[Objective] This study was to observe the trends of chemical signals when the different resistant individuals of Pinus massoniana had been inoculated with pine wood nematodes,in order to provide the theoretic support for clarifying the resistant mechanism of infected trees of P.massoniana.[Method]The high resistant and susceptible clones had been selected following a serious of breeding produce.The dynamic variation of signal moleculars including H2O2,O2,NO and Ca2+ was detected in needles of different resistant clones at 1,3,7,15 and 30 d post inoculation (dpi).[Result]The results showed that a large number of pine wood nematodes were detected in different parts of susceptible clones,while no nematodes were found in the high resistant clones.The H2 O2 content significantly increased in different resistant clones at 1,3 and 7 dpi.The H2O2 content in high resistant ones was returned to the health level after 15 dpi but the susceptible ones rose sustainably.As a result,the H2O2 content in susceptible clones was 1.77 times higher than that in resistant ones.The O2 content also significantly increased in both resistant and susceptible clones during 1 to 15 dpi.They had a same trends and no significantly differences.The high resistant clones reduced the O2 content at 3P dpi but the susceptible ones still increased it.There was no significant difference in NO content between high resistant clones and the control group during 1 to 15 dpi.It was significantly higher than control group at 30 dpi.However,the NO content in susceptible ones was significantly higher than that of the control group and high resistant ones at each time point.The variation trend of Ca2+ content was similar between different resistant clones post inoculation.They both performed in an up-down-updown trend.The Ca2+ content of high resistant clones was significantly higher than that of control group and susceptible ones at 1 dpi and 15 dpi.However,the Ca2+ content of high resistant clones maintained at an ordinary level at the other time points.The Ca2+ content of susceptible clones was significantly higher than that of control group at each point.[Conclusion] The content of H2O2,O~ and Ca2+ would increase rapidly when the pines were invaded by nematode.They could induce defensive response as signal moleculars.The high resistant clones had an effective way to control signal molecular content and finally returned to normal physiological metabolism.However,the susceptible ones could not control and the excessive ROS and Ca2+ would damage the plants.NO content was stable in the high resistant clones post inoculation.But it was accumulated at each time point in susceptible ones.The redundant NO is harmful for P.massoniana metabolism.%[目的]研究不同抗性马尾松防御松材线虫病过程中针叶内一些信号分子的变化规律,为阐明马尾松的抗性机制提供理论依据.[方法]对经严格程序选育的高抗和易感马尾松在接种松材线虫后第1、3、7、15、30天时针叶内H2O2、O2-、NO-和Ca2+等信号分子含量进行动态监测.[结果]接种松材线虫后,易感马尾松体不同部位均检测到大量松材线虫,而高抗马尾松体内未发现松材线虫.在接种后第1、3和7天,高抗与易感马尾松针叶内H2O2含量显著升高;但高抗马尾松在接种后15天,针叶内H2O2含量逐渐恢复到正常水平,而易感马尾松针叶内H2O2含量仍继续升高,在接种后30天,易感马尾松针叶内H2O2含量约为高抗马尾松的1.77倍.高抗和易感马尾松针叶内O2-含量在接种松材线虫后1～15天也显著升高,高抗与易感马尾松针叶内O2-含量差异不显著,且变化趋势一致;接种后30天,高抗马尾松针叶内O2-含量较前期显著下降,而易感马尾松针叶内O2-含量仍继续增加.高抗马尾松针叶内NO含量在接种松材线后1～15天与对照差异不显著,仅在接种后30天才显著高于对照.而易感马尾松在接种松材线虫后每个时间点,针叶内NO含量显著高于对照和高抗马尾松.高抗和易感马尾松在接种松材线虫后针叶内Ca2+含量变化趋势基本一致,呈现“升-降-升-降”趋势,但高抗马尾松除在接种后第1、15天针叶内Ca2+含量显著高于对照和易感马尾松外,其他时间点皆保持在正常水平,而易感马尾松针叶内Ca2+含量在任何时间点均显著高于对照.[结论]接种松材线虫后,针叶内H2O2、O2-和Ca2+均迅速升高,作为信号分子诱导防卫反应,且高抗马尾松能有效控制其在体内的含量,最终恢复到正常生理代谢水平,而易感马尾松不能有效控制,多余的ROS和Ca2+会对植株产生毒害.接种松材线虫后高抗马尾松针叶内NO含量在体内的变化基本不明显,但易感马尾松体针叶内内在每个时间点均积累了过多的NO,不利于植株正常代谢.
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