Study On The Mechanism Of Calcium Signaling In Cephalotaxus Fortunei Under Cold Stress

Cephalotaxus fortunei is a rarely agrestic seedling in fujian province which have a high medical value, but it is short of nature resource and difficult to renovate the resource. Presently, the articles have always fasten on studying the anticancer function of Homoharringtonine(HHT), however ,it is sparse for the physiological and chemic characteristic, so this texts study the resistance of cold and discuss the theory and technology of increasing the coldness, and apply a basic theory and technology for Cephalotaxus fortunei and other plant.Ca²⁺ is play an important role in plant as a second signal messenger, at present, all experiments study on the action of cold of Ca²⁺ in annual plant.It is sparsity in perennial plant,so this text study the regulation of Ca²⁺ in cold stress and primarily study the signal transduction paths. the result were as follows:1. With the extend of cold stress, the concentration of Ca²⁺ by freezing accumulation and CaCl₂ treatment was taken rapidly and transitory increasing, then resumed resting condition, after cold stress two minutes, the concentration of Ca²⁺ were increasing, but the concentration of Ca²⁺ by CaCl₂ treatment was increasing higher than FA which ranged from 120-885 nmol/1, then resumed in 120nmol/l; [Ca²⁺]_cyt treated by cold which ranged from 120-650nmol/l. However, the EGTA, LaCl3,CPZ were restrained the increasing of [Ca²⁺]_cyt, because LaCl₃ is the channels of Ca²⁺ inhibitor, so the origin of [Ca²⁺]_cyt might be come from out of cell by opening the channels of Ca²⁺.EGTA was a pressure dependent inhibitor of Ca²⁺,so the origin of Ca²⁺ also might be a pressure dependent channels.This test indicated that the change of [Ca²⁺]_cyt was a prophase signal of cold stress signal transduction during the cold stress.2. With the extend of cold stress, The consent of CaM were taken increasing then decreasing tendency by treatment of CaCl₂,EGTA, LaCl₃,CPZ and the consent treated by CaCl₂ was significant higher than others during the process. After freezing acclimation about 72 hours, CaM got highest,compared to CaCl₂, the content of CaM treated by EGTA,LaCl₃,CPZ ,freezing acclimation and nature growth was respectively decreased 74.4%,33.92%,37.5%,53.7% and 86.3%,the increasing of CaM enhanced freeze resistance.The result showed that Ca²⁺-CaM attended cold signal transudation, passing the signal transduction by forming the compound Ca²⁺-CaM ,and stimulating the activation of enzyme Enhancing the resistance of freeze and decreasing the hurt of Cephalotaxus fortunei by low temperature .3. Used the annual Cephalotaxus fortunei in experiment after being treated with H₂O, CaCl₂, EGTA, LaCl₃, CPZ to study the change of SOD,POD,CAT during freezing acclimation. The result showed that the activity of CAT,POD and SOD all increased first then decreased with the prolonged stress period. Under low temperature stress, the activity of CAT,POD and SOD with higher calcium was higher than that of other treatment. Those results proved that Ca²⁺-CaM intended the signal transduction of Cephalotaxus...