CONSTANS (CO)/CONSTANS-like (COL) genes play an important role in the photoperiodic flowering pathway. However, the functional roles of the CO/COL genes in mango (Mangifera indica L.) remain unknown. In this study, the MiCO gene was isolated from mango and functionally characterized. The open reading frame is 966 bp in length and encodes 322 amino acids; the protein contains two conserved B-box zinc finger domains and a CCT domain and thus belongs to the CO/COL group I protein family. The MiCO protein fused to green fluorescent protein localized to the nucleus. MiCO was expressed in all tested organs and was highly expressed especially in the leaves and stems of nonflowering branches, but its expression decreased in flowering branches. The expression level of MiCO significantly increased during the transition from vegetative to reproductive growth. MiCO was also expressed in accordance with the circadian rhythm, with the greatest expression level detected at 09:00. Overexpression of MiCO in Arabidopsis significantly delayed flowering under both long-day and short-day conditions.

CONSTANS（CO）/ CONSTANS-like（COL）基因在光周期开花途径中起着重要作用。然而，CO / COL基因在芒果（Mangifera indica L.）中的功能作用仍然未知。在这项研究中，MiCO基因是从芒果中分离出来并进行功能鉴定的。开放阅读框的长度为966 bp，编码322个氨基酸。该蛋白质包含两个保守的B-box锌指结构域和一个CCT域，因此属于CO / COL I类蛋白质家族。与绿色荧光蛋白融合的MiCO蛋白位于细胞核。MiCO在所有测试的器官中都表达了这种蛋白，并且特别是在非开花分支的叶子和茎中高表达，但是在开花分支中它的表达下降了。从营养生长到生殖生长的过程中，MiCO的表达水平显着增加。还按照昼夜节律表达MiCO，在09:00检测到最大表达水平。在长日和短日条件下，拟南芥中MiCO的过表达都显着延迟了开花。