-mediated Auxin Response During Plant Root Development

As one of the most important organs of plants,roots play a decisive role in the growth and development of plants.As an important regulator of plant growth and development,auxin participates in the regulation of root formation and development through synthesis,transport and response.Previous studies have found that chicken interferon(ChIFN)can promote the formation and development of adventitious roots of tobacco(Nicotiana tabacum L.),but the relationship between this effect and auxin has not been elucidated.In this paper,the model plant tobacco and Lotus corniculatus L.were used to study the root development,auxin distribution and molecular regulation mechanism of endogenous(transgenic plants)and exogenously treated wild-type parental plants.The aim of the study was to reveal the modulating effects of ChIFN-? and ChIFN-? on ChIFN-mediated auxin development during plant root development.The main research contents and results are as follows:1.Acquisition,identification and analysis of plants transgenic with ChIFNsThe ChIFN-? gene was genetically transformed into tobacco by Agrobacteriu mediated transformation.The histochemical staining of GUS protein and PCR amplification of the target gene showed that 15 strains of transgenic ChIFN-? gene(TP)were obtained.Molecular detection of T4 tobacco of ? gene and T0 generation of Lotus root showed that the ChIFN-? gene was stably present in the recipient plants.Observation of ChIFN-? TP tobacco seedlings transplanted within 42 days showed that TP tobacco plants were high and many leaves,and the introduction of ChIFN-?gene promoted the growth of recipient tobacco.2.Effect of ChIFN on the development of tobacco and rootsIn vitro hydroponic rooting induction experiments showed that both ChIFN-?and ChIFN-? TP tobacco and ChIFN-? TP were established 6 days earlier,and wereformed 3 days earlier when treated with 800 IU of two exogenous ChIFN.Both tissue culture and soil culture experiments showed that the number of adventitious roots and root length of ChIFN-? TP were higher than that of WT at the same time.The number and root length of WT were 9.09 times,7.06 times and 5.06 times of WT,respectively.And 2.23 times,2.66 times,2.41 times;the root development of the two TP tobacco soil culture seedlings is better than WT,the number of roots is large,the root length is large,and the root activity is high.Studies have shown that both internal and external sources of ChIFN can promote the formation and development of tobacco and roots.3.Transgenic ChIFN-? gene Adventitious roots and changes in protective substancesThe determination of the peroxidase regulating substances peroxidase(POD)and polyphenol oxidase(PPO)showed that compared with WT,exogenous ChIFN-?treatment and ChIFN-? TP plants had higher enzyme content in the same period of development.The POD and PPO activities of TP peaked at 9d and 3d,respectively,which were 141.23% and 141.97%(p<0.01)of WT,respectively.Studies have shown that PPO and POD are involved in the formation and development of adventitious roots.During the development of adventitious root flooding stress,malondialdehyde(MDA)and catalase(CAT)in the endogenous and exogenous ChIFN-? treatment groups showed changes in response and enhanced plant stress tolerance.4.ChIFN-? mediates auxin distribution during adventitious root development of Lotus japonicusThe ELISA enzyme-linked immunosorbent assay showed that the auxin content of the transgenic ChIFN-? gene was higher than that of the WT group at 6d,9d and12d(p<0.01),and the basal stem segment was at the 6th day.At 9d and 12 d,it was higher than WT(p<0.05);the top bud of 800 IU exogenous ChIFN-? treatment group was higher than WT group on the 9th and 12 th day(p<0.05),and the basal stem segment was higher than WT at 12 d.(p<0.05).Studies have shown that the internal and external sources of ChIFN-? mediate the synthesis of auxin in the apical buds of the roots of the genus,and the amount of auxin is rapidly increased and transported to the roots of the roots.5.ChIFN mediates auxin regulation during adventitious root developmentThe transcriptome of the adventitious root development of the transgenic ChIFN-? gene was constructed.The GO and KEGG enrichment analysis revealed that the auxin metabolic pathway is one of the main regulatory pathways.The pathway enriched genes mainly include auxin synthesis genes(family)and auxin.Transport genes,auxin response regulatory genes 3 categories.Within 12 days of adventitious root formation and development,YUCCA,ALDH,amiE,CYP83B1 were involved in the genes involved in auxin synthesis in the apical and basal stems,and the expression of YUCCA in the apical bud was up-regulated most significantly(p<0.01);The vector AUX1 gene and the export vector PIN gene are involved in auxin transport;the auxin-regulated genes mainly include TIR1,ARF,GH3,SAUR and AUX/IAA.Studies have shown that ChIFN-? may regulate the adventitious root development of Lotus japonicus by promoting the transcription of auxin synthesis,transport,response and other related genes.