Dynamic Model Of Blue-light-induced Cooperation Modulations Of Cryptochrome 1 And 2 In Photomorphogenesis

Plants are sessile and photo-autotrophic.In order to sense the ever-changing environment,higher plants have three types of photoreceptor families for specific light.These photoreceptors mediate plant adaptive responses and development.Light as a signal can induce changes in the morphology of seedlings,so that the seedlings grow from beneath the soil to a state that is more adaptive to growth above the ground.This process is called as photomorphogenesis.The blue-light receptors(Cryptochrome 1/2,CRY1/2)plays an important role in promoting the photomorphogenesis of plants.In the past few decades,individual genetic and molecular studies have revealed that CRY1 and CRY2,as the two kinds of blue-light receptors.However,it is unclear that how CRY1 and CRY2 signaling pathway systematically and comprehensively perform the same and different function.And it will also be exciting to know the internal detailed mechanisms of the regulation of plant growth and development.Therefore,in our research,we first use a system biology approach to develop a mathematical model to investigate difference and correlations of corresponding photoresponses of CRY1 and CRY2 at a temporal and intensity-involved scale.(1)A integration and the establishment of model of the blue-light response of Arabidopsis,and the prediction and experimental verification about the role of BIC protein in the plant growth response.Firstly,we established a systemic network model of the CRY 1-and CRY2-induced signaling pathways.Based on the model,we predicted the influence of protein BIC on the signal transduction process of CRY1 and CRY2,respectively.The results showed that protein BIC precede to interact with CRY2 receptors.The interaction makes the inhibition of CRY2 phosphorylation more sensitive to the dose of BIC.The results reveal that BIC has a significant inhibitory effect on CRY2-induced physiological response of plants,and is of vital importance in maintaining appropriate homeostasis between activity and inactivity of CRY2 and sustainability of cellular photosensitivity.Subsequently,the experimental results are consistent with our predicted results in terms of irradiation time or fluence-rate of blue light.The model is proved that it has significance and predictability in the internal mechanism of CRY 1 and CRY2 co-regulating plant growth and development in response to blue light.(2)An explanation for the different phosphorylation responses caused by CRY1 and CRY2.The two types of blue light receptors have the same signaling pathway,but they induce different phosphorylated light responses.In our research,we explored the causes of the two types of response patterns by changing the parameters of different responses in the CRY1 and CRY2 signaling pathway.The results show that CRY2 special bell-shaped response curve is connected with its fast phosphorylation and degradation.(3)The prediction for the cooperative mechanism of CRY1 and CRY2.Our model computational forecast a coordinated mechanism of two kinds of cryptochromes that production of CRY1 is positive mediation to CRY2 phosphorylation response under blue light irradiation thought COP 1-SPA complex.Subsequently,we mathematically prove that more CRY 1 is concerned with regulating form of HY5.