Physiological Response And Signal Transduction Of Calluses From Two Ecotypes Of Reed Under Heat Stress

Calluses from two ecotypes of reed (Phragmites communis Trin.) plant (dune reed and swamp reed) were used to study plant acclimations to heat stress. The protective effects of nitric oxide against oxidative stress and the signaling function of NO and ABA and the relationship between them under heat stress in the calluses from two ecotypes of reed were investigated. The main results are summarized as follows:Under heat stress, DR callus could maintain higher relative water content, relative growth rate and cell viability than SR callus. The activities of antioxidant enzymes such as SOD, CAT, POD, APX, GR in DR callus also increased more than in SR callus. Conversely, LOX activity, H₂O₂ content, MDA content and MP increased more in SR callus than in DR callus. Proline level in DR callus was 1.68 times higher than in SR callus under control condition. High temperature elevated markedly proline content in DR callus whereas it had no effect on that in SR callus. These results indicated that DR callus might survive under heat stress through retaining higher activities of antioxidant enzymes and proline level compared with SR callus.To elucidate the effect of NO in plant acclimations to heat stress, exogenous NO and cPTIO (a specific NO scavenger) were used. Application of nitric oxide donors,...