论文部分内容阅读
为鉴定转基因紫花苜蓿的耐旱能力,本研究以转基因紫花苜蓿T0代植株为材料,通过干旱胁迫,从转基因植株的表型、生理指标和分子水平等层面检测转基因植株的抗旱特性,试验表明,干旱胁迫后转基因苜蓿和对照的茎、叶片全部干枯,而复水后转基因苜蓿大部分恢复生长,对照几乎全部死亡。干旱胁迫后苜蓿叶片的Pro和MDA含量均随处理时间延长而逐渐增加,转基因植株叶片的Pro含量高于对照,而其MDA含量低于对照植株,且二者均达到了显著差异;转基因苜蓿的离体叶片失水率也明显低于对照。在20%PEG胁迫下,植株体内ProDH和P5CS基因的相对表达量都是先升后降,转基因植株和对照中ProDH和P5CS基因的表达量显著增加,且二者在转基因植株与对照间存在显著差异。这表明,在干旱胁迫条件下,由于AmDHN基因在紫花苜蓿中的过量表达,可能引起植株体内脯氨酸的大量积累,并进一步诱导脯氨酸合成相关基因的表达,最终引起植株抗旱性的提高,因此,推测转基因苜蓿的耐旱性比对照强。
In order to identify the drought-tolerance ability of transgenic alfalfa, we studied the drought-resistant characteristics of transgenic plants by the transgenic T0 plants of alfalfa under drought stress through the phenotypic, physiological and molecular levels of the transgenic plants. After drought stress, the stems and leaves of transgenic alfalfa and the control were all dry, but most of the transgenic alfalfa recovered after the rewatering, almost all the control died. Pro and MDA contents of alfalfa leaves increased gradually with the prolongation of treatment time under drought stress. The content of Pro in leaves of transgenic plants was higher than that of the control, while the content of MDA was lower than that of the control plants, and both reached significant differences. Leaf loss rate in vitro was also significantly lower than the control. Under the 20% PEG stress, the relative expression levels of ProDH and P5CS genes in plants increased first and then decreased. The expression levels of ProDH and P5CS genes in transgenic plants and controls were significantly increased, and there was significant difference between the transgenic plants and the control difference. This indicates that due to the overexpression of AmDHN gene in alfalfa under drought stress, it may cause a large accumulation of proline in plants and further induce the expression of genes related to proline synthesis, eventually leading to the improvement of drought resistance in plants Therefore, we speculated that the transgenic alfalfa had stronger drought tolerance than the control.