| SlPLL5 has been identified as a PP2 C,belonging to the C branch of PP2C.PP2Cs are the plant protein phosphatases with the largest population identified at present,which play a crucial role in plant growth,development,signal regulation and other aspects.Tomato is an important vegetable crop that is widely planted,and is also widely used in the study of plant growth and development as a model crop.Therefore,it is of great significance to study the role of SlPLL5 in tomato growth and development for us to more accurately understand the effect of PP2 C on tomato agronomic traits,and it is also of great reference significance for the study of PP2 Cs in other crops.In this study,the interaction between SlPLL5 and SlBIN2,an important component of brassinosterol(BR)signal,was found by yeast two-hybridization,and the interaction between SlPLL5 and Sl BIN2 on the cell membrane was verified by bilayer fluorescence complementation assay.SlPLL5 was overexpressed in tomato by Agrobacterium-mediated cotyledon transformation,and three overexpression lines with high,medium and low expression levels were used as the research materials.Abscisic acid(ABA)and BR had antagonistic effects.The response of SlPLL5 to ABA signal was investigated by seed germination and root length test after ABA treatment.The effect of SlPLL5 response to ABA signal on tomato drought tolerance was studied by drought treatment in tomato seedling stage.In order to study the effect of SlPLL5 overexpression on tomato agronomic traits,three lines with different levels of SlPLL5 overexpression were planted in the experimental field with tomato commercial variety Moneymaker(MM)as the control.The main results of this study are as follows:(1)GV3101::p BI121-35S-SlPLL5-GFP was transfected into tobacco by agrobacterium-mediated transient transformation method.The subcellular localization of SlPLL5 was observed by fluorescence microscopy,and SlPLL5 was found to be a membrane-localized PP2 C.GV3101::p ER8-SlPLL5-Ce YFP and GV3101::p ER8-Ne YFP-Sl BIN2 were transfected into tobacco leaves,and the interaction between SlPLL5 and Sl BIN2 on the cell membrane was observed by laser confocal display micromicroscopy.(2)GV3101::p BI121-35S-SlPLL5-GFP was genetically transformed into tomato MM wild type by agrobacterium-mediated cotyledon transformation method,and SlPLL5 overexpression lines were obtained,and three lines OE1,OE2 and OE3 with large difference in expression levels were screened out.(3)The seeds of OE1-OE3 lines were treated by ABA with MM as the control,and it was found that the seed germination rate and root length of OE1-OE3 lines were significantly lower than that of MM lines.q PCR analysis of ABA response genes in OE1-OE3 lines showed that the expression levels of ABA response genes in OE1-OE3 lines were significantly up-regulated compared with that in MM lines.Both results preliminarily indicate that SlPLL5 overexpression enhances ABA signaling.(4)With MM as the control,OE1-OE3 lines were subjected to drought treatment.After 5 days of drought treatment,the plant wilting degree of OE1-OE3 lines was significantly lower than that of MM.Moreover,the relative water content,MDA content and antioxidant enzyme expression level of leaves in the process of drought treatment were analyzed,and the results showed that OE1-OE3 lines were more drought tolerant than MM.(5)Using MM as the control,the agronomic traits of OE1-OE3 lines were measured and analyzed.It was found that after SlPLL5 overexpression in tomato,leaf curling was serious,leaf area decreased,leaf length-width ratio increased,photosynthesis weakened,fruit ripened later,fruit became smaller,yield decreased,and quality decreased. |
PDF Full Text Request