热胁迫对豌豆下胚轴生理的一些影响

Physiological Effect of Heat Stress on Pea (Pisum sativum) Hypocotyls

通过测定热驯和热胁迫下3个豌豆品种幼苗下胚轴生长、细胞膜损伤、抗坏血酸(AsA)和丙二醛(MDA)含量的变化及热激蛋白70(HSP70)表达,探讨热胁迫对豌豆生理的影响。结果表明,在48℃高温胁迫下豌豆种子萌发率下降,幼苗下胚轴生长受抑制,细胞膜受损,AsA含量下降,MDA含量升高;;经37℃热驯再48℃热激处理的下胚轴长度和AsA明显高于直接热胁迫的,细胞膜受损程度和MDA含量则低于后者。HSP70测定表明,除台湾品种外,37℃热驯1h不足以诱导HSP70表达;;而37℃热驯后常温恢复再48℃热激和直接48℃热激均能诱导HSP70表达,其中蒙自品种经热驯后再热激的HSP70表达量高于直接热激的。

To explore the physiological effect of heat stress on pea （Pisum sativum）, hypocotyl growth, membrane injury, ascorbic acid （AsA）, malondialdehyde （MDA） and the expression of Heat Shock Protein 70 （HSP70） in seedling hypocotyls of three pea varieties （produced in Mengzi, Shandong and Taiwan） under different heat treatments were examined. The results showed heat stress at 48℃ resulted in decrease in germination rate of seeds and AsA content of seedling hypocotyls, and increase in membrane injury and MDA content. Longer hypocotyls of pea seedling along with higher level of AsA content, membrane thermostability and lower MDA content were found in the germinated seeds which were acclimated at 37℃ for 1 h before heat stress at 48℃, comparing with rio heat-acllimated germinated seeds （heat stres directly at 48℃ ）. Except for the Taiwan pea, heat acclimation at 37℃ for 1 h couldn＇t induce the expression of HSP70 in the other two varieties. However, the expression of HSP70 in all three varieties was induced by two other different heat treatments, which one was treated at 37℃ for 1 h followed by 48℃ for 2 h with recovery at 22℃ for 1 h and the other treatment was at 48℃ for 2 h. Furthermore, the expression of HSP70 of Mengzi pea was higher when suffering heat stress after heat acclimation heat stress directly.