| Gray mold is a kind of common harmful fungus disease in tomato,which appeared in lots of tomato-producing region around world.At present,the prevention and control of tomato gray mold in our country mainly depend on chemical control.However,the continuous application of chemicals result in developping resistance of the bacteria,and the pollution of pesticide and environment.Therefore,it is urgent to find out the biological control method which is good control effect,pollution-free and according with the standard of organic agriculture.Calcium,as a nutrient element with the most abundant function in plants,can be actively involved in the plant immune response.Based on the study of exogenous calcium ion concentration and endogenous calcium library affecting resistance of gray mold in tomato,analyzing of how PM calcium pumps ACAs and stomata in Arabidopsis thaliana to involve in plant growth,development and plant immunity.This can provide theoretical basis for the development of new disease prevention and control strategies in plants.This study includes the following aspects:(1)Based on the hydroponic method to culture tomato plants,setting five gradient exogenous Ca2+ and with or without Botrytis cinerea.It is found that 7.50 mM Ca2+ efficiently decreased the generation of ROS and enhanced tomato disease resistance.Then measuring the contentrations of Ca2+,salicylic acid(SA),phenylalanine ammonia-lyase(PAL),and calmodulin(CaM)in leaves.It is shown that Ca2+ induces SA biosynthesis by activating PAL.High contentration of Ca2+ had a negative effect on PAL activation,which then inhibited SA synthesis.After innoculation of Botrytis cinerea,plants growing in nutrient solution containing 7.50 mM Ca2+ could induce a steady flow of CaM.And the concentrations of Ca2+-CaM and SA were negative correlated in plant immune response.(2)It is explored the relationship between endogenous calcium library and tomato gray mold through spraying on the leaf surface with intracellular calcium chelator BAPTA-AM and extracellular calcium chelator EGTA.It has been found that without the application of external calcium,12h after innoculation of Botrytis cinerea,endogenous calcium library was considered as an important factor to induce calcium oscillation under pathogen innoculation.Therefore,in the plant immune response,calcium signaling depend on not only the application of exogenous calcium,but also the release of the endogenous calcium library,which is complementary on some extent.(3)In the above two conditions,it is measured the expression of LCA1 as the calcium pump gene in tomato plants.It is found that the higher of gene expression,the lower of resistance to tomato gray mold,which indicated that calcium pump was correlated with plant immune response.Therefore,the model plant Arabidopsis is used to analyze the contribution of four PM-localized Ca2+ ATPases ACA8,ACA10,ACA12 and ACA13 in plant growth and immunity.It is found that ACA8 and ACA10 are more important than ACA12 and ACA13,which both are vital in the condition of loss-of-function of ACA8 and ACA10.(4)pGC::BON1/bon1 and pGC::SNC1 transgenic plants are used to make sure BON1 and SNC1 specific expressing in the guard cells of different background of Arabidopsis.Baesd on measuring ABA and pathogen induced stomatal movement and disease resistance of transgenic plants,it is found that BON1 is the positive regulation factor of stomatal movement and and negative regulation factor of plant disease resistance;SNC1 is the negative regulation factor of stomatal movement and and positive regulation factor of plant disease resistance.Meanwhile this illustrated the important relationship between stomatal movement and plant immune response. |
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