油桃花芽破眠过程中H2O2代谢与Ca2+转运的关系

利用化学测定法分析高温、单氰胺和TDZ 3种破眠处理对“曙光”油桃休眠花芽H₂O₂代谢的主要影响，利用非损伤微测技术检测H₂O₂对休眠芽Ca²⁺转运的影响，研究H₂O₂在芽休眠解除过程中的调控作用.结果表明： 在深休眠时期，高温和单氰胺处理均能诱导芽内H₂O₂含量升高和过氧化氢酶(CAT)活性降低，并具有显著的破眠作用；TDZ对H₂O₂含量及CAT、过氧化物酶(POD)活性影响不大，破眠效果较差.休眠花芽原基组织钙通道活跃，对外源Ca²⁺呈吸收状态.外源H₂O₂可诱导休眠花芽原基组织Ca²⁺转运发生变化，低浓度H₂O₂降低Ca²⁺吸收速率，高浓度H₂O₂使组织对Ca²⁺的转运由吸收转变为释放.这表明休眠芽内H₂O₂信号和Ca²⁺信号相关联，通过诱导H₂O₂积累调控Ca²⁺信号可能在高温和单氰胺打破休眠的信号转导过程中起重要作用.

Behavioral responses of Frankliniella occidentalis to kidney bean plants and their volatiles under different treatments

In order to explore regulatory function of H₂O₂ in bud dormancy release, main effects of three dormancy breaking treatments (high temperature, hydrogen cyanamide and TDZ) on H₂O₂ metabolism were determined, and impacts of H₂O₂ on Ca²⁺ transport were tested using non invasive micro test technique. The results showed that both high temperature and hydrogen cyanamide induced H2O2 accumulation and CAT inhibition were efficient in breaking dormancy during deep dormancy period. However, TDZ showed little impacts on H₂O₂ metabolism and was much less effective in breaking dormancy. Dormant floral primordium was absorbing state to exogenous Ca²⁺ due to active calcium channels. The Ca²⁺ transport could be changed by exogenous H₂O₂. H₂O₂ of low concentration reduced the absorption rate of Ca²⁺, and at high concentration, it changed the Ca²⁺ transport direction from absorption to release. The results indicated that H₂O₂ signals were related with Ca²⁺ signals in dormant buds. Ca²⁺ signal regulated by H₂O₂ accumulation might be important in the dormancy breaking signal transduction process induced by high temperature and hydrogen cyanamide.