盐胁迫对诱变凤仙花保护酶活性的影响

Effect of Salt Stress on Protective Enzyme Activity of Mutated Impatiens balsamina L.

以航天诱变凤仙花为试材,在实验室条件下,利用NaCl模拟盐胁迫,研究了不同NaCl浓度对2种凤仙花保护酶活性的影响,以期了解诱变后凤仙花与普通凤仙花抗性生理是否存在差异。结果表明:盐胁迫下的普通凤仙花种子萌发率和出苗整齐度表现为低浓度(0.1%)不受影响,随着浓度的增加,种子萌发率和发芽势急剧下降,当NaCl浓度达到0.4%时,虽然种子能够萌发,但是胚根长出后,不能继续生长和进行根系分蘖,根尖部位褐变坏死。诱变凤仙花对水分亏缺极为敏感,保护酶系统迅速做出响应,使植株免受逆境伤害。诱变凤仙花过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性随盐浓度的升高而显著升高,丙二醛(MDA)含量无显著变化,说明诱变凤仙花对低盐浓度具有一定的耐受性;随着盐浓度的增加,对植株生理产生抑制作用,且随着胁迫时间的推移,盐胁迫产生的毒害也逐渐显现。诱变凤仙花在盐胁迫状态下,根系分蘖和根系长度显著降低,SOD、CAT活性显著增高,通过减少生长量,提高酶活性以保护有机体减少受到逆境的伤害,从长远来看,该种保护酶系统和自由基清除机制优于普通凤仙花对逆境的应对。

With space flight-mutated Impatiens balsamina as experimental material,salt stress was stimulated using NaCl under laboratory conditions,and the effects of NaCl at different concentrations on the activity of 2protective enzymes of Impatiens balsamina were investigated,so as to explore the difference in resistance physiology between mutated Impatiens balsamina and common Impatiens balsamina.The results demonstrated that under salt stress,the germination rate and uniformity of seedling emergence of common Impatiens balsamina seeds were not affected by NaCl at low concentration(0.1%).With the increase of concentration,the germination rate and germination potential decreased sharply.With NaCl at a concentration of 0.4%,although the seeds germinated,they could not continue to grow and tiller roots after radicle growth,and the root tips became brown and necrotic.Mutated Impatiens balsamina was very sensitive to water deficit,under which the protective enzyme system responded quickly and protected plants from adversity.With the increase of salt concentration,CAT,SOD and POD activities of mutated Impatiens balsamina increased significantly,while MDA content showed no obvious change,suggesting that mutated Impatiens balsaminawas tolerant to low salt concentration.The increase of salt concentration had an inhibitory effect on plant physiology.With the stress time going on,the toxicity caused by salt stress gradually appeared.Under salt stress,root tillering and root length of mutated Impatiensbalsaminadecreased significantly,and SOD and CAT activities increased significantly.By reducing growth and enhancing enzyme activity,organisms were protected from adversity.In the long term,this protective enzyme system and free radical scavenging mechanism were superior to the response of common Impatiens balsaminato adversity.