不同逆境胁迫下杉木Cu/Zn-SOD基因表达分析

摘要

逆境胁迫会对植物的生长发育产生影响,适度的胁迫会促进一些次生代谢产物的合成和积累,因而有利于品质的提高.逆境胁迫条件下,超氧化物歧化酶(SOD)介导的活性氧清除在维持植物体内活性氧稳态平衡,保护细胞免受活性氧伤害中扮演着关键角色.为揭示Cu/Zn-SOD基因在杉木逆境胁迫中的作用,采用荧光定量PCR(qRT-PCR)技术,分析杉木组培苗Cu/Zn-SOD基因在4℃低温、0.0546 g·mL-1甘露醇、2 mmol·L-1铝离子和300 mmol·L-1的NaCl胁迫中的表达模式,同时探究SOD在不同处理下的活性变化规律.结果表明:在不同逆境胁迫下,杉木组培苗Cu/Zn-SOD基因均受到诱导,表达量总体呈现出先升高后降低的趋势.在4℃低温 、 干旱、 铝离子和盐胁迫下,分别在48、48、16、24 h时达到最高,是对照的6.4、5.3、6.4、10.4倍,且与对照组相比,不同胁迫处理下Cu/Zn-SOD基因的表达量差异均达到显著水平,与该结果类似的是,SOD也发生不同变化趋势,但均高于对照组,推测可能存在SOD基因成员增加基因的表达量从而增加SOD含量.Cu/Zn-SOD基因在杉木组培苗逆境胁迫中发挥着重要的调控作用,为今后深入了解杉木Cu/Zn-SOD基因在逆境胁迫中的分子机制和杉木抗逆育种机理提供理论依据.%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℃, 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℃, 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.