ABA及Ca^(2+)/CaM信使系统对高温逆境下棉苗根系生长的调控

Regulation of ABA and Ca^(2+)/CaM messenger system on root growth of cotton seedling under high temperature stress

以对温度敏感的杂交棉——标杂A2为研究对象,在人工气候箱培养条件下,研究了ABA和Ca2+/CaM信使系统对热激条件下棉花苗期根系抗逆生理性状的影响及调控。结果表明:在高温逆境条件下,棉株体内可以产生ABA而提高棉苗耐热性;外源ABA或Ca2+可以减轻棉苗根系热激危害,提高根系活力、基部伤流强度及根系活性恢复力,降低根系电解质外渗率;ABA和Ca2+具有明显的互作效应,棉苗对变温逆境的抗性可能通过ABA及Ca2+/CaM信使系统诱导产生并起作用;钨酸钠、LaCl3和CPZ分别是ABA和Ca2+/CaM信使系统的抑制剂,外源喷施对棉苗的耐热性具有减弱作用。复水前后的棉苗基部伤流强度能够较好地反映根系代谢活性,可以作为棉苗耐热性鉴定的有效指标。

Under artificial climate chamber culture condition, standard hybrid A2, a kind of temperature-sensitive hybrid cotton, was used as material to study the effects and regulations of ABA and Ca^2＋/CaM messenger system on root growth of cotton seedlings under heat shock stress. The results showed that： ABA in cotton body was produced to improve the heat-resistance of cotton seedlings under high temperature stress condition. By spraying exogenous ABA or Ca^2＋ ,the heat-shock hazards on cotton seedling roots could be reduced, the root activity and bleeding intensity and root activity resilience could be increased, and the rate of root electrolyte leakage could be reduced. The interactive effects of ABA and Ca^2＋ were significant, the resistance of cotton seedlings to variable-temperature stress might be induced and play a role through the ABA and Ca^2＋/CaM messenger system. Sodium tungstate, LaCl3 or CPZ was the inhibitor of ABA or Ca^2＋ / CaM messenger system, and the heat resistance of cotton seedlings could be diminished by spraying these exogenous inhibitors. The bleeding intensity of the base-stem in cotton seedlings, which could reflect the metabolic activity of root system before and after rehydration, might be used as an effective indicator to identify the heat tolerance in cotton.