Effect Of Drought Stress On Glucosinolates Content In Arabidopsis Thaliana

The aim of our work was to analyse the effect of drought stress on the composition and content of glucosinolate in Arabidopsis thaliana.We investigated the suitable intensity of drought stress on Arabidopsis thaliana of vegetative stage,analysed glucosinolate translocation and profile in rosette leaves,seeds and roots during drought stress,discussed the relationship of myrosinase activity and glucosinolate content.Our results may provide basic data for the further research of the effect of drought stress on glucosinolate metabolism.Glucosinolate composition was different among rosette leaves,seeds and roots.In rosette leaves,we detected 3MSOP(see thumbnails after catalog),4MSOB,5MSOP,6MSOH and 8MSOO of alphatic glucosinolate,40HI3M,I3M,4MTI3M and 1MTI3M of indole glucosinolate.In seeds,30HP,4MTB,5MTP,3BOP,6MTH,4BOB,7MTH and 8MTO were not detected in rosette leaves and not detected 4MTI3M and 1MTI3M,.In roots,7MTH and 8MTO were not detected in rosette leaves.The proportion of indole glucosinolate was higher.During soil drought stress,total glucosinolate content in rosette leaves of Arabidopsis thaliana was lower than fully irrigated treatments(reference)at 3 days treatment,the discrepancy was more and more significant as treatment days increasing.The greatest discrepancy was detected at 9 days treatment.Aliphatic glucosinolate was significantly changed,as well as total glucosinolate.But indole glucosinolate was not significantly changed. In seeds,aliphatic,indole and total glucosinolate content were lower than reference.High concentration PEG-6000 treatment revealed that the increasing of drought stress intensity was benefit for glucosinolate biosynthesis and accumulation.The maximum glucosinolate content yielded under the most intensitive treatment(PEG 0.06 g·mL^-1,water potential is-1.43 MPa).But the plant was proned to die.The two experiments,restriction of plant growth stage and stress intensity revealed that the suitable PEG concentration to treat with Arabidopsis thaliana of vegetative stage was 0.06 g·mL^-1(water potential is-1.43 MPa).Under low concentration of PEG treatment(0.06 g·mL^-1), change of main glucosinolate content in rosette leaves and roots were different,and the proportion of a single glucosinolate was changed in two organs.The resistable reaction of Arabidopsis thaliana was activated during low concentration of PEG treatment(0.06 g·mL^-1), total glucosinolate content in rosette leaves was consequently increased and the greatest discrepancy with reference was yielded at 4 days treatment,as well as total aliphatic and indole glucosinolate content.Change of glucosinolate content in roots was contrary,the content decreased during treatment.The primary glucosinolate in rosette leaves and roots were 4MSOB and 1MTI3M,respectively.The increase in the content of 4MSOB and 1MTI3M after drought are probably the main factor affecting the glucosinolate profile in rosette leaves of Arabidopsis thaliana.Myrosinase activity in rosette leaves and roots was also changed.The activity increased at earlier stage of drought,and decreased at later stage.Relativity between glucosinolate content and mysosinase activity during drought stress was little.