Genome-wide identification of the MADS-box gene family in Avena sativa and its role in photoperiod-insensitive oat

Abstract

Background Traditional spring-summer sown oat is a typical long-day crop that cannot head under short-day conditions. The creation of photoperiod-insensitive oats overcomes this limitation. MADS-box genes are a class of transcription factors involved in plant flowering signal transduction regulation. Previous transcriptome studies have shown that MADS-box genes may be related to the oat photoperiod. Methods Putative MADS-box genes were identified in the whole genome of oat. Bioinformatics methods were used to analyze their classification, conserved motifs, gene structure, evolution, chromosome localization, collinearity and cis-elements. Ten representative genes were further screened via qRT‒PCR analysis under short days. Results In total, sixteen AsMADS genes were identified and grouped into nine subfamilies. The domains, conserved motifs and gene structures of all AsMADS genes were conserved. All members contained light-responsive elements. Using the photoperiod-insensitive oat MENGSIYAN4HAO (MSY4) and spring-summer sown oat HongQi2hao (HQ2) as materials, qRT‒PCR analysis was used to analyze the AsMADS gene at different panicle differentiation stages under short-day conditions. Compared with HQ2, AsMADS3, AsMADS8, AsMADS11, AsMADS13, and AsMADS16 were upregulated from the initial stage to the branch differentiation stage in MSY4, while AsMADS12 was downregulated. qRT‒PCR analysis was also performed on the whole panicle differentiation stages in MSY4 under short-day conditions, the result showed that the expression levels of AsMADS9 and AsMADS11 gradually decreased. Based on the subfamily to which these genes belong, the above results indicated that AsMADS genes, especially SVP, SQUA and Mα subfamily members, regulated panicle development in MSY4 by responding to short-days. This work provides a foundation for revealing the function of the AsMADS gene family in the oat photoperiod pathway.