苹果腺苷-异戊烯基转移酶基因的组织表达分析

Expression analysis of the adenylate-isopentenyl transferase(A-IPT) genes in apple(Malus×Domestica Borkh.)

为深入研究MdIPTs基因在苹果细胞分裂素合成途径中的作用和利用转基因技术改良苹果树型,分析苹果(Malus×Domestica Borkh.)A-IPTs基因的时空表达,本研究以‘富士’苹果(M.Domestica Borkh.cv.Fuji)及其组培苗为试材,利用半定量RT-PCR方法分析7个A-IPTs基因在梢尖、幼叶、茎段节间、皮部组织、叶芽、花芽、花蕾、花、幼果和根部的表达水平。结果表明:MdIPT3a总体表达水平最高、MdIPT1b次之,在所检测的器官组织中均有表达;MdIPT5a在花蕾和花中表达量高,MdIPT5b在梢尖和幼叶中表达量高;MdIPT1a在根、皮部组织和叶芽中检测到微弱表达,MdIPT3b仅在组培苗的茎段中节间微弱表达;所检测的组织器官中未检测到MdIPT7a表达。苹果7个A-IPTs基因具有组织表达特异性,高度同源的成对基因的组织表达模式不同。

Tissue-specific expression of the A-IPTs genes in apple（ Malus × Domestica Borkh. ） were analyzed for further study of roles of MdlPTs in cytokinin biosynthesis and modifying tree form by genetic transformation in apple. In this study,the ＇Fuji＇ apple（M, domestica Borkh. cv. Fuji） and its plantlets in vitro were used as materials and semiquantitative reverse transcription-polymerase chain reaction （RT-PCR） was conducted to study expression levels of seven A-IPTs in shoot tips, young leaves,internodes,bark tissues, leaf buds, flora buds, flowers at balloon stage,open flowers,young fruits and roots of ＇Fuji＇ apple. The results showed that MdlPT3a and MdlPTIb were detected in all tested tissues and organs. The expression lever of MdlPT3a was higher than that of MdlPTlb. MdlPT5a expressed highly in flowers, while MdlPT5b in shoot tips and young leaves. The weak expression of MdlPTla was detected in roots,bark tissue,and leaf buds,while MdlPT3b was only detected in internodes of plantlets in vitro. MdlPT7a wasn＇t detected in all tested tissues. Seven A-IPTs exhibit tissue-specific expression and highly homologous genes in pairs in apple had different expression profiles.