Effects Of Exogenous Calcium On Drought Resistance And CBLs And CIPKs Gene Expression Of Camellia Sinensis

In this paper,we applied 10mmol/L exogenous Ca Cl2 to the one-year-old Shu Cha Zao cutting seedlings,and carried out drought treatment under natural conditions simultaneously with no exogenous Ca Cl2.Four drought time points of 0d,7d,14 d,21d were set,and the relative water content of leaves,free proline content,malondialdehyde content,osmotic potential,chlorophyll fluorescence,POD,CAT activity,etc.were determined respectively and directly related to drought stress.Related physiological data,and took photos during the drought to record the physiological changes of tea seedlings.The following results were obtained:The relative water content of tea leaves decreased with the extension of drought time.Compared with CK,the relative water content of the treatment group decreased relatively lower from 0 to 14 days,to 52.78%and 45.74%,respectively,and the drought was more severe from 14 to 21 days.Both处理组and CK dropped to 19.76%and 19.78%.Free proline showed an increasing trend with the extension of drought time.CK had a relatively high growth rate from 7 to 14 days.By the end of the experiment on 21 days,the proline content of the treatment group and CK were 43.81μg/g-1,39.75,respectively.μg/g-1.The content of malondialdehyde reached the highest at 21d,and there was no significant difference between the content of处理组and CK at 0-14d.The MDA content of 21d处理组was 46.36nmol/g-1 and CK was 51.80nmol/g-1.The osmotic potential decreased with time.There was a significant difference between CK and处理组at 14d and 21d,which were-2.37bar and-1.85bar at 14d;-2.64bar at 21d,and-1.70bar.Drought stress also caused PSⅡin tea plants.Injury,Fv/Fm gradually decreased with the increase of time,and the decrease in treatment group was smaller than that of CK.The activity of POD and CAT also increased with time.CAT reached the peak at 14d,and the activity of the treatment group was higher than that of CK;the activity of POD reached the peak at 14d and then decreased,and the activity of the treatment group was higher than that of CK.At the same time,this article screened and identified 8 Cs CBL and 28 Cs CIPK from the tea tree genome annotation database,and conducted bioinformatics analysis of these genes and proteins,and obtained 2 Cs CBL and 4 Cs CIPK gene full lengths through cloning.Gain a certain understanding of the CBL-CIPK signal transduction network of tea tree.At the same time,using the total RNA reverse transcribed c DNA extracted from the treated tea seedling samples as a template,the expression patterns of Cs CBL and Cs CIPK under drought stress were analyzed by q RT-PCR.Under drought stress,Cs CBL2/7 showed a high degree of sensitivity up-regulation,but Cs CBLs could respond to drought stress as a calcium-binding protein.The expression level of Cs CBLs处理组was higher than that of CK.Cs CIPK1/2/3/6/7/9/14/20/21 is sensitive to drought stress,with a high degree of upregulation.CIPK1/2/3/6/79/14/15/21/22 is significantly different between the control group and the treatment group,indicating that these genes are sensitive to calcium,and exogenous calcium can induce their expression.