Abstract: 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.

Key words: Seed germination, Seedling growth, Arabidopsis