苹果SUPERMAN家族基因的组织特异表达及MdSUP3的功能分析

Expression Analysis of the SUPERMAN Family Genes in Apple(Malus × domestica Borkh.)and Function Analysis of MdSUP3

通过半定量RT-PCR分析SUPERMAN家族基因在‘富士’苹果(Malus×domestica Borkh.‘Fuji’)叶芽、幼叶、花芽、花蕾、花、皮部组织和幼果中的表达模式,通过MdSUP3自主启动子驱动的GUS基因表达和MdSUP3异位表达分析其功能。结果表明,MdSUP3、MdSUP11和MdSUP9a在所检测的组织器官中均有表达,MdSUP9b主要在营养器官中表达,MdSUP5a、MdSUP1b主要在生殖器官中表达。MdSUP3启动子驱动GUS基因在植株根尖、幼叶、幼茎和花等器官中表达。超表达Md SUP3的转基因烟草植株矮化、节间缩短、叶片卷缩、花器官颜色改变和部分花器官形态异常;与对照相比,转基因烟草中ABA合成酶基因NtNCED3-2,花青素合成途径的NtDFR2和NtANS1基因表达显著上升,细胞分裂素氧化酶基因NtCKX和赤霉素氧化酶基因NtGA2ox4表达显著下降。异位过量表达删除C端DLELRL基序的MdSUP3基因不影响转基因烟草的生长发育,证明DLELRL是基因必不可少的功能域。

Semi-quantitative RT-PCR technique were used to reveal the expression patterns of Md SUPs in leaf buds,young leaves,flower buds,unopened flowers,flowers,bark tissue and young fruits of Malus × domestica Borkh.‘Fuji＇. Expression of GUS driven by MdSUP3 native promoter and ectopic over-expression of the MdSUP3 gene were adopted to analyze the function of this gene. The results showed that the expressions of MdSUP3,MdSUP11 and MdSUP9 a were detected in all tested tissues. MdSUP9 b mainly expressed in vegetative organs,while MdSUP5 a and MdSUP1 b mainly expressed in reproductive organs. The GUS expression was observed mainly in roots,young leaves,young stems and flower organs in the transgenic Arabidopsis. Over expression of MdSUP3 in tobacco induced morphological changes,such as dwarfism,shortened internodes,curly leaves,changed flower color and abnormal floral organs. The expression levels of the NtNCED3-2 related to ABA biosynthesis and NtDFR2 and NtANS1 related to anthocyanin biosynthesis were significantly increased while NtCKX（cytokinin oxidase/dehydrogenase）and a gibberelin 2-oxidase gene NtGA2ox4 were significantly decreased in the transgenic tobacco plants compared to that in the wild types. Over-expression of the MdSUP3 without the DLELRL motif did not generated morphological changes in transgenic tobacco plants,which indicated that DLELRL motif was essential for the function of MdSUP3.