Factors Influencing Hyperhydricity Of Dianthus Chinensis L. And The Expression Of Aquaporin

Plant tissue culture technology has been widely used in the field of rapid propagation of plants and preservation of rare species due to its advantages of shortening plant growth cycle and improving reproduction efficiency.However,the physiological and metabolic disorder phenomenon of hyperhydricity often occurs in the process of plant tissue culture.Hyperhydric plants are difficult to take root,proliferate and survive after transplantation,which brings great economic losses to the work of tissue culture.Therefore,the study on the influencing factors on the occurrence of hyperhydricity and the mechanism of it is of great significance.In this paper,we explore different factors influence the occurrence of hyperhydricity on Dianthus chinensis L and physiological metabolism;and explore different culticars'hyperpydric sensitivity and drought resistance.We also build a peptoid adapter library,and screen a peptoid with high affinity of PIP2 to detect the expression of its quantity in the normal and hyperpydric plants,and explore the role of PIP2 in hyperpydricity process.In the paper,we establish a new label-free detection method which is able to detect plant PIP2 expression quantity.The main results were as follows:1.Low concentration of agar,sucrose and 6-beninamine-adenine?6-BA?and polyethylene glycol-6000?PEG-6000?in the medium would lead to the occurrence of hyperhydricity,among which the addition of 6-BA and PEG-6000 would significantly increase the rate and index of hyperhydricity.The physiological and biochemical indexes showed that the free water content,relative electrical conductivity,peroxidase?POD?activity,bound water content,water loss rate and superoxide dismutase?SOD?activity of the hyperhydirc plants were increased under both conditions.However,the content of soluble protein and proline increased under osmotic stress,while the content of soluble protein and proline decreased under 6-BA induced hyperhydricity,indicating that the ractivated oxygen species and water metabolism of hyperhydric plants were abnormal.However,the reasons for hyperhydricity caused by different conditions may be different,which requires further explore.2.The hyperhydric sensitivity of four kind of cultivars was different.The water content,free water content and aperture of stomatal of the hyperpydricity susceptible cultivars D7 and C1 were significantly higher than that of the non-susceptible cultivars D6 and D11 with the medium contained PEG-6000.The bound water content,relative conductivity,water loss rate,ethylene content,reactive oxygen content,antioxidant enzyme activity and the reactive oxygen of guard cells were all significantly lower than D6 and D11.Histochemical staining showed that the contents of hydrogen peroxide?H₂O₂?and oxygen anion radical(O₂^·-)in D7and C1 were also significantly lower than those in D6 and D11.This indicated that D7 and C1cultivars had better drought resistance although they were more prone to hyperhydricity in the process of plant tissue culture.3.In this paper,an eight-mer peptoid library with one constant cysteine residue on the C-terminal was synthesized using the conventional split-and-pool method,and the peptoid aptamer PPA7?PIP2-binding peptoid aptamer 7?with high affinity and specific binding to higher plant aquaporin?PIP2?was screened by surface plasmon resonance imaging?SPRi?technology.Its affinity was up to 2.52×10^-9 mol/L.PPA7 was used to detect the expression of aquaporin in hyperhydric and normal plants.The results showed that the expression of aquaporin in hyperhydric plantlets was higher than that in normal ones.This paper provided a new quantitative detection strategy for plant proteins and laid a foundation for further clarifying the role of aquaporin in hyperhydricity.This study laid a foundation for further elucidation of the hyperhydricity mechanism of Dianthus chinensis L.and provided a new method for the detection of PIP2 expression in plants.