Functional analysis of a PISTILLATA-like gene CcMADS20 involved in floral organs specification in citrus
Functional analysis of a PISTILLATA-like gene CcMADS20 involved in floral organs specification in citrus
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参与柑橘花器官规格的 PISTILLATA 样基因 CcMADS20 的功能分析
DOI：
10.1016/j.plantsci.2022.111263
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发表时间：
2022-04-02
期刊：
影响因子：
5.2
通讯作者：
Zhang, Jin-Zhi
中科院分区：
文献类型：
--
作者：
Hou, Xiao-Jin;Ye, Li-Xia;Zhang, Jin-Zhi
Pistillata（PI）是MADS-Box转录因子的成员，在拟南芥中的花瓣和雄蕊规范中起着重要作用。然而，关于柑橘类pi样基因知之甚少。为了了解PI在柑橘花的发育过程中的分子机制，从柑橘clemantina分离出Pi样基因CCMADS20。序列比对和系统发育分析表明，CCMADS20与PI样同源物具有相对较高的相似性，并被分类为核心二元组组。时间和空间表达分析表明，CCMADS20在柑橘花的花瓣和雄蕊中特别表达，这与拟南芥中的PI表达模式一致。蛋白质相互作用表明CCMADS20可以与AP3样蛋白形成异二聚体。此外，拟南芥中CCMADS20的异位过表达导致萼片转化为花瓣状结构，如其他过表达功能性PI样同源物的植物中所观察到的。另外，CCMADS20的启动子片段也被克隆在代表性的21个柑橘类品种中。有趣的是，在这些柑橘类品种中发现了四种类型的启动子，这是由于两个稳定的插入/缺失片段（locus1 and locus2）产生的。每种品种中启动子等位基因的同性/异性质量与柑橘的进化起源密切相关。四个启动子活性分析表明，locus1的存在抑制了CCMADS20转录活性，而Locus2的存在促进了其转录活性。这些发现表明，CCMADS20决定了在柑橘的进化过程中的花瓣和雄蕊发育，并且发现有效的遗传标记物的四个启动子对柑橘育种实践非常有价值。
PISTILLATA (PI), as a member of MADS-box transcription factor, plays an important role in petal and stamen specification in Arabidopsis. However, little is known about PI-like genes in citrus. To understand the molecular mechanism of PI during the developmental process of citrus flower, a PI-like gene CcMADS20 was isolated from Citrus Clemantina. Sequence alignment and phylogenetic analysis revealed that CcMADS20 had relatively high similarity with PI-like homolog and was classified in the core dicotyledonous group. The temporal and spatial expression analyses showed that CcMADS20 was specifically expressed in petal and stamen of citrus flower, which was consistent with PI expression pattern in Arabidopsis. Protein interaction revealed that CcMADS20 could form heterodimer with AP3-like proteins. Furthermore, ectopic overexpression of CcMADS20 in Arabidopsis resulted in transformation of sepals into petal-like structure, as observed in other plants overexpressing a functional PI-like homolog. Additionally, promoter fragments of CcMADS20 were also cloned in the representative 21 citrus varieties. Interestingly, four types of promoters were discovered in these citrus varieties, resulting from two stable insert/deletion fragments (Locus1 and Locus2). The homo/hetero-zygosity of promoter alleles in each variety was strongly related to the evolutionary origin of citrus. Four promoters activity analysis indicated that Locus1 presence inhibited CcMADS20 transcriptional activity and Locus2 presence promoted its transcriptional activity. These findings suggested that CcMADS20 determines petal and stamen development during the evolutionary process of citrus and four promoters discovered, as effective genetic markers, are valuable for citrus breeding practices.