Genome-Wide Identification and Expression Analysis of MADS-Box Family Genes in Litchi (Litchi chinensis Sonn.) and Their Involvement in Floral Sex Determination

Hongling Guan; Han Wang; Jianjun Huang; Mingxin Liu; Ting Chen; Xiaozhen Shan; Houbin Chen; Jiyuan Shen

doi:10.3390/plants10102142

Genome-Wide Identification and Expression Analysis of MADS-Box Family Genes in Litchi (Litchi chinensis Sonn.) and Their Involvement in Floral Sex Determination

Plants (Basel). 2021 Oct 9;10(10):2142. doi: 10.3390/plants10102142.

Authors

Hongling Guan^{1

2}, Han Wang^{1

2}, Jianjun Huang^{1

2}, Mingxin Liu^{1

2}, Ting Chen^{1

2}, Xiaozhen Shan^{1

2}, Houbin Chen^{1

2

3}, Jiyuan Shen^{1

2

3}

Affiliations

¹ Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China.
² Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
³ Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming 525000, China.

Abstract

Litchi possesses unique flower morphology and adaptive reproduction strategies. Although previous attention has been intensively devoted to the mechanisms underlying its floral induction, the molecular basis of flower sex determination remains largely unknown. MADS-box genes are promising candidates for this due to their significant roles in various aspects of inflorescence and flower organogenesis. Here, we present a detailed overview of phylogeny and expression profiles of 101 MADS-box genes that were identified in litchi. These LcMADSs are unevenly located across the 15 chromosomes and can be divided into type I and type II genes. Fifty type I MADS-box genes are subdivided into Mα, Mβ and Mγ subgroups, while fifty-one type II LcMADSs consist of 37 MIKC^C -type and 14 MIKC *-type genes. Promoters of both types of LcMADS genes contain mainly ABA and MeJA response elements. Tissue-specific and development-related expression analysis reveal that LcMADS51 could be positively involved in litchi carpel formation, while six MADS-box genes, including LcMADS42/46/47/75/93/100, play a possible role in stamen development. GA is positively involved in the sex determination of litchi flowers by regulating the expression of LcMADS51 (LcSTK). However, JA down-regulates the expression of floral organ identity genes, suggesting a negative role in litchi flower development.

Keywords: MADS-box genes; flower development; litchi; phytohormones; sex determination.

Abstract

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