| Catecholamines(CAs)are a class of biological amines containing 3,4 catechol groups,which are neurological substances containing catechol and amine groups.They include three types of substances:epinephrine(E),adrenaline(Norepinephrine,NE),and dopamine(DA),and these three types of substances are obtained from tyrosine precursor conversion.Many studies have shown that catecholamine CAs can significantly affect the infectivity of pathogenic bacteria and have a certain effect on the growth and drug resistance of bacteria.In mammals,CAs are an important class of neurotransmitters,which can enhance the body’s ability to adapt to changing environmental conditions,and have important pharmacological and physiological functions in regulating nervous system activities.Like mammals,the synthetic substrate of plant CAs is also tyrosine;research in recent years has shown that plant CAs are also involved in important processes such as plant growth,development,and stress response,which may be plants that sense and respond to abiotic stress Key hormones.We treated wild-type(WT)Arabidopsis thaliana with different concentrations of NE,and analyzed and analyzed physiological parameters such as seed germination,root length,and stomatal opening.The results showed that exogenous NE treatment significantly inhibited seed germination and was concentration-dependent.Among them,with 100 μM NE treatment,the germination rate after 36 h was only 10.12%,and when NE concentration increased to 250 μM and 500 μM,WT seeds hardly germinated within 36 h.At the same time,our research also found that exogenous NE also significantly inhibited the elongation of the main root of WT,with 100 μM NE having the strongest inhibition effect.Stomatal opening experiments also found that NE treatment significantly promoted the stomata closure,and the enhancement effect was stronger as the concentration increased;of which,the stomatal opening degree was only 2.28μm after 100 μM NE treatment,which decreased compared with the control 43.28%.Using H2DCF-DA staining study found that NE treatment significantly increased the content of reactive oxygen species in guard cells.At the same time,our research found that DA and E treatments can also promote stomatal closure,but compared with NE treatment,the promotion effect is weaker.In order to study whether NE can alleviate the salt stress of plants and improve the stress resistance of plant growth,we first treated the seedlings of Arabidopsis WT with NE and NaCl,and analyzed and analyzed the physiological indicators such as root length,fresh weight and chlorophyll content.The results showed that NE treatment significantly alleviated the inhibitory effect of salt stress on root elongation and increased chlorophyll content.We treated NE and NaCl with the Arabidopsis Na+/H+ reverse transporter mutant sos1.The study found that NE did not alleviate the salt-sensitive phenotype of sos1 mutants,suggesting that NE’s regulation requires sosl protein function,which may be located upstream of the plant SOS system.Our research found that exogenous DA and E treatments also increased the salt tolerance of plants to varying degrees.After that,we applied NE to the cultivation of crops such as rice,peanuts and wheat.The experimental results showed that low concentration NE significantly increased the plant height and chlorophyll content of rice,peanuts and wheat,and alleviated the NaCl stress.The above results indicate that NE can promote the growth of plants and improve the stress resistance of plants,which may be a plant stress hormone.Finally,in order to further study the molecular mechanism of NE to improve plant salt tolerance,we conducted transcriptome analysis on the seedlings treated with NE and NaCl.Transcriptome analysis of 12 samples was completed in the experiment,and 79.27Gb Clean Data was obtained.The Q30 base percentage was 92.58%and above.The clean reads of each sample were compared with the designated reference genome,and the comparison efficiency ranged from 93.36%to 95.40%.Based on the comparison results,we carried out alternative splicing prediction analysis,gene structure optimization analysis and the discovery of new genes,and discovered 322 new genes,of which 273 were functionally annotated.Among them,under salt stress,NE treatment significantly increased the expression of multiple genes,Including AT5G15120(PCO1,Plant cysteine oxidase 1)、AT1G07160(Protein phosphatase 2C)、AT1G43800(AAD6)、AT5G64750(ABARepressorl,ABR1)、AT5G05300(IDL6)、AT5G67310(CYP81G1,Polypeptide 1)、AT3G47340(ASN1,AT-ASN1,Dark inducible 6)、AT1G10070(ATBCAT-2,BCAT2)and AT5G63770(ATDGK2,DGK2)and other genes.Identify differentially expressed genes based on their expression in different samples,and perform functional annotation and enrichment analysis on them,providing important clues and genetic resources for further revealing the effects of NE on plant regulation and development. |
