柽柳耐盐及耐镉分子机制比较分析

Tamarix is a typical halophyte,which has the ability to develop roots and secrete salt,and plays an important role in the restoration of saline soil.Research has shown that Tamarix also has high cadmium(Cd)tolerance and the ability to secrete toxic metals,demonstrating the potential for remediation of heavy metal and saline alkali contaminated soil.On the one hand,research on Tamarix is mostly related to drought resistance and salt tolerance.On the other hand,after preliminary research on the Cd tolerance mechanism of Tamarix,it was found that there is both cross adaptation and specific resistance mechanism between its salt tolerance and Cd tolerance mechanisms,which requires further research.Through high-throughput sequencing,Transcriptome sequencing was carried out on the roots of Tamarix hispida at different time points of Cd stress treatment,and the differential genes were analyzed.The top-down graphic Gaussian model(GGM)algorithm was used to construct the regulation network of T.hispida Cd stress response genes,so as to reveal the mechanism of T.hispida Cd stress response.Further,the response mechanism of T.hispida under salt stress,Cd stress and salt-Cd combined stress was analyzed by comparing Transcriptome and metabonomics.The analysis of the Transcriptome of the roots of T.hispida showed that its might respond to Cd stress by regulating cell wall components and phenylpropane biosynthesis,and regulate its tolerance to Cd stress through transcription factor mediated multi-level regulatory network(ML-hGRN)regulator gene expression.Some members of ML-hGRN,such as DRE1A MYC1 and FEZ may play a key role in the Cd stress response process of T.hispida by clearing reactive oxygen species(ROS).Conjoint analysis of metabolome and transcriptome showed that under salt stress,a large number of enzymes were activated to maintain the normal growth and development of T.hispida.Under Cd stress,T.hispida produces more Secondary metabolite to cope with Cd toxicity,and maintaining normal lipid synthesis and metabolism may be an important way to improve the Cd tolerance of T.hispida.Flavonoid play an important role in the response of T.hispida to salt,Cd and salt-Cd stress.And it was found that under salt-Cd complex stress,salt stress affects the absorption of Cd by T.hispidata by activating or inhibiting the expression of some ion transport genes.T.hispidata regulates its target gene response to Cd stress through several transcriptional factor levels.The regulation of flavonoids belongs to the cross adaptation of salt stress and Cd stress,and regulating lipid levels may be an important pathway for T.hispidata to cope with Cd stress.There may be a complex interaction mechanism between salt and Cd that affects ion absorption in T.hispidata.