脱落酸对苹果柱型基因MdCoL表达的影响

Effects of Abscisic Acid Treatment on Apple Columnar Gene MdCoL Expression

树型结构对果树整形修剪和果园管理至关重要,柱型苹果(columnar apple)是进行苹果省力化育种的重要种质资源。脱落酸(abscisic acid,ABA)作为一种负调控植物生长的植物激素被认为是研究苹果柱型性状的关键点。为进一步分析柱型性状和ABA之间的关系,本试验利用外源ABA及其生物合成抑制剂氟啶酮(fluridone)处理柱型和普通型苹果,通过qRT-PCR分析苹果中柱型性状调控基因MdCoL与ABA生物合成及信号转导相关基因表达水平的变化,并比较分析外源ABA处理对普通型和转MdCoL本生烟株系表型变化及ABA生物合成和信号转导相关基因表达情况的影响。结果显示,外源ABA处理不仅可以促进苹果中MdCoL的表达,还可以促进ABA生物合成和信号转导相关基因的表达。氟啶酮可抑制苹果中MdCoL的表达,还可以通过下调ABA生物合成相关基因和上调ABA信号转导的负调控因子MdWRKY来影响ABA的信号转导。转MdCoL可以促进本生烟中ABA生物合成和信号转导相关基因的表达;外源ABA处理可显著改变野生型本生烟的表型,使之呈现出类似转基因烟草的短分枝现象。综上所述,外源ABA处理可促进MdCoL的表达,调控苹果柱型性状形成。

Plant architecture is very important for pruning and managment in orchards.Columnar apple is an important germplasm for breeding labor-saving apple trees.Abscisic acid(ABA)as a plant hormone negatively regulating plant growth is considered to be a key point in the research of apple columnar traits.In order to further analyze the relationship between columnar habits and ABA,the expression levels of MdCoL and ABA biosynthesis and signaling genes were analyzed using qRT-PCR after exogenous hormone ABA and fluridone treatments in McIntosh(columnar apple)compared with common apple.Meanwhile,the wild and MdCoL transgenic lines of Nicotiana benthamiana were also treated with exogenous ABA,and then the differences in phenotype and expression level of MdCoL and ABA biosynthesis and signaling related genes were analyzed.The results showed that exogenous ABA could promote the expression of not only MdCoL but also the ABA biosynthesis and signaling related genes in apple.Fluridone treatment inhibited the expression of MdCoL in apple,and influenced ABA signal transduction through down-regulating ABA biosynthesis related genes and up-regulating the negative regulatory factor MdWRKY.The ABA biosynthesis and signaling related genes were also up-regulated in transgenic Nicotiana benthamiana.Exogenous ABA changed the phenotype of wild Nicotiana benthamiana significantly which was similar to MdCoL transgenic lines with short branching.In conclusion,exgenous ABA could increase the expression of MdCoL and further regulate the formation of columnar traits of apple.