转LEA基因烟草的NaHCO3抗性分析

Analysis of NaHCO_3 Resistance to Transgenic Tobacco Harboring LEA Gene

本研究以转LEA基因烟草7个株系及非转基因对照烟草组培苗为材料,用不同浓度的NaHCO3处理,通过调查转基因烟草和对照烟草的相对电导率、POD活性、SOD活性、碱害指数、生根率等指标的变化,对LEA基因功能在NaHCO3的抗性方面进行初步探索性的研究。结果表明,在非碱胁迫条件下,各转基因株系与对照烟草的相对电导率差异不明显,各株系的相对电导率随着NaHCO3浓度的增加均呈上升趋势,但各转基因株系均小于对照烟草,当NaHCO3浓度在30mmol/L和40mmol/L时,转基因株系之间及转基因株系与对照间的差异达到了显著水平;在给予NaHCO3胁迫后,将各转基因株系各个处理POD活性、SOD活性取平均值后与对照烟草做比较,可以看出,对照烟草的POD活性、SOD活性变化较小,而转基因株系活性上升较为明显,且均在NaHCO3浓度为30mmol/L处达到活性最大值;在不同浓度NaHCO3胁迫下转基因烟草的受害程度明显小于对照;在相同浓度的NaHCO3胁迫下,转基因烟草生根较对照烟草早2￣3d,当NaHCO3浓度为30mmol/L时,转基因烟草碱害指数达到50%左右,且保持有10%￣30%左右生根率,而对照烟草受害程度较大,已经不能生根。综合以上分析结果表明,转基因烟草NaHCO3的耐受临界浓度为30mmol/L。在NaHCO3胁迫下,转基因烟草的碱害程度、膜损伤较对照烟草小,POD、SOD活性及生根率均高于对照烟草,说明LEA基因的导入提高了烟草的NaHCO3抗性。

Study on seven transgenic tobacco lines harboring Late-embryogenesis-abundant protein （LEA） gene and control plants with different concentration of baking soda （NaHCO3）, measured the relative electrical conductivity, POD activity, SOD activity, alkali-injury index, rooting efficiency, growth capacity and salt injury degree of the transgenic tobaccos and control plants. The result showed that transgenic tobacco lines and control have no difference without NaHCO3, the POD activity in transformed lines is higher than it in the control line, and the activity increased along with the promoting the concentration of baking soda （NaHCO3）. There is remarkable difference between transgenic tobacco lines and control plants; The average of POD activity and SOD activity between transgenic tobacco lines and control plants under NaHCO3 stress showed that the control plants changed small, but the transgenic tobacco lines rise obviously. The activity have the maximum at 30mmol/L NaHCO3. Under different concentration of baking soda （NaHCO3）, the transgenic tobacco lines were damaged obviously lower than the control lines. Under the same concentration of baking soda （NaHCO3）, the transgenic tobacco lines rooted earlier 2 or 3 days than the control lines. Under the concentration of baking soda （NaHCO3） at 30mmol/L, the alkali-injury index of transgenic tobaccos is 50%, the rooting rate is 10%-30%, but the control line was damaged seriously and never rooted. All the results showed that the critical concentration which transgenic tobacco lines could tolerate of baking soda is 30mmol/L. Under the baking soda stress, the extent of membrane injury and alkali-injury were lower than the control line. Not only the activity of POD and SOD but also the root rate is higher than the control lines. The results prove that the transgenic tobaccos with LEA gene enhance the resistence of the tobacco to baking soda.