植物防卫的碳-养分平衡假说

碳-养分平衡假说(carbon-nutrient balance hypothesis,CNBH)认为,植物组织中次生代谢物浓度受环境碳-资源有效性控制;植物体内次生代谢物按照化学计量的要求进行分配;资源分配给防卫物的必要条件是资源供应量满足植物生长需求后仍过剩。CNBH自提出以来,其适用范围不断受到限制,解释与预测研究结果的能力逐渐显现不足。期间,对CNBH进行过优化和修改,设置了多种限制条件,以期能使CNBH得到补救,继续成为指导植物-草食动物间相互作用和植物体内资源分配的相关理论。然而,随着研究的逐渐深入,CNBH被证实缺乏逻辑性和内在一致性;CNBH不能满足假说本身的发展要求,缺乏明确可行的量化指标体系,也没有明确地标识出理论预测范围与可测试范围之间的界限。研究表明,CNBH的基本假设本身是错误的;随着人们对植物-草食动物间相互作用的认知能力加强,更深刻地认识到资源在植物体内的分配模式,意识到CNBH假说的严重缺陷。在现有的植物防卫理论中,生长-分化平衡假说(growth-differentiation balance hypothesis)较为成熟,不但具有CNBH的优点,而且更具有植物生理学和进化...

Carbon-nutrient balance hypothesis on plant defense

Carbon-nutrient balance hypothesis(CNBH) consists of the ideas that the concentration of secondary metabolites in plant tissues is determined by the availabilities of carbon and other nutrients in environment,the allocation of defensive compounds in plant tissues is dependent on basic stoichiometric requirements,and the prerequisite of resources allocation to defensive compounds is the excess of resources in satisfying plant growth.Since the introduction of CNBH,its applicability has been more restricted,and its ability in predicting and explaining experimental outcomes has become less powerful.To remedy the shortcomings of CNBH and make it continuously guide the studies of the interactions between plant and herbivore,and of the effects of resources availability in plant defense and growth,some refinements and modifications to the CNBH were made.But,instead of salvage,some natural flaws exposed more apparently.Some researches elucidated that CNBH was no longer a general or internally consistent model.With the progress in relevant researches,there is a considerable dissatisfaction to CNBH.The basic assumptions of CNBH are now known to be incorrect,and there exist alternative approaches,such as growth-differentiation balance hypothesis(GDBH),among which,GDBH is most mature on plant defense.The GDBH not only shares the benefits of CNBH,but also possesses more complete mechanistic basis in plant physiology and evolution,resulting in taking the place of CNBH.