Abstract
MADS-box transcription factors play significant roles in plant developmental processes such as floral organ conformation, flowering time, and fruit development. Pear (Pyrus), as the third-most crucial temperate fruit crop, has been fully sequenced. However, there is limited information about the MADS family and its functional divergence in pear. In this study, a total of 95 MADS-box genes were identified in the pear genome, and classified into two types by phylogenetic analysis. Type I MADS-box genes were divided into three subfamilies and type II genes into 14 subfamilies. Synteny analysis suggested that whole-genome duplications have played key roles in the expansion of the MADS family, followed by rearrangement events. Purifying selection was the primary force driving MADS-box gene evolution in pear, and one gene pairs presented three codon sites under positive selection. Full-scale expression information for PbrMADS genes in vegetative and reproductive organs was provided and proved by transcriptional and reverse transcription PCR analysis. Furthermore, the PbrMADS11(12) gene, together with partners PbMYB10 and PbbHLH3 was confirmed to activate the promoters of the structural genes in anthocyanin pathway of red pear through dual luciferase assay. In addition, the PbrMADS11 and PbrMADS12 were deduced involving in the regulation of anthocyanin synthesis response to light and temperature changes. These results provide a solid foundation for future functional analysis of PbrMADS genes in different biological processes, especially of pigmentation in pear.
Highlights
Transcription factors are usually defined as proteins that activate and/or repress gene transcription by binding to sequence-specific DNA, and play critical roles in controlling biological processes (Riechmann et al, 2000)
The results showed that PbrMADS11 and PbrMADS12 could significantly improve promoter activity of PbDFR1 when it was co-transformed with PbbHLH3 and PbMYB10, with the promoting function of PbrMADS12 higher than PbrMADS11
Neither PbrMADS11 nor PbrMADS12 showed a promoting function for the promoter of PbANS1, compared with co-transformed PbbHLH3 and PbMYB10. These results revealed that PbrMADS12 gene together with PbbHLH3 and PbMYB10 partners, was able to activate the promoters of the PbDFR1 and PbUFGT1 genes in the anthocyanin pathway, while PbrMADS11 could only activate PbDFR1
Summary
Transcription factors are usually defined as proteins that activate and/or repress gene transcription by binding to sequence-specific DNA, and play critical roles in controlling biological processes (Riechmann et al, 2000). A typical plant transcription factor generally contains a DNA-binding region, a transcription-regulation domain, an oligomerization site, and a nuclear localization signal (Liu, White & MacRae, 1999). Type I proteins contain conserved MADS (M) domains (Parenicova et al, 2003), and are divided into three subfamilies: Mα, Mβ, and Mγ. The M domain, containing about 60 amino acids, is the most conserved domain for DNA binding (Shore & Sharrocks, 1995; Melzer, Wang & Theissen, 2010). Type I genes experience a faster birth and death rate compared with type II genes (Parenicova et al, 2003; Nam et al, 2004)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
