初生根伸长对环境响应的数学模型

A Mathematical Model for the Response of Primary Root Elongation to Environment

在根组织细胞分裂和细胞体积增大亚过程基础上,建立了一个综合根生长特征参数和环境影响在内的单根伸长的数学模型,同时实验观测了大豆根在不同的环境水势下的生长过程。模型计算结果与实验结果吻合较好。最后利用模型探讨了根伸长对环境因子变化的响应,以及根内水势分布。

In order to quantify the response of rootelongation to environment, a mathematicalmodel of single root elongation has been de-veloped based on submodels for irreversibleelongation and division of meristematic cells.The osmoregulation (eq.6) and hardening ofcell wall with age (eq. 2)has been incorporatedin the model. Water absorption and trans-port of root (eq. 3) are also included in themodel. The equations used in the model weresolved by numerical integration on IBM/PCAT. Meanwhile, measurements of primaryroot elongation of soybean under differentwater potentials were made to validate themodel. The results showed that the modelsimulated well the observational data of rootelongation (Fig. 1). The model was furtherused to analyse the dynamics of root elongationunder different water potentials. It has beenshown that (1) the rate of root elongationdecreased with a decrease of water potential(Fig. 3); (2) immediately after the onset of awater potential drpp (from 0 to -0.2 MPa),the rate decreased for one day, then increasedgradually to about the same level as the origi-nal (Fig.4); (3) the water potential withinroot increased gradually with the distancefrom the root tip (Fig. 6).