| Benzene and formaldehyde were two of the"three invisible killers"indoors.They had strong carcinogenic effects and seriously threatened people’s safety and health.Plants had a strong ability to absorb and purify indoor chemical pollutants such as benzene and formaldehyde.The selection of pollution-resistant and pollution-absorbing plants for ecological restoration had become an effective way and an important means to control indoor air pollution.The resistance of plants to pollution was the basis and premise to determine whether they could continuously and stably exert their ability to absorb pollution.However,the basic biological mechanism of plant resistance to benzene and formaldehyde combined pollution stress is still unclear.Therefore,Sansevieria trifasciata var.laurentii,which had strong ability to absorb,purify and resist,was selected.Through the artificial fumigation experiment,T-test analysis,correlation analysis and principal component analysis were used to explore the resistance response mechanism of plants to the combined pollution of benzene and formaldehyde from the cellular level;Transcriptome sequencing was used to find key signaling pathways and metabolic pathways in plant resistance responses through functional annotation,differential analysis,differentially expressed gene enrichment analysis,and protein interaction network analysis.The response mechanism of resistance to benzene and formaldehyde complex pollution was analyzed at the molecular level.It broke through the bottleneck of research on the response mechanism of plant resistance to benzene and formaldehyde complex pollution,and provided a basic theoretical basis and entry point for the future selection and breeding of indoor plants with strong anti-pollution and absorbing ability.Research Shows:1.Physiological and Biochemical Resistance Responses of Sansevieria trifasciata var.laurentii to Benzene and Formaldehyde Complex Pollution（1）According to the symptomatic resistance response of the plant,its resistance class is class I.Except for the significant differences in catalase（CAT）and ascorbate peroxidase（APX）activities,the other 9 indexes and 11 indexes after 7 days of recovery were all significantly different.（2）The contents of malondialdehyde（MDA）,proline（Pro）,soluble protein（SP）and relative electrical conductivity（REC）in plant leaves were significantly and highly negatively correlated with Chlorophyl（Chl）content and CAT activity,and extremely significantly and positively correlated with superoxide anion（O2.-）production rate and peroxidase（POD）activity.There are different degrees of correlation between other physiological and biochemical indicators.O2.-,Pro,SP and superoxide dismutase（SOD）are the main resistance indicators of plants.SP,Pro,O2.-,SOD and APX are the main recovery indicators of plants.2.Transcriptomic Sequencing Results of the Complex Contamination of Benzene and Formaldehyde in Sansevieria trifasciata var.laurentii（1）Quality analysis of transcriptome sequencing data is performed,and the data used for sequencing is of good quality.（2）Sansevieria trifasciata var.laurentii homologous species is Pantholops hodgsonii.Gene Ontology（GO）functional annotations are the functional subclasses and the largest number of Unigenes in the biological process（BP）.The kyoto encyclopedia of genes and genome（KEGG）have the largest number of Unigenes functionally annotated as signal transduction.The evolutionary genealogy of genes:non-supervised orthologous groups（egg NOG）function annotations account for the largest proportion of general function predictions.（3）A total of 1325 up-regulated genes and 1172 down-regulated genes are involved in the resistance response in Sansevieria trifasciata var.laurentii.2478 up-regulated genes and2820 down-regulated genes are involved in the self-recovery in Sansevieria trifasciata var.laurentii.3.Functional of Key Genes in Sansevieria trifasciata var.laurentii Resistance Response to Benzene and Formaldehyde Complex Pollution（1）Membrane rafts,membrane domains and membrane microdomains of the cellular component（CC）class are associated with plant resistance responses and self-recovery;Molecular function（MF）classes of ATP binding,adenylate nucleotide binding and drug binding,and BP class of protein folding are associated with the resistance response of Sansevieria trifasciata var.laurentii;Drug binding,unfolded protein binding and ATP binding of MF class,protein folding,stimulation response,stress response and biostimulation response of BP class were related to the self-recovery of Sansevieria trifasciata var.laurentii.（2）MAPK signaling pathway and estrogen signaling pathway are key signaling pathways and metabolic pathways;CAM,PP2CA,PP2CB and HSP70 are key genes in plant resistance response.MAPK signaling pathway is a key signaling pathway and metabolic pathway for self-recovery.HSP70 are key genes for plant self-recovery.（3）Resistance response-related genes are involved in environmental information processing,genetic information processing and organic system pathways,mainly relate to binding,plant metabolism,immune system,plant aging,signal transduction and protein folding,sorting and degradation. |
