茶氨酸诱导烟草幼苗抵御干旱胁迫的研究

The protective role of theanine in drought tolerance of tobacco seedlings

通过施用茶氨酸来减轻干旱胁迫对烟草幼苗的毒害,并从抗氧化物质和抗氧化酶来探讨其作用机理。结果表明,在干旱胁迫下,0.25 mmol·L-1茶氨酸能显著改善烟草幼苗的生长情况,提高其存活率;外源茶氨酸预处理不仅能显著提高干旱胁迫下烟草幼苗谷胱甘肽(GSH)含量,还参与调节烟草幼苗超氧化物酶(SOD)过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸还原酶(APX)活性,降低相对电导率、脯氨酸、过氧化氢(H2O2)和丙二醛(MDA)含量。茶氨酸诱导烟草幼苗抵御干旱胁迫是通过激发植物体抗氧化物质及抗氧化酶活性调节的综合结果。

To study the role of theanine in protecting tobacco against drought stress, non-enzymic antioxidants and antioxidases in tobacco seedlings were investigated. The results showed that 0.25 mmol/L theanine could effectively improve plant growth and the survival rate of tobacco seedlings under drought stress. Meanwhile, analyses of physiological-biochemical indices indicated that theanine could increase the content of glutathione（GSH）, adjust the activities of antioxidant enzymes, such as superoxide dismutase（SOD）, acerbate peroxidase（APX）, peroxidase（POD） and catalase（CAT）, but it lowered the relative conductivity content, the proline content, the hydrogen peroxide（H2O2） level as well as the content of malondialdehyde（MDA）. In conclusion, theanine is beneficial to relieving drought stress on tobacco seedlings through stimulating non-enzymic antioxidants and antioxidases in plants.