MADS-box family genes in sheepgrass and their involvement in abiotic stress responses

Junting Jia,Pincang Zhao,Guangxiao Yuan,Shu Liu,Dongmei Qi,Shuangyan Chen,Weiguang Yang,Xiaoxia Li,Liqin Cheng,Gongshe Liu

doi:10.1186/s12870-018-1259-8

Abstract

BackgroundMADS-box genes are categorized into A, B, C, D and E classes and are involved in floral organ identity and flowering. Sheepgrass (Leymus chinensis (Trin.) Tzvel) is an important perennial forage grass and adapts well to many adverse environments. However, there are few studies on the molecular mechanisms of flower development in sheepgrass, especially studies on MADS-domain proteins.ResultsIn this study, we cloned 11 MADS-box genes from sheepgrass (Leymus chinensis (Trin.) Tzvel), and phylogenetic analysis of the 11 genes with their homologs revealed that they are divided into nine subclades. Tissue-specific expression profile analysis showed that most of these MADS-box genes were highly expressed in floral organs. LcMADS1 and LcMADS3 showed higher expression in the stamen than in the other tissues, and LcMADS7 showed high expression in the stamen, glume, lemma and palea, while expression of LcMADS2, LcMADS9 and LcMADS11 was higher in vegetative organs than floral organs. Furthermore, yeast two-hybrid analyses showed that LcMADS2 interacted with LcMADS7 and LcMADS9. LcMADS3 interacted with LcMADS4, LcMADS7 and LcMADS10, while LcMADS1 could interact with only LcMADS7. Interestingly, the expression of LcMADS1 and LcMADS2 were significantly induced by cold, and LcMADS9 was significantly up-regulated by NaCl.ConclusionHence, we proposed that LcMADS1, LcMADS2, LcMADS3, LcMADS7 and LcMADS9 play a pivotal role in sheepgrass sexual reproduction and may be involved in abiotic stress responses, and our findings provide useful information for further exploration of the functions of this gene family in rice, wheat and other graminaceous cereals.

Highlights

MADS-box genes are categorized into A, B, C, D and E classes and are involved in floral organ identity and flowering
Based on the transcriptome data, we found that the transcript profiles of 21 putative MADS-box gene sequences were significantly different in the three tissues of sheepgrass (Fig. 1b, Additional files 2: Table S2), and among them, 7 MADS-box gene sequences were only highly expressed in ovaries, 4 were highly expressed in both stigmas and ovaries, and 3 were highly expressed in ovaries and leaves
LcMADS1, LcMADS2, LcMADS3, and LcMADS9 were significantly induced by abiotic stresses (Fig. 5)

Summary

Introduction

MADS-box genes are categorized into A, B, C, D and E classes and are involved in floral organ identity and flowering. MADS-box genes play important roles in many aspects of developmental processes, especially in floral induction and flower development [1]. According to their roles in flower development, MADS-box genes are classified into A, B, C, D and E classes [2, 3]. Previous studies indicated that some plant MADS-box genes are involved in abiotic stress responses. MADS-box genes have been shown to be affected by low temperature stress in the tomato [17] All of these findings reveal that some MADS-box genes may be involved in abiotic stress-related processes. Until now, there have not been many reports about MADS-box gene involvement in abiotic stress responses

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Discussion

Conclusion