MAIN CONCLUSION The function of the first MADS-box transcription factor from endosperm of coconut, CnMADS1, was characterized via seed-specific overexpression in Arabidopsis seeds and further confirmed in protoplasts of coconut. Coconut (Cocos nucifera L.), which belongs to the palm family (Arecaceae), is one of the world's most useful economical tropical crops. However, few genes related to coconut endosperm development have been studied. In previous research, an AGAMOUS-like (AGL) MADS-box transcription factor, named CnMADS1, was identified in the endosperm of coconut through the SSH cDNA library. In this paper, functional characterization of the CnMADS1 gene was carried out by seed-specific overexpression in A. thaliana seeds and protoplasts of coconut. The results indicated that in the twelve independent T2 transgenic Arabidopsis lines with high overexpression of CnMADS1, the size of the mature seeds of transgenic plants was increased significantly (19.64% increase in the long axis and 8.6% increase in the short axis) compared to that of the wild-type seeds. Moreover, the total lipid content also increased significantly in mature seeds of transgenic plants. After comparing the expression of related genes in wild-type and transgenic plants and confirmation by EMSA, AtOSR1, a regulatory gene related to seed size, was proven to be significantly up-regulated by CnMADS1 in transgenic plants. Moreover, the transient transformation of protoplasts of coconut also proved that CnLECRK3 (the homologous gene of AtOSR1 in coconut) is up-regulated by the CnMADS1 gene in the same way. All these results indicated that a similar regulation mode existed in Arabidopsis and the endosperm of coconut and ultimately affected the yield and quality of coconut copra.

中文翻译：

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CnMADS1 是一种 MADS 转录因子，正向调节椰子 (Cocos nucifera L.) 胚乳中的细胞增殖和脂质代谢

主要结 椰子（Cocos nucifera L.）属于棕榈科（槟榔科），是世界上最有用的经济热带作物之一。然而，很少有与椰子胚乳发育相关的基因被研究。在以往的研究中，通过 SSH cDNA 文库在椰子胚乳中鉴定出一种 AGAMOUS-like (AGL) MADS-box 转录因子，命名为 CnMADS1。在本文中，通过在拟南芥种子和椰子原生质体中的种子特异性过表达对 CnMADS1 基因进行了功能表征。结果表明，与CnMADS1高表达的12个独立T2转基因拟南芥株系相比，转基因植物成熟种子的大小显着增加（长轴增加19.64%，短轴增加8.6%）。野生型种子。此外，转基因植物成熟种子的总脂质含量也显着增加。在比较野生型和转基因植物中相关基因的表达并经EMSA确认后，证明与种子大小相关的调节基因AtOSR1在转基因植物中被CnMADS1显着上调。此外，椰子原生质体的瞬时转化也证明了CnLECRK3（椰​​子中AtOSR1的同源基因）以同样的方式被CnMADS1基因上调。