Ethylene response factors 2(ERF2) are essential for plant growth, fruit ripening, metabolism, and resistance tostress. In this study, the expression levels of the genes for MdERF2 implicated in the biosynthesis, compo...Ethylene response factors 2(ERF2) are essential for plant growth, fruit ripening, metabolism, and resistance tostress. In this study, the expression levels of the genes for MdERF2 implicated in the biosynthesis, compositionand ultrastructure of fruit cuticular wax in apple(Malus domestica) were studied by the transfection of apple fruitand/or calli with MdERF2-overexpression(ERF2-OE) and MdERF2-interference(ERF2-AN) vectors. In addition,the direct target genes of MdERF2 related to wax biosynthesis were identified using electrophoretic mobility shiftassays(EMSAs) and dual-luciferase reporter(DLR) assays. The findings indicated that the expression levels offour wax biosynthetic genes, long-chain acyl-CoA synthetase 2(MdLACS2), eceriferum 1(MdCER1), eceriferum4(MdCER4), and eceriferum 6(MdCER6), were upregulated by ERF2-OE. In contrast, the expression levels ofthese genes were inhibited when MdERF2 was silenced. Furthermore, the overall structure and accumulationof fruit cuticular wax were influenced by the expression level of MdERF2. Treatment with ERF2-OE significantlyincreased the proportions of alkanes and ketones and reduced the proportions of fatty acids and esters. In addition,the EMSAs and DLR assays demonstrated that MdERF2 could bind directly to GCC-box elements in the promotersof MdLACS2, MdCER1, and MdCER6 to activate their transcription. These results confirmed that MdERF2 targetsthe up-regulation of expression of the MdLACS2, MdCER1, and MdCER6 genes, thereby altering the composition,content, and microstructure of apple epidermal wax.展开更多
基金supported by the National Natural Science Foundation of China (32272384)the Natural Science Foundation of Shandong Province, China (ZR2020MC149)。
文摘Ethylene response factors 2(ERF2) are essential for plant growth, fruit ripening, metabolism, and resistance tostress. In this study, the expression levels of the genes for MdERF2 implicated in the biosynthesis, compositionand ultrastructure of fruit cuticular wax in apple(Malus domestica) were studied by the transfection of apple fruitand/or calli with MdERF2-overexpression(ERF2-OE) and MdERF2-interference(ERF2-AN) vectors. In addition,the direct target genes of MdERF2 related to wax biosynthesis were identified using electrophoretic mobility shiftassays(EMSAs) and dual-luciferase reporter(DLR) assays. The findings indicated that the expression levels offour wax biosynthetic genes, long-chain acyl-CoA synthetase 2(MdLACS2), eceriferum 1(MdCER1), eceriferum4(MdCER4), and eceriferum 6(MdCER6), were upregulated by ERF2-OE. In contrast, the expression levels ofthese genes were inhibited when MdERF2 was silenced. Furthermore, the overall structure and accumulationof fruit cuticular wax were influenced by the expression level of MdERF2. Treatment with ERF2-OE significantlyincreased the proportions of alkanes and ketones and reduced the proportions of fatty acids and esters. In addition,the EMSAs and DLR assays demonstrated that MdERF2 could bind directly to GCC-box elements in the promotersof MdLACS2, MdCER1, and MdCER6 to activate their transcription. These results confirmed that MdERF2 targetsthe up-regulation of expression of the MdLACS2, MdCER1, and MdCER6 genes, thereby altering the composition,content, and microstructure of apple epidermal wax.
