内生细菌对盐胁迫下小麦幼苗脯氨酸和丙二醛的影响

以周麦18为试验材料,以内生菌252和254为供试菌株,试验采用盆栽法设置盐胁迫组、盐胁迫接菌组和对照组,研究不同盐浓度胁迫下接菌处理对小麦幼苗脯氨酸(Pro,proline)和丙二醛(MDA,malondialdehyde)含量的影响。结果表明:小麦幼苗在盐胁迫环境下,随着培养时间和盐浓度增加,盐胁迫组Pro含量先升后降。在前中期,盐胁迫组小麦Pro含量逐渐积累,提高了小麦抗逆性;在后期Pro含量较中期有一定程度下降,小麦逐渐对盐环境产生适应性。随着盐浓度升高,盐胁迫组小麦在不同培养阶段对盐环境的抵抗能力不同,每个时期对盐抵抗能力有一阈值,超过此盐浓度Pro含量下降,抵抗能力减弱。接菌处理后,小麦Pro含量升高,提高了抗盐胁迫能力,第14天时修复效果最明显,接菌252处理组和254处理组分别在盐浓度为200 mmol/L和250 mmol/L时高出盐胁迫组133.48%和91.48%。盐胁迫组MDA含量随时间延长先降后升,与Pro含量变化趋势相反。在前中期,盐胁迫组小麦膜质过氧化程度不高,对小麦正常代谢活动尚未造成严重影响,在后期MDA含量升高,盐胁迫组小麦逐渐枯萎。接菌后,降低了幼...

Effects of endophytic bacteria on proline and malondialdehyde of wheat seedlings under salt stress

Taking Zhoumai 18 as research materials, 252 and 254 as tested strains, wheat treatment group with salt stress, bacterial treatment group, and the control group used by artificial climate culture method were cultivated for 7d, 14d, and 21 d. The content of proline (Pro) and malondialdehyde (MDA) of wheat seedlings treated with inoculation and those of wheat under salt stress were determinated. The results showed that Pro content of salt stress group firstly rose then falled with the increase of culture time and salt concentration under salt stress environment. In the prophase and metaphase, contents of wheat Pro under salt stress gradually accumulated and improved the resistance of wheat. In the anaphase, Pro contents declined to certain degrees compared with those in metaphase, which indicated that wheat gradually adapted to salt environment. With increasing salt concentrations, wheat in various groups of salt stress exhibited different levels of resistances to salt environment at different stages of cultivation. During each period, there was a threshold of wheat resistance to salt concentration. When salt concentration was greater than such threshold, Pro content declined, and wheat resistance to salt was lessened. After inoculation with endophytes, higher Pro content of wheat improved the ability of wheat resistance to salt stress, and its respair effect of 14 d was the most obvious. When the treatment group inoculated with 252 and 254 respectively under the concentration of salt, their Pro content were higher 133.48% and 91.48% for 200 mmol/L and 250 mmol/L than those of salt stress group. MDA content of wheat with salt stress group was first drop and rose with time prolong, but Pro content changes had inverse trend. During the prophase and metaphase, in various groups of salt stress, lipid peroxidation degrees of wheat cellular membrane were not high, which brought about no severe threat to the normal metabolism of wheat. During the anaphase, MDA content increased and wheat in various groups of salt stress gradually withered. Due to the accumulation of reactive oxygen species in cells, some ingredients would be involved in severe reactions. After inoculation with endophytes, endophytes reduced the degree of lipid peroxidation of wheat cellular membrane, enhanced the survival rate of wheat, and promoted the growth of wheat seedlings. MDA content were lower than that on the 21d in salt stress group, and remediation effect was significant.