竹子水分生理整合特征及其脱落酸信号调控机制

竹子是我国重要的森林资源，也是一类典型、高度木质化克隆植物。竹鞭持续延伸和笋芽时序萌发形成大面积竹纯林。当前气候变化导致降水格局改变和季节性旱涝日趋频繁，竹林内水分时空异质性不断增强，然而异质生境竹子分株间水分传导与信号调控尚未得到充分阐释。本项目以美丽箬竹(Indocalamus decorus)为试材，采用H2O18和D2O同位素标记技术，研究异质水分生境下竹子水分生理整合条件、方向、强度与效率，阐明竹子水分生理整合特征；并在此基础上，采用脱落酸(ABA)合成抑制与中间产物标记法，研究异质水分生境下竹子分株ABA信号响应规律，ABA信号传导方向、强度及其与水分传输耦合关系，揭示生理整合的ABA信号调控机制。本项目研究将有助于揭示克隆植物耐受胁迫与种群维持、扩张机制，并将拓展对竹子耐受水分胁迫策略、限制性资源分配理论与觅养机制认识，为竹林生产力稳定与提高的水分管理和节水经营提供理论依据。

Bamboos are typical clonal plants that are highly lignified. They are an important forest resource in China. Elongation of bamboo rhizomes and sprouting of shoot buds, result in widespread pure bamboo forests in southern China. In recent years, seasonal drought and waterlogging occur more severely and frequently, and temporal and spatial heterogeneity of water resource in bamboo forests has been strengthened. These changes will influence bamboo growth and sustainable development of bamboo forests. However, the regulation mechanisms of water transport processes among interconnected bamboo ramets in heterogeneous habitats are not well known. We will disclose the characteristics of water physiological integration in Indocalamus decorus by examining the direction, intensity and efficiency of integration using H2O18 and D2O isotope technique. We will also investigate the response of abscisic acid (ABA) of bamboo ramets to heterogeneous water supply, and clarify the transport direction, strength and distribution pattern of ABA within bamboo ramets using ABA synthesis inhibitor and 14C-xanthoxin tracer. We aim to explicate the mechanism of ABA as signals for regulating water physiological integration among bamboo ramets. Our findings will help understand mechanisms of clonal plants to tolerate stress and to maintain and spread their populations. The findings will also give insight into strategies of bamboos to tolerate water stress, to allocate resources and to forage resources, and provide useful information for effective management of bamboo forests.