Calcium Iron And Zinc Vegetative Growth Regularity And Specific Calcium Binding Protein Function Of The Stipa Linn.

The Stipa capillata Linn.belongs to a member of the gramineous plants and is the common forage grasses with high nutritional value in the northern grassland of China.In the vegetative growth stage,grazing cattle and sheep like eating it.The nutrition of calcium,iron and zinc in the leaves of Stipa directly affects the nutrition of the grassland livestock eating Stipa.And it has good adaptability to the poor mineral nutrition and saline-alkali conditions of natural grassland soil.On the one hand,this study used the established hydroponic system to study the effect of root pH and the nutrition of calcium,iron and zinc on the vegetative growth of Stipa grandis and Stipa breviflora,as well as the regulation of leaf calcium,iron and zinc.On the other hand,three calmodulin-like protein?Calmodulin-likeprotein,CML?genes that can promote plant growth under low calcium and abscisic acid?ABA?stress were identified.The main experimental conclusions are as follows:?1?When the roots grew in the hydroponic solution of pH 5.7,the treatments of Ca²⁺,Fe²⁺and Zn²⁺with different solubility had no significant regulating effect on the growth of the roots and leaves of Stipa grandis.However,under the condition of pH 7.5,the depletion of Ca significantly inhibited the growth of roots and leaves.Under the condition of pH 5.7 and 7.5,high concentration of Fe²⁺?20×,20 times higher than CK?significantly increased the content of Fe in leaves,inhibited the accumulation of Zn in leaves,but had no effect on the content of Ca.?2?When the roots were grown in the solution of pH 5.7 and 7.5,high concentrations of Ca²⁺and Zn²⁺?20×?significantly inhibited the growth of roots and leaves of Stipa breviflora.Fe depletion significantly inhibited the growth of roots and leaves only under the condition of pH 7.5.Under the condition of pH 5.7 and 7.5,high concentration of Fe²⁺?20×?significantly increased the content of Fe and inhibited the accumulation of Zn in leaves.High concentration of Ca²⁺?20×?only inhibited the accumulation of Fe and Zn in leaves under the condition of pH 7.5.Under the condition of pH 7.5,Fe deficiency inhibited the accumulation of Fe in leaves,but increased the content of Zn in leaves.?3?Based on the analysis of the sequence data of Stipa breviflora transcriptome,seven calmodulin protein genes,?SbCMLs?,which are unique to Stipa breviflora,which are different from Arabidopsis thaliana,were screened.It was found by the method of tobacco transient transformation that SbCML21-GFP,SbCML36-GFP,and SbCML45-GFP were located on the endoplasmic reticulum of the plant cells.?4?We overexpressed SbCMLs in Arabidopsis thaliana,three of which ?35S::SbCML21,35S::SbCML36,35S::SbCML45?enhanced the growth of transgenic plants under the conditions of Ca²⁺depletion and ABA treatment.Among them,the mechanism of the effects of pH and calcium,iron and zinc on the vegetative growth of Stipa grandis and Stipa breviflora and the signal transduction pathways related to calmodulin proteins in Stipa breviflora are not clear,which need to be proved by further experiments.