PQQ对低温胁迫下早稻幼苗生理特性的影响

Effects of PQQ on Physiological Characteristics of Early Rice Seedlings Under Low Temperature Stress

以早稻品种湘早籼42号为材料,研究不同浓度的PQQ溶液对低温胁迫下早稻幼苗生理特性的影响。结果表明:低温胁迫前叶面喷施0.5和1μmol/L PQQ溶液,活苗率较对照大幅提高,分别达到40.23%和43.14%,与对照差异显著;而PQQ溶液浓度≥25μmol/L时活苗率反而降低;低温胁迫前喷施0.5μmol/L的PQQ,对株高、鲜重、干重和含水量的影响与对照差异不显著;而低温胁迫5 d时,PQQ处理过的幼苗电导率降低了7.19个百分点、MDA含量减少了5.23 nmol/g、脯氨酸和可溶性糖含量分别增加了8.02μg/g和23.4 mg/g、SOD和POD酶活性分别提升了9.19%和11.45%,与对照的差异均达显著水平。这表明PQQ可通过提高抗氧化酶活性和调节非酶促防御系统同时减轻低温胁迫对水稻幼苗造成的伤害,提高水稻幼苗耐冷能力。

The effects of different concentrations of pyrroloquinoline quinone(PQQ)solution on physiological characteristics of early-rice seedlings were studied with Xiangzaoxian 42 as the material.The results showed that sprayed with 0.5μmol/L and 1μmol/L PQQ solutions on the leaf surface before low temperature stress,the live seedling rates of the treatments were significantly higher than those of the control,reaching 40.23% and 43.14%,respectively;when the PQQ concentration was ≥25μmol/L,the live seedling rates contrarily decreased.Through the analysis on agronomic characteristics and physiological indices of the cold-damaged seedlings,it was found that spraying PQQ before low temperature stress had no significant effects on plant height,fresh weight,dry weight and water content in contrast with the control.After 5d low temperature treatment,PQQ reduced the conductivity by 7.19 percent,decreased the MDA content by 5.23nmol/g,increased proline and soluble sugar contents,SOD and POD activities by 8.02μg/g,23.4 mg/g,9.19% and 11.45%,respectively,all of which were significantly different from the control.It means that PQQ could reduce the damage caused by low temperature stress and improve the cold tolerance of rice seedlings by improving the activity of antioxidant enzymes and regulating non-enzymatic defense system.