切花月季Samantha失水胁迫耐性与其超氧化物歧化酶之间的关联

Relationship Between the Tolerance to Water Deficit Stress and Superoxide Dismutases (SODs) in Petal of Cut Rose Samantha

以探讨月季切花失水胁迫耐性与其超氧化物歧化酶(SOD)之间的关联为目的,选用耐失水胁迫品种Samantha,用DDTC(SOD专一性抑制剂)进行12h预处理,之后在20℃、RH35%～40%、80μEm-2·s-1光照(12h/d)条件下进行12～48h的失水胁迫处理,然后进行瓶插观察。结果表明,20mmol·L-1DDTC预处理在显著抑制花瓣SOD活性的同时,明显减弱切花失水胁迫耐性,表现在切花弯颈率明显提高,复水率和水势值明显降低,瓶插寿命显著缩短。在花朵自然开放初期,花瓣MnSOD、FeSOD和Cu/ZnSOD这3种类型都存在。其中,MnSOD有1种,FeSOD有3种,Cu/ZnSOD有2种;迁移率大小依次为Cu/ZnSOD>FeSOD>MnSOD;谱带强弱依次为FeSOD>Cu/ZnSOD>MnSOD。经失水胁迫处理花瓣中诱导产生了3条新的FeSOD(FeSOD4、FeSOD5和FeSOD6)条带,与此同时MnSOD条带消失。DDTC预处理抑制了任何与上述失水胁迫诱导有关的新的条带产生。由此推测,切花月季Samantha失水胁迫耐性与其SOD活性相关,与FeSOD4～6的诱导产生相关联。

To investigate the relationship between the tolerance to water deficit stress and superoxide dismutases in postharvest cut rose, Samantha (Bridal Pink × Seedling), a cultivar with strong tolerance to water deficit, was pulsed with 12 h DDTC pretreatment and subjected to 12–48 h water deficit stress under controlled conditions, i.e. relative humidity of 35%–40%,12 h /12 h photoperiod with photosynthetic photon flux density of 80 μE·m-2·s-1, and 20℃, then vased for observation. The results showed that SOD activity in petals was remarkably inhibited pulsed with 20 mmol·L-1 DDTC pretreatment and flower tolerance to water deficit was obviously decreased, which was evidenced by the obvious increase of bentneck rate, the significant decrease of rewater water recovery rate and flower water potential, and the dramatic shortness (reduction) of vase life. Three types of SOD were observed in the petals of control at the earlier stages of flowering, and FeSOD had three isoforms, Cu/ZnSOD two isoforms, and MnSOD one isoform, respectively. The turn of mobility of them was Cu/ZnSOD>FeSOD>MnSOD; and bands activity was FeSOD>Cu/ZnSOD>MnSOD. By water deficit stress, three new bands named as FeSOD4-6 were induced, and MnSOD disappeared simultaneously. However, the newly induced bands by water deficit stress mentioned above were inhibited by DDTC pretreatment. It is presumed that the tolerance to water deficit is highly related to SOD activity, and to newly induced FeSOD4-6 in the petals of postharvest cut rose Samantha.