Analysis Of Exogenous NO And H₂O₂Regulation To Potato Anthocyanin Synthesis And Its Signal Transduction

Anthocyanins, which are widely existed in plants, are water-soluble natural pigment,often associated with various monosaccharides formed anthocyanin. Due to the absorbancedifference, anthocyanins ashowed different colors.Anthocyanin has multiple biofunctions forhunman health, such as anti-oxidation、anti-mutagenic、anti-proliferative、protect the liver、inhibition of tumor cells.Colored potatoes have high content of anthocyanin, so they becomethe focus of agricultural and life science. Plant secondary metabolism, Ca²⁺/CaM, NO andH₂O₂constituted complex signaling networks which regulated anthocyanin synthesis. Useed4different genotype colored potato：L8、 L7、LC310-2and SD, treated with water, NO,H₂O₂and NO+H₂O₂.The experment studied the regulation function of NO and H₂O₂to colorpotato anthocyanin synthesis, and signal function of Ca²⁺/CaM and ROS response inanthocyanin synthesis and their relationshipes. The results showed that:（1） With exogenous NO and H₂O₂treatment,4genotypes potatoes anthocyanin contentof its skin and flesh accumulated, and its synthesis enzyme PAL, PPO and CHI activityincreased, the effect was NO+H₂O₂> H₂O₂> NO> Water.（2） With exogenous NO and H₂O₂treatment,4genotypes potato Ca²⁺-ATPase activityand CaM content increased, the changes of anthocyanin content was positively correlatedwith Ca²⁺-ATPase activity and CaM content, the average coefficient determination R2was0.9194and0.8859.（3） With exogenous NO and H₂O₂treatment,4genotypes potato activity oxygenradicals yield of O₂^-., H₂O₂and its scavenging enzymes SOD, CAT and POD activityincreased, the changes of anthocyanin content was positively correlated with oxygen radicalsyield and its scavenging enzymes.（4） Previous studies found that Ca²⁺itself can induce plant anthocyanin synthesis andaccumulation, as an important signaling molecule which transducted the induction ofenvironmental factors, exogenous chemicals and metal ions to plant anthocyanin synthesis.In signal transduction of NO and H₂O₂, NO and H₂O₂induced Ca²⁺/CaM pathway directly,or start Ca²⁺/CaM signal by ROS pathways. Combined with the experimental study, we caninfer that: after exogenous NO and H₂O₂treatment, the active oxygen metabolism promotion,membrane ion leakage enhancement，Ca²⁺flow extracellular, membrane Ca²⁺-ATP enzymeactivity improve, which enhance Ca²⁺transmembrane transport, combination chance of Ca²⁺and CaM increasing, thereby activate the anthocyanin regulatory protein activity, increasedanthocyanin synthesis. So，we can concolued that Ca²⁺/CaM and ROS reactio involved inpotato anthocyanin signal process of NO and H₂O₂induction.