种植与组培9年的转AhDREB1基因毛白杨耐盐性比较

为了对栽培9年后转AhDREB1基因毛白杨的耐盐性进行评价,并探究田间种植与组培继代2种不同生长条件对转基因毛白杨耐盐性的影响,以从大田种植9年的转AhDREB1基因杂种毛白杨[(Populus tomentosa×Populus bolleana)×P.tomentosa]中获得的株系(T46-F)和组培继代9年的2个转基因杂种毛白杨株系(T46、T12),以及非转基因杂种毛白杨株系(CK)为试材,通过对外源基因进行PCR检测,发现9年后AhDREB1基因仍然稳定整合在转基因植株中。通过不同浓度的Na Cl胁迫试验,对各株系的相对电导率进行分析,进一步选择测定0.6%浓度Na Cl处理水平下各株系的株高、地径生长量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、丙二醛(MDA)含量、脯氨酸含量和叶绿素相对含量,对不同转AhDREB1基因毛白杨株系的耐盐性进行分析和比较。结果表明,所有株系的相对电导率、MDA含量均随Na Cl浓度增加而增大,但高盐浓度下转基因株系T46-F、T46、T12的相对电导率、MDA含量均显著低于CK。无论是在非盐条件,还是0.6%Na Cl胁迫下,AhDREB1基因的导入均能显著提高毛白杨植株的SOD、POD活性,脯氨酸含量。其中0.6%浓度Na Cl胁迫下,T46-F、T46、T12的SOD活性分别是CK的2.51倍、3.20倍、2.55倍;POD活性分别是CK的1.23倍、1.63倍、1.10倍;脯氨酸含量分别是CK的1.51倍、1.69倍、1.62倍。此外,转AhDREB1基因毛白杨叶绿素含量下降显著低于CK,同时株高、地径生长量显著高于CK。组培继代9年的转基因株系的脯氨酸含量、株高生长量显著高于在大田种植9年的转基因毛白杨,而相对电导率显著低于大田种植转基因株系,说明组培继代培养更有利于保持转基因毛白杨的耐盐性。综上可知,转AhDREB1基因显著提高了毛白杨的抗氧化酶活性,调控渗透调节物质的积累,从而减轻细胞膜的氧化损伤,降低了相对电导率,提高了毛白杨的耐盐性,综合考虑各个指标,各株系耐盐性的大小顺序为T46T12T46-FCK。本研究为通过转AhDREB1基因提高植物耐盐性提供了理论参考。

Salt Tolerance Comparation of Field-grown and in vitro Cultured Transgenic Populus tomentosa With AhDREB1 Gene After 9 Years

In this study,the salt tolerance ability of transgenic AhDREB1 poplar after 9 years was tested and the different influence of the condition to grow the transgenic poplar by field-grown and in vitro cultured was explored.Transgenic poplar line T46 from the hybrid poplar((Populus tomentosa × Populus bolleana) × P.tomentosa) grown in field and transgenic poplar line T46,T12 of hybrid poplar from the plant in vitro consecutive subculture after 9 years,the foreign gene stability of the hybrid poplar was detected by PCR.The result showed that AhDREB1 gene was still existed in the transgenic poplar after 9 years.In order to compare the salt tolerance ability of field-grown and in vitro consecutive subcultured transgenic hybrid poplar after growing for 9 years,the relative electrical conductivity was measured and analyzed under different concentration salt stress.The physiological parameters,including the height and ground diameter growth,SOD activity,POD activity,MDA content,proline content and chlorophyll content were measured under 0.6％ NaCl stress.The results showed that the relative electrical conductivity and MDA content of all poplar lines were increased along with increased salt stress.However,the relative electrical conductivity and MDA content of transgenic lines were significantly lower than control under high salt concentration treatment.Overexpression of the AhDREB1 gene can significantly increase SOD activity,POD activity and proline content in transgenic poplar whether exposed to 0.6％ NaCl stress or not.Under 0.6％ NaCl stress,the SOD activity of transgenic poplar line T46-F,T46,T12 were 2.51,3.20 and 2.55 folds respectively compared with CK.The POD activity of transgenic poplar line T46-F,T46,T12 were 1.23,1.63 and 1.10 folds compared with CK.And the proline content of transgenic poplar line T46 -F,T46,T12 were 1.51,1.69 and 1.62 folds compared with CK.In addition,chlorophyll content decrease of transgenic lines significantly lower than control.Transgenic poplar maintained higher height and larger ground diameter growth than CK.Among the transgenic poplar,the proline content,plant height growth of in vitro cultured transgenic lines were significantly higher than field-grown transgenic poplar line after 9 years.While relative electrical conductivity of the former significantly lower than the latter suggesting that in vitro culture is a better way to maintain the ability of salt tolerance of transgenic poplar.It is concluded that AhDREB1 confers salt tolerance ability of transgenic poplar via an increase in antioxidant capacity,proline accumulation and a decrease in lipid peroxidation so as to maintain a lower relative electrical conductivity under salt stress.In summary of all the physiological traits,the salt tolerance order of all tested lines was T46 ＞ T12 ＞ T46-F ＞ CK.This research provided a reference to enhance plant salt tolerance by AhDREB1 gene transformation.