Isolation and expression analysis of eight MADS-box genes in peach (Prunus persica var. nectarina ‘Luxing’)

Abstract

The MADS-box transcription factor (TF) plays a crucial regulatory role in plant vegetative growth, flower and fruit development. Eight MADS-box genes (designated as PpMADS15, 16, 17, 26, 27, 36, 37, 38; GenBank accession nos. KU559581, KU559582, KU559583, KU559592, KU559593, KU559602, KU559603, KU559604, respectively) were isolated from ‘Luxing’ (Prunus persica var. nectarina ‘Luxing’) peach by homologous comparison and RT-PCR, which contained open reading frames (ORF) of 597, 750, 1062, 615, 699, 1 107, 678 and 564 bp, respectively. The results of phylogenetic analysis revealed that PpMADS15 belonged to the AG subgroup, PpMADS16 to the SEP subgroup, PpMADS17 to the MIKC* group, PpMADS26, 27, and 38 to the Mα group, and PpMADS36 and 37 to the Mγ group. The results of the prediction for subcellular localization showed that eight PpMADS proteins were located in the nucleus. The results of promoter analysis indicated that there were multiple putative cis-acting elements that were involved in responsiveness to the following variables: light, defense and stress, low-temperature, heat stress, wound, fungal elicitor, anaerobic induction, MeJA, gibberellin, ABA, auxin, and SA. RT-PCR results showed that PpMADS15 was expressed in leaves, stems, roots, sepals, ovaries, stamens, petals, during flower and fruit development. PpMADS16 was expressed in stems, sepals, ovaries, stamens, petals, during flower and fruit development. PpMADS17 was expressed in stems, sepals, ovaries, stamens, petals, during flower and fruit development (except for 30 d). All members in the Mα and Mγ subgroups were expressed in roots, stems, leaves, sepals, ovaries, stamens, petals and during flower development, but PpMADS27 was expressed only during fruit development. These results suggested that eight PpMADS genes played a crucial regulatory role in vegetative growth, flower and fruit development of peaches.