title: Genome-Wide Identification and Expression Analysis of the Tubby-Like Protein Family in theMalus domesticaGenome.
abstract: Tubby-like proteins (TLPs), which have a highly conserved β barrel tubby domain, have been found to be associated with some animal-specific characteristics. In the plant kingdom, more than 10 TLP family members were identified inArabidopsis, rice and maize, and they were found to be involved in responses to stress. The publication of the apple genome makes it feasible to systematically study the TLP family in apple. In this investigation, nine TLP encoding genes (TLPs for short) were identified. When combined with the TLPs from other plant species, the TLPs were divided into three groups (group A, B, and C). Most plant TLP members in group A contained an additional F-box domain at the N-terminus. However, no common domain was identified other than tubby domain either in group B or in group C. An analysis of the tubby domains ofMdTLPs identified three types of conserved motifs. Motif 1 and 2, the signature motifs in the confirmed TLPs, were always present inMdTLPs, while motif 3 was absent from group B. Homology modeling indicated that the tubby domain of mostMdTLPs had a closed β barrel, as in animal tubby domains. Expression profiling revealed that theMdTLP genes were expressed in multiple organs and were abundant in roots, stems, and leaves but low in flowers. An analysis ofcis-acting elements showed that elements related to the stress response were prevalent in the promoter sequences ofMdTLPs. Expression profiling by qRT-PCR indicated that almost allMdTLPs were up-regulated at some extent under abiotic stress, exogenous ABA and H2O2treatments in leaves and roots, though differentMdTLP members exhibited differently in leaves and roots. The results and information above may provide a basis for further investigation of TLP function in plants.
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University Taian, China.
authors.forename: Jia-Ning
authors.initials: JN
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University Taian, China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Xing
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University Taian, China.
authors.forename: Zheng-Rong
authors.initials: ZR
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University Taian, China.
authors.forename: Xue-Sen
authors.initials: XS
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University Taian, China.
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Wang
keywords: abiotic stress; apple; bioinformatics; signature motifs; tubby-like protein