摘要：
逆境脅迫會對植物的生長發育產生影響,適度的脅迫會促進一些次生代謝產物的合成和積累,因而有利于品質的提高.逆境脅迫條件下,超氧化物歧化酶(SOD)介導的活性氧清除在維持植物體內活性氧穩態平衡,保護細胞免受活性氧傷害中扮演著關鍵角色.為揭示Cu/Zn-SOD基因在杉木逆境脅迫中的作用,采用熒光定量PCR(qRT-PCR)技術,分析杉木組培苗Cu/Zn-SOD基因在4°C低溫、0.0546 g·mL-1甘露醇、2 mmol·L-1鋁離子和300 mmol·L-1的NaCl脅迫中的表達模式,同時探究SOD在不同處理下的活性變化規律.結果表明:在不同逆境脅迫下,杉木組培苗Cu/Zn-SOD基因均受到誘導,表達量總體呈現出先升高后降低的趨勢.在4°C低溫 、 干旱、 鋁離子和鹽脅迫下,分別在48、48、16、24 h時達到最高,是對照的6.4、5.3、6.4、10.4倍,且與對照組相比,不同脅迫處理下Cu/Zn-SOD基因的表達量差異均達到顯著水平,與該結果類似的是,SOD也發生不同變化趨勢,但均高于對照組,推測可能存在SOD基因成員增加基因的表達量從而增加SOD含量.Cu/Zn-SOD基因在杉木組培苗逆境脅迫中發揮著重要的調控作用,為今后深入了解杉木Cu/Zn-SOD基因在逆境脅迫中的分子機制和杉木抗逆育種機理提供理論依據.%Adverse stress affects plant growth and development, and moderate stress can promote the synthesis and accumulation of some secondary metabolites, which would greatly improve the quality of plant.Under stress treatment, superoxide dismutase ( SOD) plays a key role in protecting cells from reactive oxygen speices damage by the mediation of reactive oxygen scavenging.In order to reveal the Cu/Zn-SOD gene in Chinese fir stress effect, the expression pattern of Cu/Zn-SOD gene in Chinese fir seedlings were analyzed under low temperature of 4°C, mannitol 0.0546 g· mL-1 , aluminum ion 2 mmol· L-1 , and 300 mmol· L-1 NaCl stress using qRT-PCR technology, and the variation of SOD activity under different treatments were measured.The results showed that the Cu/Zn-SOD gene in tissue culture seedlings of Chinese fir have changed compared with CK under different stress conditions, and total expression showed a trend of increasing first and then decreasing.The gene expression reached the highest in the low temperature of 4°C, mannitol 0.0546 g· mL-1 , aluminum ion 2 mmol· L-1 , and 300 mmol· L-1 NaCl stress were 48, 48, 16 and 24 h which were 6.4, 5.3, 6.4, 10.4 times, respectively, and compared with the control group, Cu/Zn-SOD gene expression reached significant level for the different stress.SOD also showed similar changes trend, but were higher than CK which may related to increase of SOD membergene. In conclusion, Cu/Zn-SOD gene plays an important role in the regulation of Chinese fir seedlings in adverse stress which would provides a theoretical basis for resistance breeding for further understanding of molecular mechanism and stress in Chinese fir Cu/Zn-SOD mechanism.
