AUTHOR=Li Hanxi , Li Yuxi , Zhang Xinxin , Cai Kewei , Li Yan , Wang Qingcheng , Qu Guanzheng , Han Rui , Zhao Xiyang 

TITLE=Genome-wide identification and expression analysis of the MADS-box gene family during female and male flower development in Juglans mandshurica

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1020706

DOI=10.3389/fpls.2022.1020706

ISSN=1664-462X

ABSTRACT=<p>The MADS-box gene family plays a crucial role in multiple developmental processes of plants, especially in floral organ specification and the regulation of fruit development and ripening. <italic>Juglans mandshurica</italic> is a precious fruit material whose quality and yield are determined by floral organ development. The molecular mechanism of <italic>J. mandshurica</italic> female and male flower development depending on MADS-box genes remains unclear. In our study, 67 <italic>JmMADS</italic> genes were identified and unevenly distributed on 15 of 16 <italic>J. mandshurica</italic> chromosomes. These genes were divided into two types [type I (Mα, Mγ, Mδ) and type II (MIKC)]. The gene structure and motif analyses showed that most genes belonging to the same type had similar gene structures and conserved motifs. The analysis of syntenic relationships showed that MADS-box genes in <italic>J. mandshurica</italic>, <italic>J. sigillata</italic>, and <italic>J. regia</italic> exhibited the highest homology and great collinearity. Analysis of cis-acting elements showed that <italic>JmMADS</italic> gene promoter regions contained light, stress and hormone response cis-acting elements. The gene expression patterns demonstrated that 30 and 26 <italic>JmMADS</italic> genes were specifically expressed in the female and male flowers, respectively. In addition, 12 selected genes common to <italic>J. mandshurica</italic> female and male flowers were significantly upregulated at the mature stage and were used to validate the reliability of the transcriptome data using quantitative real-time PCR. This comprehensive and systematic analysis of <italic>J. mandshurica</italic> MADS-box genes lays a foundation for future studies on MADS-box gene family functions.</p>