Transcriptomic,physiological And Biochemical Analysis Of Arabidopsis With Over-expression BnNF-YA9 Under Drought And Salt Stress

Land salinization is one of the severe soil problems in China with a large population while per capita land area is small and food supply is insufficient.it is urgent to use salinized soil.Oilrape(varity,NY-1)is widely planted in the coastal area of Jiangsu province with high oil content and salt tolerance.Previous studies have found that the A subunit of the nuclear transcription factor Y family,BnNF-YA9 in rapeseed,could improve the resistance to stress.Further,NF-YA9 were found to be regulated by microRNA169 family in a class of small RNA molecules.To further investigate the function of microRNA169n and BnNF-YA9 under adversity stress,we continue to study and the result is as follows:Transcriptomic analysis of wild-type,over-expressing microRNA169 and BnNF-YA9 Arabidopsis thaliana under drought,salt and ABA treatment,identified the mechanism of resistance to stress.7081 differential expression genes(DEGs)were GO-annotated which were mainly distributed in cells and cell parts under the cellular components,and enriched in response to stress under the components of biological processes.And 3331 DEGs were annotated with KEGG Pathway.Compared to control,mainly enriched metabolic pathway is circadian rhythm-plant under drought treatment.In salt treatment,mainly enriched metabolic pathway is flavonoid biosynthesis in A9 while mainly enriched metabolic pathway are glucosinolate biosynthesis and cyanoamino acid metabolism in 169n.In ABA treatment,mainly enriched metabolic pathway is sesquiterpenoid and triterpenoid biosynthesis in A9 and 169n.Two abiotic signal pathways(MAPK signaling pathway and plant hormone signal transduction)were mainly enriched under salt,drought and ABA treatment.In this pathway,the ABA signal transduction pathway is mainly used to resist to the adverse external environment and there have two important parts:PYR/PYL,PP2C and SnRK2.The up-regulated genes in PYR/PYL are AT4G18620 and AT5G45870 and the down-regulated genes are AT1G73000,AT4G01026,AT5G05440,AT2G40330 and AT4G27920.The up-regulated genes in PP2C are AT1G07430,AT1G72870,AT2G29380,AT3G11410,AT4G11040,AT5G57050 and AT5G59220 and the down-regulated genes are AT1G07430,AT1G72770,AT5G59220,AT1G17610,AT1G17615,AT1G72910 and AT2G07599.The up-regulated genes in SnRK2 are AT5G63650 and AT2G23030 and the down-regulated genes is AT3G50470.Analysis of differentially expressed trantscription factors revealed that the MYB family,AP2/EREBP family and bHLH family accounted for a large proportion.Many previous reports showed that these families could regulate abiotic stress response.Wild-type and over-expressing BnNF-YA9 Arabidopsis thaliana were further measured for physiological and biochemical parameters under drought and salt treatment.In the determination of superoxide dismutase,over-expression of BnNF-YA9 under drought treatment was significantly different from WT(wild type)under un-treated conditions CK(control).As far as the content of malondialdehyde,over-expression of BnNF-YA9 under drought treatment was significantly different from WT in CK.In the determination of peroxidase,over-expression of BnNF-YA9 under drought treatment was significantly different from WT in CK.In the measurement of catalase,over-expression of BnNF-YA9 under drought treatment was significantly different from WT in CK.As for content of chlorophyll and total sugar,over-expression of BnNF-YA9 under drought treatment was significantly different from WT.This indicates that the BnNF-YA9 gene minimized the adverse effects of drought and salt stress on plants through a series of physiological responses.