Field Identification Of Salt Tolerance Of Transgenic Potato With Transformed Arabidopsis AtNHX1 Gene

Soil salinization is a worldwide problem, affecting agricultural production and economic development seriously. The most economic and effective way to alleviate the effect of soil salinization on agricultural production is breeding and cultivating salt-tolerant varieties to adapt to saline environment. The technology of cultivating salt-tolerant varieties by using gene engineering has received increasing attention and also certain achievements have been made. In this study, 8 lines of AtNHX1 transgenic potato and control plant of non-transgenic potato"Gannongshu NO.2"have been studied to evaluate the salt-tolerant ability in different saline land ( normal , medium and high salt) for the first time and detect the genetic stability of target gene and reporter gene. The results have been obtained as follows:1. The PCR detection proved that both of exogenous reporter gene nptII and target gene AtNHX1 can steadily inherited in the third generation of vegetative propagation of transgenic potato plants.2. No matter transgenic plants or control plants, they all exhibited injury characters with the increase of salt concentration and treatment time. Control plants injuried seriously, showed characters of low emergence rate, basal old leaves turning yellow and death, middle leaves turning wilting, crimp, yellow and death, the growth of leaves nearby growing point decreased. However, only basal old leaves of transgenic plants turning yellow and death, new leaves nearby growing point grew well.3. Plant height of transgenic potato was higher than the control under the same salt concentration stress, especially under high salt at 90 days, most plant height of transgenic lines was significantly higher than the control. Rate of leaf area expansion showed the same trend as well as plant height.4. Roots and leaves of transgenic plants had lower content of Na+ and higher content of K+, so the content of Na+/K+ was all significantly lower than the control's under same salt stress and treatment time; chlorophyll content of most transgenic plants was significantly higher than the control's under the same treatment conditions.5. With the increase of salt concentration, the content of proline and malondialdehyde of control plants increased greatly. However, transgenic plants'was significantly lower than the control's.6. SOD activity of control and transgenic plants increased with the increase of salt concentration and treatment time, but in the same condition, transgenic plants'was significantly higher than the control's.7. Transgenic lines had a higher number of tubers per plantlet than the control under the same salt concentration, but there was no obvious difference. While under medium and high salt conditions, yield per plant of transgenic lines increased by 61.97%～103.58% and 48.2%～254.67% respectively.8. Though comprehensive evaluation, all of the other transgenic lines showed significant salt-tolerance ability except for NO.6, especially the lines of No.2, No.4 and No.19 had obvious salt-tolerance ability and the yield level also was very significantly higher than the control.